Neoadjuvant chemoradiation for esophageal cancer : Surgery improves locoregional control while response based on FDG-PET/CT predicts survival

Neoadjuvant versus definitive radiochemotherapy of locoregionally advanced oesophageal cancer-who benefits?

PURPOSE

For years, there have been discussions on whether neoadjuvant radiochemotherapy followed by surgery (nRCT-S) is superior to definitive radiochemotherapy (dRCT) as the standard of care for locoregionally advanced oesophageal cancer (OC). This retrospective study aimed to evaluate our patient cohort regarding differences in survival and recurrence between nRCT‑S and dRCT.

METHODS

Data from 68 patients with dRCT and 33 patients with nRCT‑S treated from 2010 to 2018 were analysed. Comorbidities were recorded using the Charlson Comorbidity Index (CCI). Recurrence patterns were recorded as in-field or out-field. Kaplan-Meier analyses were used to compare survival data (overall survival [OS], progression-free survival [PFS], and locoregional control [LRC]).

RESULTS

Patients with nRCT‑S showed significantly lower CCI values than those with dRCT (p = 0.001). The median follow-up was 47 months. The median OS times were 31 months for nRCT‑S and 12 months for dRCT (p = 0.009), the median PFS times were 11 and 9 months, respectively (p = 0.057), and the median LRC times were not reached and 23 months, respectively (p = 0.037). The only further factor with a significant impact on OS was the CCI (p = 0.016). In subgroup analyses for comorbidities regarding differences in OS, the superiority of the nRCT‑S remained almost significant for CCI values 2-6 (p = 0.061).

CONCLUSION

Our study showed significantly longer OS and LRC for patients with nRCT‑S than for those with dRCT. Due to different comorbidities in the groups, it can be deduced from the subgroup analysis that patients with few comorbidities seem to especially profit from nRCT‑S.

[F18] FDG-PET/CT for manual or semiautomated GTV delineation of the primary tumor for radiation therapy planning in patients with esophageal cancer: is it useful?

Background

Target volume definition of the primary tumor in esophageal cancer is usually based on computed tomography (CT) supported by endoscopy and/or endoscopic ultrasound and can be difficult given the low soft-tissue contrast of CT resulting in large interobserver variability. We evaluated the value of a dedicated planning [F18] FDG-Positron emission tomography/computer tomography (PET/CT) for harmonization of gross tumor volume (GTV) delineation and the feasibility of semiautomated structures for planning purposes in a large cohort.

Methods

Patients receiving a dedicated planning [F18] FDG-PET/CT (06/2011–03/2016) were included. GTV was delineated on CT and on PET/CT (GTV_CT and GTV_PET/CT, respectively) by three independent radiation oncologists. Interobserver variability was evaluated by comparison of mean GTV and mean tumor lengths, and via Sørensen–Dice coefficients (DSC) for spatial overlap. Semiautomated volumes were constructed based on PET/CT using fixed standardized uptake values (SUV) thresholds (SUV30, 35, and 40) or background- and metabolically corrected PERCIST-TLG and Schaefer algorithms, and compared to manually delineated volumes.

Results

45 cases were evaluated. Mean GTV_CT and GTV_PET/CT were 59.2/58.0 ml, 65.4/64.1 ml, and 60.4/59.2 ml for observers A–C. No significant difference between CT- and PET/CT-based delineation was found comparing the mean volumes or lengths. Mean Dice coefficients on CT and PET/CT were 0.79/0.77, 0.81/0.78, and 0.8/0.78 for observer pairs AB, AC, and BC, respectively, with no significant differences. Mean GTV volumes delineated semiautomatically with SUV30/SUV35/SUV40/Schaefer’s and PERCIST-TLG threshold were 69.1/23.9/18.8/18.6 and 70.9 ml. The best concordance of a semiautomatically delineated structure with the manually delineated GTV_CT/GTV_PET/CT was observed for PERCIST-TLG.

