Multiple Primary Neoplasms in the Western Hospital Region, Scotland: A Survey Based on Cancer Registration Data

Abstract

A study of multiple primary neoplasms in the Western Hospital Region of Scotland {which covers about 3,000,000 inhabitants) has been carried out, using cancer registration data, for the period July 1958–66. The total registrations were 61,288. (1) After elimination of doubtful cases, 428 cases of multiple primary neoplasms remained for study, 0.73 per cent of the sample. (2) Multiple primaries occurred most commonly in people in whom the first malignant lesion appeared late in life. (3) In only a few sites did the relative prevalence of cancers in the multiple primaries (M.P.) series differ from that in the single primaries (S.P.) series. The incidence of bilateral breast cancer was less than 1 per cent. This figure is much lower than those reported by other workers. About half were cases of ‘simultaneous’ bilateral breast cancer, and of the others, about one quarter occurred within one year of discovery of the first neoplasm. Genital neoplasms were very common in the female M.P. series (40%), but in males, the M.P. and S.P. series showed identical prevalence of genital neoplasms. (4) Associations between pairs of cancers sufficiently pronounced to be statistically significant were few, occurring in 4 pairs of sites in males and in 5 in females. Skin cancers featured in all male and 2 of the female pairings, and genital cancers in three female pairings. (5) There was a very marked likelihood for cancers of the larynx, uterus (all types), bladder and skin to be the first primary to appear (70% of cases or over). (6) Almost one third of second primaries occurred within a year of the first and after this the number declined rapidly. This held good when the figures were related to the number of survivors and to the number of survival-months.