Nodal Scar but Not Proliferation Index Predicts Worse Survival in Treated Esophageal Adenocarcinoma
JK Purdy, SK Bihlmeyer, HD Appelman, AC Chang, L Zhao, MB Orringer, SG Urba, BJ McKenna. University of Michigan, Ann Arbor, MI
Background: Previous studies of esophageal adenocarcinoma (EA) treated with chemoradiation (CRT) have found post-treatment pathologic stage, quantity of residual tumor (tumor regression grade, TRG), nodal metastases and pre-CRT proliferation index (PI) in biopsies to be predictive of survival. However, these studies combined patients with EA and squamous cell carcinoma without standard CRT. No study has examined whether scar depth in areas of regressed tumor or nodal scar without tumor (presumably evidence of treated tumor) or post-CRT PI predicts survival in EA patients.
Design: 52 esophagectomies for EA without distant metastases, all receiving the same CRT, from March 2002 to April 2006 were evaluated. Cases were analyzed for depth of scar, nodal scar and amount of residual tumor using a 4-tiered TRG system and were classified according to TNM and pathologic stage. 44 cases with residual EA were stained with Ki67 to calculate post-treatment PI. Kaplan-Meier methods were used to estimate median survival. Cox regression models were performed to assess the impact of different factors on survival.
Results: After controlling for TRG and stage, patients who had 1 additional lymph node with scar were 20% more likely to die (HR=1.205, 95% CI=1.049-1.384) and 27% more likely to have disease progression (HR=1.274, 95% CI= 1.096-1.480) than patients without nodal scar (p=0.0082 and p=0.0016 respectively). Post-CRT PI did not predict overall or disease-free survival. TRG showed a trend toward predicting survival but this did not reach statistical significance. 12 patients staged as T2 according to depth of residual tumor were upstaged to T3 using scar depth, but T stage based on scar depth had no better correlation with survival than that based on tumor depth.
Conclusions: In post-CRT esophageal adenocarcinoma, nodal scar predicts worse survival and disease progression. Unlike pre-CRT EA, PI in post-CRT EA does not predict survival. While some previous studies have suggested that post-CRT TRG predicts survival, this was not statistically significant, possibly due to lack of a standard CRT protocol in those studies or to small sample size in our study. T stage based on scar depth was not a better predictor of survival than T stage based on tumor depth.
Tuesday, March 23, 2010 8:00 AM
Platform Session: Section E, Tuesday Morning