No decrease in death rate despite mammography

Recent research shows that women in their 40s who received annual mammography screening did not have a better survival rate from breast cancer than those who received usual care from their personal physician after an average 13 year follow up. A study conducted at the University of Toronto compared breast cancer mortality in two groups of 40-49 year old women. The first group received screening with annual mammography, physical examination of the breast, and instruction on breast self-examination. The second group received the usual care available in the Canadian healthcare system after a single physical breast examination and instruction on breast self-examination. Fifteen Canadian centres took part in the randomised controlled trial, which involved 50430 volunteers recruited from January 1980 to March 1985 who were not pregnant, had no previous breast cancer diagnosis, and had not had mammography in the preceding 12 months. Physical breast examination and instruction on breast self examination were done before the random assignment of 25214 women to receive annual mammography, physical breast examination, and breast self examination and 25216 women to receive usual health care with annual follow up. The 105 breast cancer deaths in the mammography group and 108 breast cancer deaths in the usual care group yielded a cumulative rate ratio, adjusted for mammography done outside the study. A total of 592 cases of invasive breast cancer and 71 cases of in situ breast cancer were diagnosed by 31 December 1993 in the mammography group compared with 552 and 29 cases, respectively, in the usual care group. The expected proportions of non-palpable and small invasive tumours were detected on mammography. After 11 to 16 years of follow-up, four or five annual screenings with mammography, breast physical examination, and breast self-examination had not reduced breast cancer mortality compared with usual community care after a single breast physical examination and instruction on breast self-examination.