Prostate cancer Q&A: How will I know if the radiotherapy worked?

Prostate cancer Q&A: How will I know if the radiotherapy worked?

  November 13, 2026    Stephen Cobb

---

Some of the articles in the 30-article series I am publishing to raise money for prostate cancer research are answers to readers' questions. This one is about assessing the results of radiotherapy treatment.

Radiotherapy machine used for for prostate cancer treatment

[Note: I pledged to produce these articles, even though I'm currently undergoing prostate cancer treatment, for a fundraising pledge to which you can donate here. Please consider doing so and sharing a link to this blog (CobbsBlog.com) on social media.]

Here is the exact wording of the reader's question: "How will they know how well the IMRT worked?" In other words, is it possible to determine the extent to which the cancer cells have been destroyed.

The chap asking the question said he was considering having a form of radiotherapy called IMRT, which is used to treat prostate cancer, where treat = kill it off. For readers who don't recognize IMRT, it stands for Intensity-Modulated Radiation Therapy (IMRT), a type of external-beam radiotherapy used to treat localised prostate cancer, i.e. cancer that is in or very close to the prostate gland. 

As it happens, this is the type of radiotherapy that I had. (It was on a machine a bit like the one in picture at the top of the article, but there were no modesty blankets involved, staff just had you lie flat on the deck and drop your trousers and underwear.) 

My IMRT was delivered using a technique called Volumetric Modulated Arc Therapy (VMAT). Rather than delivering radiation from a series of fixed positions, VMAT delivers a continuously modulated beam while the machine rotates around the patient.

The question of how to determine if this treatment has been effective in a logical one, but the answer is somewhat frustrating: it's hard to know for sure, at least not straight away. In fact, it can take years, which is not exactly encouraging, but there are reasons for this.

Unlike surgery, where the prostate is removed and examined, radiotherapy leaves the prostate in place and there is no simple test that tells you if all the cancer cells have been destroyed.

What doctors can do is monitor PSA levels using blood tests (described here in a previous article). Successful radiotherapy should cause PSA levels to fall considerably, although they won't necessarily reach zero because healthy prostate cells are still producing some PSA.

This decline can take quite a while. It may be 18 months to three years before PSA reaches its lowest level, known as the nadir. And even after that a small temporary increase in PSA may occur, but that doesn't necessarily mean the cancer is returning. (There's a recognised phenomenon called PSA bounce, where the level rises briefly before falling again.)

For patients like me, who received radiotherapy combined with androgen deprivation therapy (ADT), there's an additional complication. ADT suppresses testosterone, which also reduces PSA production. So a low PSA reading while taking ADT is encouraging, but it doesn't tell us how much of the improvement is due to radiotherapy and how much is due to hormone suppression. 

In March of this year, before any treatment, my PSA was 7.50. After 50 days of ADT it was 0.47. In July I had the IMRT. About 75 days after the IMRT was completed my PSA was 0.45. The ADT doesn't end until the end of March and the drug won't clear my system right away. Realistically, it could be MAY until I get a PSA reading that is not influenced by testosterone suppression.

When ADT ends and testosterone recovers, PSA may rise somewhat, but that does not mean the cancer has returned. As I have said before, it is the trend of PSA numbers that matters. One widely accepted definition of recurrence after radiotherapy is a PSA increase of 2 above its lowest recorded level, but a  persistent upward trend may prompt investigation even before that threshold is reached.

(In the UK, the NHS recommends PSA checks at least every six months for the first two years following radical treatment, and annually thereafter. Routine scans or biopsies are generally unnecessary unless PSA results or symptoms suggest a problem.)

So the short answer is that the success of IMRT is judged over time, through regular PSA testing. A sustained low PSA is very good news and the longer it stays low, the more confident one can be that the treatment has done its job.

Types of radiotherapy

To put IMRT in context, here is a table based on info from Prostate Cancer UK, which has an excellent page on radiotherapy that is worth reading.

