A single-institution study of demographics and outcomes of adult patients with multiple cancers

Background: Few studies have described the demographics and outcomes in patients with multiple cancers. Methods: We reviewed the health records of patients with at least 3 invasive solid-tumor malignancies (lung, colorectal, pancreatic, prostate, breast, or ovarian) diagnosed between 1995 and 2014 at our institution. Results: A total of 163 patients were identified. The median age at first cancer diagnosis was 61 years. Sixteen (10%) had a family history of cancer, and 7 (4%) had a cancer-predisposing syndrome. Most had early-stage malignancies and underwent a series of surgical resections. The median survival from the first cancer diagnosis was 14 years (95% confidence interval: 12-16). Forty-three percent developed 4 or more cancers. In univariate analyses, older age, male sex, smoking history, concurrent cancer, and stage IV disease were associated with worse survival; by contrast, breast cancer as the first cancer diagnosis yielded better survival. In multivariate analyses, older age, smoking history, and stage IV disease were associated with worse survival. Conclusions: A small group of patients with no ostensible risk factors develop multiple early-stage cancers, receive curative therapy (often surgery), and live for years. These patients merit further study to ascertain the broader prevalence rates of individuals with multiple invasive cancers and to better understand factors that contribute to cancer risk.