Characterization of residual tumours at the primary site in patients with a near pathological complete response after neoadjuvant chemoradiotherapy for oesophageal cancer

Residual tumor model in esophageal squamous cell carcinoma after neoadjuvant immunochemotherapy: Frequently involves the mucosa and/or submucosa

Objectives

The efficacy and safety of neoadjuvant immunochemotherapy (nICT) are widely explored in locally advanced esophageal squamous cell carcinoma (ESCC). Whether the "wait-and-see" strategy is applicable in ESCC after nICT is still lacking a theoretical basis. This study aimed to preliminarily explore the distribution of residual tumors and the regression pattern of ESCC after nICT.

Methods

Patients undergoing radical esophagectomy after nICT in Fujian Medical University Union Hospital between January 2020 and March 2022 were identified. The resection specimens were re-evaluated by one experienced pathologist. The pathological response was assessed by tumor regression grade (TRG) (modified Ryan scheme). The TRG grade was divided into grades 0 (pathological complete response), 1, 2, and 3. The pathological stage was evaluated in the Eighth Edition AJCC. In the non-pCR group, the residual model was divided into four types: Type I, regression towards the lumen; type II, regression towards the invasive front; type III, concentric regression; and type IV, scattered regression.

Results

A total of 95 consecutive patients were included for analysis. Seventy-six (80.0%) of 95 patients were in non-pCR (pathological complete response), and nine patients (9/76, 11.84%) had isolated residual tumors in lymph nodes. There was no significant difference in baseline characteristics between the pCR group and the non-pCR group (p > 0.05). The overall distribution of TRG for all esophageal wall layers was TRG 0 = 28 (28/95, 29.5%), TRG 1 = 17 (17/95, 17.9%), TRG 2 = 18 (18.9%, 18/95), and TRG 3 = 32 (32/95, 33.7%). In 67 patients with residual tumors in the esophageal wall (TRG ≧1), 63 (63/67, 94.0%) had residual tumor cells in the mucosa and/or submucosa, and four had isolated residual tumors in the muscle layer (4/67, 6.0%). Further analysis showed eight (8/67, 11.9%) patients with submucosal involvement but without mucosal involvement. The distribution of regression patterns was type I (n = 35, 52.2%), type II (n = 3, 4.5%), type III (n = 8, 11.9%), and type IV (n = 21, 31.3%).

Conclusions

The mucosa and/or submucosa are frequently involved in residual malignancy, and the frequent regression models are regression toward the lumen and random regression. There is an opportunity to carefully test the residual tumors in a subgroup of the population with ESCC following nICT. However, some patients had residual tumors only in the muscle layer or lymph nodes. The clinical application of the wait-and-see strategy in ESCC after nICT should be explored using an appropriate evaluation protocol.

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.

Clinical significance of evaluating endoscopic response to neoadjuvant chemotherapy in esophageal squamous cell carcinoma

BACKGROUND AND AIM

Clinical significance of endoscopic response (ER) after neoadjuvant chemotherapy (NAC) for esophageal cancer has not been fully understood. Thus, the present study aimed to investigate the association between ER to NAC and its clinicopathological outcomes in patients with esophageal squamous cell carcinoma (ESCC).

METHODS

In total, 141 patients who underwent NAC and subsequent esophagectomy for ESCC were included. ER to NAC was retrospectively evaluated based on macroscopic findings of the primary tumor, which was classified into three categories: endoscopic no response (eNR), endoscopic partial response (ePR), and endoscopic good response (eGR). An endoscopic responder was defined as patients with eGR/ePR.

RESULTS

Approximately 89.4% of patients had cStage II-III disease, and 7.1% had pathological complete response. Upon ER evaluation, eNR, ePR, and eGR were observed in 46 (32.6%), 54 (38.3%), and 41 (29.1%) patients, respectively. Pathological responders significantly increased as the ER grade became better. Among preoperative clinical factors, only ER significantly correlated with pathological response in univariate and multivariate analysis. Endoscopic responders showed a significantly better prognosis than did eNR patients (P < 0.001), although the overall survival (OS) of the patients with eGR and ePR was equivalent. Endoscopic responder, ypT, ypN, and pathological responder were significant predictors of OS in the univariate analysis, and endoscopic responder, ypN, and pathological responder were independent predictors in the multivariate analysis.

CONCLUSION

This study suggests that ER can be a simple and important tool to predict the pathological response and survival of patients who undergo NAC for ESCC.

Diagnostic performance of MRI for assessment of response to neoadjuvant chemoradiotherapy in oesophageal cancer

Background

Patients with a pathological complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) for oesophageal cancer may benefit from non‐surgical management. The aim of this study was to determine the diagnostic performance of visual response assessment of the primary tumour after nCRT on T2‐weighted (T2W) and diffusion‐weighted (DW) MRI.

Methods

Patients with locally advanced oesophageal cancer who underwent T2W‐ and DW‐MRI (1·5 T) before and after nCRT in two hospitals, between July 2013 and September 2017, were included in this prospective study. Three radiologists evaluated T2W images retrospectively using a five‐point score for the assessment of residual tumour in a blinded manner and immediately rescored after adding DW‐MRI. Histopathology of the resection specimen was used as the reference standard; ypT0 represented a pCR. Sensitivity, specificity, area under the receiver operating characteristic (ROC) curve (AUC) and interobserver agreement were calculated.

