Factors associated with survival in patients with oesophageal cancer who achieve pathological complete response after chemoradiotherapy: a nationwide population-based study

OBJECTIVES: Few data are currently available on the factors associated with survival in oesophageal cancer patients who achieve pathological complete response (pCR) after chemoradiotherapy (CRT). Using a nationwide database, we investigated the predictors of survival in this patient group. METHODS: Data were retrieved from the Taiwan Cancer Registry to identify patients with oesophageal squamous cell carcinoma (OSCC) who achieved pCR after CRT followed by oesophagectomy between 2008 and 2013. The median number of dissected nodes (20) was used as the cut-off to classify the extent of lymph node dissection (LND). Tumour location was defined according to the seventh edition of the American Joint Committee on Cancer staging system. Cox proportional hazard regression analyses were used to identify factors associated with survival. RESULTS: Of the 1103 patients who underwent CRT followed by surgery, 319 (28.9%) achieved pCR. Thirty- and 90-day mortality rates were 3.5 and 4.7%, respectively. The 3-year overall survival rate was 55.9%. Multivariate Cox survival analysis identified age ≥55 years [hazard ratio (HR): 1.72, 95% confidence interval (CI): 1.07 to 2.78, P = 0.025], an LND number of <20 (HR: 1.62, 95% CI: 1.01 to 2.61, P = 0.047) and lesions located in the upper third (HR: 2.35, 95% CI: 1.18 to 4.65, P = 0.015) as adverse prognostic factors for survival in pCR patients. CONCLUSIONS: Patient age ≥55 years, upper third lesions and an LND number of <20 are adverse prognostic factors in OSCC patients who achieve pCR following CRT. High-risk patients should be strictly followed.