Conclusion

We were not able to show that the integration of PET/CT for GTV delineation of the primary tumor resulted in reduced interobserver variability. The PERCIST-TLG algorithm seemed most promising compared to other thresholds for further evaluation of semiautomated delineation of esophageal cancer.

Radiochemotherapy with or without cetuximab for unresectable esophageal cancer: final results of a randomized phase 2 trial (LEOPARD-2)

Purpose

To investigate the efficacy and toxicity of cetuximab when added to radiochemotherapy for unresectable esophageal cancer.

Methods

This randomized phase 2 trial (clinicaltrials.gov, identifier NCT01787006) compared radiochemotherapy plus cetuximab (arm A) to radiochemotherapy (arm B) for unresectable esophageal cancer. Primary objective was 2‑year overall survival (OS). Arm A was considered insufficiently active if 2‑year OS was ≤40% (null hypothesis = H₀), and promising if the lower limit of the 95% confidence interval was >45%. If that lower limit was >40%, H₀ was rejected. Secondary objectives included progression-free survival (PFS), locoregional control (LC), metastases-free survival (MFS), response, and toxicity. The study was terminated early after 74 patients; 68 patients were evaluable.

Results

Two-year OS was 71% in arm A (95% CI: 55–87%) vs. 53% in arm B (95% CI: 36–71%); H₀ was rejected. Median OS was 49.1 vs. 24.1 months (p = 0.147). Hazard ratio (HR) for death was 0.60 (95% CI: 0.30–1.21). At 2 years, PFS was 56% vs. 44%, LC 84% vs. 72%, and MFS 74% vs. 54%. HRs were 0.51 (0.25–1.04) for progression, 0.43 (0.13–1.40) for locoregional failure, and 0.43 (0.17–1.05) for distant metastasis. Overall response was 81% vs. 69% (p = 0.262). Twenty-six and 27 patients, respectively, experienced at least one toxicity grade ≥3 (p = 0.573). A significant difference was found for grade ≥3 allergic reactions (12.5% vs. 0%, p = 0.044).

Conclusion

Given the limitations of this trial, radiochemotherapy plus cetuximab was feasible. There was a trend towards improved PFS and MFS. Larger studies are required to better define the role of cetuximab for unresectable esophageal cancer.

Neoadjuvant and Definitive Radiochemotherapeutic Approaches in Esophageal Cancer: A Retrospective Evaluation of 122 Cases in Daily Clinical Routine

INTRODUCTION

Esophageal cancer (EC) is a common malignant tumor entity with increasing occurrence. The incidence of esophageal adenocarcinoma (AC), particularly, is constantly rising in the Western world. The mainstays of therapy with curative intent for EC in advanced stages are neoadjuvant radiochemotherapy (neoRCT) with surgery and definitive radiochemotherapy (defRCT).

METHODS

We examined our internal files to identify patients suffering from EC. Palliative cases were excluded. Statistical testing was performed by χ2 test, Student's t test, Kaplan-Meier analyses, and the Mann-Whitney U test.

RESULTS

One hundred and twenty-two cases were included. Histology revealed squamous cell carcinoma in 92 cases and AC in 23 cases. Ninety-five patients underwent defRCT, 27 underwent neoRCT, and 114 (in both therapy regimes) received simultaneous chemotherapy. There was no difference in the overall survival (OS) (p = 0.654; HR 1.145; 95% CI 0.629-2.086) or and progression-free survival (PFS) (p = 0.912) of patients who underwent neoRCT or defRCT. Median OS was 13.5 (2-197) months for defRCT patients and 19.5 (2-134) months for neoRCT patients (p = 0.751). Karnofsky index (KI) with a cut-off of 70% was strongest, but not a significant parameter for OS (p = 0.608) or PFS (p = 0.137).

CONCLUSION

defRCT is a valid and an equal alternative to neoRCT for patients suffering from EC. Selection of patients for therapy is of crucial relevance. Further studies and improvements in follow-up are needed when neoRCT has been completed before surgery, in order to spare the patient undergoing operative treatment if there is complete remission. The identification of valid markers urgently needed to limit treatment side effects.