Effectiveness of proton beam therapy for liver oligometastatic recurrence in patients with postoperative esophagus cancer

Proton Therapy in The Treatment of Head And Neck Cancers- Review

PURPOSE OF REVIEW

Head and neck cancers rank as the seventh most common cancer worldwide, nearly half of which result in death. The most common treatment methods for head and neck cancers include radiotherapy and surgery. Proton therapy has emerged in radiotherapy for cases where tumors are located near anatomically sensitive areas where the radiation dose must be strictly limited. The purpose of the work is to discuss the role of the proton therapy in the treatment in various types of cancer, and particularly head and neck tumors.

RECENT FINDINGS

Proton therapy allows for the delivery of radiation doses to critical organs to be reduced, resulting in a decrease in the occurrence of late adverse effects on these organs. The occurrence of side effects caused by proton therapy depends on the relative and absolute volume of organs at risk receiving specific radiation doses. Proton therapy represents a promising alternative to conventional radiotherapy due to the reduced number of complications in healthy tissues by delivering a lower radiation dose outside the tumor area.

Prognosis for local radical treatment in patients with esophageal squamous cell carcinoma with low-risk oligometastatic recurrence after curative resection: a retrospective cohort study

Background

Patients with esophageal carcinoma (EC) with recurrent disease have a poor prognosis. A limited numbers of metastases, safely treatable with curative intent, diagnosed after curative esophagectomy may be defined as oligometastatic recurrence (OLR). However, the appropriate number of metastases and metastatic organs involved remains incompletely characterized. And the role of local therapy in OLR after radical esophagectomy remains unknown. Therefore, this study aimed to more accurately define low-risk OLR in patients with esophageal squamous cell carcinoma (ESCC) treated with radical resection and investigate the role of chemotherapy combined with local treatment (CCLT) in these patients.

Methods

A total of 83 sequential patients with ESCC who underwent radical esophagectomy, with an Eastern Cooperative Oncology Group (ECOG) performance status ≤2, with ability to tolerate chemotherapy (CT) and local treatment, and with newly diagnosed recurrence between January 2010 and May 2019 in our hospital were recruited. Overall survival (OS) curves after recurrence were analyzed using the Kaplan-Meier method, and a log-rank test was used to assess the OS differences. Cox proportional hazards regression analysis was performed to identify independent factors associated with 2-year OS. Regular follow-up examinations were assessed by thoracic and upper abdominal computed tomography (CT) scanning every 3 months in the first year, every 6 months over the next 2 years, and yearly thereafter.

Results

Of the 83 patients with ESCC (71 males and 12 females), the median age was 56 years (range, 37-79 years). Thirty-five patients with ESCC with ≤5 metastases safely treatable with curative intent located in a single organ had a favorable OS compared to 48 patients with metastases located in 2-3 organs with or without regional recurrence and/or regional lymph node (LN) metastases. In our study, low-risk OLR was defined as the presence of ≤5 metastases safely treatable with curative intent in a single organ and was compared to patients with 2-3 organs involved. The 2-year OS of patients with low-risk OLR with liver oligometastases was significantly worse than survival in patients with lung oligometastases (0% vs. 61.1%, P=0.009). Patients with ESCC in the low-risk OLR group treated with CCLT had a better 2-year OS after recurrence than those who received CT alone (66.7% vs. 30.4%, P=0.003). The multivariable Cox regression model identified treatment method [hazard ratio (HR) 3.920, P=0.02] as an independent factor affecting OS after recurrence for low-risk OLR.

Conclusions

Low-risk OLR was defined as ≤5 metastases safely treatable with curative intent in a single organ. Patients with ESCC with low-risk OLR after curative resection treated with CCLT have a favorable OS compared to those treated with CT alone. CCLT is a promising treatment option for patients with ESCC and low-risk OLR.

Proton Beam Therapy for Lung Oligometastatic Recurrence in Patients With Esophageal Cancer

Local treatment of oligometastatic esophagogastric cancer has been reported to improve overall survival (OS) compared to systemic therapy alone. This study evaluated the feasibility and safety of proton beam therapy (PBT) for the treatment of lung oligometastatic recurrence in esophageal cancer patients. This single-center historical cohort study enrolled 11 patients who underwent PBT for lung oligometastasis from esophageal cancer between 2010 and 2019. The selection criteria were that the primary esophageal cancer was controlled and no more than three lung metastases without outside lung tumors were present. OS, progression-free survival (PFS), and local control (LC) rates and adverse events (AEs) were assessed. Factors that may be related to OS were also investigated. The median follow-up period was 27.8 months (8.8-141.3 months). The one-, two-, and three-year OS rates were 81.8%, 72.7%, and 51.9%, respectively (median OS time: 43.7 months); PFS rates were 45.5%, 27.3%, and 27.3%, respectively (median PFS time: 8.8 months); and LC rates were 92.3%, 72.7%, and 72.7%, respectively. The eighth edition of tumor-node-metastasis (TNM) classification for esophageal cancer was the only significant OS-related factor (p = 0.0309). No grade ≥ 3 AEs were observed. Based on the low incidence of AEs and acceptable LC rate, PBT is a feasible option for the treatment of lung oligometastasis in esophageal cancer patients.

The Japanese nationwide cohort data of proton beam therapy for liver oligometastasis in esophagogastric cancer patients

A nationwide multicenter cohort study on particle therapy was launched by the Japanese Society for Radiation Oncology in Japan in May 2016. We analyzed the outcome of proton beam therapy (PBT) for liver oligometastasis of esophagogastric cancers. Cases in which PBT was performed at all PBT facilities in Japan between May 2016 and February 2019 were enrolled. The patients were selected based on the following criteria: controlled primary cancer, liver recurrence without extrahepatic tumors and no more than three liver lesions. Twenty-two males and two females with a median age of 69 (range, 52-80) years and 35 lesions were included. This study included 6 patients with esophageal and 18 patients with gastric cancer. The median lesion size, fraction size and biological effective dose (BED)10 were 32 (7-104) mm, 3.8 gray (relative biological effect)/fractions (Gy (RBE)/fr) (2-8 Gy (RBE)/fr) and 96.9 (88.8-115.2) Gy, respectively. The median follow-up period was 18 (4-47) months. The 1-, 2- and 3-year overall survival (OS) rates were 75, 51.8 and 45.3%, respectively, and the median OS was 25.3 months. The 1-, 2- and 3-year cumulative local recurrence (LR) rates were 3, 6 and 6%, respectively. Patients' age (P < 0.01), performance status (P = 0.017) and tumor size (P = 0.024) were significant OS-related factors. No Grade 3 or higher adverse events (AEs) were observed. Owing to the low incidence of AEs and the low LR cumulative incidence, PBT is a feasible option for liver oligometastasis of esophagogastric cancers.