Technique	How it works	Current role
3D Conformal Radiotherapy (3D-CRT)	Uses CT-based planning to shape radiation beams to the prostate.	Older technique, largely superseded by IMRT for prostate cancer.
Intensity-Modulated Radiotherapy (IMRT)	Adjusts the intensity of radiation across individual beams, reducing exposure to surrounding tissues.	Standard UK treatment.
Volumetric Modulated Arc Therapy (VMAT)	A form of IMRT in which the machine rotates around the patient, continuously adjusting the beam.	Widely used in NHS radiotherapy centres.
Stereotactic Body Radiotherapy (SBRT/SABR)	Delivers very precise, higher doses of radiation in fewer sessions, often five.	Increasingly used for selected prostate cancers.
Proton Beam Therapy (PBT)	Uses protons rather than X-ray photons, potentially reducing radiation beyond the target.	Not routine NHS treatment for localised prostate cancer; clinical benefit over modern IMRT remains uncertain.

One of the leading makers of radiotherapy equipment is Elekta. The company's website has some useful educational materials including more extensive list of different types of radiotherapy.

Read More

Prostate cancer: where to get help, advice, and support

Prostate cancer: where to get help, advice, and support

  November 13, 2026    Stephen Cobb

---

This article is one of 30 that I am publishing to raise money for prostate cancer research. It lists major sources of help and support across multiple countries..

Prostate cancer prevalence is 1 in 8, even higher among black men
(from Prostate Cancer UK) 

[Note: I pledged to produce these articles, even though I'm currently undergoing prostate cancer treatment, for a fundraising pledge to which you can donate here. Please consider doing so and sharing a link to this blog (CobbsBlog.com) on social media.]

Getting a prostate cancer diagnosis can leave you with a lot of questions. Even after treatment has started, questions will likely keep coming up. Some concern the disease itself, others the side effects of treatment, and still others the impact on relationships, work, and everyday life (whether you are working or retired or retired but caring for a loved one). 

Fortunately, there are organisations that can help. Some have specialist nurses available to answer questions, while others can put you in touch with people who have already been through similar experiences. Most offer their services free of charge, and many also provide support for partners and families. 

For me, online support forums have been helpful. I starting hanging out at Prostate Cancer UK even before I had the results of my first MRI. Everyone was understanding and supportive. I suggest finding a forum sooner rather than later. Problems involving sexual function, fatigue, sleep, mood, continence, or relationships are legitimate reasons to engage with fellow patients, in addition to contacting a support organisation's clinical team about treatment or rehabilitation options.

I also found the nurse specialists at my cancer treatment centre to be very helpful. They pointed me to a local support group and I have found it helpful to attend some of their meetings.

United Kingdom

Prostate Cancer UK: Support services. Specialist nurses, confidential advice, online communities, and one-to-one peer support. Free helpline: 0800 074 8383. 

Tackle Prostate Cancer: tackleprostate.org. The National Federation of Prostate Cancer Support Groups. Particularly useful for finding local groups, meeting fellow patients and getting help with treatment decisions. 

Macmillan Cancer Support: Website and support line. Advice on cancer treatment, emotional wellbeing, finances, benefits and practical problems. Free helpline: 0808 808 00 00. 

Prostate Cancer Research: The Infopool. Patient-friendly information on diagnosis, treatment choices, clinical trials, managing side effects and life after treatment. Includes personal experiences from patients and partners. 

United States

ZERO Prostate Cancer: Help and support. National prostate cancer support organisation offering patient navigation, local and online support groups, one-to-one mentoring, and financial assistance guidance. ZERO360 helpline: 1-844-937-6360. 

Prostate Cancer Foundation (PCF): Support includes extensive patient education covering diagnosis, treatments, side effects, sexual health, clinical trials and survivorship. Free patient guides and webinars. 

Prostate Cancer Research Institute (PCRI): Evidence-based information, videos, educational conferences and a free patient helpline. Particularly useful when understanding treatment options and navigating complex decisions. 

