Abstract B27: Socioeconomic influences on survival in adolescents and young adults diagnosed with lymphoma in California

Purpose: Lymphoma (including Hodgkin's Disease and Non-Hodgkin's Lymphoma (NHL)) represents the most common type of cancer in adolescents and young adults (AYA) in the U.S. In California, lymphoma represents 17.28% and 10.37% of all cancers in AYA, ages 15–29 and 30–39, respectively. Although poorer survival has been previously attributed to individuals residing in residing in lower socioeconomic (SES) neighborhoods at diagnosis, it is difficult to determine whether the variability in survival is primarily the result of SES itself, or due to later stage at diagnosis, insurance status, or other unmeasured factors. We explored the California Cancer Registry (CCR), a large, population-based database, to investigate this.

Patients and Methods: A case-only analysis of CCR data including first primary cases diagnosed from 1996–2005 was conducted along with a descriptive analysis of related clinical variables and neighborhood SES. The neighborhood SES variable used was derived from principle component analysis of census block-level CCR data that aggregated seven indicators of SES. Univariate analyses of overall survival (OS) were conducted using the Kaplan-Meier method. Multivariate survival analyses using Cox proportional hazards methods were performed to calculate hazard ratios (HRs).

Results: A total of 7,042 incident patient cases of first primary lymphoma in individuals age 15–39 at diagnosis were analyzed, including 3,907 non-Hispanic Whites (NHW), 506 African Americans (AA), 1,953 Hispanics (H), and 590 Asian Americans/Pacific Islanders (API). Median overall survival time in months for the five SES categories was 31 for the highest SES group, 38 for the second highest SES group, 38 for the middle SES group, 41 for the second lowest SES group, and 45 for the lowest SES group. In the multivariate analysis, overall survival was reduced in males compared to females (P < 0.001), in patients with NHL as compared to Hodgkin's (P < 0.001), in individuals with later stage diagnosis (P < 0.01), in older AYAs (ages 30–39) compared to younger AYAs (ages 15–29) (P = 0.03), and in AAs (P < 0.01) and Hs (P < 0.01) compared to NHWs. In addition, there was a significant gradient in survival, with higher all-cause mortality at each decreasing quintile of SES (P < 0.001), although there was no significant difference in survival time according to insurance status (P = 0.47) after controlling for the previously listed factors.

Conclusions: In addition to a reduction in survival for AYA lymphoma cases with later stage at diagnosis, reduction in survival was also associated with a reduction in SES. These findings warrant further investigation and intervention. An approach for identifying possible social determinants of barriers to care will be discussed.