BACKGROUNDThe incidence of anal cancer has increased among both men (160%) and women (78%) from 1973 to 2000 in the U.S. The authors conducted a population‐based case–control study of anal cancer to examine factors that may account for this increase.METHODSMen (n = 119 patients) and women (n = 187 patients) who were diagnosed with anal cancer between 1986 and 1998 in the Seattle area were ascertained through the local Surveillance, Epidemiology, and End Results registry. Control participants (n = 1700) were ascertained through random‐digit telephone dialing. Participants were interviewed in person and provided blood samples. Archival tumor tissue was tested for human papilloma virus (HPV) DNA, and serum samples were tested for HPV type 16 (HPV‐16).RESULTSOverall, 88% of tumors (all histologies) in the study were found to be positive for HPV. HPV‐16 was the most frequent HPV type detected (73% of all tumors), followed by HPV‐18 (6.9%), regardless of gender. However, 97.7% of tumors from men who were not exclusively heterosexual contained HPV DNA. The risk of anal cancer increased among men (odds ratio [OR], 5.3; 95% confidence interval [95% CI], 2.4–12.0) and women (OR, 11.0; 95% CI, 5.5–22.1) who had ≥ 15 sexual partners during their lifetime. Among men who were not exclusively heterosexual and women, receptive anal intercourse was related strongly to the risk of anal cancer (OR, 6.8 [95% CI, 1.4–33.8] and OR, 2.2 [95% CI, 1.4–3.3], respectively). Current smokers among men and women were at particularly high risk for anal cancer, independent of age and other risk factors (OR, 3.9 [95% CI, 1.9–8.0] and OR, 3.8 [95% CI, 2.4–6.2], respectively).CONCLUSIONSThe high proportion of tumors with detectable HPV suggests that infection with HPV is a necessary cause of anal cancer, similar to that of cervical cancer. Increases in the prevalence of exposures, such as cigarette smoking, anal intercourse, HPV infection, and the number of lifetime sexual partners, may account for the increasing incidence of anal cancer in men and women. Cancer 2004. © 2004 American Cancer Society.

BACKGROUNDAnal cancer is a rare malignancy of the anogenital tract that historically has affected women at a greater rate than men.METHODSThe authors analyzed changing trends in incidence rates and 5‐year relative survival percentages for patients with anal cancer. The publicly available data used in the current study were obtained from the Surveillance, Epidemiology, and End Results (SEER) Program, a system of population‐based tumor registries in the United States.RESULTSThe incidence of anal cancer was similar for men and women between 1994 and 2000 (2.04 per 100,000 and 2.06 per 100,000, respectively), the most recent period for which data were available, whereas men had lower rates than did women between 1973 and 1979 (1.06 per 100,000, compared with 1.39 per 100,000), the earliest period for which data were available. In addition, recently, black men had higher incidence rates than did other race‐specific and gender‐specific groups (2.71 per 100,000). From the earliest period for which data were available to the most recent period, relative 5‐year survival improved from 59% to 73% among women, was unchanged among men (∼60%), and decreased from 45% to 27% among black men. Eighteen percent of patients who had distant disease were alive at 5 years, compared with 78% of patients who had localized disease.CONCLUSIONSThe incidence of anal cancer in the United States increased between 1973 and 2000, particularly among men. There were higher incidence rates and lower survival rates for black men compared with other race‐specific and gender‐specific groups. Later disease stage was inversely associated with the survival rate, indicating that earlier detection may improve the survival of patients with anal cancer. Cancer 2004. © 2004 American Cancer Society.

