Purpose: Lower socioeconomic status is associated with more advanced cancer at the time of cancer diagnosis. It is unknown whether this leads to inferior survival in low- and middle-income countries. Here, we explore the association between educational level and survival in South India.
Methods: The Trivandrum Cancer Registry (3.3 million population) was used to identify all cases of breast and cervical cancer (women) and oral cavity (OC) and lung cancer (men) diagnosed during 2012-2014. Educational level was classified as illiterate/primary school, middle school, and secondary school and above. Survival was measured from date of diagnosis using the Kaplan-Meier method. Cox proportional hazards regression modeling was used to describe the associations among education, stage of cancer at diagnosis, and survival.
Results: The study population included 3,640 patients with breast (n = 1,727), cervical (n = 425), OC (n = 702), and lung (n = 786) cancer. Educational level was 27%, 23%, and 32% for illiterate/primary, middle, and secondary school and above, respectively. The 5-year survival rate for breast cancer was 59%, 68%, and 73% (P = .001); for cervical cancer, 51%, 52%, and 60% (P = .146); and for OC cancer, 42%, 35%, and 48% (P = .012) for illiterate/primary, middle school, and secondary school and above, respectively. The survival gradient across social groups was substantially attenuated when stage was added to the multivariable model. There was no observed difference in survival across educational groups for lung cancer (2%, 4%, and 3%; P = .224).
Conclusion: Data from this population-based study in South India demonstrate that patients from a lower educational background have inferior survival and that this is at least partially explained by having more advanced disease at the time of diagnosis. Public health efforts are needed to facilitate timely diagnosis and reduce disparities in cancer outcomes.