Effect of neoadjuvant radiation dose on outcome in locally advanced oesophageal cancer

Introduction : Neoadjuvant multimodality treatment confers a survival benefit in locally advanced oesophageal cancer patients. The optimal dose of radiotherapy (RT) remains undefined. Aim : To analyse the effect of RT dose on surgical outcome and survival in patients treated with multimodality treatment followed by surgery in locally advanced oesophageal cancer. Methods : This was a retrospective comparative study based on a prospectively collected database. Patients with clinical stage III oesophageal cancer were treated with a combination of RT, cisplatin 80 mg/m2, and 5-FU 800 mg/m2. Radiation dose was 36 Gy (group 1) or 45-50 Gy (group 2), depending on the referring physician. Ivor Lewis oesophagectomy was performed after a 6-8 weeks period. Surgical and pathological outcome was compared using Fisher exact test. Overall survival (OS) and disease free survival (DFS) were calculated using the Kaplan Meier method, and the effect of RT dose on survival was tested using univariate (log rank test) analysis. Results : A total of 134 patients were evaluated : 108 received 36 Gy, and 26 received 45-50 Gy. Mean age at surgery was 61 ± 9.43 years, and 84% were male. Median length of postoperative hospital stay was 17 days. Overall postoperative 30 day or in hospital mortality was 7.5%, and anastomotic leakage occurred in 4.1% ; neither was influenced by RT dose. Pathological complete response (pCR) was observed in 15.5% (group 1) and 31% (group 2), P = 0.09. No differences were observed in downstaging of either the T stage or the N stage. Overall five year OS and DFS were 35.1% and 38.3% respectively. In univariate analysis, a higher RT dose was associated with a significantly better DFS (P = 0.01), but not OS (P = 0.6). Conclusion : In patients with locally advanced oesophageal cancer treated with neoadjuvant chemoradiation, a higher RT dose does not affect surgical outcome, enhances pCR rate and improves DFS without affecting OS