Cancer incidence in young adults in Canada: preliminary results of a cancer surveillance project.

Surveillance of cancer in young adults has been neglected, despite Sir Richard Doll's having emphasized its importance a decade ago. This report describes the patterns, time trends and regional variation in cancer incidence in Canada's young adults. In 1987 96, 97,469 cancers were diagnosed in Canadians aged 20 44, with almost two-thirds in females. Ten types of cancer accounted for 83% of diagnoses in women and 74% in men. The most common cancers in young women were breast, cervix, melanoma, thyroid and ovary, and in young men were testis, non- Hodgkin's lymphoma, melanoma, colorectal and lung. Although incidence rose only slightly for total cancer between 1969 and 1996, it increased dramatically for several specific types of cancer: lung (women), melanoma, testis, thyroid and non-Hodgkin's lymphoma. Incidence declined for a few cancers (colorectal, lung (men), cervix and ovary). Lung cancer incidence was significantly lower than the Canadian average in Prairie women and non-significantly high in Quebec (both sexes), while the rate of melanoma was significantly low in Quebec (both sexes) and high in women in the Pacific region.