Nodal Downstaging of Esophageal Squamous Cell Carcinoma after Neoadjuvant Chemoradiotherapy: Survival Analysis if ypN0 Is Achieved

Molecular and immunological characteristics of postoperative relapse in lymph node-positive esophageal squamous cell cancer

BACKGROUND

The molecular and immunological characteristics of primary tumors and positive lymph nodes in esophageal squamous cell carcinoma (ESCC) are unknown and the relationship with recurrence is unclear, which this study attempted to explore.

METHODS

A total of 30 ESCC patients with lymph node positive (IIB-IVA) were enrolled. Among them, primary tumor and lymph node specimens were collected from each patient, and subjected to 551-tumor-targeted DNA sequencing and 289-immuno-oncology RNA panel sequencing to identify the different molecular basis and immunological features, respectively.

RESULTS

The primary tumors exhibited a higher mutation burden than lymph nodes (p < 0.001). One-year recurrent ESCC exhibited a higher Mucin16 (MUC16) mutation rate (p = 0.038), as well as univariate and multivariate analysis revealed that MUC16 mutation is independent genetic factor associated with reduced relapse-free survival (univariate, HR: 5.39, 95% CI: 1.67-17.4, p = 0.005; multivariate, HR: 7.36, 95% CI: 1.79-30.23, p = 0.006). Transcriptomic results showed non-relapse group had higher cytolytic activity (CYT) score (p = 0.025), and was enriched in the IFN-α pathway (p = 0.036), while those in the relapsed group were enriched in the TNF-α/NF-κB (p = 0.001) and PI3K/Akt pathway (p = 0.014).

CONCLUSION

The difference in molecular characteristics between primary lesions and lymph nodes may be the cause of the inconsistent clinical outcomes. Mutations of MUC16 and poor immune infiltration are associated with rapid relapse of nodes-positive ESCC.

The Impact of Pretreatment PET/CT Nodal Status on Esophageal Squamous Cell Carcinoma After Neoadjuvant Chemoradiation

BACKGROUND

For advanced esophageal cancer, the clinical significance of pretreatment nodal status (cN) as determined by different examinations remains unclear.

PATIENTS AND METHODS

Patients with esophageal squamous cell carcinoma who underwent neoadjuvant chemoradiation and surgery were analyzed in this study. Pretreatment cN status assessed by CT, EUS, and PET/CT and clinicopathological features were used to evaluate tumor recurrence and long-term survival.

RESULTS

Two hundred and twenty-two patients were identified in this study. Pretreatment PET/CT cN0 [odds ratio (OR) cN0 versus cN+, 5.316, p < 0.001] and pretreatment CT cN0 (OR 1.957, p = 0.032) both independently predicted ypN0. Pretreatment PET/CT cN0 was also associated with a lower recurrence rate and longer survival across the entire study group. Among patients with ypN0, pretreatment PET/CT cN+ indicated poor disease-free survival [hazard ratio (HR) 2.777, p = 0.001] and overall survival (HR 2.211, p = 0.034) compared with pretreatment PET/CT cN0, which predicted a favorable prognosis.

CONCLUSIONS

Data from the current study suggest that pretreatment lymph node status as assessed by PET/CT is strongly correlated with survival outcomes after neoadjuvant chemoradiation and surgery in patients with esophageal squamous cell carcinoma. ypN0 patients can achieve better survival outcomes when pretreatment cN0 is assessed by PET/CT.

Residual tumor characteristics of esophageal squamous cell carcinoma after neoadjuvant chemoradiotherapy

OBJECTIVE

The study was to investigate the characteristics of residual tumors of esophageal squamous cell carcinoma after neoadjuvant chemoradiotherapy.

METHODS

The resection specimens of 187 patients undergoing surgery after neoadjuvant chemoradiotherapy in Zhongshan Hospital of Fudan University were reevaluated. Tumor regression grade determined by residual tumor ratios was scored for each specific layer of the esophageal wall and all removed lymph nodes for 4 grades as tumor regression grade 1, 0% residual tumors, tumor regression grade 2, less than 10%; tumor regression grade 3, 10% to 50%; tumor regression grade 4, greater than 50%. The pretreatment pathologic tumor stage and pretreatment pathologic lymph node stage before neoadjuvant chemoradiotherapy were recorded reflecting the original depth of primary tumor and number of originally involved lymph nodes, respectively. According to regression directionality, regression pattern was classified into 4 categories as type I: regression toward the lumen, type II: regression toward the invasive front, type III: concentric regression, and type IV: scattered regression. Statistical analyses were performed using Mann-Whitney, chi-square, Cochran Q tests, and Kendall τ-b coefficient, appropriately.

RESULTS

A total of 138 patients have residual tumors, and 97 patients (70.3%), 100 patients (72.5%), 89 patients (64.5%), 63 patients (45.7%), and 68 patients (49.3%) have malignant cells in mucosa, submucosa, muscularis propria, adventitia/surrounding stroma, and lymph nodes, respectively. A total of 115 patients (83.3%) had residual tumors in the mucosa or submucosa, but 63 (54.8%) were graded as tumor regression grade 2 with small amounts of tumors in these 2 layers, 9 patients (6.5%) had residual tumors only in the deep 2 layers, and 14 patients (10.1%) had residual tumors only in lymph nodes. Overall, 86 patients (62.7%) with residual tumors are difficult to identify via present techniques. In patients with tumors that involved all esophageal layers before neoadjuvant chemoradiotherapy, only muscularis propria contained residual tumors significantly more frequently than the adventitia/surrounding stroma (P < .001). The random type IV and nonrandom regression patterns of type I to III were comparable with 48.9% and 51.1%, respectively. In patients with positive lymph node before neoadjuvant chemoradiotherapy, only a small portion of patients (29.2%, 28/96) achieved ypN0 status (nodes pathological complete response), even worse than the primary lesions (33.6%, 63/187) in esophageal squamous cell carcinoma.

CONCLUSIONS

The small amount of viable tumor cells in the superficial layers, low pathological complete response rate of lymph nodes, and diverse regression patterns lead to difficulty of detecting residual tumors in esophageal squamous cell carcinoma.