Objective: The objective of the study was to determine whether the epidemiology of low-grade ovarian serous cancers is distinct from that of high-grade ovarian serous cancers.
Study design: The National Cancer Institute's Surveillance Epidemiology and End Results (SEER) program reports incidence, and survival, data from representative population based cancer registries. The SEER data are analyzed to compare the descriptive epidemiologies of low- and high-grade lesions.
Results: Mean survival (99 vs 57 months) and age (55.5 vs 62.6 years) trends in annual incidence rate (-3.8% vs 1.4%), rate ratio of advanced to early disease (1.9 vs 10.2), rate ratio of post- to premenopausal incidence (5.0 vs 13.0). and difference in average age between advanced and early stage (none vs 2.5 years) are significantly different for patients with low-grade, compared with high-grade, disease.
Conclusion: Epidemiology of low-grade tumors appears sufficiently different from that of high-grade lesions to support the concept that low-grade ovarian serous cancers constitute a distinct clinical, and perhaps biologic, entity.