eP369 - NCCN Guideline-Adherence in Rectal Cancer and Outcomes in Low-volume vs. High-volume Centers

Purpose/Background: There is a plethora of literature focused on improved outcomes for cancer patients when treated at “high-volume centers”. The recommendation to travel to high-volume, specialized centers can be both geographically and financially burdensome, as well as impractical for some cancer patients. We hypothesized that adherence to National Comprehensive Cancer Network (NCCN) guidelines would reduce disparities in oncologic outcomes between rectal cancer patients treated at high-volume and low-volume centers.Methods/Interventions: We conducted a retrospective review of the National Cancer Database (NCDB) including adult patients treated with definitive surgical resection for clinical stage II-III rectal adenocarcinoma from 2010-2020. We excluded patients with stage I or IV disease, those who underwent palliative surgical resection, and patients with missing data on surgical resection/radiation/chemotherapy. We determined that a patient’s treatment was “adherent” to NCCN guidelines if they received neoadjuvant radiation and either neoadjuvant or adjuvant chemotherapy (unless pathologic stage I disease or complete clinical response post-operatively). Our primary outcome was overall survival. Secondary outcomes included 30-day readmission, 30-day mortality, and 90-day mortality. Statistical analysis was conducted using Kaplan-Meier univariable analysis and Cox regression models for multivariable analysis, including the following covariates: age, sex, race, income, Charlson-Deyo score, distance to treating center, histology, grade, lymph nodes examined, stage, CEA, perineural invasion, lymphovascular invasion, surgical margins, surgical approach, and post-operative length of stay.Results/Outcomes: Of the 55,497 patients included in the study, 52,721 (95.0%) were found to be “adherent” to NCCN guidelines. Adherence rates were 94.8% in low-volume centers (lowest quartile of case volume), 95.0% in medium-volume centers (middle two quartiles), and 95.1% in high-volume centers (highest quartile). The primary outcome of overall survival was found to be a median of 142.2 months in NCCN-compliant patients and 69.2 months in noncompliant patients (p < 0.001). In multivariable analysis, the hazard ratio for death was found to be 0.66 (CI 0.58-0.75, p < 0.001) for those who were NCCN-adherent when compared to those who were nonadherent. In univariable Kaplan-Meier analysis of only NCCN-adherent patients, survival was significantly increased in high-volume centers when compared to medium or low-volume centers (p < 0.001). However, in multivariable Cox analysis controlling for other covariates, the hazard ratio was found to be 1.07 (CI 0.82-1.40, p=0.6) in low-volume centers and 1.12 (CI .96-1.31, p=0.15) in medium-volume centers when compared to high-volume centers.Conclusion/

Discussion: There is a survival benefit associated with adherence to NCCN guidelines and treatment at high-volume centers. When controlling for other factors, including adherence with NCCN guidelines, the survival benefit seen at high-volume centers was no longer found to be significant."Kaplan-Meier survival analysis by NCCN-adherence

Figure 1. Kaplan-Meier survival analysis by NCCN-adherence.
Multivariable Cox regression analysis.

Table 1. Multivariable Cox regression analysis. "