Randomized phase II trial comparing tumor bed alone with tumor bed and elective nodal postoperative radiotherapy in patients with locoregionally advanced thoracic esophageal squamous cell carcinoma

Effect of Adjuvant Radiation Dose on Survival in Patients with Esophageal Squamous Cell Carcinoma

Background: For patients with esophageal squamous cell carcinoma (ESCC) treated with surgery alone, the incidence of local-regional recurrence remains unfavorable. Postoperative radiotherapy (PORT) has been associated with increased local-regional recurrence-free survival (LRFS), although its application is limited by concerns of PORT-related toxicities. Methods: Among 3591 patients with ESCC analyzed in this study, 2765 patients with T3-4N0 and T1-4N1-3 lesions and specific local-regional status information were analyzed in a subsequent analysis of adjuvant radiation dose (aRTD) effect. Application of the restricted cubic spline regression model revealed a non-linear relationship between aRTD and survival/radiotoxicity. Linear regression analysis (LRA) was performed to evaluate correlations between LRFS and overall survival (OS)/ disease-free survival (DFS). Results: For patients staged T1−2N0, T1−2N1−3, T3−4N0, and T3−4N1−3, 5-year OS in PORT and non-PORT groups were 77.38% vs. 72.91%, p = 0.919, 52.35% vs. 46.60%, p = 0.032, 73.41% vs. 61.19%, p = 0.005 and 38.30% vs. 25.97%, p < 0.001. With aRTD escalation, hazard ratios (HRs) of OS/DFS declined until aRTD exceeded 50Gy, then increased, whereas that of LRFS declined until aRTD exceeded 50 Gy, then remained steady. HR of treatment-related mortality was stable until aRTD exceeded 50 Gy, then increased. LRA revealed strong correlations between LRFS and OS/DFS (r = 0.984 and r = 0.952, respectively). An absolute 1% advancement in LRFS resulted in 0.32% and 0.34% improvements in OS and DFS. Conclusions: An aRTD of 50Gy was well-tolerated, with favorable survival resulting from PORT-related LRFS improvement in patients staged T3−4N0 or T1-4N1−3. Further stratification analyses based on tumor burden would help determine potential PORT-beneficiaries.

Preliminary evaluation of postoperative radiotherapy with small T-shaped field in thoracic esophageal squamous cell carcinoma

Background

The optimal extent of clinical target volume (CTV) for postoperative radiotherapy in complete resection thoracic esophageal squamous cell carcinoma (ESCC) patients remains controversial. This study aimed to evaluate the primary outcome of postoperative radiotherapy with small T-shaped field encompassing the tumor bed, positive lymph node areas, bilateral supraclavicular areas, and upper and middle mediastinal areas.

Methods

A total of 96 thoracic ESCC patients were enrolled, with 49 and 47 cases in the small T-shaped field group and tumor bed field group, respectively. All of the patients received intensity-modulated radiotherapy (IMRT), and chemotherapy was administrated concurrently or sequentially. The median time of follow-up was 25 (range, 7-47) months.

Results

At the end of the follow-up period, in the small T-shaped field group, 8 (16.3%) patients had locoregional recurrence (LRR) and 12 (24.5%) had distant metastasis (DM), while in the tumor bed field group, 15 (31.9%) patients had LRR and 11 (23.4%) had DM. Although the rates of LRR and DM were not statistically different, LRR incidence in the mediastinal lymph nodes of the small T-shaped field group was strikingly lower than that of the tumor bed field group. The overall survival (OS) of the small T-shaped field group was higher than that of the tumor bed field group, but the difference was not statistically significance. In addition, we observed grade 2 radiation pneumonitis and grade 2 radiation esophagitis in both groups; all of these side effects were tolerable and controllable, and none of the patients experienced ≥ grade 3 pneumonitis, esophagitis, esophageal stricture, or life-threatening hemorrhage.

Conclusions

In conclusion, radiotherapy with small T-shaped field might be a feasible and efficacious postoperative approach for ESCC patients.

Difference in failure patterns of pT3-4N0-3M0 esophageal cancer treated by surgery vs surgery plus radiotherapy

BACKGROUND

There has been no study comparing the difference in the failure patterns between patients with or without postoperative radiotherapy (PORT) after esophagectomy for pT3-4N0-3M0 esophageal squamous cell carcinoma (ESCC).

AIM

To investigate the difference in the failure patterns of stage pT3-4N0-3M0 ESCC patients with or without PORT.

METHODS

Patients with stage pT3-4N0-3M0 ESCC, who underwent surgery with or without PORT, were enrolled in this study. The primary endpoint was to investigate the difference in the failure patterns between patients with or without PORT after esophagectomy. The secondary endpoint was to estimate whether patients with stage pT3-4 ESCC could achieve a disease-free survival (DFS) advantage after receiving adjuvant PORT. Statistical analyses were performed by the Kaplan-Meier method, Cox regression model, and Chi-squared test or Fisher’s exact test.

RESULTS

In total, 230 patients with stage pT3-4N0-3M0 ESCC were included in this study. Fifty-six patients who received PORT were screened from a prospective cohort (S + R arm). And 174 patients involving surgery alone were retrospectively selected from July 2006 to October 2014 (S arm). There were no significant differences in the clinical or pathological characteristics of patients between the two arms, except for tumor location (P = 0.031). The failure patterns between the two arms were significantly different (P < 0.001). Patients in the S arm had a significantly higher proportion of locoregional recurrence and a lower proportion of distant metastasis than those in the S + R arm (92.0% vs 35.7%, P < 0.001 and 19.0% vs 75.0%, P < 0.001, respectively). The difference in the median DFS between the two arms was statistically significant (12.7 vs 8 mo, P = 0.048). Univariate analysis and multivariate analysis both demonstrated that the number of lymph node metastases ≥ 3 (HR = 0.572, 95%CI: 0.430-0.762, P < 0.001) was an independent poor prognostic factor for DFS in patients with stage pT3-4N0-3M0 ESCC.

CONCLUSION

PORT could improve DFS and local control of patients with stage pT3-4N0-3M0 ESCC. However, further studies need to be conducted to control hematogenous metastasis after PORT.