N1c Colon Cancer and the Use of Adjuvant Chemotherapy: A Current Audit of the National Cancer Database (NCDB)

Colorectal Dis. 2020 Oct 16. doi: 10.1111/codi.15406. Online ahead of print.


AIM: Colorectal cancer staging has evolved to define N1c as the presence of tumour deposits without concurrent positive lymph nodes. Work to date reports poor prognosis in N1c colon cancer, with Stage III categorization and adjuvant chemotherapy (AC) recommended. No study has evaluated the prevalence, treatment compliance, or treatment-related outcomes on a national scale. We aimed to evaluate the prevalence of N1c colon cancer, use, outcomes, and factors associated with AC in the United States (US).

METHODS: The National Cancer Database was reviewed for N1cM0 colon adenocarcinomas that underwent resection from 2010-2016. Cases were stratified into “AC” or “no AC” cohorts. Kaplan-Meier method was used to estimate overall survival(OS) and compare the AC and no AC cohorts using the log-rank test. Multivariable logistic regression identified factors associated with AC. The main outcome measures were the prevalence and factors associated with AC use, and its impact in N1c disease.

RESULTS: 5,684(1.59% of 357,752) colon adenocarcinomas were N1c; 55%(n-3,071) received AC. AC significantly improved 1-, 3-and 5-year OS compared to no AC (96.2%, 80%, 67.4% and 72.9%, 48.5%, 33.8%; p<0.001). Compared to the no AC group, AC patients were younger, had less comorbidity, male gender, and received minimally invasive surgery at an academic treatment center(all p<0.05). Socioeconomic and procedural factors significantly impacted AC use.

CONCLUSION: In the US, AC is underutilized in N1c colon cancer despite significantly improved OS. Socioeconomic and procedural factors associated with AC were identified, highlighting disparities in AC use and opportunities to improve oncological outcomes and survival.

PMID:33064353 | DOI:10.1111/codi.15406