Introduction: Ovarian clear cell carcinoma (CCC) is regarded as grade 3 tumor, and the National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines recommend adjuvant chemotherapy for the tumor even at stage IA. However, CCC often showed chemo-resistant phenotype, and the effect of adjuvant chemotherapy still remained uncertain.
Methods: Clear cell carcinoma cases treated at collaborating institutions during the period 1992-2005 were retrospectively identified. After a central pathological review, survival analysis was estimated by the Kaplan-Meier method, and prognostic factors were evaluated using a Cox regression model.
Results: Among 219 patients with stage I CCC, 195 patients received adjuvant chemotherapy (C+) and 24 patients (C−) did not. The C+ group had 77 pT1a and 118 pT1c cases, and the C− group included 18 pT1a and 6 pT1c tumors (P < 0.001). The median age was 52 years in the C+ group and 57 years in C− group (P = 0.04). During the median follow-up period of 48 months (range, 7-160 years), relapse was observed in one patient (4%) in the C− group and in 35 patients (18%) in the C+ group. There were no statistical differences of progression-free survival and overall survival between the C+ and the C− groups. Multivariate analysis revealed that peritoneal cytology status (P = 0.02) and pT status (P = 0.04) were independent prognostic factors for progression-free survival; however, adjuvant chemotherapy was not a prognostic factor (P = 0.80).
Conclusions: Although the present study was a limited retrospective investigation, it suggested that adjuvant chemotherapy had little impact on the survival of stage I CCC patients. Further strategy, such as a molecular targeting agent, is needed to improve survival of CCC, especially in cases with positive peritoneal washing.
*Department of Obstetrics and Gynecology, National Defense Medical College, Tokorozawa, Japan; †Department of Obstetrics and Gynecology, Iwate Medical University School of Medicine, Morioka, Japan; ‡Department of Obstetrics and Gynecology, Tohoku University Graduate School of Medicine, Sendai, Japan; §Department of Obstetrics and Gynecology, JR Sapporo Railway Hospital, Sapporo, Japan; ∥Department of Gynecology, Kuzuya Clinic, Nagoya, Japan; ¶Department of Obstetrics and Gynecology, Fujita Health University School of Medicine, Toyoake, Japan; **Department of Obstetrics and Gynecology, Keio University School of Medicine, Shinano-machi, Japan; ††Department of Obstetrics and Gynecology, Jichi Medical University School of Medicine, Shimotsuke, Japan; ‡‡Cancer Center, Tottori University Hospital, Yonago, Japan; §§Department of Pathology, National Cancer Institute, Tsukiji, Japan; ∥∥Department of Pathology, Kawasaki Medical School, Kurashiki, Japan; and ¶¶Department of Gynecology, Ohki Memorial Kikuchi Cancer Clinic for Women, Tokorozawa, Japan.
Received August 4, 2010, and in revised form September 15, 2010.
Accepted for publication September 16, 2010.
Address correspondence and reprint requests to Masashi Takano, MD, PhD, Department of Obstetrics and Gynecology, National Defense Medical College, Tokorozawa, Saitama 359-8513, Japan. E-mail: firstname.lastname@example.org.
The authors declare no conflicts of interest.
This study was presented in part at: Takano M, et al. The impact of adjuvant chemotherapy for stage I clear cell carcinoma of the ovary: a retrospective Japan Clear Cell Carcinoma Study. Proceedings of the Annual Meeting of the American Society of Clinical Oncology, June 4-8, 2010; 28(15S) Chicago, IL. Abstract No. 5052. p 403s.