Tumor‐infiltrating CD8 + T cell is prognostic and predicts adjuvant chemotherapy benefit in patients with limited‐stage small cell esophageal carcinoma

摘要

The current study conducted the first exploration of biomarkers for prediction of adjuvant chemotherapy (aCT) benefit in patients with small cell esophageal carcinoma (SCEC). SCEC is a rather rare and aggressive malignant neuroendocrine gastrointestinal tumor. Unlike other two major pathological subtypes of esophageal carcinoma (EC)—esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC)—SCEC only accounts for ?1.5% of the different subtypes of ECs.1 Southeast Asian countries have the highest incidence rates of SCEC worldwide, especially in China/ Its prognosis is dismal, with a median survival of 8-21 months owing to its high recurrence, rapid progression, and widespread metastases.1 Additionally, due to its extreme rarity, there is no standard therapy. The current combination of surgery and aCT— adopted from well-established therapeutic strategies for small cell lung cancer (SCLC)—is the most common treatments for patients with limited-stage SCECs. This treatment was designed considering the histological and clin-ical similarity of SCECs and SCLCs.2 Despite initially high response rates, patients, outcomes have been heterogeneous and many patients fail to benefit from this therapy while enduring its unnecessary side effects.2 Therefore, more precise and clinically feasible classification strategies are urgently needed to identify aCT responders.