CancerCare: Prostate cancer support. Free professional counselling, support groups, practical advice and financial assistance resources for patients and their families. 

Canada

Prostate Cancer Foundation Canada: National network offering prostate cancer support groups, peer support, information and education. Patient support: 604-834-7757. Toll-free general contact: 1-877-840-9173. 

Canadian Cancer Society: Cancer Information Helpline. Confidential information about cancer treatment, side effects, emotional wellbeing, clinical trials and community services. Available in English and French, with interpretation for other languages. Toll-free: 1-888-939-3333. 

CancerConnection.ca: Online support community. A free, moderated online community operated by the Canadian Cancer Society, connecting patients, survivors, partners and caregivers to share experiences and advice. 

Australia

Prostate Cancer Foundation of Australia (PCFA): National prostate cancer support services including specialist nurses, peer mentoring through MatesCONNECT, online communities and local support groups. Free helpline: 1800 22 00 99. 

PCFA Prostate Cancer Counselling Service: Counselling service. Specialised counselling for the emotional and psychological effects of prostate cancer, including sexual concerns, relationships, anxiety and depression. Offers up to five consultations without charge. Access via 1800 22 00 99. 

Cancer Council Australia: National cancer information, emotional and practical support, and referrals to local services. Telephone: 13 11 20. 

New Zealand

Prostate Cancer Foundation of New Zealand (PCFNZ): Support services. Specialist information, counselling, online forums, local support groups, exercise programmes and assistance for patients and their families. Information service: 0800 66 0800. 

Cancer Society of New Zealand: Cancer information nurses, counselling and practical support, including transport to treatment and assistance for families and carers. Free helpline: 0800 CANCER (0800 226 237). 

PCFNZ Local Support Groups: Nationwide directory connecting patients and families with local groups and experienced volunteers. Includes groups specifically for partners and informal one-to-one support. 

Read More

Prostate cancer treatment: side effects and impacts

Prostate cancer treatment: side effects and impacts

  November 11, 2026    Stephen Cobb

---

In this, the ninth article in my 30-article series to raise money for prostate cancer research during November, 2026, I look at things you need to think about if doctors recommend "radical treatment" for your prostate cancer.

[Note: I pledged to produce these articles, even though I'm currently undergoing prostate cancer treatment, for a fundraising pledge to which you can donate here. Please consider doing so and sharing a link to this blog (CobbsBlog.com) on social media.]

As I discussed in a previous article, "radical treatment" for prostate cancer means taking drastic action to get rid of the cancer cells. There are two main courses of action and both come with serious side effects. On the one hand there is surgery to remove the prostate. 

On the other hand there is RT+ADT, which involves leaving the prostate in place and killing the cancer cells by targeting them with X-rays (radiotherapy or RT). The +ADT comes from the use of drugs to deprive prostate cancer cells of the testosterone on which they thrive. This drug component of prostate cancer treatment is called hormone ablation.

The most common form of hormone ablation is called Androgen Deprivation Therapy or ADT. In the words of my urologist, "ADT will totally crush your testosterone." He was not wrong, after 50 days on ADT tablets (Relugolix) my testosterone was 0.69 nmol/L or 19.90 ng/dL in American terms. That is well below the level known as chemical castration (1.7 nmol/L or 50 ng/dL).

As far as I can tell, using ADT with radiotherapy is standard practice in the UK although the length of time you are on the ADT can vary (from six months to 18 months or sometimes longer — I'm 7.5 months into a 12 month course).

Surgery side effects

The main side effects of surgery involve urinary control and sexual function. Many men experience urinary incontinence following surgery and this may mean wearing a catheter for a while, although the incontinence often diminishes over time.

Erectile dysfunction is also common because the nerves responsible for erections run alongside the prostate and can be damaged during its removal. 

If the cancer is caught soon enough and is confined to certain parts of the prostate, there is a form of prostate surgery called nerve-sparing that can try to avoid nerve damage. Regrettably my cancer was not caught in time for the nerve-sparing option to be available; however, even nerve-sparing surgery cannot guarantee that erectile function will recover. 

