Specialized hospital care associated with better survival in Dutch ovarian cancer patients

Dutch ovarian cancer patients who were treated at a semispecialized or specialized hospital survived longer than those treated at a general hospital, according to a study published online March 11 in the Journal of the National Cancer Institute.

Several studies have suggested that concentrating ovarian cancer care at regional centers improves patient outcomes. The necessity of such an approach in The Netherlands was unknown. The Dutch system already allows for collaboration between specialized and general gynecologists.

Flora Vernooij, M.D., of the University Medical Center Utrecht in The Netherlands and colleagues conducted a retrospective study of all of the ovarian cancer patients treated in The Netherlands between 1996 and 2003.

Of 8,621 women diagnosed with ovarian cancer, 40 percent were treated in general hospitals, 41 percent in semispecialized hospitals, and 18 percent in specialized centers. The estimated five year survival improved with increasing specialization of the treatment facility, from 38 percent to 39.4 percent and 40.3 percent, respectively. The difference was statistically significant for women between the ages of 50 and 75 years who were diagnosed with early cancer. Their risk of death due to ovarian cancer dropped by 30 percent and 42 percent following treatment at a semispecialized and specialized hospital, relative to treatment at a general hospital.

“This result indicates that the level of collaboration during the study period did not suffice to deliver optimal care to all Dutch ovarian cancer patients, and regionalization of the care for such patients thus seems necessary,” the authors write.

In an accompanying editorial, Deborah Schrag, M.D., of the Dana-Farber Cancer Institute in Boston argues that while population-based studies that correlate patterns of care and clinical outcomes are important, they must be interpreted with caution. Confounding variables and information that is not tracked in such data sets could lead to inaccurate conclusions.

For example, in the study by Vernooij and colleagues, the patients treated at general hospitals appear to differ from those treated at specialized centers in terms of age and the types of treatment they underwent. Moreover, information about patients' comorbidity and performance status was not available. “Therefore, this analysis in and of itself does not justify regionalization of ovarian cancer surgery in The Netherlands to specialty centers,” she writes.

To allow for more valuable analyses, Schrag calls for an expansion of the types of information cancer registries collect. “As the number of cancer therapies increases and as the need to systematically evaluate their real-world clinical effectiveness grows, there is a need to optimize the data that can be gleaned from observational data sources,” she writes. “A compelling case can be made for expanding the scope of data that tumor registries collect.”