Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Division of Cancer Prevention and Control, Epidemiology and Applied Research Branch, Atlanta, GA, USA. Electronic address: yzs2@cdc.gov.
Declines in cervical cancer incidence and mortality in Canada and in the United States have been widely attributed to the introduction of the Papanicolaou (Pap) test. This article reviews changes in screening and introduction of HPV vaccination.
Sentinel events in cervical cancer screening and primary prevention through HPV vaccination in the US and Canada are described.
Despite commonalities, cervical cancer screening and prevention differ between the two countries. Canada has a combination of opportunistic and organized programs at the provincial and territorial level, while the US has opportunistic screening and vaccination systems. In the US, the HPV test along with the Pap test (co-testing) is part of national recommendations for routine cervical cancer screening for women age 30 and older. Co-testing is not being considered anywhere in Canada, but primary HPV testing is currently recommended (but not implemented) in one province in Canada.
Many prevention strategies are available for cervical cancer. Continued public health efforts should focus on increasing vaccine coverage in the target age groups and cervical cancer screening for women at appropriate intervals. Ongoing evaluation will be needed to ensure appropriate use of health resources, as vaccinated women become eligible for screening.
Non-cervical anogenital cancers (i.e. anal, vulvar, vaginal and penile cancers) associated with the human papillomavirus (HPV), for which HPV is known to be the necessary cause of carcinogenesis, are poorly documented due to their relatively low incidence rate. The aim of this study is to describe the incidence rates of these cancers between 1984 and 2001, and their relative survival probabilities, in Quebec (Canada) between 1984 and 1998. The incidence of these cancers is on the rise, particularly anal cancer in women and, more recently (since 1993-95), vulvar cancer. Between 1984-86 and 1993-95, the 5-year relative survival probability for men with anal cancer decreased from 57% to 46%, while that for penile cancer dropped from 75% to 59%. However, during the same period, the 5-year relative survival probability for women with anal cancer rose from 56% to 65%, and remained stable for cervical and vulvar cancers, at 74% and 82%, respectively.
The role of primary care physicians in providing care for hepatitis C virus (HCV) infection is increasingly emphasized, but many gaps and challenges remain. This study explores family physicians' knowledge, attitudes and practices associated with providing care for HCV infection. Seven hundred and forty-nine members of the College of Family Physicians of Canada (CFPC) completed a self-administered survey examining knowledge, attitudes and behaviours regarding HCV infection screening and care. Multivariate analyses were performed using the outcome, HCV care provision, and variables based on a conceptual model of practice guideline adherence. Family physicians providing basic-advanced HCV care were more likely to be older, practice in a rural setting, have injection drug users (IDU) in their practice and have higher levels of knowledge about the initial assessment (OR = 1.77; 95% CI = 1.23-2.54) and treatment of HCV (OR = 1.74; 95% CI = 1.24-2.43). They were also less likely to believe that family physicians do not have a role in HCV care (OR = 0.41; 95% CI = 0.30-0.58). Educational programmes should target physicians less likely to provide HCV care, namely family physicians practicing in urban areas and those who do not care for any IDU patients. Training and continuing medical education programmes that aim to shift family physicians' attitudes about the provision of HCV care by promoting their roles as integral to HCV care could contribute to easing the burden on consultant physicians and lead to improved access to treatment for HCV infection.
Infection with high risk human papillomavirus (HPV) is strongly associated with anal cancer. However, detailed studies on HPV type distribution by gender and age are limited.
Retrospective study of 606 invasive anal cancers diagnosed between 1990 and 2005 in two large urban areas of the province of Québec, Canada. Cases were identified from hospitalization registry. Patient characteristics were collected from medical files. Archived anal squamous cancer specimens were available from 96 patients and were tested for HPV DNA and typing. Variant analysis was performed on 16 consecutive and 24 non-consecutive HPV16-positive samples to assess potential contamination during amplification.
Among the 606 patients with anal cancers, 366 (60%) were women. Median age at diagnosis was 63 years. HPV was detected in 88/96 (92%) of cases. HPV16 was the most frequent type detected in 90% of HPV-positive specimens. Other types including 6, 11, 18, 33, 52, 53, 56, 58, 62 and 82 were also found. HPV 97 was not detected. HPV prevalence was associated with female gender and younger age. No contamination occurred during amplification as shown by the subset of 41 HPV16-positive samples, as 37, 2 and 1 isolates were from the European, African and Asian lineages, respectively. The most frequent variants were G1 (n=22) and the prototype (n=12).
Women with anal cancer are at higher risk for anal HPV infection, and HPV infection, especially HPV16, is strongly associated with squamous anal cancer. Therefore, HPV vaccine could potentially prevent the occurrence of anal cancer in both men and women.
