A phase II study of capecitabine and cisplatin (XP) as first-line chemotherapy in patients with advanced esophageal squamous cell carcinoma

Purpose The combination of 5-fluorouracil (5-FU) and cisplatin (FP) remains the mostly used regimen for metastatic esophageal squamous carcinoma. This phase II study assessed the efficacy and safety of capecitabine/cisplatin (XP) as a first-line chemotherapy in a homogenous cohort of patients with metastatic or recurrent esophageal squamous cell carcinoma. Materials and methods Patients received 60 mg/m² of cisplatin intravenously (IV) on day 1 and capecitabine 1,250 mg/m²/dose orally twice a day on days 1–14. Treatment cycles were repeated every 3 weeks until the documented disease progression, unacceptable toxicity, or patient’s refusal. Immunohistochemical studies against thymidylate synthase (TS) and thymidine phosphorylase (TP) were performed to seek predictive markers for treatment response. Results Between December 2003 and March 2006, 45 patients entered the study. All patients had histologically proven squamous cell carcinoma of the esophagus. The overall response rate (ORR) was 57.8% (95% CI, 43.3–72.2) with 0 CR and 26 PRs. The median duration of response in responders was 4.6 months (1.0–15.6 months). With a median follow-up duration of 25.7 months (10.8–42.6 months), the median time to progression was 4.7 months (95% CI, 2.5–7.0) and the median survival time was 11.2 months (95% CI, 8.5–13.9). Common grade 3 or 4 non-hematological adverse events were anorexia (18/191, 9.4%), fatigue (9/191, 4.7%), constipation (6/191, 3.1%), hand-foot syndrome (6/191, 3.1%) and diarrhea (4/191, 2.1%). The most common grade 3 or 4 hematological adverse events were neutropenia (33/191, 17.3%), followed by leucopenia (11/191, 5.8%), anemia (2/191, 1.0%) and thrombocytopenia (1/191, 0.5%). There was no treatment-related death. Neither TS nor TP showed predictive value for treatment response. Conclusion The XP regimen demonstrated a promising antitumor activity in metastatic esophageal squamous cell carcinoma, which may potentially replace the FP regimen.