EsophaCap Sponge Cytology Screening for Esophageal Squamous Cell Dysplasia and Carcinoma is Feasible in a High-Risk Area in Western India

Abstract

Objective: Conventional endoscopy remains the gold standard for detecting esophageal squamous cell carcinoma (ESCC) despite its high cost and need for expertise. In resource-poor regions, a less labor-intensive yet accurate screening tool is needed. The purpose of this study is to assess feasibility of establishing a non-endoscopic screening program in rural India and to test the diagnostic accuracy of the EsophaCap swallowable sponge in detecting ESCC in a high-risk patient population. Methods: A prospective cohort study was conducted between 2017 and 2019, in which subjects with risk factors for ESCC (tobacco smoking or chewing, betel nut/leaf, alcohol and hot beverage consumption) were approached during upper endoscopy visits at a clinic in Western India. After obtaining EsophaCap sponge cytology samples, random endoscopic biopsies were obtained at 20 and 30 cm from the incisors. Histologic diagnoses were confirmed and select biopsy samples were sequenced for genomic aberrations. Visual Analog Scale (VAS) scores were used to assess patient experience of sponge swallowing (range 1-5, “very comfortable” to “very uncomfortable”). Results: In our cohort of 178 patients, 157 (88%) were males. Mean age was 52 ± 12 years. Sixty-eight (38%) patients were current cigarette or bidi smokers; 132 (74%) patients were daily tobacco chewers, and 83 (47%) patients chewed betel nuts/leaves on a daily basis. Forty-six (26%) patients were daily alcohol users and 151 (85%) patients drank ≥3 hot beverages per day. The median number of risk factors per patient was 3. The first-time swallow rate of the encapsulated sponge was successful in 190/200 (95%) patients. Median VAS score was 2 (“comfortable”). EsophaCap cytology revealed 6 (3%) patients with atypical squamous cells of unknown significance (ASCUS) and 3 (1%) patients with dysplasia. Based on the endoscopic biopsies, 6 (3%) patients had ESCC, 4 (2%) patients had lesions with squamous dysplasia, and 63 (35%) patients had esophageal leukoplakia. Four patients classified as ASCUS pathology via EsophaCap were normal, benign, or leukoplakia via endoscopy. EsophaCap’s sensitivity and specificity for detecting dysplasia or ESCC by histology was 30% and 97%, respectively. Conclusions: Establishing a non-endoscopic screening program in a high-risk area with language barriers and low medical literacy is very safe and feasible. EsophaCap may help identify ASCUS patients in need of serial endoscopic monitoring. Further studies of combined sponge cytology with immunohistochemistry studies are necessary to improve accuracy of ESCC screening.