Evidence that data from the largest trial of treatments for breast cancer in the US were, falsified has shaken both the public and the scientific community. The national surgical adjuvant breast and bowel project studied more than 5000 patients in 485 academic and community hospitals. When it reported in the New England Journal of Medicine in 1985 that lumpectomy plus radiotherapy was as effective as mastectomy it was influential in the move away from mastectomy as the operation of choice for women with breast cancer.

But this month the Chicago Tribune reported that about 16% of the patients came from St Luc's Hospital, a small centre in Montreal, and that Dr Roger Poisson there had included ineligible patients. Within 24 hours telephone lines at the American Cancer Society were jammed by women who had had lumpectomies …