http://www.cirp.org/library/disease/cancer/vanhowe/
Christopher J. Cold, MD; Michelle R. Storms, MD; and Robert S. Van Howe, MD
Minoqua, Wisconsin
The commonly believed notion that circumcised men cannot develop penile cancer can result in delays in diagnosis. Recent medical literature has failed to confirm the protective effect of circumcision on penile neoplasms. Physicians need to be aware that men circumcised after 1 month of age may be at higher risk for penile cancer than those never circumcised.
Key Words. Penile neoplasms; circumcision; Bowen's disease.
(J Fam Pract 1997; 44:407-410.)DISCUSSION
Cancer of the penis is an extremely rare malignancy with a predicted lifetime risk of 1 in 1437 men in the United States5 and 1 in 1694 in Denmark,6 representing 0.09% of all cancers and 0.16% of cancers in the male adult.5 The risk factors for penile cancer (Table) include genital warts,7,8 smoking,8,9 past sexually transmitted diseases,7,10 a sexual relationship outside marriage,7 multiple sexual partners,8 poor genital hygiene,7,8,11,12 phimosis,7-10,13 previous genital conditions (including urinary tract infection, genital warts, yeast infections, chlamydia, genital crabs, gonorrhea, genital herpes, syphilis, genital ulcers or sores),7 penile rash (which lasted longer than 1 month) or penile tear,8 chewing tobacco or areca nut, using snuff,9 and postnatal circumcision.7,8 Of these risk factors, a history of genital warts appears to be the most significant, leading experts to identify human papillomavirus (HPV) as the most common causative factor in penile cancer.14
Interestingly, genital warts are now more common in circumcised men,15 and HPV-associated lesions are equally prevalent in circumcised and intact men. Penile intraepithelial neoplasia, although found rarely, is slightly more common in men with foreskins.16 In one study of 11 men with carcinoma in situ of the penis, 10 had been circumcised as infants.17
The role of circumcision in preventing penile cancer has recently been called into question.19 In addition to several publications documenting cancer in circumcised men,19-26 a recent case control study of 110 men with penile cancer from the Pacific Northwest revealed that 41 (37%) had been circumcised.8 Relative to men circumcised at birth, the risk for penile cancer was 3.04 times as great among men who were never circumcised and 3.55 times as great among men who were circumcised after the neonatal period. The magnitude of risk for developing penile cancer was similar in smokers, but a history of multiple sex partners or genital warts were the strongest risk factors (Table). While neonatal circumcision may play a small role in preventing penile carcinoma, 20% of the patients in this study were circumcised at birth.8 When the control group was properly adjusted for age, there was no difference between the case group and control group in circumcision status.
Circumcision performed after the newborn period may increase the likelihood of penile neoplasms. In a Danish study, men with localized squamous cell carcinoma of the penis were 7.81 times as likely to have been circumcised after the newborn period as the general population.8,27 Maden et al8 demonstrated that men circumcised after the newborn period had a slightly higher risk when compared with those circumcised at birth.8
In an epidemiologic study with both retrospective and prospective cases from China, 157 men with penile neoplasms were identified. Circumcised men were markedly more likely to develop penile cancer than controls.7 The circumcision scar is often the focus of tumor formation.19 In Africa an uncontrolled study found that all of the circumcised men who developed penile cancer were circumcised late in adolescence or adulthood.28 Why the timing of circumcision is a significant factor is unclear.
For the circumcision status of the patient to be missing from the chart for the past 60 years is indefensible, but not uncommon. In a series of penile cancer patients from the Mayo Clinic, 15% did not have their circumcision status documented in the chart.14 Because circumcision is so prevalent in the United States, a circumcised penis is often described as "normal" in medical records, thus providing no useful information.
In spite of the body of evidence to the contrary, several circumcision advocates still profess that penile cancer is "virtually eliminated" by neonatal circumcision.1,28-31 Having been given access to respectable medical journals, their errant message has been adopted by many mainstream physicians.14 The persistence and prevalence of his myth may be detrimental, as evidenced by the 3-year delay in this patient between the time the penile lesion was noted and a biopsy taken.
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Officials of the American Cancer Society do not recommend circumcision as a cancer preventative measure. (personal correspondence, H. Shingleton and C. W. Heath, Jr, to Peter Rappo, MD, Feb 16, 1996). Recognizing that circumcised men can acquire penile cancer are are at equal or higher risk for HPV-associated lesions is the first step in preventing penile cancer. Screening for, recognizing, and treating these lesions as they develop on the penis as is currently performed on the uterine cervix may be the most responsible approach to controlling both cervical and penile cancer; however the utility of such screening needs to be explored.16,32Persistent penile rashs are a highly significant risk factor for penile cancer8 and should not be ignored.Because of the absence of a national tumor registry in the United States, most of the epidemiological studies have been performed outside the United States. When the incidence of penile cancers from different countries are compared, the biggest factor appears to be indoor plumbing.33 The downward trend in the incidence of penile cancer over the past 47 years in Denmark, where 1.6% of men are circumcised, has been partly attributed to better penile hygiene.6
Ironically, Denmark, in spite of its low circumcision rate, currently has a lower incidence of penile cancer than the United States, where 60% to 80% of men are circumcised.
So, apparently, the circumcision should be done before 1 month of age for there to be a clear health benefit.
Of course, that is just one study; my experience with studies such as that is that the data may or may not say anything, and the interpretations often reflect the biases of the researchers; i.e., other conclusions could be made with the same data. And the study results absolutely must be corroborated with other studies, and meta-analyses need to be done, etc.
I did a search of Pubmed (keywords: circumcision, circumcision risks, circumcision risks benefits) and couldn’t find anything on dangers of circumcision. One thing I found out is that the practice of circumcision is being introduced into Africa to try to reduce the incidence of AIDS. In Africa, unlike in the US, heterosexual AIDS is a huge problem.