Histopathologic Features are more Important Prognostic Factors than Primary Tumour Location in Gastro-oesophageal Adenocarcinoma Treated with Preoperative Chemoradiation and Surgery

The effect of histologic grade on neoadjuvant treatment outcomes in esophageal cancer

BACKGROUND AND OBJECTIVES

The gold standard for locoregional esophageal cancer (LEC) treatment includes preoperative chemoradiation and surgical resection, with possible perioperative or adjuvant systemic therapy. With few data associating histologic grade and prognosis in LEC patients receiving neoadjuvant chemoradiation followed by resection, we seek to evaluate this association.

METHODS

Our institutional esophagectomy database between 1999 and 2019 was queried, selecting esophageal adenocarcinoma patients who completed neoadjuvant therapy (NAT), followed by esophagectomy. Propensity-score matching of low- and high-histologic grade groups was performed to assess survival metrics using initial clinical grade (cG) and final pathologic grade (pG). We performed a multivariable logistic regression to study predictors of pathologic complete response as a secondary objective.

RESULTS

A total of 518 patients met the inclusion criteria. Kaplan-Meier analysis of the matched dataset showed no difference in initial or 5-year recurrence-free survival or overall survival (OS) between cG1 and cG2 versus cG3 based on original grade. When matched according to pG, cG1-2 had improved median survival parameters compared to cG3, with 5-year OS for cG1-2 of 45% versus 27% (p = 0.001). Higher pG, pathologic N stage, and poor response to NAT are predictors of poor survival.

CONCLUSION

Patients with post-NAT pG1-2 demonstrated improved survival. Integrating histologic grade into postneoadjuvant staging may be warranted.

Modified ypTNM Staging Classification for Gastric Cancer after Neoadjuvant Therapy: A Multi-Institutional Study

BACKGROUND

The benefits of neoadjuvant therapy for patients with locally advanced gastric cancer (GC) are increasingly recognized. The 8th edition of the American Joint Committee on Cancer (AJCC) Staging Manual first proposed ypTNM staging, but its accuracy is controversial. This study aims to develop a modified ypTNM staging.

PATIENTS AND METHODS

Clinicopathological data of 1,791 patients who underwent curative-intent gastrectomy after neoadjuvant therapy in the Surveillance, Epidemiology, and End Results database, as the development cohort, were retrospectively analyzed. Modified ypTNM staging was established based on overall survival (OS). We compared the prognostic performance of the AJCC 8th edition ypTNM staging and the modified staging for patients after neoadjuvant therapy.

RESULTS

In the development cohort, the 5-year OS for AJCC stages I, II, and III was 58.8%, 39.1%, and 21.6%, respectively, compared with 69.9%, 54.4%, 34.4%, 24.1%, and 13.6% for modified ypTNM stages IA, IB, II, IIIA, and IIIB. The modified staging had better discriminatory ability (C-index: 0.620 vs. 0.589, p < .001), predictive homogeneity (likelihood ratio chi-square: 140.71 vs. 218.66, p < .001), predictive accuracy (mean difference in Bayesian information criterion: 64.94; net reclassification index: 35.54%; integrated discrimination improvement index: 0.032; all p < .001), and model stability (time-dependent receiver operating characteristics curves) over AJCC. Decision curve analysis showed that the modified staging achieved a better net benefit than AJCC. In external validation (n = 266), the modified ypTNM staging had superior prognostic predictive power (all p < .05).

CONCLUSION

We have developed and validated a modified ypTNM staging through multicenter data that is superior to the AJCC 8th edition ypTNM staging, allowing more accurate assessment of the prognosis of patients with GC after neoadjuvant therapy.

IMPLICATIONS FOR PRACTICE

The 8th edition of the American Joint Committee on Cancer (AJCC) Staging Manual first proposed ypTNM staging, but its accuracy is controversial. Based on multi-institutional data, this study developed a modified ypTNM staging, which is superior to the AJCC 8th edition ypTNM staging, allowing more accurate assessment of the prognosis of patients with gastric cancer after neoadjuvant therapy.

Perineural invasion predicts for locoregional failure in patients with oesophageal adenocarcinoma treated with neoadjuvant chemoradiotherapy

AIM

The prognostic significance of perineural invasion (PNI) in oesophageal adenocarcinoma (EAC) is unclear. We examined the association of PNI with clinical outcomes in patients treated with neoadjuvant chemoradiotherapy (nCRT) and surgery.

METHODS

We performed a single institutional retrospective study. We evaluated the association of PNI with locoregional recurrence-free survival (LRFS), distant metastasis-free survival, disease-free survival (DFS) and overall survival using log-rank and Cox proportional hazard modelling.

RESULTS

29 out of 73 patients (40%) had PNI at the time of surgery. The median follow-up was 20.1 months. The median DFS was 18.4 months for patients with PNI vs 41.3 months for patients without PNI (p<0.05). The median LRFS was 23.3 months for patients with PNI and median not reached for patients without PNI (p<0.01). In a multivariate model including age and pathological variables, PNI remained a significant independent predictor of LRFS (HR 0.20, 95% CI 0.07 to 0.60; p=0.004).

CONCLUSIONS

For patients with EAC treated with nCRT, PNI found at the time of surgery is significantly associated with worse LRFS. Our data support attempts to validate this finding and perhaps testing the role of adjuvant therapy in patients with PNI.