Conditional relative survival of cancer patients and conditional probability of death

Abstract

Little information is available on the conditional probabilities of death among patients who survive for >5 years after a diagnosis with cancer. The objective of this study was to estimate the conditional probabilities of death for breast cancer, prostate cancer, colorectal cancer, and lung cancer in France. The study included data from the French Network of Cancer Registries from 205,562 patients aged <75 years who were diagnosed with cancer between 1989 and 1997. The conditional probabilities of death were calculated by using a relative survival regression model in which age was included as a covariate. After the first year and until 10 years after diagnosis, the annual probability of death decreased dramatically for colorectal cancer: It was the same in all age groups after 3 years, and it was approximately 1% at 10 years. For prostate cancer, the decrease was not as great, and the conditional probability of death remained higher among younger patients at >4% at 10 years. During the 3 years after diagnosis, the probability of death was greater for older patients with breast cancer; then, it decreased less for younger patients compared with older patients, leading to a greater conditional probability of death among younger patients at 4 years and up to 10 years. The annual probability of death in patients with lung cancer decreased for both sexes but remained substantially higher for men than for women, reaching approximately 8% and 5%, respectively, at 10 years. Further studies would facilitate a better understanding of the observed differences in relative survival within European countries.