The areca nut chewing habit and oral squamous cell carcinoma in South African Indians. A retrospective study.

A retrospective study (1983-1989) of oral squamous carcinomas and concomitant oral habits was undertaken in South African Indians from Natal. Information came from hospital records and interviews with patients, families and friends. There were 143 oral squamous carcinomas; these occurred in a ratio of 1:1,6 for men and women respectively. Squamous carcinomas of the cheek (buccal mucosa, alveolar sulcus and gingiva) occurred most frequently, especially in women (57/89--64%), while in men tongue cancer predominated (22/54--41%). Ninety-three per cent of women (83/87) and 17% of men (9/54) habitually chewed the areca nut. Thirty-nine of 57 women (68%) with cheek cancer and 21/25 (84%) with tongue cancer only chewed the nut (no tobacco, snuff or smoking). Analyses confirmed an association between nut chewing and cheek cancer. The odds ratio (OR) for oral cancer in women 25 years and older who only chewed the nut was 43,9 and the attributable risk (AR) 0,89 (89%). With tobacco the OR increases to 47,42 and the AR to 0,91 (91%). The data showed that the areca nut habit with or without tobacco use is important in the development of oral squamous carcinoma. Elimination of this habit can reduce the risk in these women substantially (89-91%) if all other factors remain the same.