especially for older women with advanced disease, according to a recent study.
The findings suggest additional research is needed to evaluate international differences in both treatment- and patient-specific factors affecting survival.
“This study [evaluated] differences in survival by age and stage at diagnosis within and across seven high-income countries,” wrote Citadel J. Cabasag, PhD, of the International Agency for Research on Cancer in Lyon, France, and colleagues. The results were published in Gynecologic Oncology.
The researchers conducted a retrospective analysis of population-based registry data from 2010 to 2014. Data were collected from 21 cancer registries located in Canada, United Kingdom, New Zealand, Norway, Ireland, Australia, and Denmark.
The cohort included 58,161 women with epithelial and nonepithelial ovarian cancer. The majority of cases were advanced stage, with a median age of 63-67 years at diagnosis, depending on the country.
The researchers compared age- and stage-specific net survival between countries at 1 and 3 years post diagnosis.
The 3-year all-ages net survival was highest for Norway (57%) and Australia (56%), followed by Denmark (54%), Canada (50%), United Kingdom (47%), New Zealand (46%), and Ireland (45%).
Most patients were diagnosed with distant disease (range, 64%-71%), with the greatest proportion of women in the 65- to 74- and 75- to 99-year age categories. The lowest 3-year age-specific survival (range, 20%-34%) was observed in the 75- to 99-year age category.
Marked differences in 3-year net survival between countries were found for women in the 75- to 99-year age group with distant disease (range, 12%-25%).
“International survival differences by age groups were less stark for early-stage disease,” the researchers reported. “Interjurisdictional differences within countries were also observed.”
The researchers acknowledged a key limitation of the analysis was the use of registry data. Variability between, and incomplete data within, registries could have lowered the accuracy of the survival estimates.
“[F]urther research investigating international differences in access to and quality of treatment, and prevalence of comorbid conditions particularly in older women with advanced disease [is needed],” the researchers concluded.
The study was supported by funding provided to the International Cancer Benchmarking Partnership. The authors reported having no conflicts of interest.
SOURCE: Cabasag CJ et al. Gynecol Oncol. 2020 Jan 28. doi: 10.1016/j.ygyno.2019.12.047.