The potential benefit of 6 vs. 3 cycles of chemotherapy in subsets of women with early-stage high-risk epithelial ovarian cancer: an exploratory analysis of a Gynecologic Oncology Group study.
OBJECTIVE
A prior clinical trial on early-stage high risk ovarian cancer showed a lower recurrence rate in those treated with six vs. three cycles of chemotherapy. We proposed to identify subsets of patients who may benefit from more cycles of chemotherapy.


METHODS
Outcomes of patients who underwent six vs. three cycles of chemotherapy were analyzed based on clinico-pathologic factors. Kaplan-Meier estimates and Cox Regression Model were used for analyses.


RESULTS
Of 427 patients (median age: 55 years), 69% had stage I disease, 30% had clear cell, 25% endometrioid, 23% serous, 7% mucinous, and 15% had other cell types. The risk of recurrence in those who had six vs. three cycles of chemotherapy was not different based on age, performance status, stage, grade of disease, presence of ascites, tumor rupture, or positive cytology. However, those with serous tumors had a significantly lower risk of recurrence after six vs. three cycles of chemotherapy (HR=0.33, CI=0.14-0.77; p=0.04) in contrast to non-serous tumors (HR=0.94, CI=0.60-1.49). Nevertheless, a test of homogeneity did not show a difference in treatment effects across cell types (p=0.285). Of those with serous tumors, the 5-year recurrence-free survival was 83% and 60% in those who received six vs. three cycles of chemotherapy, respectively (p=0.007).


CONCLUSIONS
In this exploratory analysis of early-stage high risk ovarian cancer, our data suggest that six rather than three cycles of chemotherapy may decrease the recurrence of patients with serous tumors. Further studies are needed to confirm these findings.
Chan
John K
JK
Division of Gynecologic Oncology, Department of Obstetrics, Gynecology, & Reproductive Sciences, University of California, San Francisco School of Medicine, UCSF Helen Diller Family Comprehensive Cancer Center, San Francisco, CA 94143-1702, USA. chanjohn@obgyn.ucsf.edu
Tian
Chunqiao
C
Fleming
Gini F
GF
Monk
Bradley J
BJ
Herzog
Thomas J
TJ
Kapp
Daniel S
DS
Bell
Jeffrey
J
D018262:Adenocarcinoma, Clear Cell / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D002288:Adenocarcinoma, Mucinous / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage*; D016190:Carboplatin / Q000008:administration & dosage; D018269:Carcinoma, Endometrioid / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D017024:Chemotherapy, Adjuvant; D018572:Disease-Free Survival; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery; D017239:Paclitaxel / Q000008:administration & dosage; D012307:Risk Factors; D015996:Survival Rate
D016190:Carboplatin; D017239:Paclitaxel