Abstract 2011P
Background
When treating patients (pts) with GIC who underwent neoadjuvant chemotherapy (NAC) and resection, the decision to change to a different AC regimen based on PR remains controversial. We aimed to understand factors associated with changes in AC and whether these impacted patient outcomes.
Methods
Medical records of GIC pts treated with NAC at a single institution between 1/2012-12/2018 were reviewed. Favorable PR (FPR) was defined as College of American Pathologists (CAP) score 0/1 and unfavorable PR (UPR) as score 2/3. RECIST 1.1 radiologic responses and serum tumor markers pre and post NAC were recorded. Univariable and multivariable logistic regression and survival analyses were performed. Kaplan-Meier method was used to estimate recurrence-free and overall survival (RFS, OS).
Results
155 pts (58% male, median age 64 [27-84] years) were identified. Primary tumor sites were: 43 (27.7%) pancreas, 62 (40%) esophagogastric, and 50 (32.3%) colorectal. After NAC, 31 (20%) pts had FPR, and 124 (80%) had UPR. Of 106 pts with radiological data, 59 (55.7%) demonstrated partial or complete response after NAC. Of 112 pts with serological data, 61 (54.5%) demonstrated >50% tumor marker reduction after NAC. FPR was associated with reduced odds of changing AC (OR 0.05; CI, 0.01 - 0.39); radiographic (OR 0.92; CI, 0.38 - 2.26) and serologic (OR 1.18; CI, 0.49 - 2.87) responses were not. RFS in pts with UPR did not differ between those who changed vs. did not change AC (HR 1.01; CI, 0.55 - 1.86) nor those who received vs. did not receive AC (HR 1.96; CI, 0.97 - 3.96) after adjusting for pathological stage, surgical margin, and cancer type. Though OS in pts with UPR did not differ between those who changed vs. did not change AC (HR 1.30; CI, 0.48 - 3.51), survival was decreased in those who did not receive AC vs. those who did (HR 3.34; CI, 1.3 - 8.53).
Conclusions
We found that UPR, but not serologic or radiographic response, was associated with a change in AC in GIC pts who received NAC. In patients with UPR, changing AC did not impact RFS and OS, though not receiving AC was associated with decreased survival. Prospective studies are needed to better understand the role of PR in AC decisions and patient outcomes.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.