Surgical pathology findings of neoadjuvant full-dose irinotecan and cisplatin (IP) with concurrent thoracic radiation therapy (C-TRT) in stage III non-small cell lung cancer (NSCLC).

Abstract

e17550 Background: Neoadjuvant C-TRT in stage IIIA NSCLC has become a standard of care. C-TRT sterilizes N2 nodes far better than primary tumors. TRT dose does seem to make a difference. In Intergroup 0139 with 45 Gy pre-op TRT, ypT0N0 was 18% and ypN0 46% (Albain et al Lancet 2009). Pre-op TRT dose escalation to 60+ Gy improves ypN0 clearance up to 80% and ypT0N0 to 45% (Sonett et al Ann Thorac Surg 2004; Cerfolio et al Ann Thorac Surg 2005). However there is no known difference in pathologic response and outcome with different chemotherapy approaches. Irinotecan with radiation therapy has been studied in locally advanced NSCLC with similar outcomes as with any cisplatin doublet and no undue toxicities (Langer et al J Thorac Oncol 2007; Bastos et al J Thorac Oncol 2010). We reviewed our multidisciplinary thoracic oncology program experience with neoadjuvant full-dosing IP and C-TRT in stage IIIA NSCLC assessing ypTN response. Methods: All patients with stage IIIA NSCLC undergoing pre-operative IP and C-TRT between September 2008 and December 2011 were searched through our program database and included. 14 patients were identified. Irinotecan 65mg/m2 and cisplatin 30mg/m2 D1 and D8 q 21 days with C-TRT 60-66 Gy was administered followed by surgical resections. Pathologic response (ypT0N0) was assessed. Results: Median age 61 (36-72). 85% males; 85% squamous. PET N2 positive in 85% with 2 patients T3N1. 6/14 (43%) pathologic complete response (pCR)/ypT0N0; plus 4 with < 10% primary tumor viability (one isolated tumor cells on IHC staining, two with just 3 mm residual islands); 70% of patients had a pCR or had < 10% primary tumor viability. 11/12 (91%) downstaged PET N2 to ypN0. Conclusions: Full dose IP with C-TRT 60+ Gy is a very effective neoadjuvant treatment with very high pathologic complete responses and N2 clearance in squamous cell lung cancers. Just as in stage IV NSCLC, histology-based chemotherapy in stage IIIA/IIIB NSCLC C-TRT could well achieve outcome differences.