A phase II study of isoflavones, erlotinib, and gemcitabine in advanced pancreatic cancer

Background: The EGFR/Akt/NF-kappa B signalling pathway is frequently deregulated in pancreatic cancer and contributes to cell growth, metastasis and chemoresistance. An isoflavone, genistein, inactivates Akt and NF-kappa B and enhances the anti-tumor activity of erlotinib and gemcitabine in experimental systems of pancreas cancer. This phase II study was undertaken to determine the effects of adding isoflavone to a regimen of gemcitabine and erlotinib on survival in patients with advanced pancreatic cancer. Methods: Eligibility included previously untreated patients with advanced pancreatic adenocarcinoma. Patients received gemcitabine 1,000 mg/m(2) on days 1, 8, and 15, and erlotinib 150 mg once daily P.O. on day 1 to day 28. Soy isoflavones (NovasoyA (R)) were administered at a dose of 531 mg twice daily P.O. starting day -7 until the end of study participation. Results: Twenty patients with advanced pancreas cancer were enrolled (median age 57.9 years). Sixteen patients had stage IV disease. The median number of cycles was 2 per patient. The median survival time was 5.2 months (95% CI, 4.6-N/A months). The probability of survival at 6 months was 50% (95% CI, 32-78%). Conclusions: The addition of soy isoflavones to gemcitabine and erlotinib did not appear to increase the survival of patients with advanced pancreatic cancer.