Predictors of oropharyngeal cancer survival in Europe

OBJECTIVES

HPV16-positive oropharyngeal cancer (OPC) patients experience better outcomes compared to HPV16-negative patients. Currently, strategies for treatment de-escalation are based on HPV status, smoking history and disease stage. However, the appropriate cut-point for smoking and the role of other non-clinical factors in OPC survival remains uncertain.

MATERIALS AND METHODS

We examined factors associated with OPC outcome in 321 patients recruited in a large European multi-center study. Seropositivity for HPV16 E6 was used as a marker of HPV16 positive cancer. Hazard ratios (HR) and confidence intervals (CI) were estimated using Cox proportional models adjusted for potential confounders.

RESULTS

Overall 5-year survival following OPC diagnosis was 50%. HPV16-positive OPC cases were at significantly lower risk of death (aHR = 0.51, 95% CI: 0.32-0.80). A significant effect on OPC survival was apparent for female sex (aHR 0.50: 95% CI: 0.29-0.85) and being underweight at diagnosis (aHR: 2.41, 95% CI: 1.38-4.21). A 10 pack year smoking history was not associated with overall survival. Higher stage at diagnosis appeared as the only factor significantly associated with OPC recurrence (aHR: 4.88, 95% CI: 2.12-11.21).

CONCLUSION

This study confirms that HPV16 status is an independent prognostic factor for OPC survival while female sex lowers risk of death and being underweight at diagnosis increases the risk of death. Smoking was not an independent predictor of OPC survival.

A Discrete Choice Model When Context Matters

This paper contributes to the description of the choice behavior of an individual who, as a result of capacity limitations, is unable to deal with a large number of alternatives and who is also unsure about his most preferred alternative in any given set. Hence, there is a conflict in that the individual wants both to reduce the choice set and to keep as many alternatives as possible. A natural way to solve this conflict is to view the individual as choosing sequentially while giving a weight to each corresponding subset of alternatives. We assume that the weights are defined by Choquet capacities which are independent of the path followed in the choice process. These choice capacities are obtained from a utility defined on the power set of alternatives. This implies that the context, identified as the opportunity set, influences the choice made by the individual. However, the choice capacities are not observable. It is shown that they can be converted into probabilities which have intuitive and appealing properties. In particular, using these probabilities allows for a sensible solution to the blue bus-red bus paradox when the individual has a natural preference for flexibility. Copyright 1999 Academic Press.