Oncologic outcomes in the era of modern radiation therapy using FIGO 2018 staging system for cervical cancer

Abstract

Background: The recently published ASTRO cervical cancer guidelines recommend the use of modern radiotherapy. Imaging is now incorporated in the updated FIGO 2018 staging with a new stage IIIC. This study aims to evaluate the oncologic outcomes and predictors of survival using FIGO 2018 staging in a cohort of patients treated in an era of high-precision image-guided radiotherapy.

Methods: We performed a retrospective cohort study of 216 adult cervical cancer patients treated with definitive chemoradiotherapy between 2010 and 2018. Eligible patients had non-metastatic cervical cancer treated at a single academic institution. All patients had pre-treatment MRI and CT/PET. Treatment protocol consisted of external beam intensity-modulated radiotherapy and 3D image-guided brachytherapy. Kaplan-Meier curves were used for survival analysis. Multivariate cox proportional-hazards model was performed to identify potential prognostic factors.

Results: Median age at diagnosis was 50 and median BMI was 26.4 kg/m². Median follow-up time was 44.3 months. Five-year overall survival (OS), disease-free survival and loco-regional disease-free survival rates were 76.8%, 68.5% and 82.6%, respectively. FIGO 2018 showed better OS discrimination compared to FIGO 2009 classification. OS was increasingly worse with positive pelvic and para-aortic nodes (p < 0.001). In a multivariate prediction model, performance status (p = 0.044) and FIGO 2018 classification (stage III p = 0.016; stage IVA p = 0.010) were predictors of mortality; FIGO 2018 classification (stage III p = 0.003; stage IVA p = 0.001) was a predictor of any recurrence; MRI tumor diameter (p ≤ 0.001) and nodal metastases (p = 0.024) were predictors of loco-regional recurrence.

Conclusions: Integration of state-of-the-art imaging in cervical cancer staging and in radiotherapy planning leads to good loco-regional control rates, however distant recurrence remains an important issue. FIGO 2018 staging better reflects patient prognosis, highlighting the need for new treatment strategies for stage IIIC cervical cancer.

Keywords: Brachytherapy; Image-guided; Intensity-modulated; Magnetic resonance imaging; Positron-emission tomography; Radiotherapy; Uterine cervical neoplasms.