Recombinant erythropoietin for the anaemia of patients with advanced Gastrointestinal Stromal Tumours (GIST) receiving imatinib: an active agent only in non progressive patients

ABSTRACT: Recombinant erythropoietin for the anaemia of patients with advanced Gastrointestinal Stromal Tumours (GIST) receiving imatinib : an active agent only in non progressive patients. BACKGROUND: Imatinib is a standard treatment for advanced/metastatic GIST and in adjuvant setting. Anaemia is frequently observed in patients with advanced GIST, and is one of the most frequent side effects of imatinib with grade 3–4 anaemia in 10% of patients. Whether EPO treatment is useful in the management of GIST patients receiving imatinib treatment is unknown. METHODS: A retrospective study of EPO treatment in GIST patients receiving imatinib was undertaken in 4 centres. Thirty four patients received EPO treatment among the 319 GIST patients treated with imatinib in clinical trials or with compassionate use between 2001 and 2003. The efficacy of EPO on the anaemia of patients with GIST treated with imatinib was analyzed. RESULTS: There were 18 males and 16 females with a median age of 59 years. Median WHO-PS was 1. Primary tumour sites were mainly gastric (32%) and small bowel (29%). Sites of metastases were mainly liver (82%) and peritoneum (79%). The median delay between the initiation of imatinib treatment and EPO was 58 days (range 0–553). Median haemoglobin (Hb) level prior to EPO was 9 g/dL (range 6,9-11,8) and 11,7 g/dL (range 6,8-14,4) after 2 months. An increase of more than 2 g/dL was observed in 18 (53%) of patients. None of the 7 patients who progressed (PD) under imatinib treatment (400 mg/day) experienced HB response, as compared to 66% (18/27) of the remaining patients (PR + SD) (p = 0,002). Primary tumour site, liver metastases, peritoneal metastases, age, gender did not correlate with HB response to EPO. Response to EPO was observed in 2/11 patients receiving high-dose imatinib (800 mg/day) vs 16/23 of others. Using logistic regression, only PD before EPO treatment was retained as a predictive factor for EPO response. CONCLUSION: EPO enables to increase Hb in most anaemic GIST patients who do not progress under imatinib, but not in patients with progressive disease.