Assessing non-cancer-related health status of US cancer patients: other-cause survival and comorbidity prevalence

Abstract

With advances in prevention, screening, and treatment, cancer patients are living longer; hence, non-cancer-related health status will likely play a larger role in determining their life expectancy. In this study, we present a novel method for characterizing non-cancer--related health status of cancer patients using population-based cancer registry data. We assessed non-cancer-related health status in the context of survival from other causes of death and prevalence of comorbidities. Data from the Surveillance, Epidemiology, and End Results program (2000-2006) were used to analyze cancer patients' survival probabilities by cause of death. Other-cause survival was estimated using a left-truncated survival method with the hazard of death due to other causes characterized as a function of age. Surveillance, Epidemiology, and End Results data linked to Medicare claims (1992-2005) were used to quantify comorbidity prevalence. Relative to the US population, survival from a non-cancer-related death was higher for patients diagnosed with early stage breast and prostate cancer but lower for lung cancer patients at all stages. Lung cancer patients had worse comorbidity status than did other cancer patients. The present study represents the first attempt to evaluate the non-cancer-related health status of US cancer patients by cancer site (breast, prostate, colorectal, and lung) and stage. The findings provide insight into non-cancer-related health issues among cancer patients and their risk of dying from other causes.

Keywords: SEER; cancer survival; cancer survivorship; comorbidity; health status; left-truncated survival; non-cancer-related survival; other-cause mortality.

Figure 1.

Estimated non-cancer survival probability for cancer patients conditional on surviving to 50 years of age, Surveillance, Epidemiology, and End Results (SEER), 2000–2006. All malignant first primary tumors in (A) white male, (B) black male, (C) white female, and (D) black female participants are included. The solid lines denote non-cancer survival probability for cancer patients in SEER; the dashed lines denote survival probabilities for the US populations estimated from the US life tables including all causes of death; and the dotted lines denote survival probabilities for the US population excluding all types of cancer death. The estimated survival probabilities from the life tables excluding all types of cancer death were approximately 10% higher than those from the US life tables that included all causes of death.

Figure 2.

Estimated non-cancer survival probability for male cancer patients conditional on surviving to 50 years of age, Surveillance, Epidemiology, and End Results, 2000–2006. A) Cancer by type for all stages combined; B) prostate cancer by stage; C) colorectal cancer by stage; and D) lung cancer by stage. Survival probability for the US male population was estimated from the US life table.

Figure 3.

Estimated non-cancer survival probability for female cancer patients conditional on surviving to 50 years of age, Surveillance, Epidemiology, and End Results, 2000–2006. A) Cancer by type for all stages combined; B) breast cancer by stage; C) colorectal cancer by stage; and D) lung cancer by stage. Survival probability for the US female population was estimated from the US life table.

Figure 4.

Comorbidity status from ages 66 years to 90 years in 2-year increments from Surveillance, Epidemiology, and End Results data linked to Medicare claims, 1992–2005. A) Non-cancer patients; B) cancer patients, all sites combined; C) female breast cancer patients; D) prostate cancer patients; E) colorectal cancer patients; and F) lung cancer patients. White bars denote the percentage of individuals with no comorbid conditions; gray bars denote the percentage of individuals in the low or medium comorbidity category; and black bars denote the percentage of individuals in the high comorbidity category.