BackgroundLocally advanced oesophageal cancer can be treated with definitive chemoradiation (dCRT) or with neoadjuvant chemoradiation followed by surgery (nCRT + S), but treatment modality choice is not always clear. The aim of this study was to investigate the factors associated with the choice of treatment modality in locally advanced oesophageal cancer.MethodsThis was a retrospective cohort study of 149 patients treated with dCRT(n = 85) or nCRT + S (n = 64) for oesophageal cancer in Helsinki University Hospital in 2008–2018. Logistic regression was used to analyse factors associated with choice of treatment modality and to compare dosimetric factors with postoperative complications. Multivariate analyses identified factors associated with survival.ResultsSurgery was performed after chemoradiation as planned on 64/91 patients (70%). 28/64 had pathological complete response (44%). Probability of nCRT + S was higher in stages I-III versus IV (OR 3.62, 95% CI 1.53–8.53;P= .003), ECOG 0–1 versus 2 (OR 6.99, 95% CI 1.81–26.96;P= .005) or in the middle/lower vs upper oesophageal tumours (OR 5.61, 95% CI 1.83–17.16,P= .003). Probability for surgery was lower, if patient had lost > 10% of body weight (OR 0.46, 95% CI 0.21–0.98,P= 0.043). Patients in the nCRT + S group had significantly better median overall survival (mOS) and local control than the dCRT group (60 vs. 10 months,P< .001 and 53 vs. 6 months,P< 0.0001, respectively). 10/85 (12%) patients died within three months after dCRT. In multivariate analysis, nCRT + S was associated with improved mOS (HR 0.28, 95% CI 0.17–0.44,P< .001). Current smokers had worse mOS (HR 2.02, 95% CI 1.04–3.92,P= .037) compared to never-smokers. No significant dosimetric factor associated with postoperative complications was found.ConclusionThe overall clinical status of the patients and the stage of the cancer guide the choice of treatment modalities, leading to overtreatment. Patients with better prognoses were more likely operated after chemoradiation, although there is no evidence of OS benefit in previous randomized trials. On the other hand, the prognosis was poor for patients with poor general health and advanced cancers, despite the chemoradiation. Thus, there are signs of overtreatment. MDT practice should be recommended to optimise the choice of treatment modalities. Smoking status is an independent factor associated with survival.