Prospective seroepidemiological evidence that human papillomavirus type 16 infection is a risk factor for oesophageal squamous cell carcinoma

Abstract

During 1968-72 the mobile clinic of the Social Insurance Institution of Finland collected serum samples from 39268 subjects resident in most parts of Finland.4 Registry linkage with the nationwide Finnish Cancer Registry identified 165 cases of head and neck cancers that had occurred in the cohort up to 1991. For each patient with cancer, two controls (free of any cancer at baseline) were selected, matched for sex, age, and municipality. In 134/165 matched sets the ages were exactly matched. The maximum age discrepancy (in 4/165 sets) was seven years. The matching for municipality also resulted in a matching for time of sample collection. Detection of IgG against HPV16 capsids was performed by standard enzyme linked immunosorbent assay (ELISA).3 Relative risks, estimated as odds ratios, were calculated using conditional logistic regression of non-dissociable matched sets.