Impact of Tumor Deposits on Oncologic Outcomes in Stage III Colon Cancer

BACKGROUND: The prognosis of tumor deposits in stage III colon adenocarcinoma is poorly described. OBJECTIVE: The purpose of this study was to determine the impact of tumor deposits on oncologic outcomes in patients with stage III colon cancer. DESIGN: This was a multicenter retrospective cohort study. SETTINGS: The 2010 to 2014 National Cancer Database was queried for patients with resected stage III colon adenocarcinoma on final pathology. PATIENTS: Patients were divided into 3 groups: lymph nodes+tumor deposits-, lymph nodes+tumor deposits+, and lymph nodes-tumor deposits+. MAIN OUTCOME MEASURES: The main outcome was 5-year overall survival. RESULTS: Of 74,577 patients, there were 55,800 patients with lymph nodes+tumor deposits-, 13,740 patients with lymph nodes+tumor deposits+, and 5037 patients with lymph nodes-tumor deposits+. The groups had similar patient and facility characteristics, but patients with lymph nodes+tumor deposits+ had more advanced tumor characteristics. Patients with lymph nodes-tumor deposits+ were less likely to receive adjuvant systemic therapy (52% vs 74% lymph nodes+tumor deposits- and 75% lymph nodes+tumor deposits+, p < 0.001) and had a longer delay to initiation of adjuvant treatment (>8 weeks; 43% vs 33% lymph nodes+tumor deposits- and 33% lymph nodes+tumor deposits+, p < 0.001). Patients with lymph nodes+tumor deposits+ had the lowest 5-year overall survival (46.0% vs 63.4% lymph nodes+tumor deposits- vs 61.9% lymph nodes-tumor deposits+, p < 0.001). On multivariate analysis, patients with lymph nodes-tumor deposits+ had similar 5-year overall survival compared with patients with lymph nodes+tumor deposits- with 3 positive lymph nodes (HR, 0.93; 95% CI, 0.87-1.01). Patients with lymph nodes+tumor deposits+ had worse prognosis regardless of the number of involved lymph nodes (3 +lymph nodes: HR, 1.37; 95% CI, 1.28-1.47 and 4 +lymph nodes: HR, 1.30; 95% CI, 1.22-1.38). Of those not receiving adjuvant treatment, patients with lymph nodes-tumor deposits+ were younger and had more adverse tumor features than lymph node+ disease. Lymph nodes-tumor deposits+ was independently associated with less delivery of adjuvant systemic therapy (OR, 0.81; 95% CI, 0.80-0.82). LIMITATIONS: This study was limited by its retrospective analysis of a prospective database. CONCLUSIONS: The prognosis of patients with N1c disease is similar to nodal involvement without tumor deposits, yet these patients were less likely to receive adjuvant systemic therapy. Improvement in the delivery of appropriate care in these patients may increase survival and should be a target of future quality initiatives. See Video Abstract at http://links.lww.com/DCR/A666.