Furthermore, removing the prostate and seminal vesicles means that ejaculation of semen becomes permanently impossible. Men can still experience orgasms, but these are dry orgasms, which may feel different or less satisfying. 

Surgery also eliminates the ability to father children through sexual intercourse. For younger men this may be a major concern, but sperm banking (cryopreservation) is an option: you provide a semen sample at a specialized fertility clinic or hospital before your surgery takes place. The sample is frozen in liquid nitrogen and can be stored for years

All in all, prostate surgery comes with some pretty drastic effects that need to be processed. For some men these consequences may be manageable; for others they may represent a profound change in their sexual identity, relationships and sense of wellbeing. Age, culture, and personal circumstances will all play a part in the processing.

RT+ADT side effects

The side effects of RTHA come from two directions. Radiotherapy can irritate or damage nearby tissues, causing urinary urgency, frequent urination, bowel disturbances, rectal bleeding and, sometimes, long-term erectile dysfunction. 

Hormone therapy (ADT) adds a second and potentially more widespread set of problems. Suppressing testosterone can dramatically reduce sexual desire and erectile function, while also producing fatigue, hot flushes, disturbed sleep, loss of muscle mass, weight gain, mood changes and difficulties with concentration or motivation. 

Longer-term treatment with ADT can weaken bones, alter cholesterol levels, increase insulin resistance and raise the risk of diabetes and cardiovascular disease. Some effects improve after hormone treatment stops, but recovery can take months or even years, and some changes may persist. 

As someone who chose RT+ADT over surgery, I will be documenting how things go at the end of my hormone treatment. I take my last Relugolix pill on the morning of March 31, 2026 — not that I'm counting the days). 

The immediate post-ADT phase comes with its own stress factors because the extent to which the radiotherapy eradicated your cancer cells cannot be determined until you stop suppressing your testosterone.

The future of prostate cancer treatment 

The current irony of prostate cancer treatment is that something intended to prolong your life can simultaneously make that life considerably more difficult to enjoy. I firmly believe that this will change over time. Later this month I will be talking about promising new directions in prostate cancer treatment, like the one I described here.

In the meantime, donating to prostate cancer research programs makes sense to me, as does lobbying your government, spreading the word, and taking part in research projects. I hope to highlight some of those in a future article as well as describe one in which I participated.

Read More

The two main prostate cancer treatment paths

The two main prostate cancer treatment paths

  November 10, 2026    Stephen Cobb

---

The eighth article in my 30-article series to raise money for prostate cancer research during November, 2026, describes what happens during the two main "radical treatment" options for prostate cancer.

(Note: I pledged to produce these articles, even though I am currently undergoing prostate cancer treatment, for a fundraising pledge which you can donate to here. Please consider doing so and sharing a link to this blog (CobbsBlog.com) on social media.)

Prostate Removal Surgery or Radiotherapy + Hormone-Ablation Therapy 

These are the two main pathways for treating prostate cancer, particularly when the cancer has not spread beyond the prostate itself. For brevity I am calling these options Surgery and RT+ADT for Radiotherapy and Androgen Deprivation Therapy (ADT) because ADT is the most common form of Hormone-Ablation therapy (it's those testosterone-crushing chemicals that I have described elsewhere).

Notice that the heading says surgery OR radiotherapy, not surgery VS. radiotherapy. As I described here, the probability of success is about equal for both pathways. Choosing between them begins with understanding them and their respective side effects and implications, addressed in this article. In my own experience I found that my urologists did not try to influence my decision one way or the other, which I appreciated.

Surgery

Surgery involves removing the prostate (radical prostatectomy). The entire prostate gland is taken out, usually along with the seminal vesicles (their job ito produce much of the fluid in semen). The goal of surgery is straightforward: remove the cancer before it spreads elsewhere. Modern procedures often use robotic assistance, allowing surgeons to operate with great precision. 

