Treatment outcomes for patients receiving radiation therapy for stage iiib cervical cancer with lower third vaginal involvement in the department of radiation oncology, Charlotte Maxeke Johannesburg academic hospital

Abstract

Cervical cancer remains a major healthcare problem in sub–Saharan Africa. Morbidity and mortality rates are disproportionately high compared to high income countries (HICs). This, in part, is due to late clinical presentation and diagnosis. Only two previous studies have evaluated treatment outcomes for patients with FIGO 2018 stage IIIB cervical cancer with lower third vaginal involvement. Both of these studies evaluated Asian populations (Thailand, China). All patients in these studies were treated with standard fractionated external beam radiation therapy. This single institution, retrospective study aims to report on local control and survival rates in an African group of patients with stage IIIB cervical cancer with lower third vaginal involvement, where a large portion were treated with hypofractionated external beam radiation therapy.

Methods A retrospective review of treatment outcomes was conducted of patients with stage IIIB cervical cancer with lower third vaginal involvement who completed radiation therapy with curative intent at the Department of Radiation Oncology, Charlotte Maxeke Johannesburg Academic Hospital in Johannesburg, South Africa and whose first presentation was between 01 January 2016 and 31 December 2019. Local control was evaluated based on clinical examination at 6 months post completion of radiation therapy and survival data was recorded for patients at 2 years post completion of radiotherapy. Association analysis was performed between treatment outcomes and radiation fractionation and brachytherapy applicator choice.

Results Of the 179 patients available, 22 received standard fractionated external beam radiotherapy (50Gy/25#) and 157 patients received hypofractionated external beam radiotherapy with 42.5Gy in 17 fractions. 118 patients were available at 6 months for analysis of local response of which 77% (n=91) had a clinical complete response and 23% (n=27) had treatment failure. At 2 years post completion of radiotherapy, 99 patients (55%) were lost to follow up. Of the patients with documented 2-year survival data, 65% (n=52) of patients were alive and 35% (n=28) of patients were dead. Median overall survival for the whole group was 9 months. External beam fractionation schedule had no association with local control (p=0.391) or overall survival (p=0.59). Choice of brachytherapy applicator also had no effect on local control (p=0.395) or overall survival (p=0.41).

Conclusion The analysis was compromised by poor patient follow up, but local control rates and overall survival rates were comparable to the other two published studies on this group of patients, despite the use of a hypofractionated external beam protocol in this study. The use of a hypofractionated versus standard fractionated external beam radiation schedule had no correlation with either local control rates or survival. This should prompt prospective studies evaluating the efficacy of hypofractionated radiation therapy in the treatment of locally advanced cervical cancer. This study has managed to demonstrate meaningful local control and survival rates for patients with this advanced stage of disease.