Rummel, Keaton A

Objectives: For locally advanced rectal adenocarcinoma (R-ACA), a nonoperative management (NOM) approach has emerged as a guideline-supported treatment option. However, the variables associated with NOM receipt are unknown. Methods: Utilizing the National Cancer Database, we performed a retrospective cohort study of adults with stage 1 to 3 R-ACA managed with curative intent from 2004 to 2018. The primary outcome was the proportion of patients receiving NOM versus surgery. The secondary outcome was survival among NOM patients. Results: A total of 128,297 patients were included. In all, 115,888 (90.3%) received surgery and 12,409 (9.7%) received NOM. Receipt of NOM was associated with age above 70, Charlson-Deyo score of 0, race (Black, Asian or Pacific Islander, or other vs. White), insurance status, geographical region, treatment in a community facility, year of diagnosis (2012-2018 vs. 2004-2011), tumor grade 1 versus ≥ 2, clinical T-stage ≥ 2, and clinical N1 or N2 versus N0. In the NOM cohort, poorer overall survival was associated with age 70 and above, male sex, Charlson-Deyo score ≥ 1, insurance status, geographical region, rural urban density versus metro/urban, treatment in a community facility, year of diagnosis (2004-2011 vs. 2012-2018), clinical T4 versus T1, clinical N1 or N2 versus N0, grade 3 versus 1, treatment with a radiotherapy dose <45 Gy versus 45 to 54 Gy, and omission of chemotherapy. Conclusions: Several demographic factors and social determinants of health were associated with receipt of NOM and overall survival. With the increasing utilization of NOM, it will be important to understand the drivers of treatment decisions and influences on access to the desired treatment approach.