Map of life expectancy at birth from Global Education Project.

Wednesday, March 18, 2009

As Dr. Ruth is always careful to say . . .

I am not a physician, I cannot advise. However, my loyal 4 1/2 readers know that I have been something of a skeptic of some of the most widely promoted routine cancer screening procedures, notably PSA and even DRE screening for prostate cancer and mammographic screening for breast cancer. The basics are well-trodden ground here: the cost and hassle of the screening itself, followed by the angst and cost and pain of biopsies when they are positive, often falsely, followed by surgery and chemotherapy and all the associated horrors when the biopsies are positive even though many prostate cancers and breast "cancers" called ductal carcinoma in situ might just have sat there and done nothing if you'd just left them alone -- is it worth it?

This randomized controlled trial of prostate cancer screening, with 10 years of follow up, finds that men in the screening group were diagnosed with more cancers, but had no mortality benefit. In fact, the men who were not screened were actually less likely to die of prostate cancer than those who were screened, although the difference is considered not statistically significant. Who knows, with longer term follow-up, whether this trend would reverse? But it seems unlikely. If it's real, then it follows that you are more likely to die from the treatment than you are from the cancer.

The information women are given about mammography is often presented in misleading form. Here's the bottom line: If 2,000 women are regularly screened for breast cancer for 10 years, precisely 1 will benefit by avoiding dying of breast cancer. On the other hand, 10 women who would not have died from breast cancer will undergo breast cancer surgery, and possibly radiotherapy or chemotherapy.*

You will have to decide for yourself what to do with this information.

* Gotzsche, et al. BMJ, February 21, 2009.


kathy a. said...

isn't this where access to medical care and advice on an individual level is important?

maybe, because you are in a medical setting, nearly everyone gets every recommended screening yearly. [i know that isn't true in practice.] and some regular folks do, too, because they are all organized and diligent. but a LOT of people do not do the yearly screenings, even with insurance, for one reason or another.

i'm not sure how this kind of trial relates to behaviors and outcomes in the real world. and as usual, this response is based on experiences in my own family, bolstered by experiences of friends -- anecdotal, in other words. but you hit on a bunch of issues that affect my family and others.

to start, you mention PSA screening for prostate cancer. my BIL [age 51] has/had prostate cancer; it was caught early; he had surgery and he's doing well. he got that test because he had some suspicious symptoms, and he asked about them. his outcome is good, because there was that testing. do i think my wonderful husband will go get a screening w/o a reason? no.

things are more complicated about mammography, in my family. my 3 female sibs and i are the sisterhood of lumpy breasts, and i am all in favor of checking that out -- plus, baseline mams are good references for later changes. we all had needle or surgical biopsies at some point, all negative in the past. our only aunt had/has ductal carcinoma in situ, which she described as "pre-cancerous," and she declined surgery but went with tamoxifan as a precaution, because one of her first cousins died of breast cancer.

i'm really bad with following recommended guidelines, so i never got around to the "yearly" mammogram for ~cough~ a decade or so, until one of my sisters was recently diagnosed with invasive ductal carcinoma, stage II, triple negative. that shit will scare you. i had no noticeable changes, but a repeat mammo and ultrasound turned up 2 tiny cysts. gotta go back in 6 months to "keep an eye" on them.

i'm as cynical [and lazy] as the next person about yearly screenings, but wouldn't want to deny baselines AND especially followups on any changes in circumstances: symptoms; a new lump; a new family history boosting danger; etc.

Cervantes said...

Well, your brother in law did not have prostate cancer screening -- he had a diagnostic test because he had symptoms. That's an entirely different kettle of pirahnas.

Since your sister has had real breast cancer (not DCIS), your personal calculus about screening is different -- it makes much more sense for you than it does for women in general. What I'm talking about here is 100% population screening, not targeted testing of people at relatively high risk.

kathy a. said...

i still think baselines and occasional screenings are useful for mammos. can't speak to prostates; i don't own one, and the only other prostate cancer in the extended family [that i've heard about] was a slow one in a very elderly great-uncle-by-marriage.

my SIL's breast cancer was diagnosed a few years back by routine mammo, followed by surgical biopsy -- which actually removed all the cancer, although they went back in to be sure. it was staged 0/1, because it was tiny [1 cm.] and contained -- too small to be palpable, no spreading to other tissues. maybe this is the one in 2,000 case; but her outpatient surgery plus some very easy radiation was ever so much better than my sister's more extensive surgery, drains, and big ugly 4 months of chemo -- for starters.

no, i don't know if these cases are fair to compare -- or how representative they are. i do know, i can't go a decade without a check. and my daughter has a BC history with aunts on both sides -- she has to pay attention.

kathy a. said...

we may be talking apples and oranges here, trying to compare mammos and PSA tests.