Association of Cumulative Social Risk and Cancer-Specific Survival Among Patients With Advanced Colorectal Cancer.

Background: Socioeconomic disadvantage is widely associated with poor clinical outcomes among patients with colorectal cancer. Interventions to address these pervasive public health problems have had mixed success, potentially related to their development based on aggregated data (e.g., average zip code income) and short-term outcomes, rather than individual level data and meaningful long-term cancer outcomes.

Objective: To examine associations of individual and cumulative multiple, co-occurring individual-level social risk factors with long-term cancer-specific survival among patients with advanced colorectal cancer.

Design: Prospective cohort study.

Setting: Between 2011-2014, we collaborated with Surveillance, Epidemiology and End Result in Georgia and Detroit to survey patients with Stage III colorectal cancer in the prior year. Cumulative social risk was calculated by summing significant factors associated with colorectal cancer-specific mortality: employment, insurance, health literacy, income, and marital status.

Patients: Patients with stage III colorectal cancer.

Main outcome measures: Time from diagnosis to cancer-specific mortality, adjusted for age, race, sex, and chemotherapy receipt, with comparisons provided in hazard ratios with 95% confidence intervals.

Results: Among 1173 patients, pre-operative unemployment (1.76 [1.30-2.39]), uninsured or Medicaid insurance (1.54 [1.12-2.11]), low health literacy (1.40 [1.00-1.95]), annual income < $50,000 (1.34 [1.01-1.77]) and being unpartnered (1.34 [1.02-1.77]) were associated with higher likelihood of cancer-specific mortality. In cumulative risk analyses, each added social risk was associated with 24% higher adjusted likelihood of cancer-specific mortality (1.24 [1.12-1.37]).

Limitations: This study has limitations inherent to survey research including the potential lack of generalizability and responses subject to recall bias. Additionally, the cross-sectional survey and linked longitudinal clinical data do not allow for determination of causality.

Conclusion: Cumulative social risk was associated with long-term cancer-specific survival after treatment for Stage III colorectal cancer. Assessing social risk may help identify patients with colorectal cancer who are at higher risk of mortality to receive support programs designed to mitigate social disadvantage. See Video Abstract.