However, the prostate sits in a crowded and sensitive part of the male anatomy, to say the least. It is surrounded by nerves, blood vessels and structures essential to urination and sexual function. Removing it without disturbing these structures is difficult, even for highly skilled surgeons. 

While surgery can be very effective against cancer that has not spread, it can also produce lasting changes to the patient's body and quality of life. (I cover this in the blog post "Prostate cancer treatment: side effects and impacts.")

RT+ADT

Radiotherapy combined with androgen deprivation therapy (RT+ADT) takes a very different approach from surgery. Instead of removing the prostate, high-energy photon beams are precisely aimed at the gland to damage the DNA of cancer cells, preventing them from reproducing. 

For men with sufficiently significant disease, radiotherapy is often combined with androgen deprivation therapy (ADT), drugs that dramatically reduce the body's production of testosterone or block its effects. This is because testosterone encourages most prostate cancers to grow, so depriving the cancer of this hormone makes treatment more effective. 

However, as I quickly learned when I started taking ADT tablets, testosterone is not simply a hormone that makes men interested in sex. It plays an important role in physical strength, metabolism, bone health and mental wellbeing. Removing testosterone from your body will have consequences throughout the body. (I cover this in the blog post "Prostate cancer treatment: side effects and impacts.")

Read More

Time for treatment: Surgery, radiotherapy plus ADT, or wait and see?

Time for treatment: Surgery, radiotherapy plus ADT, or wait and see?

  November 10, 2026    Stephen Cobb

---

This article, the seventh in my 30-article series to raise money for prostate cancer research during November, 2026, discusses some of the things you need to think about if doctors recommend "radical treatment" for your prostate cancer.

(Note: I pledged to produce these articles, even though I am currently undergoing prostate cancer treatment, for a fundraising pledge which you can donate to here. Please consider doing so and sharing a link to this blog (CobbsBlog.com) on social media.)

How do you arrive at radical treatment?

First of all radical treatment is, in my opinion a poor choice of words when talking to patients about life-altering conditions. When they say "radical treatment" doctors are not considering doing anything out of the ordinary to you or your prostate. 

I feel the same way about deranged results from blood tests. These are results outside the "normal" or "preferred" range. In fact, your prostate cancer may have come to light due to one or more deranged PSA test results. Those can lead to an MRI, the results of which can lead to a biopsy. 

I discuss PSA number in this section an section of a post I wrote after my first biopsy. In my case, that first biopsy did find cancer cells, but only a tiny amount of them (tiny is the word urologist used and he recorded it on a CD for posterity, as described in this post). 

From then on my PSA was checked several times over the years until the point at which it had doubled. This was five years and that triggered a fresh MRI, of which my urologist said the following:

Thank you for attending for multi parametric surveillance MRI of your prostate. This shows changes, which suggest a more significant cancer than your known grade group 1 (Gleason 3+3) cancer. In light of this I recommend transperineal biopsy.

Some weeks later, after the biopsy, my urologist wrote to say that the MRI indicated: "grade progression of your cancer from Gleason 6 to Gleason 4+3 (grade group 3) cancer." And as a result of this:

...the specialist MDT now recommends radical treatment. We can offer either robot-assisted radical prostatectomy or hormone-ablation and radical radiotherapy...

There's that word radical again, and this time it is feeling very real. Either option is going to make a big difference to my life. If you are reaching this point, I think the first advice I would give is: don't panic. The general medical consensus is that most cases of prostate cancer don't get worse overnight, they develop over time, so you have time to weigh the options. 

I'm going to call these options Surgery, and RT+ADT for Radiotherapy and Androgen Deprivation Therapy (ADT) because the latter is the most common form of Hormone-Ablation therapy, the testosterone-crushing chemicals I have described elsewhere.

