Adjuvant Chemoradiotherapy Associated with Improved Overall Survival in Resected Esophageal Squamous Cell Carcinoma after Neoadjuvant Chemoradiotherapy in Intensity-Modulated Radiotherapy Era

Adjuvant chemoradiotherapy plus pembrolizumab for locally advanced esophageal squamous cell carcinoma with high risk of recurrence following neoadjuvant chemoradiotherapy: a single-arm phase II study

BACKGROUND

Adjuvant nivolumab reduces recurrence in patients with locoregional esophageal cancer who had pathological residual disease after neoadjuvant chemoradiotherapy and R0 resection. However, the efficacy of adjuvant anti-PD-1 therapy in patients at higher risk of recurrence remains unclear.

METHODS

This phase II trial (ClinicalTrials.gov identifier: NCT03322267) enrolled patients with locally advanced esophageal squamous cell carcinoma (ESCC) received neoadjuvant chemoradiotherapy plus esophagectomy but still had various risk factors for recurrence, such as involved or close margins (≤ 1 mm), extranodal extension of the involved lymph nodes, and the ypN2-3 stage. Patients received adjuvant therapy composed of a course of cisplatin-based chemoradiotherapy and pembrolizumab (200 mg, IV every 3 weeks) for 18 cycles. The primary endpoint was 1-year relapse-free survival (RFS) rate.

RESULTS

Twenty-five patients were enrolled. The risk factors were tumor margins of ≤ 1 mm (18 patients), extranodal extension of the involved lymph nodes (9 patients), and the ypN2-3 stage (9 patients). The median follow-up duration was 21.6 months (95% CI: 18.7-33.2). The rate of 1-year RFS was 60.0%. The median duration of RFS and overall survival was 14.3 (95% CI: 9.0-19.5) and 21.6 (95% CI: 0.0-45.5) months, respectively. Treatment-emergent adverse events of any grade and those of ≥ 3 grade occurred in 56% and 8% of all patients receiving cisplatin-based chemoradiotherapy and in 79.2% and 12.5% of those receiving pembrolizumab.

CONCLUSIONS

Adjuvant chemoradiotherapy followed by pembrolizumab is feasible and may be associated with improved 1-year RFS rate in patients at high risk of recurrence after trimodality therapy for locally advanced ESCC. Trial registration number ClinicalTrials.gov (No. NCT03322267).

Is postoperative adjuvant radiotherapy necessary for patients with esophageal cancer after neoadjuvant chemoradiotherapy? An analysis based on the SEER database

OBJECTIVES

To evaluate the outcomes of adjuvant radiotherapy in patients with esophageal cancer (EC) who underwent esophagectomy following neoadjuvant chemoradiotherapy (NCRT).

METHODS

The data of EC patients who received adjuvant therapy after NCRT between 2004 to 2019 was retrieved from the SEER database. The patients were split into the adjuvant radiotherapy with or without chemotherapy (RT±CT) and the adjuvant chemotherapy (CT) groups. The process of propensity score matching (PSM) was employed.

RESULTS

Following PSM, 157 patients in total were recruited in each treatment group. There were no significant variations in either overall survival (OS) or cancer-specific survival (CSS) between the RT±CT and CT groups (median OS: 28 months versus. 51 months, p=0.063; median CSS: 31 months versus. 52 months, p=0.16). Within the CT group, patients with ypI/II or cI/II tumor stage, positive lymph node ratio (LNR) ≤0.1, and tumor size ≥50 mm (p<0.05) had higher OS compared to the RT±CT groups. Among patients with cT3-4 tumors in N-stage downstaging group, the OS and CSS were significantly greater for those underwent RT±CT as opposed to the CT group (5-year OS:56.6% versus 19.4%, p=0.042; 5-year CSS:67.9% versus. 19.4%, p=0.023). Multivariate Cox regression analysis identified the tumor histology grade as an independent prognostic factor of OS and CSS.

CONCLUSION

Radiotherapy-based adjuvant therapy does not significantly improve the prognosis of EC patients after NCRT, although it may provide a survival benefit for patients with cT3-4 tumors in N-stage downstaging.

Review - The impact of pharmacogenetics on the outcome of immune checkpoint inhibitors

The development of immune checkpoint inhibitors (ICIs) has a tremendous effect on the treatment options for multiple types of cancer. Nonetheless, there is a large interpatient variability in response, survival, and the development of immune-related adverse events (irAEs). Pharmacogenetics is the general term for germline genetic variations, which may cause the observed interindividual differences in response or toxicity to treatment. These genetic variations can either be single-nucleotide polymorphisms (SNPs) or structural variants, such as gene deletions, amplifications or rearrangements. For ICIs, pharmacogenetic variation in the human leukocyte antigen molecules has also been studied with regard to treatment outcome. This review presents a summary of the literature regarding the pharmacogenetics of ICI treatment, discusses the most important known genetic variations and offers recommendations on the application of pharmacogenetics for ICI treatment.