Canadian contributions to cancer control.

Cancer control comprises prevention, screening, treatment, rehabilitation and palliative care. Preventive approaches need to be congruent with those adopted for other chronic diseases, with a major impact to be expected from smoking control and dietary modification. Canadian studies have contributed substantially to knowledge in both areas. Increasing interest is now being paid to other environmental causes of cancer, and to gene-environment interactions. Canadian studies have shown that screening for cancer of the cervix is effective, but improved organization of services is required to make it realize its full potential. The National Breast Screening Study has reminded us that a prerequisite for effective screening is effective therapy for the detected abnormalities, yet as therapy improves, so the contribution of screening may fall. Treatment has improved dramatically in recent decades for childhood cancer, where it is the mainstay of control. For adults, Canadian studies have contributed to improved therapy for some solid and hematogenous tumors, but important breakthroughs from molecular biology are still awaited. Finally, Canadians have been at the forefront of palliative care, as well as recognizing the need for improvement in the organization of cancer control.