Speaking of terminology, note that the recommendation for radical treatment did not come from my urologist, it came from. the "specialist MDT" where MDT stands for Multidisciplinary Team. This typically consists of:

• Urology Consultants: Surgeons who specialize in urological conditions. They perform diagnostic procedures (like transperineal prostate biopsies) and surgical treatments, such as robot-assisted radical prostatectomy (RARP).
• Oncologists: Cancer specialists who plan and oversee non-surgical treatments like hormone therapy or advanced radiotherapy techniques (such as stereotactic ablative radiotherapy / SABR).
• Radiologists: Specialized doctors who interpret your prostate MRI, CT, or bone scans.
• Histopathologists: Experts who examine the tissue samples from your biopsy under a microscope to determine the exact stage and grade (Gleason score) of the cancer.

I mention this because for a long time it bothered me to think that I had cancer but had not been seen by a cancer specialist. Turns out the MDT is where oncologists get involved, and that involvement precedes any treatment suggestions.

That same letter from my urologist included one more crucial piece of information: "we need a bone scan to complete your cancer staging". This is a type of scan that can look at your entire body for signs of cancer spreading, technically known as metastasizing. What you hope for is what my bone scan found: no sign of spread. This means it's likely that your cancer in limited to, or contained by, your prostate. Encapsulated is another term for this. 

In practical terms, encapsulated means that removing your prostate, or zapping it with radio waves stands while taking hormone pills, stands a good chance of preventing the cancer from spreading. If that is the case, you then need to choose between Surgery or RT+ADT.

Weighing the options

I will go into more detail on what Surgery or RT+ADT involves in another post. I will also cover side effects. These can be very serious for both options. Hopefully, if you are at the decision stage you will have be told about the side effects. You will definitely have to sign a piece of paper stating you understand them before you can receive your chosen treatment. (There is one notable exception to this informed consent — the ADT, which is a prescription for tablets, the implications of which I will discuss in another post). 

Based on the research I did, it seems the outcomes for both surgery and radiotherapy combined with hormone therapy (RT+ADT) have excellent records of success when prostate cancer is detected before it has spread. One of the most important studies, the British ProtecT trial, followed more than 1,600 men with localised prostate cancer for an average of 15 years. Among those assigned to surgery, just 2.2% died from prostate cancer, compared with 2.9% of those assigned to radiotherapy. The difference was not statistically significant. 

The likelihood of the cancer spreading to other parts of the body was also remarkably similar: 4.7% for surgery and 5.0% for radiotherapy. In other words, both treatments offered a roughly 97% probability of surviving prostate cancer for 15 years. Those are encouraging numbers, however there are caveats on both sides: the study included many men with less aggressive cancers, but the stats were for treatments that have since been improved.

Of course, these figures are averages, not guarantees. The probability of successful treatment depends on several factors, including how aggressive your cancer is (its Gleason score or Grade Group), how far it has developed, your PSA level and general health. Nor does successful treatment necessarily mean that every cancer cell has been permanently eliminated. Some men experience a recurrence years later and require additional treatment.

With all that said, current evidence does not establish surgery as universally more effective than RT+ADT, or vice versa. Both are established treatments intended to cure cancer that remains confined to the prostate or its immediate surroundings. For many patients, therefore, the decision comes down not simply to which treatment offers the best chance of staying alive, but which offers the best chance of staying alive with an acceptable quality of life.

The treatment decision

The factors involved in choosing a prostate cancer treatment option are many and varied. I chose RT+ADT partly because of age but there were other factors that I might blog about when I get a chance. Both choices put your sexual functionality a risk. Neither is conclusive. The cancer could come back in either scenario. You could have surgery then later need RT+ADT. I have a friend who has not had any recurrence after surgery, but another who had a prostatectomy and later needed RT+ADT.

Something you can't expect to do is have RT+ADT then later opt for surgery. The radiotherapy damages the prostate to a point where surgeon's are loathe to operate. It is possible, but more risky than removal before RT.

There is one other treatment option that needs to mentioned: no treatment at all. Some men may prefer to take their chances without surgery or radiotherapy and hormone tablets. This could be due to specific circumstances or beliefs and I am not qualified to say whether this is a good idea. However, I'm pretty sure your urologist will be honest about the implications. From what I have read, if your prostate cancer is not very aggressive and you are over 80 for example, they might be okay with "wait and see." 

