Anal Prevention?

April 17, 2005 11:55 AM

Are gay men less likely than hetero men to contract prostate cancer?

I have a friend who claims so - that prostate cancer is due to an inactive prostate, thereby making gay men less likely candidates. My bullshit detector went up immediately, as it seems too simple an answer. But I haven't found anything specifically on this, which makes me more skeptical. Has anyone ever heard this theory before?

posted by hellbient to health & fitness (12 comments total)

If you're ready to go nuts on me with a comment, I do understand that gay men can get it and that it's cause is generally unknown.
posted by hellbient at 11:55 AM on April 17, 2005

I believe your friend is confusing 'active prostate' with 'frequency of orgasm.' There was a study in Australia a couple years ago that seemed to show that men who experienced more frequent orgasms had lower incidences of prostate cancer.

So, from that point of view, I'd say it's a somewhat reasonable extrapolation to suggest that gay men would have a lower incidence. On average, gay men have sex more frequently than straight men.

However, you might want to rephrase your question to "anally-receptive gay men" or, even better, "what is the incidence of prostate cancer in men who enjoy receptive anal penetration?"
posted by dirtynumbangelboy at 11:59 AM on April 17, 2005

Yes dirtynumbangelboy, the anal-receptive thing was what I was getting at. Should have been more specific there. I certainly didn't mean to suggest that all gay men are "bottoms".
posted by hellbient at 12:09 PM on April 17, 2005

From a scientific perspective, the australian study, and the subsequent study by Leitzmann (published in JAMA of all places) were a little dubious to say the least. Those were studies on ejaculatory frequency, which isn't exactly the question you're dancing around. To date, there is only one study on pub med reporting any trend based on sexual orientation. I can't access the study to review its quality, but the results they report are that men with an increased frequency of sexual partners who were men actually had an increased relative risk of prostate cancer.

So basically, the research available is far from proving your friend's point.
posted by drpynchon at 12:16 PM on April 17, 2005

I haven't seen any literature on sexuality correlating with anal sex as being a causal factor, but clearly unprotected sex with male or female partners infected with STDs indirectly contributes to prostate cancer. In the sense that some gay men may have condomless sex, and are at higher risk for spreading common STDs, that would seem to increase their risk for secondary diseases.

Anecdotally, gay men have more sex in general, compared with straight men, and stimulation of the prostate does seem to lower cancer rates. Further, some gay men tend to eat healthier in general, including diets high in fiber and antioxidant-rich vegetables, which would seem to reduce incidence rates.

I'm not sure there's a quick yes/no answer just yet, but I'm copying a little bit of the epidemiological work below, with some references to get you started on your own research:

Is prostate cancer an infectious disease?
International Journal of Epidemiology 2005 34(1):197-198

Pelayo Correa

Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA. E-mail: [e-mail]

In this issue, Leticia Fernandez and her fellow epidemiologists from Cuba, Barcelona, and Lyon report interesting findings of their case–control study in Havana, Cuba.1 The report adds relevant information supporting the causal relationship between chronic inflammation and cancer development. The list of infections and chronic inflammatory states aetiologically linked to cancer is increasing and includes major human burdens such as carcinomas of the cervix, stomach, colon, liver, and bladder as well as some lymphomas. Although the cancer risk attributable to infections has been quoted as ~15.6%,2 that estimate does not take into account the risk enhancement effect of chronic inflammation in multifactorial causal associations in common cancers such as those of the breast and colon. It is also well accepted that chronic inflammation affects the prognosis of cancer by as yet unclear mechanisms. This knowledge has led to many ongoing intervention trials of inhibitors of inflammation such as the non-steroidal anti-inflammatory drugs and the cyclooxygenase (Cox-2) inhibitors in dozens of cancer sites, with convincing beneficial effects on prognosis.

Prostatic cancer is the second most frequent malignant neoplasia worldwide, accounting for 542 990 new cases and 204 313 deaths in 2000.3 The incidence has been increasing recently in many countries, but the extent of confounding by the recent introduction and generalization of the PSA test for screening is difficult to evaluate. The experience in Cuba, where PSA testing is not done, clearly shows that the increasing trend is real.

