Showing papers by "Freddie Bray published in 2008"

Age-Incidence Curves of Nasopharyngeal Carcinoma Worldwide: Bimodality in Low-Risk Populations and Aetiologic Implications

Abstract: The distinct geographic variation in the global incidence of nasopharyngeal carcinoma reflects a complex etiology involving viral, environmental, and genetic components. The high to intermediate rates observed in endemic areas contrast markedly with the uniformly low rates seen in much of the world. An interesting epidemiologic observation is the early peak in age-incidence curves observed in certain geographically disparate populations, suggestive of distinct causal entities and the possible exhaustion of susceptible individuals from the population at a certain age. The aim of this study was to systematically evaluate the age-incidence profiles of NPC worldwide on partitioning populations according to level of risk, in an effort to provide clues about the importance of early-in-life factors and genetic susceptibility. Using data from 23 high-quality population-based cancer registries for the period 1983-1997, a key finding was the consistent pattern of bimodality that emerged across low-risk populations, irrespective of geographic location. Continual increases in NPC risk by age up to a first peak in late adolescence/early adulthood (ages 15-24 years) were observed, followed by a second peak later in life (ages 65-79 years). No such early peak in NPC incidence by age group was evident among the high-risk populations studied. These findings are discussed according to existing lines of biological and epidemiologic evidence related to level of population risk, age at diagnosis, and histologic subtype. A modified model for NPC tumor development is proposed on the basis of these observations.

Strengthening prevention programs to eliminate cervical cancer in the Nordic countries.

Abstract: Disease trend studies based on birth cohort analysis and serological studies indicate that recent generations have a higher prevalence of oncogenic Human Papilloma Virus (HPV) types, and are likely to be at higher risk of cancer than previous generations. This implies that prevention strategies to protect young populations from HPV-associated cancers need to be strengthened, and hence organized implementation of vaccination and better screening programs are being considered. In this context, randomized large-scale policy evaluations will be instrumental in accelerating disease control and improve effective prevention programs. This report shares experiences from Nordic countries with examples of prevention strategies through vaccination and cervical screening. The same principles as set up for organized programs and new HPV technologies may apply for screening and vaccination as key tools to eliminate cervical cancer in the Nordic countries and globally.