Risk of second primary cancer after primary radiotherapy for PC

[dentaltwin]

Personally, I wouldn't make TOO much of this (the increase in incidence isn't huge), but that doesn't mean it shouldn't be considered. Also, a prospective study would likely be more meaningful. Note that the lead author is a RO.

jamanetwork.com/journals/ja...

[AlanMeyer Moderator]

I think you're right that a prospective study would give us more information than this retrospective study does and I think you're also right that the increase in incidence of new primary cancers is small.

There seem to be a lot of factors that influence outcomes of primary therapies. My suspicion is that the biggest factors are the knowledge, skill, and commitment to patients of the doctor(s) responsible for the treatment. All other things being equal I'd rather have an excellent surgeon than an average radiation oncologist and an excellent RO rather than an average surgeon. A great RO won't negate the increased risk of new primary cancers from his treatment - though maybe it will if he's able to better avoid radiation to spots that don't need it, but I suspect that the difference between between excellent vs. average doctors is significantly larger than the difference in getting new primary cancers due to radiation treatment.

[dentaltwin in reply to AlanMeyer]

Well, that's speculation, but I'd speculate the same ;-). Might also be helpful to stratify by type of radiotherapy.

[AlanMeyer Moderator in reply to dentaltwin]

dentalwin wrote:

> Might also be helpful to stratify by type of radiotherapy.

Yes. I would imagine that brachytherapy concentrates radiation in the area of the tumors where the seeds are placed and it only damages those areas plus at most a few millimeters of nearby tissue, declining rapidly with distance. On the other hand, external beam radiation may have to penetrate centimeters of non-prostate tissue before it reaches the tumor, and also radiates some tissue on the other side of the tumor. If that speculation is right it makes me wonder if the targeting benefits of proton therapy can also be realized with brachytherapy, at a much lower cost.

But someone more knowledgeable than I am needs to weigh in on this.

Alan

[jazzy53 in reply to AlanMeyer]

My father developed primary bladder cancer about 30 years after receiving radiation for prostate cancer. Due the bladder's brittle appearance, his urologist and oncologist were sure that the new cancer stemmed from the initial radiation. (As it turned out, he developed and died of an unrelated cancer, pancreatic, at age 90 shortly after being treated for bladder cancer.) I take some solace in current practice, which required that I show up for radiation with a full bladder and empty rectum, strategies intended to get those organs out of harm's way during radiation. If I get another cancer, so be it, but I'm glad to have taken those precautions.

[Currumpaw]

When I met with my first uro to discuss the results of my first biopsy he told me that I had an aggressive cancer. When discussing treatment options, he looked at me, he looked at the extensive data from my physical as I had been a first responder for HAZ-MAT incidents and Confined Space Rescue Operations. He advised against radiation as a treatment option as it could lead to other cancers as well as urinary and fecal incontinence.

If the cancer has escaped from the prostate capsule, then as the saying goes, "Do what you have to do".

Second Cancers After Prostate Cancer - WebMD

webmd.com/prostate-cancer/s...--Fresh off the presses, May 25th, 2022.

An excerpt:

"In some studies, radiation to the prostate upped the odds of rectal cancer as much as 70%, but not all studies found this. A lot depends on the type of radiation. "

The below was posted online July 29th, 2022--

Risk of Secondary Cancer From Prostate Cancer Radiation Treatment …

appliedradiationoncology.co......

Excepts:

“We’ve known for a long time that radiation can cause cancer,” said the study’s senior author, Arden Morris, MD, a professor of surgery. “But for prostate cancer, the difference is shown to be relatively small. Because there is risk every year of developing cancer and it increases as patients age, radiation becomes more important as a treatment option for older men who are less worried about long-term effects.”

“If you’re in your 80s and you have a handful of years left to live, developing a second primary cancer 15 to 20 years later isn’t as much of a concern,” Morris said. “Compared to 40-year-olds with decades left to live, someone in their 80s might be more likely to pursue radiation.”

If you have had radiation therapy and it has failed, there is hope for a treatment known as "PGA" or, partial gland ablation.

The author and his association --Note the date--recent

"April 2, 2021

By Charlie Schmidt, Editor, Harvard Medical School Annual Report on Prostate Diseases"

The article:

An emerging treatment option for men with recurring …

health.harvard.edu/blog/an-......

Currumpaw

[dentaltwin in reply to Currumpaw]

Yeah--they're pretty specific on the increased risk of rectal cancer (+70%) before saying not all studies demonstrated this. So why put the number in there?

This was not a consideration for me when I had treatment. And I didn't consult with a RO--I probably should have. I'm not sorry I had surgery--this is just one more (probably minor) consideration.

[Currumpaw in reply to dentaltwin]

May your treatment be durable. Stay healthy my friend!!

Currumpaw

[dentaltwin]

Yes--this kind of stratification is good. And yes, the non-pelvic secondary cancers were higher in the "advanced RT" group. But I wouldn't lose sleep over a 1.17 hazard ratio--just go for your periodic screenings.

[dentaltwin]

Personally I don't think they should for most people.