NEOADJUVANT CHEMORADIOTHERAPY FOLLOWED BY TRANSHITAL ESOPHAGECTOMY IN LOCALLY ADVANCED ESOPHAGEAL SQUAMOUS CELL CARCINOMA: IMPACT OF PATHOLOGICAL COMPLETE RESPONSE

Potential therapeutic targets in myeloid cell therapy for overcoming chemoresistance and immune suppression in gastrointestinal tumors

In the tumor microenvironment (TME), myeloid cells play a pivotal role. Myeloid-derived immunosuppressive cells, including tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs), are central components in shaping the immunosuppressive milieu of the tumor. Within the TME, a majority of TAMs assume an M2 phenotype, characterized by their pro-tumoral activity. These cells promote tumor cell growth, angiogenesis, invasion, and migration. In contrast, M1 macrophages, under appropriate activation conditions, exhibit cytotoxic capabilities against cancer cells. However, an excessive M1 response may lead to pro-tumoral inflammation. As a result, myeloid cells have emerged as crucial targets in cancer therapy. This review concentrates on gastrointestinal tumors, detailing methods for targeting macrophages to enhance tumor radiotherapy and immunotherapy sensitivity. We specifically delve into monocytes and tumor-associated macrophages' various functions, establishing an immunosuppressive microenvironment, promoting tumorigenic inflammation, and fostering neovascularization and stromal remodeling. Additionally, we examine combination therapeutic strategies.

Neoadjuvant PD-1 blockade combined with chemotherapy is not superior to neoadjuvant chemotherapy alone in resectable locally advanced esophageal carcinoma

BACKGROUND

Neoadjuvant chemotherapy (nCT) or neoadjuvant chemoradiotherapy followed by surgery has been recommended as standard treatment in patients with locally advanced esophageal cancer (LAEC). But the risk of tumor recurrence still remained, and many patients refused or abandoned radiotherapy because of the intolerable adverse effects in China. Neoadjuvant immunochemotherapy (nICT) followed by surgery has become an emerging treatment in patients with esophageal cancer. There was still no consensus on whether nICT was superior to nCT alone in patients with esophageal cancer.

METHODS

In this retrospective study, patients with resectable esophageal cancer who received surgery after nICT (n=26, 40%) or nCT alone (n=39, 60%) were included. The patients were classified as nICT or nCT arm. The primary endpoints were pathological tumor response (PTR) and event-free survival (EFS). The different clinic-pathological features were compared by the Kruskal-Wallis test for continuous variables and the Chi-square (χ²) test for categorical variables. Kaplan-Meier curves were used to estimate EFS from the date of treatment to recurrence or death. All tests were 2-sided with a significative P-value defined <.05.

RESULTS

Three (11.5%) of the 26 patients achieved pathological complete remission (pCR) in the nICT group, and four (10.3%) of the 39 patients achieved pCR in the nCT group, respectively (P=1.000). Six (23.1%) of the 26 patients achieved major pathological response (MPR) in the nICT group, and 11 (28.2%) of the 39 patients achieved MPR in the nCT group, respectively (P=0.645). Downstaging was achieved in 13 (44.8%) patients in the nICT group and 16 (55.2%) patients in the nCT group, respectively (P=0.732). To verify the tumor regression grade (TRG) results, we compared them with MPR and pCR, which showed a significant dependency (P< 0.001). Patients who achieved downgrading showed better MPR and pCR rates (P<0.001 and P =0.010). There was no significant difference in EFS between the nICT and nCT groups (HR=1.011, 95% CI: 0.421-2.425, P = 0.981).

CONCLUSIONS

Neoadjuvant PD-1 blockade combined with chemotherapy was not superior to chemotherapy alone for patients with resectable locally advanced esophageal carcinoma. However, more studies with long-term follow-up were needed to confirm this result.

DOES NEOADJUVANT CHEMORADIOTHERAPY FOR ESOPHAGEAL AND GASTROESOPHAGEAL JUNCTION CANCER PATIENTS AFFECT POSTOPERATIVE OUTCOMES? A STUDY USING THE BECKER TUMOR REGRESSION GRADE SYSTEM AND LYMPH NODE REGRESSION

BACKGROUND

The effect of neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced esophageal cancer can be determined by assessing the Becker tumor regression grade in the primary tumor, as well as in lymph nodes.

AIMS

The aim of this study was to investigate the anatomopathological changes caused by neoadjuvant chemoradiotherapy and their impact on clinical parameters. Specifically, we analyzed the Becker tumor regression grade, lymph node status, and regression changes and evaluated their association with the Clavien-Dindo classification of surgical complications and overall patient survival.

METHODS

This is a retrospective and observational study including 139 patients diagnosed with adenocarcinoma or squamous cell carcinoma of the esophagus and treated with either neoadjuvant chemoradiotherapy followed by surgery or surgery alone. For the 94 patients who underwent neoadjuvant chemoradiotherapy, we evaluated tumor regression by Becker tumor regression grade in primary tumors. We also analyzed lymph node status and regression changes on lymph nodes with or without metastases. Overall survival analysis was performed using Kaplan-Meier curves.

RESULTS

Becker tumor regression grade is associated with lower lymphatic permeation (p<0.01) and vascular invasion (p<0.001), but not with lymph node regression rate (p=0.10). Clavien-Dindo classification was associated neither with lymph node regression rate (odds ratio=0.784, p=0.795) nor with tumor regression grade (p=0.68). Patients who presented with lymphatic permeation and vascular invasion had statistically significantly lower median survival (17 vs. 30 months, p=0.006 for lymphatic permeation, and 14 vs. 29 months, p=0.024 for vascular invasion).

CONCLUSION

In our series, we were unable to demonstrate an association between Becker tumor regression grade and lymph node regression rate with any postoperative complications. Patients with lower lymphatic permeation and vascular invasion have higher overall survival, correlating with a better response in the Becker tumor regression grade system.