Neoadjuvant Chemotherapy, Excision, and Observation for Early Rectal Cancer: The Phase II NEO Trial (CCTG CO.28) Primary End Point Results.

PURPOSE: Organ-sparing therapy for early-stage I/IIA rectal cancer is intended to avoid functional disturbances or a permanent ostomy associated with total mesorectal excision (TME). The objective of this phase II trial was to determine the outcomes and organ-sparing rate of patients with early-stage rectal cancer treated with neoadjuvant chemotherapy followed by transanal excision surgery (TES). METHODS: This phase II trial included patients with clinical T1-T3abN0 low- or mid-rectal adenocarcinoma eligible for endoscopic resection who were treated with 3 months of chemotherapy (modified folinic acid-fluorouracil-oxaliplatin 6 or capecitabine-oxaliplatin). Those with evidence of response proceeded to transanal endoscopic surgery 2-6 weeks later. The primary end point was protocol-specified organ preservation rate, defined as the proportion of patients with tumor downstaging to ypT0/T1N0/X and who avoided radical surgery. RESULTS: Of 58 patients enrolled, all commenced chemotherapy and 56 proceeded to surgery. A total of 33/58 patients had tumor downstaging to ypT0/1N0/X on the surgery specimen, resulting in an intention-to-treat protocol-specified organ preservation rate of 57% (90% CI, 45 to 68). Of 23 remaining patients recommended for TME surgery on the basis of protocol requirements, 13 declined and elected to proceed directly to observation resulting in 79% (90% CI, 69 to 88) achieving organ preservation. The remaining 10/23 patients proceeded to recommended TME of whom seven had no histopathologic residual disease. The 1-year and 2-year locoregional relapse-free survival was, respectively, 98% (95% CI, 86 to 100) and 90% (95% CI, 58 to 98), and there were no distant recurrences or deaths. Minimal change in quality of life and rectal function scores was observed. CONCLUSION: Three months of induction chemotherapy may successfully downstage a significant proportion of patients with early-stage rectal cancer, allowing well-tolerated organ-preserving surgery

Adjuvant Chemoradiotherapy (Gemcitabine-based) in Pancreatic Adenocarcinoma: The Pisa University Experience

Introduction: The role of adjuvant chemoradiotherapy in patients with pancreatic adenocarcinoma (PA) is controversial. In this study we aimed to assess the feasibility, disease-free survival (DFS) and overall survival (OS) of adjuvant chemoradiotherapy (gemcitabine based) in patients with resected PA and their correlation with prognostic factors. Methods: 122 resected patients (stage â¥IIa) treated between February 1999 and December 2013 were analyzed. Two cycles of gemcitabine (1,000 mg/m2 on days 1, 8 and 15 every 28 days) were administered before concomitant radiotherapy (45 Gy/25 fractions) and chemotherapy (gemcitabine 300 mg/m2weekly). Results: Median follow-up was 22.7 months (range 4-109). Gastrointestinal toxicity (G3), neutropenia (G3-G4) and cardiac toxicity (G2-G3) were observed in 2.4%, 10.6% and 1.6% of patients, respectively. OS at 12, 24 and 60 months was 79%, 55% and 31%, respectively (median 25 months). Two-year OS in patients with postoperative Karnofsky performance status (KPS) â¤70 and â¥80 was 37.1% and 62.3%, respectively (p<0.0001). OS was better in the group of patients with a postoperative CA 19-9 level â¤100 U/mL (p = 0.014). Median DFS was 17 months. Conclusions: The combination of concomitant gemcitabine and radiotherapy in patients with radically resected PA was well tolerated and associated with a low incidence of local recurrences. Five-year OS was significantly influenced by postoperative KPS and CA 19-9 values

An unconventional pathway for reduction of CO(2) to methane in CO-grown Methanosarcina acetivorans revealed by proteomics

Methanosarcina acetivorans produces acetate, formate, and methane when cultured with CO as the growth substrate [Rother M, Metcalf WW (2004) Proc Natl Acad Sci USA 101:16929–16934], which suggests novel features of CO metabolism. Here we present a genome-wide proteomic approach to identify and quantify proteins differentially abundant in response to growth on CO versus methanol or acetate. The results indicate that oxidation of CO to CO(2) supplies electrons for reduction of CO(2) to a methyl group by steps and enzymes of the pathway for CO(2) reduction determined for other methane-producing species. However, proteomic and quantitative RT-PCR results suggest that reduction of the methyl group to methane involves novel methyltransferases and a coenzyme F(420)H(2):heterodisulfide oxidoreductase system that generates a proton gradient for ATP synthesis not previously described for pathways reducing CO(2) to methane. Biochemical assays support a role for the oxidoreductase, and transcriptional mapping identified an unusual operon structure encoding the oxidoreductase. The proteomic results further indicate that acetate is synthesized from the methyl group and CO by a reversal of initial steps in the pathway for conversion of acetate to methane that yields ATP by substrate level phosphorylation. The results indicate that M. acetivorans utilizes a pathway distinct from all known CO(2) reduction pathways for methane formation that reflects an adaptation to the marine environment. Finally, the pathway supports the basis for a recently proposed primitive CO-dependent energy-conservation cycle that drove and directed the early evolution of life on Earth