Descriptive Analysis and Factors Influencing Survival in Patients With Primary Cutaneous Gamma-Delta T Cell Lymphoma. A Retrospective National Cancer Database Study.

Background Gamma delta T cells gives rise to a rare malignancy called Primary cutaneous Gamma-Delta T cell lymphoma (PCGDTCL). Methods From the National Cancer Database (NCDB), 110 (0.015%) patients with PCGDTCL were identified. Results Males aged >60 years were the commonest cohort. Caucasian race was the most common (Caucasian: 79.09%, African American:16.36%). Most patients were diagnosed at stage 1 (52.33%), followed by stage 4 (30.23%). On analyzing income categories, <$48,000 group had 48.15% stage 4 (13/27) and 40.74% (11/27) stage 1. Overall survival (OS) of the study group at 3 years by Kaplan-Meier (KM) analysis was 46.6%. African American race (37.5%), income of <$48,000 (27.6%) and government insurance (38.8%) had lower survival rates in KM analysis. In the adjusted hazard ratio (HR) analysis, only age <=40 years compared to >60 years (0.165 [0.036, 0.768], P= .0217) reached significance. Although the group that did not receive any chemotherapy or radiation seemed to have a better survival by KM analysis at 74.3% at 3 years, significance was not seen in the adjusted HR estimates and majority of the patients in this group were stage 1. This group may have received topical treatments which may have not been captured in NCDB. Adjusted analysis also revealed chemoradiation to have a lower mortality risk compared to chemotherapy alone (0.229 [0.079, 0.670], P = .0071), suggesting that aggressive strategies may be required for management when needed. Conclusion Socioeconomic disparities significantly impact access to healthcare and are of particular importance in rare lymphomas.