Stesura Seveso Archivio Italiano di Urologia e Andrologia 2015; 87, 3214 ORIGINAL PAPER Sexual activity and the risk of prostate cancer: Review article Ahmed Fouad Kotb, Ahmad Beltagy, Asmaa Mohamed Ismail, Mohamed Mohie Hashad Urology Department, Faculty of Medicine, Alexandria University, Alexandria, Egypt. Introduction: Sexual activity can affect prostate cancer pathogenesis in a variety of ways; including the proposed high androgen status, risk of sexually transmitted infections and the potential effect of retained carcinogens within the prostatic cells. Methods: PubMed review of all publications concerning sex- ual activity and the risk of prostate cancer was done by two researchers. Results: Few publications could be detected and data were classified as a prostate cancer risk in association with either heterosexual or homosexual activities. Conclusion: Frequent ejaculation seems to be protective from the development of prostate cancer. Multiple sexual partners may be protective from prostate cancer, excluding the risk of sexually transmitted infections. Homosexual men are at a greater risk for the diagnosis of prostate cancer. KEY WORDS: Prostate cancer; Ejaculation; Homosexuality; Heterosexuality. Submitted 16 January 2015; Accepted 31 March 2015 Summary No conflict of interest declared. female sexual partner was observed during most age periods, and was associated with increased exposure to sexually transmitted diseases. A meta-analysis in 2002 confirmed the positive association between multiple female sexual partners, STDs and the resulting higher risk of prostate cancer (RR 1.2) (5) Fernández et al. (6) found that men who had sex- ual intercourse more than 7 times per week had a signif- icant positive risk of having prostate cancer. Included men were in the old age group, with only 7% of men younger than 55 years, and that was associated with the risk of having STDs. Giles et al. (7) studied 2.338 men and found no associa- tion of prostate cancer with the number of sexual part- ners and argued against infection as a cause of prostate cancer. They, however, could detect that men who aver- aged 5 or more ejaculations weekly in their 20s had a rel- ative risk of 0.66 compared to those who ejaculated less frequently. Spence et al. (8) reported a protective effect of having sev- eral female sexual partners over the lifetime. In their study, they found that those men having > 20 female sex- ual partners had a reduced risk of overall (OR 0.72) and less aggressive PCa (OR 0.68) compared to men report- ing having had only one female sexual partner over the lifetime. They explained this protective effect may be related to higher ejaculation frequency which is sup- posed to be PCa protective. Frequent ejaculation is thought to reduce the concentra- tion of carcinogenic substances within prostatic fluid (3) or reduce production of intraluminal prostatic crystal- loids (9). Early on 1986, a study found that the average ejaculato- ry frequency in PCa patients was significantly lower than in the control group and mentioned that reduced ejacu- latory frequency appears to promote the pathogenesis of PCa by retained prostatic secretions promoting dysplasia of the prostatic gland epithelium (10). Age of the first intercourse was a factor that was also studied in the literatures. Ahmadi et al. (11) found that early age of first marriage was significantly associated with a lower risk of prostate cancer. A study in 1993 detected that PCa patients were significantly older at the time of their first marriage, compared with men who first married under the age of 25 years (12). DOI: 10.4081/aiua.2015.3.214 Sexual activity is hypothesized to affect prostate cancer (PCa) pathogenesis through numerous etiologic path- ways. One of the proposed mechanism associates increased sexual activity to higher androgenic activity that may be an indicator for a higher PCa risk (1). Another mechanism proposes that sexual activity increase exposure to sexually transmitted infectious dis- eases (STDs), which have been hypothesized to play a role in PCa development (2). A different hypothesis sug- gests that a reduced ejaculation frequency in otherwise normal men might be an etiologic risk factor for PCa. Such proposition is based on the theory that infrequent ejaculation causes carcinogenic secretions to be retained within the prostatic acini (3). HETEROSEXUALITY AND PCA Several studies were found concerning the heterosexual activity and prostate cancer risk. Rosenblatt et al. (4) sug- gested that there is a direct positive correlation between the number of lifetime female sexual partners and the risk of prostate cancer in middle-aged men. The increased risk associated with having more than one Kotb_Stesura Seveso 23/09/15 12:35 Pagina 214 215Archivio Italiano di Urologia e Andrologia 2015; 87, 3 Sexuality