EP577 - Native American Colorectal Cancer Mortality, Does Surgical Approach Matter?

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Purpose/Background: Native Americans (NA) have a higher mortality when compared to Whites for unknown reasons when controlled for stage. Laparoscopic surgery requires a highly trained surgeon and often implies they are a high-volume surgeon which is known to improve cancer survival. We hypothesized that worsened survival seen in NA’s may be partially explained by surgical approach.

Methods/Interventions: This was a retrospective study of colorectal cancer patient data from the 2020 ACS NCDB participant user files. Exposures of interest were NA race using white race as the reference and surgical approach defined as robotic, robotic conversion to open, laparoscopic, laparoscopic conversion to open, and open. Open approach was used as the reference category. Race was collapsed to NA, White, Black, Asian, Pacific Islander, and Unknown. The outcome of interest was 5-year survival. Adjustment variables included age, sex, Charlson-Deyo score (CDS), histology, facility type, days to definitive surgery, urbanicity, and insurance type. Cox proportional hazard models were used to obtain adjusted hazard ratios (HR) with 95% confidence intervals.

Results/Outcomes: A total of 680,275 patients had complete surgery approach and disease stage available. Less than 1% of patients (n=2516) were recorded as NA. The difference in surgical approach was small, with 52.5% and 49.9% of NA and whites respectively, eventually undergoing an open approach. In an initial model of the entire cohort adjusted for age, sex, stage and CDS the NA 5-year mortality hazard was 24% higher for NA than whites (Table1-Model 1). The addition of surgical approach only slightly lowered the NA HR to 1.22. Compared to open, the mortality hazard was 29% and 43% lower for laparoscopic and robotic-assisted respectively. A second model adjusted the remaining covariates, which reduced the sample to 486,952 patients and lowered the NA HR to 1.19 (Table 1 -Model 2). Addition of surgical approach resulted in no change in the HR. In this model, the surgical approach mortality hazard was 27% lower for laparoscopic approach and 38% lower for robotic-assisted.

NCDB data are received from COC accredited facilities, which likely reduces variability in treatment as compared to what might be observed in a broader cancer population. This may be particularly limiting for NA patients that appear to be underrepresented in the NCDB.

Conclusion/Discussion: The higher rate of death at 60 months for NA patients was not explained by differences in surgical approach. Moreover, the increased risk of death remained after adjustment for numerous other factors associated with mortality. For all patients, laparoscopic and robotic approaches, even with conversion to open, had lower mortality at 60 months compared to planned open procedures. There are well established benefits to minimally invasive surgery other than oncologic survival, and its use should be promoted in this population.