The effect of diameter of largest residual disease on survival after primary cytoreductive surgery in patients with suboptimal residual epithelial ovarian carcinoma

Abstract

Objective: The Gynecologic Oncology Group has divided patients with advanced epithelial ovarian cancer into those with optimal residual cancer, in which the maximum diameter of residual is < or = 1 cm, and suboptimal residual cancer, in which the residual disease is > 1 cm. Within the optimal group of patients there is a survival difference between patients with microscopic residual disease and those with any macroscopic disease < or = 1 cm. No analysis of the effect of various residual disease diameters in patients with residual disease > or = 1 cm has been performed. This study evaluates the effect of residual disease diameter in patients with suboptimal disease entered on a randomized trial of intense versus standard chemotherapy.

Study design: Gynecologic Oncology Group protocol 97 compared cisplatin 50 mg/m2 and cyclophosphamide 500 mg/m2 for eight courses with the same drugs at 100 mg/m2 and 1000 mg/m2 for four courses, respectively. There was no difference in progression-free interval or survival between the two arms. Of the 458 stage III (with residual disease > 1 cm) and stage IV patients entered in this study, 294 stage III patients comprise the current analysis. Surgical reporting forms, operation reports, and pathology reports were reviewed to determine initial greatest tumor diameter and residual tumor diameter. Patients were grouped by residual diameter. Multivariate analysis considered residual diameter of disease, age, histologic characteristics, performance status, and ascites. An adjusted relative hazard of dying of ovarian cancer was calculated for each residual disease group.

Results: Patients ranged in age from 20 to 80 years, with a median of 60 years. All patients were Gynecologic Oncology Group performance status 0 to 2. Fifty-two percent had grade 3 tumors, and 39% and 9%, respectively, had grade 2 or 1 tumors. All patients had stage III disease. Ninety percent had serous, endometrioid, or mixed epithelial cell type tumors. Multivariate analysis revealed a relative risk of dying as follows: residual disease < 2 cm, relative risk 1.00; 2 to 2.9 cm, relative risk 1.90; 3 to 3.9 cm, relative risk 1.91; 4 to 5.9 cm, relative risk 1.74; 6 to 7.9 cm, relative risk 1.85; 8 to 9.9 cm, relative risk 2.16; > or = 10 cm, relative risk 1.82. The difference in survival between those with < 2 cm residual disease and those with > or = 2 cm residual disease was significant (p < 0.01). There is no significant difference in the risk of dying between groups with residual disease > or = 2 cm.

Conclusions: Among patients with suboptimal (> 1 cm residual disease) epithelial ovarian cancer, those who have small diameter residual disease (< 2 cm) tend to survive longer than those who have larger residual disease. Among those with larger residual disease, size does not affect prognosis appreciably.