A study of 490 cases of breast cancer a t the Johns Hopkins Hospital revealed 42 cases (8.6%) with bilateral disease. There were 8 cases (1.7%) of bilateral primary simultaneous breast cancer and 34 cases (6.9%) of bilateral primary non-simulaneous breast cancer. There were 6 cases of lobular carcinoma in situ included in this series; 3 cases were simultaneous and 3 cases were non-simultam-OW. I f these 6 cases were deleted from the study, the total incidence of bilateral breast cancer would be 7.3%. A similar study of 67 cases of breast cancer in private patients revealed only I case (1.5%) with bilateral breast cancer over a long period of follow-up. T h e incidence of latent or occult cancer of the contralateral breast is discussed in relation to the incidence of overt bilateral breast cancer. Careful follow-up examination is the recommended method of management for all patients with primary breast cancer. Periodic physical examinations supplemented by mammography and other meaningful diagnostic aids (thermography, xeroradiography, and ultrasonography) are to be preferred to random biopsy or prophylactic mastectomy of the asymptomatic contralateral breast.
ATIENTS W I T H CANCER OF ONE BREAST HAVE P a higher than average risk of developing cancer of the opposite breast. This foreboding for the second breast was the somber omen observed by Stewart" who said that "the most frequent precancerous lesion of the breast is a cancer of the opposite breast."
The natural history of breast cancer is variable and unpredictable in its clinical manifestations, and this poses for physicians, surgeons, and patients a Gordian knot of treatment choices. It is the most common single site of malignancy in women, and in the United States alone more than 65,000 women will develop this malignancy during the coming year. Almost 6% of all women will ultimately develop breast cancer during their lifetime, and for the past 30 years there has been very little improvement in either the morbidity or mortality of this destructive disease.
No small reason for dread in this particular malignancy is the double jeopardy breast cancer threatens for its victims. This higher risk of a second primary breast cancer is important