UNDER-UTILIZATION OF NEOADJUVANT THERAPY FOR ELDERLY PATIENTS WITH LOCALLY ADVANCED GASTRIC CANCER
Julia M. Greene*1,2, Sean Nassoiy1,2, Jessica Weiss1,2, Stephanie Young1,2, Daniel P. Milgrom1,2, Douglas A. Hanes2, Melanie Goldfarb2
1Surgical Oncology, Donald L Morton CGSO Fellowship, Santa Monica, CA; 2Providence Health and Services, Portland, WA
Background: Due to the aging population, the number of elderly patients (>80 years old) diagnosed with locally advanced gastric cancer (LAGC) in the US will continue to rise. According to NCCN guidelines, neoadjuvant treatment (NAT) is a recommended approach for locally advanced disease. However, most patients over the age of 80 have upfront surgery.
Methods: Patients 80 years and older who had a surgical resection for LAGC (stage IB-IIIC) were identified in the 2003-2017 National Cancer Database. Patients were grouped based on therapy sequence: those that received NAT prior to surgery, those that underwent surgery alone, and those that underwent up front surgery followed adjuvant therapy (UFS+AT). Multivariable logistic regressions were used to determine independent factors for R0 resection and receipt of AT and NAT. Overall survival (OS) from time of surgery was assessed using Kaplan-Meier analyses and Cox-proportional-hazards regression analyses examined for the impact of treatment pathway on the risk of death.
Results: Of 2731 patients, 68% received surgery alone, 18% had UFS+AT, and the remaining 15% NAT. During the latter half of the study period there was an increase in usage of NAT to 23% from 6%. Factors independently associated with receipt of NAT were diagnosis year 2011-2017, age <86, male gender, treatment at an academic facility, comorbidity score of 0, cT3 tumors, and cN1-2 disease (all p<0.001). Factors independently associated with receipt of adjuvant therapy were diagnosis year 2011-2017, age <86, Asian/Pacific Islander race, comorbidity score of 0, travel distance of 50-100mi, and node positive disease (all p<0.001). Factors independently associated with R0 resection include extent of surgery more than local excision, later date of diagnosis, treatment at an academic center, cT1 and cN0 disease, and grade I-II tumors (all p<0.001). Kaplan-Meier analyses showed a 29.5 month median OS for the NAT group (95% CI, 22.8-35.9) vs 29.5 months for surgery with AT (95% CI, 25.9-39.6) and 17.8 months for surgery alone (95% CI, 16.1-19.6) (P <0.0001). In a landmark analysis used to account for immortal time bias, NAT significantly improved overall survival compared to the UFS+AT group (p=0.018).
Conclusion: Of older patients with LAGC, less than 1/3 received some form of adjuvant or neoadjuvant therapy, which is the standard of care. NAT was associated with improved survival when compared to surgery followed by adjuvant therapy. Clinicians should advocate for receipt of NAT in older patients with LAGC.
Back to 2023 Abstracts