E476: Impact of Delays in Surgery after Preoperative Chemotherapy for Gastric Cancer

Treatment of gastric cancer requires multidisciplinary management including preoperative chemotherapy and surgery. Delays in receipt of care routinely occurs and is of concern to both patient and providers. We investigated rates of delay, associated factors, and outcomes. We hypothesized that delay in gastrectomy after chemotherapy would be associated with worse surgical quality metrics and reduced survival.

Methods:

The National Cancer Database was queried for patients diagnosed from 2010-2019 with stage II/III gastric adenocarcinoma. Time between initial chemotherapy initiation and receipt of surgery was quantified (>30, >60, >90, >120, >150 days). Cox regression analysis was used to determine overall survival as a function of chemotherapy initiation and receipt of surgery. Logistic regression was used to investigate patient and facility level factors associated with surgical management >120 days from chemotherapy initiation and associations between surgical outcomes (margins, adequate lymph node harvest: >15 nodes) and time intervals to surgery.

Results:

The patient cohort included 21,920 patients for analysis, including 9,694 patients with Stage II disease and 12,226 with Stage III disease. The median time from chemotherapy initiation to surgery was 103 days (IQR 85-128 days). In multivariable Cox analysis, time between chemotherapy and surgery >120 days was associated with increased risk of death (HR 1.35, 95%CI 1.27-1.44, p< 0.001) (Table 1). Delays were associated with worse surgical quality metrics: 120 days or greater between chemotherapy and surgery was associated with a decreased likelihood of adequate lymph node harvest (OR 0.61, 95% CI 0.54-0.68, p< 0.001) and an increased likelihood of positive margins (OR 1.20, 95% CI 1.05-1.36, p=0.007). African American race (OR 1.14, p=0.03) and income in the lowest quartile (OR 1.19, p=0.01) were associated with >120 days between chemotherapy and surgery initiation. Treatment at an academic facility (OR 0.60, p< 0.001) and facility in highest quartile of surgical gastric cancer volume (OR 0.70, p=0.02) were associated with decreased likelihood of surgical care >120 days following chemotherapy.

Conclusions:

Delays in surgery for gastric cancer following chemotherapy were associated with poorer surgical outcomes, including lymph node harvest, surgical margins, and overall survival. These delays in care were associated with patient and facility level-factors, including race, socioeconomic status, and facility volume.