and prostate cancer In 2004, a large prospective study on 29.342 men by Leitzmann et al. (13) concluded that higher ejaculation frequency was related to decreased risk of total and organ confined prostate cancer. The relative risk for men reporting 21 or more ejacula- tions per month across a lifetime was 0.67 (33% lower risk) compared to 0.89 for men reporting 4 to 7 ejacula- tions per month across a lifetime. Chavez et al. (14) con- ducted a retrospective study on 4,974 men with erectile dysfunction (ED). They could find that men treated for ED with phospho- diesterase inhibitors (47.5%) had a significantly lower risk for prostate cancer than non-treated patients that could be attributed to more frequent ejaculations and retaining of sexual activities. HOMOSEXUALITY AND PCA Sexual orientation and PCa has received little attention in the literature. A published study in 2002 found no asso- ciation between sexual orientation and PCa. (4) Potential mechanisms underlying a possible greater risk of PCa among men having had several male partners or bisexu- als are still unclear. Homosexual men have been found to report more often a diagnosis of prostate cancer than het- erosexual men (15). HIV is more in homosexual men and being immunosuppressed, making them more vul- nerable to develop cancer (15). Another potential mechanism attributes physical trauma to the prostate. Receptive anal intercourse, significantly result in increased serum PSA levels causing higher PCa diagnosis rates (16). Potentially, the physical pounding of the prostate gland itself may possibly lead to a greater risk of PCa like pre- vious studies have linked the receipt of physical trauma to with breast and testicular cancers. Spence et al. (8) found that men who ever had 2-3 male sexual partners over their lifetime were at a significantly greater risk of less aggressive PCa compared to men who never had male partners (OR 3.01). CONCLUSION Frequent ejaculation seems to be a protective factor for the development of prostate cancer. Homosexual men may be at a higher risk of being diagnosed with prostate cancer, during their lifetime, more than heterosexual men. REFERENCES 1. Krain LS. Some epidemiologic variables in prostatic carcinoma in California. Prev Med. 1974; 3:154- 9. 2. Taylor ML, Mainous AG 3rd, Wells BJ. Prostate cancer and sex- ually transmitted diseases: a meta-analysis. Fam Med. 2005; 37:506-12. 3. Isaacs JT. Prostatic structure and function in relation to the etiol- ogy of prostatic cancer. Prostate. 1983; 4:351-66. 4. Rosenblatt KA, Wicklund KG, Stanford JL. Sexual factors and the risk of prostate cancer. Am J Epidemiol. 2001; 153:1152-8. 5. Dennis LK, Dawson DV. Meta-analysis of measures of sexual activity and prostate cancer. Epidemiology. 2002; 13:72-9. 6. Fernández L, Galán Y, Jiménez R, et al. Sexual behaviour, histo- ry of sexually transmitted diseases, and the risk of prostate cancer: a case-control study in Cuba. Int J Epidemiol. 2005; 34:193-7. 7. Giles GG, Severi G, English DR, et al. Sexual factors and prostate cancer. BJU Int. 2003; 92:211-6. 8. Spence AR, Rousseau MC, Parent MÉ. Sexual partners, sexually transmitted infections, and prostate cancer risk. Cancer Epidemiol. 2014; 38:700-7. 9. Del Rosario AD, Bui HX, Abdulla M, Ross JS. Sulfur-rich prosta- tic intraluminal crystalloids: a surgical pathologic and electron probe x-ray microanalytic study. Hum Pathol. 1993; 24:1159-67. 10. Banerjee AK. Carcinoma of prostate and sexual activity. Urology. 1986; 28:159. 11. Ahmadi H, Allameh F, Baradaran N, et al. Circulating sex hor- mones play no role in the association between sexual activity and the risk of prostate cancer. J Sex Med. 2011; 8:905-13. 12. La Vecchia C, Franceschi S, Talamini R, et al. Marital status, indicators of sexual activity and prostatic cancer. J Epidemiol Community Health. 1993; 47:450- 3. 13. Leitzmann MF, Platz EA, Stampfer MJ, Willett WC, Giovannucci E. Ejaculation frequency and subsequent risk of prostate cancer. JAMA. 2004; 291:1578- 86. 14. Chavez AH, Coffield KS, Rajab MH, Jo C. Incidence rate of prostate cancer in men treated for erectile dysfunction with phos- phodiesterase type 5 inhibitors: retrospective analysis. Asian J Androl 2013; 15:246-248. 15. Boehmer U, Miao X, Ozonoff A. Cancer survivorship and sexu- al orientation. Cancer. 2011; 117:3796-804. 16. Stephan C, Jung K, Diamandis EP, et al. Prostate-specific anti- gen, its molecular forms, and other kallikrein markers for detection of prostate cancer. Urology. 2002; 59:2-8. Correspondence Ahmed Fouad Kotb; M.D, PhD, MRCS, FEBU drahmedfali@gmail.com Ahmad Beltagy, MD bil_doctor@hotmail.com Asmaa Mohamed Ismail, MD asmaaismail@rocketmail.com Urology Department, Faculty of Medicine, Alexandria University, Azarita, Sultan Hussein Street, Alexandria, Egypt Kotb_Stesura Seveso 23/09/15 12:35 Pagina 215