Though not often the first line of defense, clinicians should consider endometrial cancer screening using either CT or MRI after a patient undergoes radiation therapy for cervical carcinoma, Portuguese researchers argue in the first-ever study published on the subject.
Radiation therapy and chemoradiation are both standard treatments for locoregionally advanced cervical carcinoma, corresponding author João Lopes, MD, and colleagues wrote in the European Journal of Radiology this month. But the therapies, while successful, can have some harmful consequences.
“With longer survival rates after treatment, long-term effects of pelvic irradiation become clearer,” Lopes, a radiologist at Hospital de Santa Marta in Lisbon, Portugal, wrote. “Radiation used to treat the first malignancy can damage normal tissues and predispose patients to a second tumor.”
Furthermore, Lopes and co-authors said, those second occurrences are usually more aggressive histological endometrial cancers that are poorly differentiated and present most commonly in advanced stages.
“The precise mechanism of development of these cancers is still unknown, and a direct relation with radiation is not established,” the authors wrote. “However, the long latency period of 15 years between radiation therapy and the appearance of the endometrial carcinoma supports radiation as the possible etiologic factor.”
Imaging of cervical carcinomas and endometrial cancers, including their presence, persistence and recurrence, is “an area of intense study,” the researchers said, but no literature exists on the imaging features and diagnostic challenges of the illnesses after radiation therapy.
To expand on current research, Lopes et al. performed a retrospective review of clinical, histological and radiological data of 13 women diagnosed with endometrial cancer at their practice. All women had a history of radiation therapy for cervical carcinoma and underwent either MRI or CT between 2005 and 2016.
The authors said they found a wide range of morphologies in the women, including single mixed tumors, large heterogeneous multifocal tumors and multifocal small polypoid tumors. By far the most common occurrences were single solid tumors, which made up 46 percent of the data. Large tumors were also frequent, with 65 percent of lesions measuring more than five centimeters.
Hematometra was another common player in 85 percent of cases, according to the study, and usually involved large volumes of blood averaging 318 milliliters. The condition was associated with cervical stenosis in 91 percent of patients.
“Cervical stenosis is a known complication after radiation therapy for cervical carcinoma, and the association with tumor hemorrhage could explain the development of large hematometra with delayed symptoms,” Lopes and colleagues wrote. “Patients with a history of cervical carcinoma treated with radiation therapy with a fluid-filled endometrial cavity should be carefully evaluated to exclude an endometrial malignancy.”
Hematometra and post-radiotherapy changes limited the utility of MRI in local staging, the authors said, but distant metastases could be quickly diagnosed with CT or MRI and were found in 42 percent of the women studied.
“These rare heterogeneous tumors should be considered after radiotherapy for cervical carcinoma, especially when hematometra is observed,” Lopes et al. said. “Aggressive histological presentations and delayed symptoms due to cervical stenosis are responsible for an unfavorable prognosis.”