Researchers found that the link between a history of uterine leiomyoma, also known as fibroids, and cancer was strongest for cancer diagnosed within two years of uterine fibroids being found. The results could be explained by greater surveillance of women with fibroids or misdiagnosis of cancer as uterine leiomyoma.
An association also was observed for cancer reported 10 or more years after fibroids were detected.
Earlier studies have found that incidence rates for endometrial cancers have risen across all racial and ethnic groups in the United States, with the highest annual increase observed among non-Hispanic black women.
Compared to caucasian women, black women have two to three times the incidence of uterine fibroids, an earlier age at first diagnosis, and greater disease severity.
Because endometrial bleeding is a symptom of both fibroids and uterine cancer, it is possible that some cancers are initially misdiagnosed as fibroids, says lead researcher Lauren Wise, professor of epidemiology at Boston University.
That could help explain the study’s finding of a stronger association between fibroids and uterine cancer that is diagnosed at later stages (stage 2 or greater), the authors write.
It remains unclear whether there is a causal association between uterine fibroids and the incidence of endometrial cancer. Studies of genetic alterations in uterine fibroids have identified several distinct pathways of tumor development.