The effect of adjuvant radiation on survival in early stage clear cell ovarian carcinoma

• Published in: Gynecologic oncology 2016-11, Vol.143 (2), p.258-263
• Main Authors: Hogen, Liat, Thomas, Gillian, Bernardini, Marcus, Bassiouny, Dina, Brar, Harinder, Gien, Lilian T, Rosen, Barry, Le, Lisa, Vicus, Danielle
• Format: Article
• Language: English
• Subjects: Adenocarcinoma, Clear Cell - mortality; Adenocarcinoma, Clear Cell - pathology; Adenocarcinoma, Clear Cell - radiotherapy; Adult; Aged; Aged, 80 and over; Clear cell carcinoma; Early stage; Female; Hematology, Oncology and Palliative Medicine; Humans; Middle Aged; Neoplasm Staging; Obstetrics and Gynecology; Ovarian cancer; Ovarian Neoplasms - mortality; Ovarian Neoplasms - pathology; Ovarian Neoplasms - radiotherapy; Radiotherapy; Radiotherapy, Adjuvant; Survival
• ISSN: 0090-8258; 1095-6859
• DOI: 10.1016/j.ygyno.2016.09.006

Abstract Objective To assess the impact of adjuvant radiotherapy (RT) on survival in patients with stage I and II ovarian clear cell carcinoma (OCCC). Methods Data collection and analysis of stage I and II OCCC patients treated at two tertiary centers in Toronto, between 1995 and 2014, was performed. Descriptive statistics and Kaplan-Meier survival probability estimates were completed. The log-rank test was used to compare survival curves. Results 163 patients were eligible. 44 (27%) patients were treated with adjuvant RT: 37 of them received adjuvant chemotherapy (CT), and 7 had RT only. In the no-RT group, there were 119 patients: 83 patients received adjuvant CT and 36 had no adjuvant treatment. The 10 year progression free survival (PFS) was 65% for patients treated with RT, and 59% no-RT patients. There were a total of 41 (25%) recurrences in the cohort: 12 (27.2%) patients in RT group and 29 (24.3%) in the no-RT group. On multivariable analysis, adjuvant RT was not significantly associated with an increased PFS (0.85 (0.44–1.63) p = 0.63) or overall survival (OS) (0.84 (0.39–1.82) p = 0.66). In the subset of 59 patients defined as high-risk: stage IC with positive cytology and/or surface involvement and stage II: RT was not found to be associated with a better PFS (HR 1.18 (95% CI: 0.55–2.54) or O S(HR 1.04 (95% CI: 0.40–2.69)). Conclusion Adjuvant RT was not found to be associated with a survival benefit in patients with stage I and II ovarian clear cell carcinoma or in a high risk subset of patients including stage IC cytology positive/surface involvement and stage II patients.