Understanding Factors Leading to Surgical Attrition for "Resectable" Gastric Cancer

We used a novel combined analysis to evaluate various factors associated with failure to surgical resection in non-metastatic gastric cancer.

We identified factors associated with the receipt of surgery in publicly available clinical trial data for gastric cancer and in the National Cancer Database (NCDB) for patients with stages I-III gastric adenocarcinoma. Next, we evaluated variable importance in predicting the receipt of surgery in the NCDB.

In published clinical trial data, 10% of patients in surgery-first arms did not undergo surgery, mostly due to disease progression and 15% of patients in neoadjuvant therapy arms failed to reach surgery. Effects related to neoadjuvant administration explained the increased attrition (5%). In the NCDB, 61.7% of patients underwent definitive surgery. In a subset of NCDB patients resembling those enrolled in clinical trials (younger, healthier, and privately insured patients treated at high-volume and academic centers) the rate of surgery was 79.2%. Decreased likelihood of surgery was associated with advanced age (OR 0.97, p < 0.01), Charlson-Deyo score of 2+ (OR 0.90, p < 0.01), T4 tumors (OR 0.39, p < 0.01), N+ disease (OR 0.84, p < 0.01), low socioeconomic status (OR 0.86, p = 0.01), uninsured or on Medicaid (OR 0.58 and 0.69, respectively, p < 0.01), low facility volume (OR 0.64, p < 0.01), and non-academic cancer programs (OR 0.79, p < 0.01).

Review of clinical trials shows attrition due to unavoidable tumor and treatment factors (~ 15%). The NCDB indicates non-medical patient and provider characteristics (i.e., age, insurance status, facility volume) associated with attrition. This combined analysis highlights specific opportunities for improving potentially curative surgery rates.