National Trends in Multimodality Therapy for Locally Advanced Gastric Cancer

Abstract

Background: Multimodality therapy (MMT) is recommended for patients with resectable gastric cancer, but no single approach has been established as standard. Little is presently known about current national practice patterns and sequencing of MMT.

Methods: Retrospective cohort study of patients with gastric cancer aged 18 to 80 y in the National Cancer Database (2006-2014) with ≥T2 and/or node-positive disease (i.e., stage Ib to III) treated with MMT. Clinical nodal staging accuracy was ascertained among those treated with upfront surgery by comparing clinical and pathologic nodal staging. Multivariable Cox regression was used to evaluate the association between overall risk of death and MMT approach (i.e., radiation used versus not and treatment sequence).

Results: Among 5817 patients, 16.1% received perioperative MMT, 50.6% preoperative only, and 33.3% postoperative only. The sensitivity, specificity, positive predictive value, and negative predictive values of clinical nodal staging were 68.4%, 88.8%, 91.1%, and 62.7%, respectively. Current clinical nodal staging modalities understage 37.3% of clinically node-negative patients. Over time, radiation utilization decreased (74.3% in 2006 versus 53.9% in 2014; trend test, P < 0.001), perioperative MMT increased (8.9% versus 22.2%%; trend test, P < 0.001), and postoperative MMT decreased (43.1% versus 21.0%; trend test, P < 0.001). Neither type of MMT nor treatment sequence is associated with risk of death.

Conclusions: One-third of patients with gastric cancer who are candidates to receive MMT are treated with upfront surgery. Given the high false negative rate of clinical nodal staging and high noncompletion rate of postoperative treatment, efforts should be directed at improving and optimizing preoperative therapy utilization.

Keywords: Chemotherapy; Gastric cancer; Locally advanced; Multimodality therapy; Radiation; Surgery.