Genetic Change May Distinguish Rare Benign Ovarian Tumors From Cancerous Tumors
Posted: Tuesday, March 17, 2020
An oncogenic fusion appears to be the root cause of a rare type of ovarian tumor called sclerosing stromal tumor, according to a study published in Nature Communications. Britta Weigelt, PhD, of Memorial Sloan Kettering (MSK) Cancer Center, New York, and colleagues found that 80% of the sclerosing stromal tumors tested in their lab contained either FHL2-GLI2 fusion genes or GLI2 rearrangements, resulting in the activation of the Sonic hedgehog pathway.
This type of benign tumor may be misdiagnosed as malignant and accounts for less than 5% of sex cord stromal tumors, a heterogeneous group of benign and malignant neoplasms derived from the primitive sex cords or stromal components of the ovaries. “If a woman with a [sclerosing stromal tumor] is misdiagnosed as having ovarian cancer, she would likely be given more aggressive treatments that she wouldn’t need,” explained Dr. Weigelt in an MSK press release. “Although these tumors can cause a lot of pain and other symptoms, they can be successfully treated with surgery alone because they do not spread.”
Of the 26 samples confirmed to be sclerosing stromal tumors, the researchers identified recurrent FHL2-GLI2 fusion genes in 65% of samples (17/26) and GLI2 rearrangements in an additional 15% of samples (4/26). Neither of these genetic changes was detected in other types of sex cord stromal tumors (n = 48) or common cancer types (n = 9,950), confirming this fusion is unique to sclerosing stromal tumors.
In vitro analyses established that expression of the FHL2-GLI2 fusion increases signaling via the Sonic hedgehog pathway and results in the acquisition of oncogenic properties, including increased proliferation, migration, and colony formation. “This study provides new biologic clues about Sonic hedgehog and its role in cancer,” Dr. Weigelt stated.
Disclosure: The full disclosures of the study authors can be found at www.nature.com.