Additional chemoradiotherapy for superficial esophageal squamous cell carcinoma after near-circumferential or full-circumferential noncurative endoscopic submucosal dissection: a retrospective study.

BACKGROUND: Endoscopic submucosal dissection (ESD) is a potentially efficient therapeutic intervention for superficial esophageal cancer. Additional treatment such as chemoradiotherapy (CRT) or esophagectomy is recommended in cases of muscularis mucosa invasion with positive resection margins or lymphovascular invasion or submucosal layer invasion, which are considered noncurative ESD, due to an increased risk of lymph node metastasis. However, the adequacy of additional CRT after near-circumferential or full-circumferential noncurative ESD has not been fully discussed. In this study, we retrospectively evaluated the efficacy and toxicity of additional CRT for superficial esophageal squamous cell carcinoma (SCC) after near-circumferential or full-circumferential noncurative ESD, which was defined as a mucosal defect measuring ≥ 3/4 of the esophageal circumference. METHODS: We retrospectively evaluated 24 patients who received additional CRT for superficial esophageal SCC after near-circumferential or full-circumferential noncurative ESD between 2012 and 2018. Elective nodal irradiation (ENI) was performed in all patients and boost irradiation (BI) was performed after ENI in 4 patients with positive resection margins. The prescription doses of ENI and BI were 41.4 Gy in 23 fractions and 9 Gy in 5 fractions, respectively. Concurrent chemotherapy (a combination of cisplatin or nedaplatin and 5-fluorouracil) was administered to all patients. RESULTS: The 3-year and 5-year overall survival rates were 92% and 78%, respectively, while the 3-year and 5-year progression-free survival rates were 83% and 70%, respectively. Grade 2 esophageal stenosis occurred in 8 (33%) patients. There was no case of Grade 3 or worse esophageal stenosis. Among them, 4 (17%) patients developed stenosis before additional CRT, which persisted after the completion of additional CRT. The remaining 4 (17%) patients developed de novo stenosis within 5 months following the completion of additional CRT. One patient (4%) still requires regular bougie dilation. Grade 3 and Grade 4 acute toxicity, including anemia, neutropenia, thrombocytopenia, and esophagitis occurred in 1 (4%) and 0 (0%), 6 (25%) and 1 (4%), 1 (4%) and 0 (0%), and 1 (4%) and 0 (0%) patients, respectively. One (4%) patient who underwent salvage CRT for the out-of-field lymph node recurrence died with acute myeloid leukemia. CONCLUSIONS: Additional CRT is a viable treatment option even in patients who have undergone near-circumferential or full-circumferential noncurative ESD. Esophageal stenosis after additional CRT following near-circumferential or full-circumferential noncurative ESD is manageable and acceptable.

Clinical Outcomes of Definitive Chemoradiotherapy for Cervical Esophageal Cancer.

BACKGROUND/AIM: To investigate the clinical outcomes of concurrent chemoradiotherapy (CCRT) in patients with cervical esophageal carcinoma and analyze the prognostic factors. PATIENTS AND METHODS: Thirty-nine patients with cervical esophageal carcinoma were retrospectively identified among consecutive patients who received CCRT between November 2009 and September 2019 at our institution. The patients were treated by intensity-modulated radiation therapy (N=13) or three-dimensional conformal radiotherapy (N=26). RESULTS: The median follow-up period was 35 months (range=2-158 months). There were 32 men and 7 women with a median age of 66 years (range=50-83 years). Clinical stages were I in 6 patients, II in 4, III in 19, and IV in 10. Hypopharyngeal invasion was noted in 8 patients. The initial treatment responses were evaluated 3-6 weeks after the final session of CCRT: a complete response (CR) in 24 patients, a partial response (PR) in 13, and stable disease (SD) in 2. Two- and 5-year overall survival (OS) rates were 73.8 and 59.4%, respectively. Two- and 5-year progression-free survival (PFS) rates were 57.8 and 48.0%, respectively. A univariate analysis identified the initial treatment response (CR or non-CR) as a significant factor for OS (p=0.0002) and PFS (p=0.0026). The CR rate was 81.0% in patients with T1-3 and 33.3% in those with T4 (p=0.0038). CONCLUSION: Patients with cervical esophageal carcinoma in Nagasaki University Hospital in Japan achieved superior outcomes compared with previous studies. CR rate was higher in patients with T1-3 and correlated with better OS.

Zinc-induced modulation of SRSF6 activity alters Bim splicing to promote generation of the most potent apoptotic isoform BimS.

Bim is a member of the pro-apoptotic BH3-only Bcl-2 family of proteins. Bim gene undergoes alternative splicing to produce three predominant splicing variants (BimEL, BimL and BimS). The smallest variant BimS is the most potent inducer of apoptosis. Zinc (Zn(2+)) has been reported to stimulate apoptosis in various cell types. In this study, we examined whether Zn(2+) affects the expression of Bim in human neuroblastoma SH-SY5Y cells. Zn(2+) triggered alterations in Bim splicing and induced preferential generation of BimS, but not BimEL and BimL, in a dose- and time-dependent manner. Other metals (cadmium, cobalt and copper) and stresses (oxidative, endoplasmic reticulum and genotoxic stresses) had little or no effect on the expression of BimS. To address the mechanism of Zn(2+)-induced preferential generation of BimS, which lacks exon 4, we developed a Bim mini-gene construct. Deletion analysis using the Bim mini-gene revealed that predicted binding sites of the SR protein SRSF6, also known as SRp55, are located in the intronic region adjacent to exon 4. We also found that mutations in the predicted SRSF6-binding sites abolished generation of BimS mRNA from the mutated Bim mini-gene. In addition, a UV cross-linking assay followed by Western blotting showed that SRSF6 directly bound to the predicted binding site and Zn(2+) suppressed this binding. Moreover, Zn(2+) stimulated SRSF6 hyper-phosphorylation. TG003, a cdc2-like kinase inhibitor, partially prevented Zn(2+)-induced generation of BimS and SRSF6 hyper-phosphorylation. Taken together, our findings suggest that Zn(2+) inhibits the activity of SRSF6 and promotes elimination of exon 4, leading to preferential generation of BimS.