A case report of trastuzumab dose in gastric cancer
1Department of Medicine and Center for Advanced Digestive Care, New York-Presbyterian Hospital, Weill Cornell Medical Center, New York, NY 10021, USA.
Introduction:
Trastuzumab (Herceptin®, F. Hoffman-La Roche) is now approved for the treatment of metastatic HER2-positive gastric cancer based on the improved survival observed on the phase III Trastuzumab for Gastric Adenocarcinoma (ToGA) study. Standard dosing of trastuzumab is currently extrapolated from breast cancer data: a 3-week schedule (8 mg/kg load, 6 mg/kg q 3 weeks) or a weekly schedule (4 mg/kg load, 2 mg/kg q week).
Case Study:
Our case study examines an HER2-positive metastatic gastric cancer patient that required a higher than currently recommended standard dose of trastuzumab to achieve treatment response.
Discussion:
Several mechanisms may explain these findings and include higher clearance of trastuzumab, higher tumor burden, and pharmacologic resistance in metastatic gastric cancer versus breast cancer. The question of trastuzumab dosing in gastric cancer is currently being evaluated in a phase III clinical trial.
