Health inequities and cancer survival in Manizales, Colombia: a population-based study

Objective: To analyze differences in survival of breast, cervical, lung, prostate and stomach cancer by health insurance regime (HIR) and socioeconomic position (SEP) in an intermediate city in a middle-income country.
Methods: All patients with breast, cervix uteri, lung, prostate and stomach cancer diagnosed between 2003 and 2007 and characterized by the Manizales population-based Cancer Registry (MCR) were included and followed up to a maximum of 5 years for identifying deaths. Survival probabilities estimated by HIR were defined according to the type of affiliation at the date of diagnosis, and by socioeconomic stratification of residence (SS) as indicator of SEP, stratifying for other prognostic factors using Kaplan-Meier methods. Cox proportional hazard models were fitted for multivariate analysis.
Results: A total of 1,384 cases and 700 deaths were analyzed. Five-year observed survival was 71.0% (95% IC: 66.1-75.3) for breast, 51.4% (95% IC: 44.6-57.9) for cervix, 15.4% (95% IC: 10.7-20.8) for lung, 71.1% (95% IC: 65.3-76.1) for prostate and 23.8% (95% IC: 19.3-28.6) for stomach. Statistically significant differences in survival by HIR were observed for breast, lung, prostate, and stomach - with poorer survival for the subsidized and uninsured patients. Differences by SS were observed for lung and prostate. Differences in survival by HIR were independent of SS, and viceversa.
Conclusions: Important inequities in cancer survival exist related to HIR and SEP. Possible explanations include underlying comorbidities, late stage at diagnosis, or barriers to timely and effective treatment.

Keywords
Malignant neoplasms; survival analysis; socioeconomic factors; insurance; health