In my next post, I will describe Surgery and RT+ADT in more detail. In a further post I will compare the side effects of each. Please bear in mind that every case of prostate cancer is different. In these articles I am drawing on my own experience combined with many hours of research. I am not a doctor and nothing on this website is to be taken as advice from a medical professional.

Read More

Refining existing prostate cancer treatments: radiotherapy timing

Refining existing prostate cancer treatments: radiotherapy timing

  November 08, 2026    Stephen Cobb

---

One of the main treatment options for prostate cancer is radiotherapy. This article, the sixth in my 30-article series to raise money for prostate cancer research during November, 2026, describes a fascinating example of the potential for progress in reducing the adverse effects of radiotherapy treatment.

(Note: I pledged to produce these articles, even though I am currently undergoing prostate cancer treatment, for a fundraising pledge which you can donate to here. Please consider doing so and sharing a link to this blog (CobbsBlog.com) on social media.)

Prostate cancer radiotherapy 101

The impressive collection of high tech equipment you see in the photo at the top of this article is a state-of-the-art radio therapy system configured for a prostate cancer patient. The horizontal unit is the 'bed' where the patient lies down, feet on the right, head on the left. This bed then slides to the left while the four large modules on the left rotate around the body to deliver the radio waves to the target, i.e. the prostate.

The idea is that accurately focused radio waves damage and kill cancer cells. That accuracy depends in part on the patient. I will go into more detail about all of this a future post, and I provide tips on meeting the rather exacting biological requirements for the patient. In crude terms: fill bladder, empty bowel, clear gas, lie very still. 

Fortunately, each treatment session takes only a few minutes and they do not hurt. A typical course of treatment is 20 sessions performed on consecutive weekdays (mine went: Wed/Thu/Fri; Mon thru Fri; Mon thru Fri;  Mon thru Fri; Mon/Tue).

Is there a "right time of day" for safer prostate cancer radiotherapy?

When I was going through my radiotherapy, in July of 2026, I found that meeting the biological requirements for morning appointments was easier than for those later in the day. I spoke to several fellow patients that felt the same way. 

In fact most of my appointments were for 9:30 in the morning, but not all. The same equipment is used to treat a range of cancers in patients of all ages and genders and levels of health. Not everyone can walk in and hop up on the treatment bed. Also, the equipment is on strict maintenance schedules that take it offline.

Basically, prostate cancer radiotherapy is scheduled around practical questions: when is the machine available, when can the patient get to hospital, and how can the staff fit everyone in? But intriguing new research suggests another question may need to be added: what does the patient's body clock think is a good time?

Researchers at the University of Leicester, working with European colleagues, have found evidence that the time of day at which prostate cancer patients receive radiotherapy may influence their chances of developing long-term side effects. (I will be talking about what those side effects are in a separate article.) 

Crucially, the answer appears to depend on their genes. (As reported here.) The researchers used data from the international REQUITE study, which followed 1,760 men undergoing external-beam radiotherapy, the kind described above. For 877 of these men, researchers had sufficiently detailed information about treatment times, genetic variations and side effects over the following two years.

Researchers focused on variations in PER3, a gene involved in regulating circadian rhythms, that internal 24-hour clock which influences our sleep, hormone activity, and our body's ability to repair damaged cells. The findings were striking:

• For men carrying one particular PER3 variant, the researchers' model predicted that avoiding radiotherapy around midday could reduce the risk of subsequent urinary incontinence from 15% to 5%.
• For another genetic group, receiving treatment at 5pm rather than 9am was associated with a predicted reduction in rectal bleeding risk from 11% to 5%.

But apparently this is not a case of simply declaring afternoon appointments safer. Some genetic groups appeared to benefit from midday treatment, while others showed little effect from timing at all. There are also important caveats. 

