The American Cancer Society (ACS), the Centers for Disease Control and Prevention (CDC), the National Cancer Institute (NCI), and the North American Association of Central Cancer Registries (NAACCR) collaborate annually to provide updates on cancer incidence and death rates and trends in these outcomes for the United States. This year's report includes the prevalence of comorbidity at the time of first cancer diagnosis among patients with lung, colorectal, breast, or prostate cancer and survival among cancer patients based on comorbidity level. Data on cancer incidence were obtained from the NCI, the CDC, and the NAACCR; and data on mortality were obtained from the CDC. Long-term (1975/1992-2010) and short-term (2001-2010) trends in age-adjusted incidence and death rates for all cancers combined and for the leading cancers among men and women were examined by joinpoint analysis. Through linkage with Medicare claims, the prevalence of comorbidity among cancer patients who were diagnosed between 1992 through 2005 residing in 11 Surveillance, Epidemiology, and End Results (SEER) areas were estimated and compared with the prevalence in a 5% random sample of cancer-free Medicare beneficiaries. Among cancer patients, survival and the probabilities of dying of their cancer and of other causes by comorbidity level, age, and stage were calculated. Death rates continued to decline for all cancers combined for men and women of all major racial and ethnic groups and for most major cancer sites; rates for both sexes combined decreased by 1.5% per year from 2001 through 2010. Overall incidence rates decreased in men and stabilized in women. The prevalence of comorbidity was similar among cancer-free Medicare beneficiaries (31.8%), breast cancer patients (32.2%), and prostate cancer patients (30.5%); highest among lung cancer patients (52.9%); and intermediate among colorectal cancer patients (40.7%). Among all cancer patients and especially for patients diagnosed with local and regional disease, age and comorbidity level were important influences on the probability of dying of other causes and, consequently, on overall survival. For patients diagnosed with distant disease, the probability of dying of cancer was much higher than the probability of dying of other causes, and age and comorbidity had a smaller effect on overall survival. Cancer death rates in the United States continue to decline. Estimates of survival that include the probability of dying of cancer and other causes stratified by comorbidity level, age, and stage can provide important information to facilitate treatment decisions. © 2013 American Cancer Society.