Results

Twelve of 51 patients (24 per cent) had a pCR. The sensitivity and specificity of T2W‐MRI for detection of residual tumour ranged from 90 to 100 and 8 to 25 per cent respectively. Respective values for T2W + DW‐MRI were 90–97 and 42–50 per cent. AUCs for the three readers were 0·65, 0·66 and 0·68 on T2W‐MRI, and 0·71, 0·70 and 0·70 on T2W + DW‐MRI (P = 0·441, P = 0·611 and P = 0·828 for readers 1, 2 and 3 respectively). The κ value for interobserver agreement improved from 0·24–0·55 on T2W‐MRI to 0·55–0·71 with DW‐MRI.

Conclusion

Preoperative assessment of residual tumour on MRI after nCRT for oesophageal cancer is feasible with high sensitivity, reflecting a low chance of missing residual tumour. However, the specificity was low; this results in overstaging of complete responders as having residual tumour and, consequently, overtreatment.

Clinical predictors of pathologically response after neoadjuvant chemoradiotherapy for esophageal squamous cell carcinoma: long term outcomes of a phase II study

Background

A pathologically complete response (pCR) or near pCR to neoadjuvant chemoradiotherapy (NCRT) might imply a better prognosis in patients with esophageal cancer. The aim of the study is to identify clinical factors associated with a pCR or near pCR.

Methods

We retrospectively analyzed 40 patients with radical esophagectomy after NCRT for esophageal squamous cell carcinoma (ESCC) from January 2001 to December 2006 in Sun Yat-sen University Cancer Center. Clinical factors included age, gender, weight loss, dysphagia, drinking status, smoking status, tumor location, tumor length, tumor grade, cT status, cN status, the regimen of chemotherapy and the interval between NCRT and surgery as potential predictors for a pCR or near pCR. Logistic regression was used to estimate the independent factors for a pCR or near pCR.

Results

After surgical resection, 22.5% of the patients obtained the pCR. Patients with pCR had a better prognosis than those with non-pCR. However, there was no statistically significantly difference between the two groups (P=0.124). We separated the patients into pCR or near pCR (good responders, GRs) and poor responders (PR) based on the histology. GR showed better overall survival (OS) than PR (P=0.014). Univariate analysis indicated that short tumor length, good tumor grade and never drinking were associated with GR to NCRT. Using logistic regression analysis, good tumor grade was the only independent factor for the GR to NCRT (P=0.021). Cox regression revealed that weight loss, drinking status and GR were independent factors in ESCC patients with radical esophagectomy after NCRT.

Conclusions

Our study indicated that good tumor grade were an independent significant factor for the GR to NCRT. Weight loss, drinking status and GR were independent factors in patients with radical esophagectomy after NCRT. GR may improve OS of ESCC patients receiving NCRT.

Targeting minimal residual disease: a path to cure?

Therapeutics that block kinases, transcriptional modifiers, immune checkpoints and other biological vulnerabilities are transforming cancer treatment. As a result, many patients achieve dramatic responses, including complete radiographical or pathological remission, yet retain minimal residual disease (MRD), which results in relapse. New functional approaches can characterize clonal heterogeneity and predict therapeutic sensitivity of MRD at a single-cell level. Preliminary evidence suggests that iterative detection, profiling and targeting of MRD would meaningfully improve outcomes and may even lead to cure.

Non responders to neoadjuvant chemoradiation for esophageal cancer: why better prediction is necessary

BACKGROUND

Patients with pathologic limited or no response (pNR) to neoadjuvant chemoradiation (nCRT) are subjected to curative intended esophagectomy with subsequent perioperative morbidity and mortality, but potentially only harm from nCRT. The primary aim of this study was to compare the overall survival (OS) of patients with pNR and patients who underwent primary esophagectomy to evaluate potentially benefits of nCRT in these patients. The secondary aim was to identify predictive clinicopathologic factors for pNR and pathologic complete response (pCR) to nCRT with the goal to preselect these patients before the start of treatment.

METHODS

From the period 2005 to 2016, 206 esophageal cancer (EC) patients treated with Carboplatin/Paclitaxel and radiotherapy with complementary esophagectomy were included in this cohort. OS of patients with pNR was compared with a historical cohort of primary surgically treated patients (n=218) after a propensity score matching resulting in a group of 68 patients with pNR after nCRT versus a group of 68 primary esophagectomy patients.

RESULTS

The OS in the pNR group and the primary esophagectomy group was comparable (P=0.986). No predictive factors were found in this cohort for pNR. Female gender (OR 2.5, 95% CI 1.2-5.3) and squamous cell carcinoma (SCC) (OR 2.6, 95% CI 1.3-5.3) were identified as independent predictive factors for pCR.

CONCLUSIONS

Patients with a pNR do not benefit from nCRT followed by resection. These patients had a similar OS as those who had a primary esophagectomy alone. Although this indicates that nCRT does not negatively impact the OS of patients with pNR, patients still have an increased morbidity because of nCRT. Hence, it is important to identify factors that predict pNR. The ability to predict pNR (and pCR) will enable tailored and personalized care preventing unnecessary nCRT with increased morbidity.