Women with endometriosis could be at higher risk of ovarian cancer, with the type of the condition potentially affecting the risk and cancer type.
Researchers have found that women with endometriosis had a 4.2-fold higher ovarian cancer risk than those without endometriosis, with the associations being much higher for type I ovarian cancer compared to type II ovarian cancer.
Similarly, women with ovarian endometriomas or deep infiltrating endometriosis had a 9.7-fold higher risk compared to those without.
Researcher Dr Karen Schliep said recent studies had suggested the simultaneous role of the PTEN tumour-suppressor gene in the early malignant transformation of endometriosis and the contribution of deficient MMR (mismatch repair) protein status in the pathogenesis of endometriosis-associated ovarian carcinoma (EAOC).
“In addition to activating and inactivating mutations in cancer driver genes, the complex pathogenesis of EAOC involves multiple other mechanisms such as the modulation of cancer driver genes via the transcriptional and post-translational (miRNA) modulation of cancer driver genes and the interplay with the inflammatory tissue microenvironment,” she said.
“This knowledge is being translated into the clinical management of endometriosis and EAOC, including the identification of the new biomarkers to predict of the risk of endometriosis and cancer, and will shape the precision oncology treatment of EAOC.”
The study also found that endometrial cysts could sometimes give rise to EAOC.
“Additionally, there is a reported correlation between 15%–20% of ovarian endometrial cancer and endometrioid adenocarcinomas of the endometrium,” Dr Schlieb said.
“However, overall, given the rarity of ovarian cancer the excess risk was relatively small, with 10–20 additional cases per 100,000 women. Nevertheless, women with endometriosis, notably the more severe subtypes, may be an important population for targeted cancer screening and prevention studies.
“Precision medicine is more than just genetics. Clinical features, including a woman’s history of endometriosis and type of endometriosis, may inform ovarian cancer risk prediction models.
“There was evidence that several mechanisms could contribute to the conversion of endometriosis into a malignant form, but the processes by which this transformation occurred have remained unclear.”