Radiation After Surgery May Lower the Risk for Disease Spread in Uterine Carcinosarcomas

Radiation after initial cancer treatment in women with uterine carcinosarcomas may reduce the rate of distant metastases (or cancer development in another part of the body), according to a study published in the American Journal of Clinical Oncology.

Despite this benefit, radiation after initial cancer treatment did not significantly improve survival in these women, as survival did not differ in women regardless of whether they underwent chemotherapy, radiation or a combination of both after surgery.

“This study did not detect survival differences in patients treated with surgery alone compared with surgery and adjuvant therapy (chemotherapy or (radiation),” the study authors wrote. “Adjuvant chemotherapy remains a common treatment component even for patients with early-stage (uterine carcinosarcomas), given the high rate of local and distant recurrence. Adjuvant chemotherapy has been demonstrated to improve (overall survival) compared with surgery alone in multiple studies, though many patients suffer from significant (side) effects associated with alkylating and platinum-based therapies.”

Uterine carcinosarcomas are relatively rare and account for approximately 5% of all uterine malignancies diagnosed annually. It is also an aggressive cancer that can lead to approximately 15% of deaths associated with uterine cancer.

“The optimal treatment algorithm is still debated extensively, as its low incidence has made it impractical to investigate prospectively and difficult to draw conclusions from small retrospective studies,” the study authors wrote. “While the benefits of surgery and chemotherapy are widely agreed upon, the utility and efficacy of adjuvant radiotherapy is less known.”

In this study, researchers assessed 24 patients (mean age at diagnosis, 61 years) with uterine carcinosarcomas who underwent surgical resection to remove cancer-affected areas between 1993 and 2011. Of these patients, all underwent surgical resection, 29% underwent surgery and radiation afterwards, 25% underwent surgery and chemotherapy afterwards and 33% underwent surgery and both chemotherapy and radiation afterwards.

Several metrics were calculated including disease-free survival at three years (time from surgery to death or three years after surgery), distant metastases-free survival (time from surgery to cancer recurrence not related to previously affected areas in the body or death), locoregional recurrence-free survival (time from surgery to cancer recurrence in previously involved areas of the body or death) and overall survival (time from surgery to death or last known follow-up). Patients were followed up on for a median of 22.1 months.

At three years, overall survival did not significantly differ between treatment groups: surgery alone (100%), surgery and chemotherapy (60%), surgery and radiation (100%) and all three treatments (88%). Patients who underwent radiation, chemotherapy and surgery had a distant metastases-free survival rate of 83% compared with 44% in those who underwent surgery and chemotherapy, indicating that radiation therapy may provide additional benefit.

The eight patients with lymph node involvement had a lower locoregional recurrence-free survival compared with those without lymph node involvement (38% versus 92%).

“The importance of thorough lymphadenectomy (the removal of one or more lymph nodes to assess for cancer) for prognosis and staging has been demonstrated consistently, as this tumor and other endometrial carcinomas spread via the lymphatic system,” the study authors wrote. “It is likely that future developments in the surgical management of (uterine carcinosarcomas) will focus heavily on lymphatic monitoring strategies such as sentinel lymph node mapping (or locating the first lymph node where cancer is most likely to spread from the primary tumor).”

The study authors added that there were some limitations to their analysis. They wrote, “This study is primarily limited by its small sample size, increasing the chance … complicating more in-depth analysis. Given the rare nature of (uterine carcinosarcomas), it is difficult to enroll a larger sample size at a single institution, though we hope this study will contribute to the current literature and improve the accuracy of multi-institution meta-analyses.”

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