Impact of hypofractionated radiotherapy on pathologic response in locally advanced cervical cancer.

Abstract

e17518 Background: Cervical cancer remains a significant global health burden, particularly in low- and middle-income countries, where limited radiotherapy infrastructure restricts access to standard treatment. Although concurrent chemoradiotherapy is the standard of care, hypofractionated radiotherapy may improve treatment efficiency while maintaining oncologic outcomes. Our purpose is to compare pathologic response outcomes between hypofractionated and standard radiotherapy in patients with locally advanced cervical cancer. Methods: Pathologic response was evaluated in patients with FIGO stage IB3–IIIC1 cervical cancer enrolled in a phase II randomized trial. Patients received concurrent chemotherapy with either standard external-beam radiotherapy (50 Gy in 25 fractions) or hypofractionated radiotherapy (37.5 Gy in 15 fractions), followed by radical hysterectomy and bilateral pelvic lymphadenectomy. Pathologic response and lymph node involvement were compared between groups using chi-square or Student’s t tests, as appropriate. A p value < 0.05 was considered statistically significant. Results: Ninety-three patients were included (50 standard fractionation; 43 hypofractionation). Baseline clinical and tumor characteristics were balanced between groups. Squamous cell carcinoma was the most common histology (84%). Complete pathologic response was observed in 48% of patients in the standard arm and 35% in the hypofractionated arm, while residual microscopic disease was identified in 38% and 44%, respectively ( p = 0.46). Additional treatment due to partial response was required in 14% of patients receiving standard fractionation and 21% receiving hypofractionation. Adverse pathologic features prompting further treatment included residual tumor >1 cm, lymphovascular space invasion, deep stromal invasion, and positive surgical margins. The mean number of lymph nodes resected was similar between groups (14 vs. 15; p = 0.291). Among 1,399 lymph nodes examined, 0.85% were positive on final pathology. Conclusions: Pathologic response following hypofractionated radiotherapy appeared comparable to that achieved with standard fractionation. While hypofractionation is not currently standard for cervical cancer, these findings suggest it may represent a feasible alternative in settings with limited radiotherapy capacity. Larger studies with longer follow-up are required to further assess efficacy, safety, and pathological response patterns. Clinical trial information: NCT03750539 .