As always, the recent 2011 Gastrointestinal Cancers Symposium in San Francisco offered more research news than any one publication could present. The following are capsule summaries of some of the most interesting findings.

Postsurgical 'Wait Time'

The time interval between surgery and adjuvant chemotherapy for colorectal cancer does matter, according to a meta-analysis performed at Queen's University Cancer Research Institute in Canada (abstract 364). Based on a meta-analysis of nine studies involving 14,357 patients, for every 4 weeks of postsurgical "wait time," mortality risk was increased by more than 12%. "This means that for a patient fit to initiate chemotherapy 4 weeks after surgery, if he is treated instead at 8 weeks he has a 12% increased mortality risk, which becomes a 25% increased risk if he is treated at 12 weeks," said Jim Biagi, MD.

HGF and IGF-IR Pathway Inhibitors

Promising efficacy was shown by a hepatocyte growth factor (HGF) inhibitor when combined with panitumumab (Vectibix) in patients with metastatic colorectal cancer in an international randomized phase I/II trial (abstract 366). The study in 142 patients evaluated the HGF inhibitor rilotumumab (AMG 102) as well as an antagonist of insulin growth factor type 1 receptor (IGF-1R) ganitumumab (AMG 479). The HGF and IGF-1R pathways are thought to be interdependent of the epidermal growth factor receptor pathway. Thus, there is a rationale for combining them with panitumumab, explained Eric Van Cutsem, MD, of University Hospital Gasthuisberg, Leuven, Belgium. The rilotumumab/panitumumab combination was promising, as responses were observed in 31% of that arm, compared with 22% receiving panitumumab plus ganitumuab and 21% receiving only panitumumab. Median progression-free survival was 5.2 months with rilotumumab/panitumumab, 5.3 months with the ganitumumab combination, and 3.7 months with panitumumab alone.

Neoadjuvant Regimen for Pancreatic Cancer

Neoadjuvant therapy with full-dose gemcitabine, oxaliplatin, and radiation proved feasible and safe in a phase II multi-institutional study of 68 patients with localized pancreatic cancer whose tumors were resectable (n = 24) or borderline resectable (n = 44) (abstract 239). "This neoadjuvant regimen achieved a high percentage of R0 resections in both groups," reported Edward J. Kim, MD, PhD, of the University of Michigan. Patients were treated with two 28-day cycles of gemcitabine (1 g/m² over 30 min on days 1, 8, 15) and oxaliplatin (85 mg/m² on days 1, 15) with radiotherapy during cycle 1 (30 Gy in 2-Gy fractions). After treatment, in those undergoing tumor removal, 82% of patients achieved R0 resections and 18% achieved R1. The 1-year disease-free survival rate was 41%. Median overall survival was 31 months for resectable patients and 21 months for borderline resectable patients. "In borderline resectable patients, intensification of radiation may further increase R0 resection rates," he added.

Lanreotide for Vomiting

The somatostatin analog lanreotide (Somatuline) reduced the frequency of vomiting in 80 patients with malignant small bowel obstruction, in a multicenter French study ( abstract 242). "We showed that lanreotide may reduce the frequency of vomiting and allow the removal of nasogastric tubes, which makes hospital discharge possible," said Pascale Mariani, MD, of the Institut Curie in Paris. The study compared lanreotide microparticles (30 mg) to placebo in patients experiencing at least two vomiting episodes a day or with nasogastric tubes. In the per-protocol analysis (patients received at least one assigned treatment), responses (≤ 1 vomiting episode per day for 3 consecutive days or no recurrence of vomiting after nasogastric tube removal for 3 consecutive days) were observed in 57.7% of patients receiving lanreotide vs 30.4% of those receiving placebo, for an odds ratio of 3.599 favoring lanreotide (P = .0455). Vomiting frequency was reduced by 2.3 episodes by day 7 with lanreotide and by 1.3 episodes with placebo (P = .4510). Well-being was significantly improved in the lanreotide arm, while it was diminished in the placebo arm. ■