We showed that among males
We showed that among males, the ASIR and ASMR for HNC varied by Thonzonium Bromide group with Coloured men having the highest incidence and mortality rates. This confirms a previous NCR report , and studies in other countries . This may be related to the higher prevalence rates of tobacco smoking among Coloured men compared to men of other population groups in the country . White men had lower mortality rates compared to Black men despite having higher incidence rates than Black men. Quite likely, this relates to better access to healthcare among White men compared to Black men which results in early detection of cancer and thus better prognostic outcomes . Prior to 1994, access to healthcare was determined by race; in the post-apartheid era legal restrictions have changed but race is still an indicator of socio-economic access .
Public health implications of the findings The significant decline in incidence and mortality rates for OCC and LC, whose main risk factor is tobacco smoking, suggests that the anti-smoking legislation is yielding positive outcomes and should be further strengthened. On the other hand, the rising incidence and mortality rates of anal, vulval cancer and the relatively slower decline in incidence rates for OPC, highlight the need for regular monitoring of the trends of these cancers. This is particularly important now as ART access is widespread and the resulting increased life expectancy coupled to changes in sexual behaviour might result in an increased burden of these cancers . The current girls-only HPV vaccination program, could provide more benefit for cervical cancer, however these data suggest that there is need to consider inclusion for boys. This is because of the absence of effective screening especially for men and the emerging evidence which suggest that the impact and herd immunity of a girls-only program will likely be reduced [51,52]. Modelling studies are required to understand the cost-effectiveness of including boys. In addition, studies investigating effectiveness of single dose HPV vaccine compared to the current two doses could remove the cost obstacle and make it feasible for the HPV vaccine programme to include boys This study has some limitations. Data from a NCR could have under-estimated cancer incidence as cases that are not biopsied are excluded. Mortality data from Stats SA could have missed deaths that were not registered. For umbilical cord analysis, HPV-related cancers were defined based on the anatomic sites in which HPV DNA is frequently found, however all these cancers may not necessarily be HPV-positive because no testing was conducted. The antenatal HIV prevalence which was used as a proxy for monitoring the HIV epidemic overestimates the national prevalence as pregnant women are likely to be at higher risk of HIV infection. Despite these limitations, this study provides an important contribution to the epidemiology of HPV-related cancers in the country .
Conflicts of interests
Introduction Lung cancer remains the leading cause of cancer-related mortality globally . Tobacco consumption is unquestionably the predominant risk factor for the disease with 80–90% of cases occurring among former or current smokers [2,3]. As larger cohorts and consortia efforts mature, the ability to estimate less prominent risk factors in large datasets emerge. A multitude of risk additional factors for lung cancer have been identified [, , , ]. One additional risk factor of potential interest is the intake of alcohol and the interaction between alcohol and tobacco consumption . Alcohol has shown to be inconsistently associated with lung cancer risk in previous meta-analyses of case-control and cohort studies, with several previous studies reporting an increased risk for high doses [9,10] in a non-linear fashion , while others reporting that the associations are dependent upon beverage type with increased risks for liquor and beer and an inverse relationship with consumption of red wine . While meaningful associations have been observed across different studies designs, many of these studies have been unable to reach conclusive associations due to the potential for residual confounding or inadequate statistical power. Systematic reviews by the International Agency for Research on Cancer and the World Cancer Research Fund/American Institute for Cancer Research stated that there is inadequate evidence to support an association between alcohol consumption and lung cancer risk . An examination of the associations between alcohol and lung cancer by beverage type, histology groups as well as the interaction with tobacco consumption within a standard analytical framework confounders is warranted.