Most epidemiological studies have shown that sexual activity and prostatic cancer are causally associated. Indicators of sexual activity vary in their association with prostatic cancer in different studies, but the trend for a risk increase is clear and consistent.4–6 The association with venereal diseases is also significant and consistent. These two sets of aetiological factors are obviously interrelated: greater sexual activity increases the chances of infection. It seems clear, however, that androgen secretion, which increases the sexual drive, has an independent risk-enhancing effect. Men whose testicles are never developed or are removed, never develop prostatic cancer.7–9 The beneficial effects of chemical or surgical castration in the prognosis of advanced prostatic cancer are well known.

It is not clear which of the venereal diseases or which combination of them are responsible for the increase in risk. The most consistent finding refers to gonorrhoea, but syphilis and herpes have also been implicated.4 Human papilloma virus infections have been suggested, but no good evidence supporting the association has been found.5 The determinant factors may be related to the potential of the infection to establish a chronic active inflammation. In that scenario, the prospects for gonorrhoea are more plausible since the bacteria can survive in the secretion of the prostatic glands, where they can escape the effects blood-borne antibiotics and at the same time induce an indolent, but active, chronic inflammatory state which attracts neutrophilic leukocytes and macrophages carrying mutagenic agents such as myloperoxidase and nitric oxides. Chronic prostatitis may be clinically silent but is a frequent cause of elevated blood PSA levels.

The Cuban study clearly contributes to our understanding of the complex host–environment interactions in cancer causation, and in particular of the role of chronic inflammation

1 Fernandez L, Galan Y, Jimenz R et al. Sexual behaviour, history of sexually transmitted diseases and risk of prostate cancer: a case-control study in Cuba. Int J Epidemiol 2005;34:193–97.

2 Pisani P, Parkin DM, Muñoz N et al. Cancer and infection: estimates of the attributable fraction in 1990. Cancer Epidemiol Biomarkers Prev 1997; 6:387–400.[Abstract]

3 Ferlay J, Bray P, Pisani P, Parkin DM. GLOBOCAN 2000: Cancer Incidence, Mortality and Prevalence Worldwide, version 1.0. IARC Cancer Base No. 5. Lyon, France: IARC Press, 2001.

4 Key T. Risk factors for prostate cancer. Cancer Surv 1985; 23:63–77.

5 Dennis LK, Dawson DV. Meta-analysis of measures of sexual activity and prostate cancer. Epidemiology 2004; 13:72–79.[CrossRef]

6 Rosenblatt KA, Wicklund KG, Stanford JL. Sexual factors and the risk of prostate cancer. Am J Epidemiol 2001; 12:1152–58.[CrossRef]

7 Ross BK, Shimizu H, Paganini-Hill A et al. Case-control studies of prostate cancer in blacks and whites in Southern California. J Natl Cancer Inst 1987; 78:869–74.[ISI][Medline]

8 Perez CA, Fair WR, Ihde DC. Carcinoma of the Prostate. In: Devita VT, Hellmann S, Rosenberg SA (eds). Cancer: Practices and Principles of Oncology. Philadelphia: JB Lippincott Co, 1989.

9 Wilson JD. Recent studies on the mechanism of action of testosterone. N Engl J Med 1972; 287:1284–91.[ISI][Medline]
posted by AlexReynolds at 12:25 PM on April 17, 2005

A bit older than AlexReynold's article (and only an astract) but:

There was no relation between sexual orientation and prostate cancer, although the number of men who had sex with men was small.

I personally would have thought that 'irritation' of the prostate through anal sex might provoke carcinogenesis if anything.
posted by peacay at 1:22 AM on April 18, 2005

If one considers receptive anal sex, the bigger issue seemingly would be the incidence of colon cancer.
posted by mischief at 7:10 AM on April 18, 2005

interesting stuff everyone...thanks.
mischief, I'm curious about your above comment, is there documentation of this?
posted by hellbient at 10:25 AM on April 18, 2005

On average, gay men have sex more frequently than straight men.

They do? Can you document this?
posted by Specklet at 10:32 AM on April 18, 2005

They'd have to, specklet. You're talking about two male sex drives colliding.
posted by jonmc at 12:49 PM on April 18, 2005

Hell if I know, hellbient, but if you consider the mechanics and chemistry of taking it up the ass, the potential for colon cancer seems possible over the long run.

[fwiw: I am bi and a bottom in my male-male relationships.]
posted by mischief at 2:37 PM on April 18, 2005

"male homosexuals who practice anal sex are about 33 times more likely to have anal cancers than heterosexual men"

And this suggests that smoking and a papillo virus STD are the biggest risk factors for both men and women getting anal cancer.
posted by peacay at 7:32 PM on April 18, 2005