Cancer Patients Mortality From Other Causes: A European Population-Based Study.

introductionCancer patients may face elevated mortality not only from their malignancy but also from other factors including multi-morbidity and the impact of treatment-related complications. This study analyses mortality from all causes other than the index cancer among cancer patients compared to the general population.

methodsWe analysed EUROCARE-6 data on 1,894,057 cancers diagnosed in 13 European countries and collected by 17 cancer registries with complete official cause-of-death information. Included were first-primary head and neck (H&N), stomach, colorectal, lung, breast, cervical, endometrial, ovarian, prostatic, kidney, and bladder cancers diagnosed between 1998 and 2013 in patients aged 15-79, with follow-up until 31st December 2014. We estimated the relative risk (RR) of death from all other causes for patients relative to population mortality rates. Cause-specific survival (CSS) was compared to relative survival (RS) at 5 and 10 years.

resultsRR were > 2 for H&N and female lung cancers, between 1 and 2 for stomach, male lung, cervix, endometrial, ovary, kidney and bladder, and < 1 for prostate and female breast cancers. Relative risk declined with increasing age for almost all cancer types. Ten-year CSS exceeded RS by 7%-11% points (pp) in H&N cancers, with smaller differences in bladder (2-6 pp), stomach, lung, cervix, ovary and kidney (2-3 pp). CSS was lower than RS in breast and prostate cancers.

conclusionDifferentiation between deaths due to the index cancer and to all other causes is crucial for patient follow-up and to improve quality of life. Cause-of-death data should be a core component of population-based cancer registries to inform interpretation of survivorship data.