Curative endoscopic submucosal dissection for esophageal squamous cell carcinoma after chemoradiotherapy for pharyngeal cancer: A case report.

Background: Esophageal squamous cell carcinoma (ESCC) is often managed with surgery, which is the first-line treatment option for stage I-III lesions. However, definitive chemoradiotherapy (dCRT) is associated with a recurrence rate of 30% in stage I ESCC and higher rates in advanced-staged lesions. However, several patients prefer dCRT because their general condition is poor. Salvage therapies, including esophagectomy and endoscopic resection [endoscopic submucosal dissection (ESD)/endoscopic mucosal resection], are important for residual or recurrent tumors that develop after dCRT. Esophagectomy can have curative potential. However, it has high complication and mortality rates. Therefore, ESD is a safer alternative.

Methods: A Japanese man in his 70s was concurrently diagnosed with right hypopharyngeal cancer (T2N1M0, cStage III), left oropharyngeal cancer (T1N0M0, cStage I), and left hard palate cancer (T1N0M0, cStage I). Esophagogastroduodenoscopy (EGD) revealed a 20 mm reddish 0-Is+IIb lesion in the upper thoracic esophagus, with an invasion depth of SM2. The lesion was diagnosed as an esophageal moderately differentiated squamous cell carcinoma (T1bN0M0, cStage I). As the pharyngeal cancers were in advanced stages, chemoradiotherapy (docetaxel and cisplatin with a radiation dose of 66 Gy) was prioritized. Post-chemoradiotherapy EGD showed that the lesion had flattened into a 0-IIb lesion, thereby indicating a reduced invasion depth (epithelium or lamina propria mucosa). ESD achieved en bloc and histologically confirmed curative resection. At 22 months after ESD, the patient did not present with signs of recurrence.

Conclusions: This case emphasizes that ESD can be successfully utilized as a salvage treatment for ESCC after chemoradiotherapy for otolaryngological cancers.