A pilot study of low-dose capecitabine plus trastuzumab as first-line treatment for patients older than 75 years with HER2-positive advanced gastric cancer.

Abstract

165 Background: Elderly patients often present with concomitant co-morbidities and age-associated physiologic problems, such as impaired organ function and functional changes that make the selection of optimal treatment difficult. We report the treatment outcome in 13 elderly patients with HER2-positve advanced gastric cancer who treated with low-dose capecitabine plus trastuzumab. Methods: Patients older than 75 years with gastric cancer were eligible for inclusion if their tumors showed overexpression of HER2 protein by immunohistochemistry (IHC) (3+) or gene amplification by FISH and IHC 2+. Capecitabine 1000 mg/m2was given orally twice a day for 14 days followed by a 1-week rest. Trastuzumab was given by intravenous infusion as a dose of 8 mg/kg on day 1 of the first cycle, followed by 6 mg/kg every 3 weeks. Chemotherapy was given every 3 weeks for eight cycles. Results: Between December 2011 and July 2013, 13 consecutive patients (IHC 3+;7, IHC 2+ and FISH+;6) with a median age of 79 years (range, 75-92 years) were enrolled in this study. ECOG PS was 0/1/2:1/7/5, respectively. A total of 54 cycles of capecitabine plus trastuzumab were administered (median, three cycles; range, 2-8 cycles). Of the 12 patients with measurable lesions, the overall response rate was 41.6% (95% CI, 13.7 to 69.5%). Disease control was achieved in 75.0% of patients. Median progression-free survival was 8.2 months (95% CI, 2.5-13.7 months) and median overall survival was 10.9 months (95% CI, 1.4-20.4 months). Grade 3-4 toxicities were stomatitis (7.6%) and anemia (7.6%). No treatment-related deaths and symptomatic congestive heart failure were observed. Conclusions: Our findings suggest that low-dose capecitabine plus trastuzumab is effective and well tolerated in elderly patients with advanced HER2-positive gastric cancer who are considered ineligible for combination chemotherapy. Prospective trials investigating this regimen in elderly patients with advanced gastric cancer are warranted. Clinical trial information: Gachon University IRB.