Endometrial carcinoma in women under 40 years of age: comparison of cases in oral contraceptive users and non-users.

Women under 40 years of age rarely develop carcinoma of the endometrium, this age group comprising less than 3% of all cases in most large series. The Registry for Endometrial Carcinoma in Young Women Taking Oral Contraceptive Agents has recorded and studied 30 cases in women under 40 with a history of oral contraceptive administration, and these are compared with 25 cases in the same age group which were accessioned at the Armed Forces Institute of Pathology prior to the era during which these agents have been available, and with series reported in the literature totaling 137 cases with no contraceptive history. In the first group, special attention is paid to the 20 women who received sequential agents exclusively or predominantly, since the association with these agents (primarily Oracon) is much higher than would be expected from the fact that less that 10% of oral contraceptives used in this country are of the sequential type. An analysis of the three groups reveals a similar incidence of the various histologic types (primarily well differentiated tumors with a relatively favorable prognosis), the only difference being the presence of secretory features in 14 of 29 oral contraceptive users vs. only two of 25 women not taking these agents. Clinical and pathologic staging were also predominantly favorable, and comparable in all groups. There were, however, notably higher incidences of nulliparity, obesity, and sclerocystic ovaries--all features traditionally associated with endometrial carcinoma--in the patients not receiving oral contraceptives or receiving combined agents, suggesting that the group receiving sequentials may not represent the same constitutionally predisposed population. Only three of 55 women among our personally reviewed cases have thus far died of cancer (one in the contraceptive group and two in the non-user group) and all three of these had poorly differentiated tumors with myometrial invasion. The excellent prognosis for most patients in this age group is thus confirmed.