This was an observational study, not a clinical trial in which men were deliberately assigned different treatment times. The percentages are model-based predictions, not demonstrated improvements. Further research is required to establish whether adjusting appointment times actually reduces harm without affecting cancer control. (Full study published in Clinical Cancer Research.)

Despite tohse caveats, I find the implications fascinating. If the results hold up, a relatively simple genetic test could help hospitals allocate radiotherapy appointments according to patients' biological clocks. No new radiation machine, miracle drug or expensive treatment would be required, just a more "intelligent" timetable.

As someone who recently completed prostate radiotherapy, I find this a particularly appealing idea. The goal should not simply be to eradicate the cancer, but to minimise the price patients pay for surviving it. Kudos to all involved in this research!

P.S. My enthusiasm for this research has nothing to do with the fact that the University of Leicester is only 25 miles from where I live and also my alma mater (MSc in Security and Risk Management, School of Criminology, 2016).

Read More

Good news about prostate cancer: three pieces of progress

Good news about prostate cancer: three pieces of progress

  November 07, 2026    Stephen Cobb

---

Not all the news about prostate cancer is bad. For the fifth article in my 30-article series for Movember, 2026, I present the first of three examples of progress in treatment and diagnosis.

 

(I pledged to produce these articles, even though I am currently undergoing prostate cancer treatment, as part of a fundraising pledge to which you can donate here. Please consider doing so and sharing a link to this blog (CobbsBlog.com) on social media.)

Prostate cancer drugs

Prostate cancer is a large and growing challenge to men's health, as documented in this article, and that means there's plenty of financial incentive, as well as compassionate incentive, to find drugs that can help treat prostate cancer.

I am on a prostate cancer drug right now, Relugolix, which belongs to a class of drugs called GnRH antagonists, which are used in androgen deprivation therapy (ADT). The goal of this therapy is to suppress the body's production of testosterone, a hormone that fuels the growth of most prostate cancers. 

To get technical, GnRH stands for gonadotropin-releasing hormone receptor antagonists. Relugolix does not block testosterone itself. It blocks hormonal signals from the pituitary gland that tell the testicles to produce testosterone. Unfortunately, while it makes sense to starve prostate cancer cells of the testosterone they need to grow, testosterone is also essential to a healthy male body; that means the implications of going without testosterone for months at a time are quite serious, something I will get into in a separate post.

A promising new PCa drug

But I digress, the new drug I wanted to highlight comes from pharmaceutical giant Johnson & Johnson. Last month the company announced promising results from an early clinical trial of an experimental drug with the snappy name of JNJ-6143. Like Relugolix, this drug is taken as a daily pill. But unlike conventional hormone treatments, which attempt to control prostate cancer by depriving it of testosterone, this drug is designed to interfere directly with proteins that cancer cells need to survive, triggering their destruction. 

The results are striking: among patients receiving the selected dose, 77% experienced a reduction in PSA levels of at least 50%, and nearly half saw their PSA fall by 90% or more. Even more encouraging, among patients with tumours that could be measured on scans, 75% experienced significant tumour shrinkage or complete disappearance of the measurable tumours. These were men with advanced prostate cancer who had already undergone several other treatments, making the results particularly encouraging. 

This trial was small and much larger studies are needed to establish whether the benefits last and whether patients actually live longer. Nevertheless, this is an exciting development, suggesting that researchers may be able to find new ways to attack prostate cancer beyond the familiar strategy of suppressing testosterone. 

If, like me, you are familiar with having your testosterone suppressed, you know that avoiding this would be a big help. Unfortunately, JNJ-6143 is not yet an alternative to testosterone suppression. In fact, the Phase 2 trial requires patients to continue ADT. Right now the focus of the drug's developers is fighting metastatic castration-resistant prostate cancer—cancer that continues growing despite very low testosterone levels. 

Nevertheless, what I take from learning about this new drug is that, in the future, it is may be possible to defeat prostate cancer without chronic testosterone suppression.

Next up: an exciting development in "Refining existing treatments." That will be followed by progress in the genetics of prostate cancer which could help find men at risk earlier than current technology allows.

Read More