Development of a Risk Score and Nomogram to Predict Individual Benefit Attained from the Addition of Adjuvant Chemotherapy in the Treatment of Stage II Colon Cancer.

Publication Title

Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract

Authors

Daniel W Nelson
Clay Merritt
Shu-Ching Chang, Medical Data Research Center, Providence Health & Services, Portland, OR, USAFollow
Gary Grunkemeier, Medical Data Research Center, Providence St. Joseph Health, Portland, OR, USAFollow
Scott R Steele
Melanie Goldfarb, Medical Data Research Center, Providence St. Joseph Health, Portland, OR, USA; Center for Endocrine Tumors and Disorders, John Wayne Cancer Institute at Providence Saint John's Health Center, Santa Monica, CA, USAFollow

Document Type

Article

Publication Date

8-3-2020

Keywords

Adjuvant chemotherapy; Colon cancer; High risk; Stage II

Abstract

BACKGROUND: Current guidelines recommend considering adjuvant chemotherapy (AC) for stage II colon cancer (CC) with poor prognostic clinicopathologic and molecular features. However, the relative impact of individual or constellations of high-risk features remains undefined. We developed an individualized point-of-care tool to predict survival benefit attained from the addition of AC.

METHODS: The National Cancer Database was queried for all patients with resected stage II CC from 2004 to 2015. A prognostic risk score and nomogram were constructed using twelve clinicopathologic and molecular prognostic factors associated with outcomes for CC. Overall survival (OS) was compared between surgery alone and AC groups. The nomogram was validated for discrimination and calibration using bootstrap-adjusted Harrell's concordance index (C-index). For population-level estimation, OS was compared based on quartiles.

RESULTS: Of 132,666 patients with stage II CC, 16.8% received AC. The calibration curve of the constructed nomogram showed a good agreement between predicted and observed median and 3-, 5-, and 10-year survival (bootstrap-adjusted C-index 0.699, CI: 0.698-0.703). Population-level risk score analysis (median [Q1, Q3]; 4.9 [4.6, 5.5]) demonstrated that patients with scores > 3.34 had significantly decreased risk of death with the addition of AC (all p < 0.001). No survival advantage was associated with AC among patients with low risk scores (risk score < 3.34: HR: 0.94, 95% CI: 0.80-1.11, p = 0.47).

DISCUSSION: A composite weighted risk score is critical to individualizing AC in select high-risk patients. Our nomogram provides individualized prognostication and estimation of benefit attained from AC. This may better inform treatment decisions and aid future trial design.

Clinical Institute

Digestive Health

Clinical Institute

Cancer

Specialty/Research Institute

Gastroenterology

Specialty/Research Institute

Oncology

Specialty/Research Institute

Surgery