Carcinoma of the breast associated with pregnancy.

Abstract

The coexistence of pregnancy with carcinoma of the breast has been generally accepted as indicating an unfavourable prognosis. The author's clinical observations over a period of years, however, have cast some doubt on the truth of this conclusion and have led to a formal study of the experience of the Ontario Cancer Institute, incorporating the Princess Margaret Hospital. The confusion about the management of the carcinoma, the necessity of a therapeutic abortion, and the wisdom of castration has been a further incentive to this study. While theoretically the added impetus of the increased circulating estrogens during pregnancy could be expected to accelerate the growth of mammary carcinoma, this response cannot always be demonstrated clinically. The breast lump may remain quiescent during the course of the pregnancy and increase rapidly in size after parturition, or it may enlarge progressively during gestation and become smaller after the pregnancy is terminated. It may not grow appreciably during the early months but increase rapidly during the third trimester, when the estrogen circulation is reduced and the luteal hormone increased. Although there are no other accounts of the possible luteal hormone influence, Aaron et al. (1) have reported one case of carcinoma of the breast associated with pregnancy in which a radical mastectomy was performed at twenty-four weeks gestation and an abdominal hysterotomy and bilateral salpingo-oophorectomy at thirty-seven weeks. The right ovary was found to be enlarged and cystic, the pathological diagnosis being hyperplastic corpus luteum of pregnancy. Contradictions in the clinical course are also evident in the lactation period. Some tumours remain quiescent, while others seem to grow rapidly; some appear to be accelerated and others retarded after weaning. Nevertheless, one can accept the premise that, if pregnancy or lactation seems to accelerate the disease at any stage, the life expectancy of the pregnant patient is probably shorter than for a comparable patient, with disease of similar extent, in the absence of the pregnancy factor. An excellent review of 1,375 cases collected from the literature from 1866 to 1953 was published by T. T. White in 1955, and a further report the same year on 1,413 cases (2, 3). Incidence studies by that author revealed only 3 cases of carcinoma of the breast occurring per 10,000 pregnancies. Pregnancy or lactation, however, was a complicating factor in approximately 3 per cent of all cases of mammary carcinoma. The average age of the patients was thirty-five years. McCaffrey (4) has reported a case in a patient forty-nine years of age, and Nelson (5, 5A) saw an inflammatory carcinoma of the breast complicated by pregnancy at the age of twenty.