Among cystic-fibrosis patients, 37 cancers were observed, whereas 45.6 cancers were expected. What distribution can be used to model the distribution of the number of cancers among cystic-fibrosis patients?

Cancer, Neurology

A study concerned the risk of cancer among patients with cystic fibrosis [5]. Given registries of patients with cystic fibrosis in the United States and Canada, cancer incidence among cystic-fibrosis patients between January 1, 1985, and December 31, 1992, was compared with expected cancer-incidence rates based on the Surveillance Epidemiology and End Results program from the National Cancer Institute from 1984 to 1988.