RF10. The Impact of Tumor Response on Outcomes Following Chemotherapy and Esophagectomy for Bulky Distal Esophageal Adenocarcinoma

Objective: A recent trial showed induction chemotherapy had improved survival compared to chemoradiation for esophageal adenocarcinoma. Our study evaluates the impact of tumor downstaging to investigate the potential continued role of preoperative radiation for bulky tumors that may have limited local response to chemotherapy alone.

Methods: Patients with cT3-4N0-1M0 distal esophageal adenocarcinoma who underwent chemotherapy alone or chemoradiation followed by esophagectomy in the National Cancer Database from 2006-2019 were compared using Kaplan-Meier and Cox analyses. The impact of tumor downstaging (cT4-pT0-3, cT3-pT0-2, or cN1-pN0) after chemotherapy was assessed with additional survival analyses.

Results: Among the entire cohort (n=9744), only 743 (7.6%) were treated with induction chemotherapy alone. Although chemotherapy did not have as good a local response as chemoradiation – higher rates of positive margins (10.2% [74/743] vs 5.7% [504/9001], p<0.001), lower rates of either T or N downstaging (53.0% [394/743] vs 66.1% [5953/9001], p<0.001) and complete pathologic response (9.7% [72/743] vs 18.4% [1,658/9,001], p<0.001) – 5-year survival in univariable analysis was better after chemotherapy (41.4% [95% confidence interval {CI} 37.6-45.6%] vs 38.9% [95% CI 37.8-40.0%], p=0.011), though the association was not statistically significant in multivariable analysis (hazard ratio [HR] 0.91 [95% CI 0.82-1.01], p<0.083). In the chemotherapy subset, having either T or N downstaging was associated with a lower incidence of positive margins (5.2% [20/394] vs 15.9% [54/349], p<0.001] as well as significantly better survival in both univariable (5-year survival 53.5% [95%CI 48.1-59.4] vs 28.7% [23.8-34.6%], p<0.001) and multivariable analysis (HR 0.48 [95%CI 0.39-0.58, p<0.001) (Figure 1). Compared to chemoradiation, the chemotherapy patients with downstaging had significantly better survival (HR 0.65 [95%CI 0.55-0.76], p<0.001) while the chemotherapy patients without downstaging had significantly worse survival (HR 1.29 [95%CI 1.12-1.48, p<0.001).

Conclusions: Survival of patients treated with chemotherapy and then esophagectomy for cT3-4 distal esophageal adenocarcinoma is dependent on the response to induction therapy. These results suggest that additional preoperative chemoradiation prior to surgery may be beneficial for patients who do not have significant clinical or radiologic response after an initial course of chemotherapy.

Carolyn C. Chang (1), Ntemena Kapula (1), Douglas Liou (1), Irmina Elliott (1), Brandon Guenthart (1), Natalie Lui (1), Leah Backhus (1), Joseph Shrager (1), Mark Berry (1), (1) Stanford University Medical Center, Stanford, CA

Carolyn C. Chang

Rapid Fire Abstract Presenter

I am a general surgery resident at Oregon Health & Science University and am currently in my second year as a postdoctoral research fellow in the Department of Thoracic Surgery at Stanford University. My time at Stanford has been extremely fulfilling, and I am excited to apply for the 2027 Thoracic Surgery Fellowship Match upon my return to residency. My goal is to build a career as an academic thoracic surgeon focused on thoracic oncology.

 

Specialties: Thoracic