Impact of ethnicity on the incidence of high-risk endometrial carcinoma.

OBJECTIVE

To evaluate the impact of race/ethnicity on histology in endometrial cancer.

METHODS

California Cancer Registry data on 11,674 white and 423 black women with endometrial cancer registered from 1988 to 1992 were used to compare the average annual age-adjusted incidence rate/100,000 women of low-risk (grades 1 and 2 endometrioid adenocarcinoma) and high-risk (grade >2 endometrioid carcinomas, papillary serous, clear cell, and adenosquamous histologies) lesions in black and white women.

RESULTS

Of the white patients, 9059 (78%) had low-risk and 2615 (22%) had high-risk lesions. Of the black patients, 236 (56%) had low-risk and 187 (44%) had high-risk lesions. The overall average annual age-adjusted incidence of endometrial cancer in white women is 20.1/100,000 and for black women is 9.4/100,000; however, the incidence of low-risk tumors is 15.9/100,000 in white women and only 5.3/100,000 in black women. The incidence of high-risk disease is identical in black and white women (4.2/100,000).

CONCLUSIONS

Black women in the general population have the same likelihood as white women of developing high-risk endometrial cancer. Black women have a significantly lower incidence of low-risk tumors compared to white women. The increased incidence of low-grade lesions in white women may be due to differences in socioeconomic factors or other factors yet to be identified.