[Erlotinib plus gemcitabine combination therapy in patients with unresectable advanced pancreatic cancer - a single-institution experience].

Pancreatic adenocarcinoma is one of the leading causes of cancer deaths in Japan. Erlotinib plus gemcitabine( GEM) combination therapy provided significant improvements in the overall and progression-free survival in a phase III trial in Canada and a phase II trial in Japan. As a result, this combination therapy was approved for use in Japan. We evaluated the efficacy of erlotinib plus GEM in patients with unresectable pancreatic cancer. GEM at a dose of 1,000 mg/m2 was administered on days 1, 8, and 15 in a 4-week cycle. Erlotinib was taken orally at 100 mg/day until disease progression or unmanageable toxicity. Between October 2011 and April 2013, 9 patients were enrolled. The mean age was 62.3 years (range, 48-70 years), and 66.7% of patients were men. Eight patients had no prior therapy. All patients had an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0. Eight patients had metastatic and 1 had locally advanced disease. Five patients had a history of smoking. The median duration of erlotinib administration was 133 days, and the median dose intensity was 100 mg/day, with the majority of patients( 88.9%) receiving 100% of the relative dose intensity. The median duration of GEM treatment was 5 cycles, and its median dose intensity was 890 mg/m2/week, with approximately half of the patients (66.7%) receiving >85% of the relative dose intensity. The most frequently reported adverse event was skin rash, which occurred in 44.4% of the patients. Other common non-hematological adverse events included facial edema, diarrhea, nausea, depilation, pruritus, and cholangitis. Most patients experienced some degree of hematological toxicity, with Grade 3 or 4 neutropenia, leukopenia, and anemia. Interstitial lung disease was not observed. The median overall survival was 7.63 months, and the 1-year survival rate was 15%. The median progression-free survival was 5.60 months. The overall response rate was 11.1%,and the disease control rate was 88.9% [complete response (CR), n =0; partial response( PR), n=1; stable disease( SD), n=7]. In conclusion, erlotinib plus GEM combination therapy is well tolerated and associated with efficacy and survival outcomes.