Introduction
New neoadjuvant regimens for oesophageal cancer are based on trial evidence of improved survival. For clinical complete responders (cCR), the SANO trial reports a surveillance strategy may offer non-inferior survival to surgery, but long-term data are awaited to guide practice. In the interim, information about the likelihood and clinical significance of pCR is needed to inform patient discussions.
This systematic review aimed to fill this knowledge gap by evaluating the frequency of pCR in oesophageal and gastroesophageal junctional adenocarcinoma (OAC/GOJ) treated with neoadjuvant therapies, changes over time, and correlation with overall survival (OS).
Methods
We searched MEDLINE, Embase, and CENTRAL to identify clinical trials of neoadjuvant therapy for patients with Stage I-III OAC/GOJ. We assessed pCR by treatment year and type, and the correlation between pCR and OS using weighted linear regression.
Results
36 trials (47 treatment arms) enrolled 2845 participants (median n=42 per arm, range:23-184) between 1990─2021 to investigate: chemotherapy (NCT) 12, chemoradiation (NCRT) 24, NCT/NCRT+immunotherapy (NIT) 5, NCT/NCRT+targeted therapy 6. Median age 63 years (range:22-84), median node-positive 67% (range:18%-95%). pCR was more common in trials conducted since 2010 (median 24%,range:4%-41%); versus pre-2010 (median 13%,range:0%-41%), p=0.01. Since 2010, pCR was more common for NIT/targeted regimens (range:14%-33%) than other treatment types. Correlation was modest between pCR and 3-year OS (r=0.05).
Conclusions
pCR has become more common following neoadjuvant therapy for OAC/GOJ but frequency varies widely among trials and is not strongly correlated with survival. Further research is needed to identify predictors of survival for pathological (and clinical) complete responders.