A FOLLOW-UP-STUDY OF DETERMINANTS OF 2ND TUMOR AND METASTASIS AMONG SUBJECTS WITH CANCER OF THE ORAL CAVITY, PHARYNX, AND LARYNX

We conducted a follow up study of 380 incident cases of cancer of the oral cavity, pharynx, or larynx, who had been included in a previous c ase-control study. Information pertaining to potential risk factors, c linical characteristics, and evolution of the tumor (vital status, met astases, and second primary tumors) was obtained. From a multivariate proportional hazard model including terms for risk factors and clinica l variables, the incidence of metachronous second primary tumors occur ring in the head and neck was positively associated with employment as a farmer as opposed to white collar (hazard ratio [HR] 3.3) and with tobacco smoking before first tumor diagnosis (HR = 4.3 for heavy versu s never or very light smoker). The risk of second primary tumor decrea sed with increasing dietary ''beta carotene'' intake (HR = 0.4 for hig h versus low intake in tertiles). Less differentiated first primary tu mors were followed more frequently by second tumors as compared to gra de 1 tumors. The incidence of metastases was not associated with etiol ogical factors of the first tumor, but with stage.