Consolidation chemoradiation improves survival in responders to first-line chemotherapy (CT) in locally advanced GBC (LA-GBC).

97 Background: CT is the standard of care in advanced GBC [LA-GBC and metastatic GBC (M-GBC)]. The survival rates with CT are better in LA-GBC than M-GBC. Should responders to CT with good performance status (PS) be offered consolidation chemo-radiation (cCTRT) to delay progression and improve survival? There is scarcity of literature on this approach in the literature. We present our experience with this approach in LA-GBC which presents in endemic proportions in this region. Methods: We reviewed the records of consecutive GBC patients over 3 year period (2014-2016) after ethics approval. Out of 550 patients, 145 were LA-GBC who were treated with radical intent. Patients with good PS and responders to CT (partial and stable disease) but unresectable, were treated with cCTRT. Radiotherapy was given to GB bed, peri-portal, common hepatic, coeliac, superior mesentric and para aortic lymph-nodes (upto L2 vertebra) upto a dose of 45-54 Gy in 25 to 28 fractions along with concurrent capecitabine @ 1250 mg/m2. Response to treatment was categorised according to RECIST criteria based on CECT abdomen. Treatment toxicity, OS and factors affecting OS were computed by Cox-Regression analysis. Results: Burden of disease was [T3 (55%), T4 (45%), N1 (30%), N2 (70%)]. 65% patients underwent CT alone and 35% received CT followed by cCTRT. 10 patients underwent Radical Surgery ( 6 after CT and 3 after cCTRT). The incidence of grade 2 toxicity were: gastritis (10%) and diarrhoea (5%). 65% patients achieved partial response (PR), 12% static disease (SD), 10% progressive disease (PD) and 13% were non-evaluable (NE) [ did not complete 6 cycles CT or lost to follow-up]. At a median follow-up of 8 months (IQR 5-15 months), the median OS was 9 months for all, 7 months with CT and 14 months with cCTRT arm (p=0.04).The median OS was 57 months for CR, 12 months for PR and SD, 7 months for PD and 5 months for NE (p=0.008). OS was 10 months for KPS >80 and 5 months for KPS <80 (p=0.008). Type of treatment and response to treatment were retained as independent prognostic factors affecting OS. Conclusions: CT followed by cCTRT doubles survival in responders with good PS. This innovative approach should be tested in a randomised study.