Median Household Income May Predict Survival in Patients With Anal Cancer
Socioeconomic inequalities may affect cancer-specific survival and overall survival in patients with squamous cell carcinoma of the anus (SCCA), according to a study published in Cancer (online March 12, 2018; doi:10.1002/cncr.31186).
While survival outcomes have improved overall for patients with SCCA, patients with disparate socioeconomic status may not be included in this trend.
Daniel Lin, MD, Perlmutter Cancer Center, NYU Langone Medical Center (New York, NY), and colleagues investigated whether area-based median household income is predictive of survival among patients with SCCA. A total of 9550 patients with SCCA from 2004 through 2013 in the Surveillance, Epidemiology, and End Results registry were included in the study.
Socioeconomic status was pre-defined by census-tract median household income level and divided into quintiles. Multivariable Cox proportional hazards models and logistic regression were utilized to assess predictors of survival and radiotherapy receipt.
Results of the study showed that patients living in areas with lower median household income were likely to have worse overall survival and cancer-specific survival compared with those in the highest income areas. Researchers observed increasing mortality hazard ratios from lowest to highest income: 1.32, 1.31, 1.19, and 1.16. Hazard ratios for cancer-specific survival followed a similar trend, ranging from 1.34 to 1.22 for lowest to highest median household income.
Among the characteristics associated with worse cancer-specific survival were older age, black race, male sex, unmarried marital status, an earlier year of diagnosis, higher tumor grade, and later American Joint Committee on Cancer stage of disease.
Additionally, Dr Lin and colleagues noted that income was not associated with the odds of initiating radiotherapy in multivariable analysis (odds ratio of 0.87 for lowest to highest median household income level).
"Our findings reveal that US residents who have anal cancer and live in areas of poverty have worse survival than those who live in more affluent areas, even after accounting for differences in age, stage, and race," said Daniel Becker, MD, co-author of the study, in an interview (March 12, 2018). “The ultimate goal is to make sure that all patients receive high quality care, regardless of their wealth or zip code."
Further research is warranted to better understand the mechanisms by which socioeconomic inequalities affect cancer care and outcomes, authors of the study acknowledged.—Zachary Bessette