USEFULNESS OF ULTRASONOGRAPHY COMBINED WITH CONVENTIONAL PHYSICAL-EXAMINATION IN MASS-SCREENING FOR BREAST-CANCER - A RETROSPECTIVE STUDY OF YAMANASHI HEALTH-CARE CENTER RESULTS FROM 1989 TO 1994

We retrospectively analyzed the records for 34,474 women who participa ted in mass screening for breast cancer by physical examination with o r without ultrasonography (US) at Yamanashi Health Care Center between April, 1989 and March, 1994 to evaluate the usefulness of US in mass screening. In one group (15,935 women) conventional physical examinati on with inspection and palpation alone had been performed, and in anot her (18,539 women) both conventional physical and US examinations were performed. Breast cancer was detected in 27 of the women (0.08% of th e total group screened), 22 of whom were in the group examined by US; moreover, 16 of these 22 women had early breast cancer, which was a no n-palpable tumor in 13. Half of the 22 women were examinees under the age of 50 years. Of the 22 tumors detected in the groups examined by U S, 16 (73%) were early breast cancer. The overall detection of early b reast cancer (0.09%) in the US group was significantly higher than tha t (0.01%) in the group examined by conventional methods (P < 0.05). Of the tumors detected in the US group, 59.1% were non-palpable. These r esults suggest that early and non-palpable breast cancer can be detect ed using US, and the incidence of detection of such tumors in women un der the age 50 years is increased in mass screening including US exami nation. This examination is effective in mass screening for breast can cer, especially for early and non-palpable breast cancer tumors.