Few population-based case-control studies have assessed etiologic factors for penile cancer. Past infection with high-risk human papillomavirus (HPV) is a known risk factor for penile cancer; however, few previous studies have related the HPV DNA status of the tumor to potential demographic and behavioral risk factors for the disease or evaluated whether in situ and invasive penile cancer share risk factors. Little information is available on the role and timing of circumcision in the etiology of penile cancer. We conducted a population-based case-control study in western Washington state that included 137 men diagnosed with in situ (n 5 75) or invasive (n 5 62) penile cancer between January 1, 1979, and December 31, 1998, and 671 control men identified through random digit dialing. Cases and controls were interviewed in person and provided peripheral blood samples. Case and control blood samples were tested for antibodies to HPV16 and HSV-2, and tumor specimens from cases were tested for HPV DNA. Men not circumcised during childhood were at increased risk of invasive (OR 5 2.3, 95% CI 1.3-4.1) but not in situ (OR 5 1.1, 95% CI 0.6-1.8) penile cancer. Approximately 35% of men with penile cancer who had not been circumcised in childhood reported a history of phimosis compared to 7.6% of controls (OR 5 7.4, 95% CI 3.7-15.0). Penile conditions such as tear, rash and injury were associated with increased risk of disease. Among men not circumcised in childhood, phimosis was strongly associated with development of invasive penile cancer (OR 5 11.4, 95% CI 5.0-25.9). When we restricted our analysis to men who did not have phimosis, the risk of invasive penile cancer associated with not having been circumcised in childhood was not elevated (OR 5 0.5, 95% CI 0.1-2.5). Cigarette smoking was associated with a 4.5-fold risk (95% CI 2.0-10.1) of invasive penile cancer. HPV DNA was detected in 79.8% of tumor specimens, and 69.1% of tumors were HPV16-positive. The proportion of HPV DNA-positive tumors did not vary by any risk factors evaluated. Many risk factors were common for both in situ and invasive disease. However, 3 factors that did not increase the risk for in situ cancer proved significant risk factors for invasive penile cancer: lack of circumcision during childhood, phimosis and cigarette smoking. The high percentage of HPV DNA-positive tumors in our study is consistent with a strong association between HPV infection and the development of penile cancer regardless of circumcision status. Circumcision in early childhood may help prevent penile cancer by eliminating phimosis, a significant risk factor for the disease. ' 2005 Wiley-Liss, Inc.

BackgroundMerkel cell polyomavirus (MCPyV) has been detected in approximately 75% of patients with the rare skin cancer Merkel cell carcinoma. We investigated the prevalence of antibodies against MCPyV in the general population and the association between these antibodies and Merkel cell carcinoma.MethodsMultiplex antibody-binding assays were used to assess levels of antibodies against polyomaviruses in plasma. MCPyV VP1 antibody levels were determined in plasma from 41 patients with Merkel cell carcinoma and 76 matched control subjects. MCPyV DNA was detected in tumor tissue specimens by quantitative polymerase chain reaction. Seroprevalence of polyomavirus-specific antibodies was determined in 451 control subjects. MCPyV strain–specific antibody recognition was investigated by replacing coding sequences from MCPyV strain 350 with those from MCPyV strain w162.ResultsWe found that 36 (88%) of 41 patients with Merkel cell carcinoma carried antibodies against VP1 from MCPyV w162 compared with 40 (53%) of the 76 control subjects (odds ratio adjusted for age and sex = 6.6, 95% confidence interval [CI] = 2.3 to 18.8). MCPyV DNA was detectable in 24 (77%) of the 31 Merkel cell carcinoma tumors available, with 22 (92%) of these 24 patients also carrying antibodies against MCPyV. Among 451 control subjects from the general population, prevalence of antibodies against human polyomaviruses was 92% (95% CI = 89% to 94%) for BK virus, 45% (95% CI = 40% to 50%) for JC virus, 98% (95% CI = 96% to 99%) for WU polyomavirus, 90% (95% CI = 87% to 93%) for KI polyomavirus, and 59% (95% CI = 55% to 64%) for MCPyV. Few case patients had reactivity against MCPyV strain 350; however, indistinguishable reactivities were found with VP1 from strain 350 carrying a double mutation (residues 288 and 316) and VP1 from strain w162.ConclusionInfection with MCPyV is common in the general population. MCPyV, but not other human polyomaviruses, appears to be associated with Merkel cell carcinoma.