Cancers in multiple primary sites

Seventy-six patients with multiple primary cancers have been found among 9180 cancer patients admitted to the Center of Oncology & Nuclear Medicine, Okmeydani Hospital, Istanbul, Turkey between 1980 and 1984. Overall incidence of multiple primary cancers (MPC) among all cancer patients was 0.83%. The majority of the patients were male in both MPC and all patients, i.e. 64.5% and 63.1%, respectively. In MPC patients, the great majority of the patients was in the 51-70 years age group (57.9%) at the time of initial cancer diagnosis. Combination of larynx cancer and lung cancer was the most commonly seen combination. It was followed by lip cancer-larynx cancer (6.6%), skin cancer-larynx cancer and skin cancer-lung cancer (5.3%), breast cancer-ovary cancer and breast cancer-endometrium cancer (4%) combinations. Larynx cancer was the most commonly seen multiple primary cancer component in all patients (46%) and in male patients (61.2%). It was followed by lung cancer, i.e. 39.5% in all patients and 55.1% in male patients. In female patients, breast cancer was a component in 63% of the cases. In eleven patients, two cancers were diagnosed concurrently. In other cases, the interval between two cancers varied between 1 month and 30 years. The mean interval was 4.1 +/- 0.6 years (median 3.0 years). In 62% of the cases, the interval between two cancers was shorter than 3 years. Smoking rate was 75.5% in male patients whereas it was only 18.5% in females. In larynx cancer-lung cancer patients, smoking rate was 81.2% and reached 83.3% when lip cancers were included.(ABSTRACT TRUNCATED AT 250 WORDS)