SCALOP: Results of a randomized phase II study of induction chemotherapy followed by gemcitabine (G) or capecitabine (Cap) based chemoradiation (CRT) in locally advanced pancreatic cancer (LANPC).

Abstract

LBA146 Background: CRT with G or 5FU (F) is used to treat LAPC. No multicenter, randomized studies have compared G-CRT vs. F-CRT or the oral fluropyrimidine, Cap-CRT. In the UK, where chemotherapy is traditionally standard of care for LAPC, a trial was conducted to assess the safety, efficacy, and deliverability of G-CRT and Cap-CRT. Methods: Eligibility: histologically proven inoperable LAPC < 7 cm in diameter. Induction chemotherapy: 3 cycles of GEMCAP (G 1,000 mg/m2 days 1, 8, 15; Cap 830 mg/m2 days 1-21 q28 days). Patients with stable/responding disease, tumor diameter ≤ 6cm, and PS 0-1 were eligible for CRT randomisation where patients received a further cycle of GEMCAP followed by either Cap (830 mg/m2 bd weekdays only) or G (300 mg/m2 weekly) with radiation (50.4 Gy/28 fractions). Treatment volume = tumour plus enlarged nodes and margins of 2 cm sup-inf and 1.5 cm radially. Prospective RT quality assurance was mandated. Primary end-point was 9-month PFS (Fleming’s design). Funder: Cancer Research UK (CR UK 07/040). Results: Between July 2009 and October 2011, 114 patients from 28 UK centres were registered of whom 74 patients were randomised. Randomised patient characteristics: median age 64.6; 55.4% male; WHO PS (0:1) 41.9%:58.1%; median tumor diameter 4cm; site (head:body) 85.1%:14.9%. During CRT, more patients in the G arm experienced grade 3/4 haematological (18.4% vs 0%, p=0.007) and non-haematological (26.3% vs 11.1%, p=0.095) toxicity. Both C and G arms passed the primary endpoint with 9-month PFS of 62.9% (80% CIs: 50.6%-73.9%) and 51.4% (80% CIs: 39.4%-63.4%) respectively. OS was significantly superior in the Cap-CRT arm (median OS 15.2 vs 13.4 months, HR=0.50, log rank p=0.025). Conclusions: SCALOP is the largest RCT comparing radio-sensitizers in pancreatic cancer and demonstrates that both G-CRT and Cap-CRT can be delivered safely and effectively. Both regimens met the pre-specified PFS criteria. Compared to G-CRT, Cap-CRT demonstrated significantly better survival and toxicity and should form the template regimen for future trials investigating RT dose escalation and combination with novel radio-sensitizers. Clinical trial information: NCT01032057.