Comprehensive Cancer Center Designation Trumps High Volume as Predictor for Outcomes in Ovarian Cancer
Chicago, IL—The National Cancer Institute (NCI) designation of a comprehensive cancer center trumps high case volume as a predictor of outcomes in ovarian cancer, according to a single-region analysis.
NCI-designated centers had a median survival of almost 80 months compared with 52 months for patients who received treatment at high-volume centers that were not part of the National Comprehensive Cancer Network (NCCN). Low-volume centers lagged further behind with a median overall survival of 43 months.
Similar differences emerged from an analysis of ovarian cancer–specific survival, according to a presentation at the 2015 Society of Gynecologic Oncology annual meeting.
“NCI comprehensive cancer center status is an independent predictor of adherence to ovarian cancer treatment guidelines and improved disease-specific survival,” said Robert E. Bristow, MD, MBA, Director of Gynecologic Oncology, University of California, Irvine, Orange. “NCI comprehensive cancer center status is a structural healthcare characteristic correlating with superior ovarian cancer quality-measure performance. Improving access to NCI-designated centers through regional concentration of care may be a mechanism to improve ovarian cancer clinical outcomes.”
NCI designation represents exclusivity among the nation’s cancer centers. The designation comes with restrictive entry criteria that include research infrastructure and programs, innovative clinical trials, outreach, and education. NCI-designated centers account for 4% of the nation’s 1500 cancer centers. However, a center’s benefit to the regional cancer population served remains poorly defined, said Dr Bristow.
To examine the impact of NCI designation on ovarian cancer care in Southern California, investigators reviewed the clinical records of NCI comprehensive cancer centers serving Los Angeles, Orange, Riverside, San Bernardino, and San Diego counties. They searched records of the California Cancer Registry for the years 1996 through 2006. The search was limited to a first or only diagnosis of epithelial ovarian cancer.
Cancer centers in the region were classified according to NCI designation or on the basis of case volume, which was defined as fewer than 10 cases annually (low) or more than 10 annual cases (high). The quality of care was assessed on the basis of NCCN guidelines for 1997 through 2005.
The study comprised 192 hospitals, including 5 NCI-designated cancer centers (averaging 14.5 cases annually), 29 high-volume facilities (14.6 cases annually), and 158 low-volume facilities (2.6 cases annually). The data analysis comprised 9933 patients who had a median age of 61 years, International Federation of Gynecology and Obstetrics (FIGO) stage III or IV disease in 69.3% of cases, and serous histology in 40.3% of cases.
With respect to health insurance, NCI-designated centers had a fairly even distribution of patients covered by managed care plans, Medicare, and Medicaid. A majority of patients in high-volume facilities were in managed care systems, and the low-volume facilities predominantly treated patients covered by managed care plans and Medicare.
Patients in the lowest socioeconomic status (SES-1) accounted for almost 25% of patients in NCI-designated centers, and patients in SES-2 through SES-5 accounted for roughly equal proportions. SES-4 and SES-5 accounted for more than 50% of the patients in high-volume centers; and SES-2, SES-3, and SES-4 constituted approximately 66% of the patients in low-volume centers.
Adherence to NCCN Guidelines
Complete adherence to NCCN treatment guidelines was modest, at 35.7% of the almost 10,000 patients. Adherence to surgery recommendations was 51.2%, and adherence to chemotherapy recommendations was 62.0%. Adherence to all 3 categories decreased from NCI centers to high-volume centers, and from high-volume centers to low-volume centers (P <.0001).
By multivariate logistic analysis, high-volume centers were 17% less likely to follow all NCCN guidelines, 17% less likely to adhere to surgical guidelines, and 18% less likely to adhere to chemotherapy recommendations; the corresponding figures for low-volume hospitals were 44%, 32%, and 56%, respectively.
The median overall survival for all 9933 patients was 49.9 months, but ranged from 77.9 months at NCI-designated centers to 51.9 months at high-volume centers and 43.4 months at low-volume centers (P <.0001).
The median ovarian cancer–specific survival times were 46.1 months overall, 67.0 months at NCI-designated centers, 50.8 months at high-volume centers, and 38.5 months at low-volume centers (P <.0001).
Dr Bristow acknowledged that there are limitations of the analysis, including its retrospective design, inability to account for uncontrolled variables, a lack of adjustment for survival by NCCN guideline adherence, no evaluation of treating physicians’ specialty, and patient willingness or ability to travel to a specific center.