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Eleni Papadopulos-Eleopulos,
Department of Medical Physics, Royal Perth Hospital, Western Australia, 6001,
Valendar F Turner, John Papadimitriou, Barry Page, David Causer, Helman Alfonso, Sam Mhlongo, Todd Miller, Christian Fiala

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In his rapid response: "Re: "HIV", HHV-8 and KS", 21 August, Nicholas Bennett wrote: "I greatly question whether nitrites and semen are carcinogenic for KS. HHV-8 is present in 95-100% of cases whereas the other two factor are not (okay, semen is 100% associated but then so is water, and I give semen about the same carcinogenic properties!)."

Semen has two of the main properties of carcinogens: it is mitogenic and oxidising. In our paper, "Kaposi's Sarcoma and HIV" (1) we gave the following evidence to support our claim that semen is carcinogenic. "a) Apart from nitrite abuse the second factor which changed in the lifestyle of homosexuals in the mid 1970s was the high promiscuity rate (35). There are also many examples from clinical practice of homosexual men who admit to approximately 1000 partners per year. At 2-3ml per ejaculate this provides evidence that deposition of unusually large amounts of semen into the rectum of an individual can occur, and that as a consequence, semen may interact with and be absorbed by the intact or traumatised bowel. b) Unlike all the other sexually transmitted diseases, where the possibility of infection is directly related to the number of sexual partners, in homosexuals the number of sexual partners is only a risk in relation to the number of episodes of passive anal intercourse (40). c) Homosexuals have a relatively high incidence of gastrointestinal cancers other than KS and several researchers have implicated semen in the development of these neoplasms (41, 42). d) Reid and Coppelson described the relative high incidence of cervical cancers in promiscuous Australian women. Amongst other factors, this was attributed to semen (43). e) Spermatozoal penetration into the submucosa of the rat uterine epithelium can induce pre-cancerous changes in the cervix (44). f) In humans spermatozoa fulfil a well known mitogenic role in embryogenesis. There is also in vitro evidence that spermatozoa can penetrate somatic mammalian cells and that sperm DNA is incorporated into recipient nuclei (45). Permanent transformation occurs within a few days and this is associated with abnormalities in morphology and growth of recipient cells including the appearance of bi- and multi-nucleated cells (45, 46). g) Extracts of pooled human semen are potent promoters of skin tumour production in the skin of mice previously treated with topical carcinogen (47). h) Injection of sperm suspensions directly into the anterior prostate of experimental rats can produce carcinoma of the prostate with metastases (48). i) Intratesticular injection of autologous spermatozoa in the rat can produce malignant testicular neoplasms (49). j) Seminal plasma is especially rich in polyamines, a group of positively charged substances which have a significant role in cellular proliferation (50, 51). Moreover, in human semen the polyamine spermine is present in higher concentrations than in many other tissue or body fluid and it, like other seminal polyamines, is oxidised by enzymes derived from seminal vesicle secretion. The presence of polyamines in higher than normal concentration is malignant tissue has prompted their assay as a diagnostic aid in cancer patients and serial measurement has been suggested as a treatment marker during chemotherapy. (Interestingly it appears that polyamines are essential for optimal growth of most microorganisms and inhibitors of their biosynthesis have been successfully employed for the treatment of protozoal diseases including Pneumocystis carinii pneumonia (52).

Thus a mitogenic and carcinogenic effect of nitrites and semen (or their derivatives) may better account for the presently available epidemiological data on KS in homosexuals than a currently unspecified, unknown new, sexually transmitted infectious agent." (The numbered references are those in our Kaposis sarcoma paper (1)).

Would Nicholas Bennett please give us a principle study and a few confirmatory studies with evidence showing that:

(a) Water is carcinogenic

(b) "HIV" is carcinogenic

(c) HHV-8 is carcinogenic.


1. Papadopulos-Eleopulos E, Turner VF, Papadimitriou JM. Kaposi's sarcoma and HIV. Med Hypotheses 1992;39:22-9. http://www.theperthgroup.com/SCIPAPERS/ks.html)

Competing interests: None declared