However I still don't buy the concept that just because these guys say that sperm can merge with healthy cells that it must be true.
As the original article points out, anal sex transmits a host of virus and bacteria to a place they don't belong. To wit, a different study (http://www.innovations-report.com/html/reports/medicine_health/report-30966.html) says in part... "The study tested for the presence of human papillomavirus, or HPV – a well-known sexually transmitted viral marker of anal cancer – in both blood and tumor tissue. It also assessed the impact of various lifestyle factors associated with the disease, such as smoking, sexual orientation, number of sexual partners and history of anal intercourse.
"We found that infection with HPV is necessary in most if not all cases of anal cancer, as close to 90 percent of the tumors studied were positive for the virus," said Daling, a pioneer in studying the link between HPV and anogenital-cancer risk.
Overall, regardless of the patient’s sexual orientation or gender, the researchers found that 88 percent of the tumors were positive for HPV DNA. Of these, 73 percent tested positive for a strain called HPV-16, and 7 percent contained a strain called HPV-18. Both strains of HPV are implicated in cervical-cancer development as well. The researchers also found significantly higher amounts of circulating HPV antibodies in the blood of anal-cancer patients as compared to healthy controls. Approximately 40 percent of the women and 50 percent of the men with anal cancer tested positive for HPV antibodies as compared to about 15 percent of the men and women in the control group."
This would appear to contradict the the author that inspired this thread's assertion that there are signals that the female body understands that the male body does not, and that those signals somehow protect the female while the male is endangered. Both sexes are in danger of being infected with the HPV virus which appears to cause "most, if not all" anal cancer. So much for the "signals".
More can be found at:
http://www.fhcrc.org/pubs/center_news/2004/jul15/sart2.html
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9358129&dopt=Abstract
http://webcenter.health.webmd.netscape.com/content/article/90/100756.htm
So it would appear that rather than through the alchemy of sperm merging with healthy cells, the real cause of anal cancer in both men and women that engage in anal sex is from virus that are transmitted during the act. Both sexes are obviously at risk of anal cancer if they participate in anal sex. Again, the article that started this thread goes down in flames.
It appears your contention is centered on the following statements:
This fusing is what often results in the development of cancerous malignancies.Is it possible the cause of anal cancer in both men and women that engage in anal sex is from virus that are transmitted during the act and the above statements are not mutually exclusive?and
They conclude that male seminal plasma "may directly and/or indirectly contribute to an immunopermissive environment favorable for the perpetuation of spermatozoa (or otherwise) induced tumors."