The MRC Randomised-controlled Trial of Interferon-α, Interleukin-2 and 5-Fluorouracil vs Interferon-α Alone in Patients with Advanced Renal cell Carcinoma (RE04): Rationale and Progress

Abstract

Renal cell carcinoma is diagnosed in over 6000 people, and accounts for about 2% of malignant disease annually in the UK [1]. For early stage disease, surgery with curative intent is the treatment of choice, although 30–40% of patients diagnosed with disease, apparently limited to the kidney, subsequently will relapse systemically [2]. A further 25% of patients have metastatic disease at presentation. The prognosis for metastatic renal-cell carcinoma is poor, with a median survival of 6–8 months [3]. Response rates to combination chemotherapy [4] and hormonal agents [5] have been around 5–10%. It has been known for some time that the immune system has a role in the natural history of renal-cell carcinoma. For example, spontaneous regressions are rare but well documented [6,7]. Immunotherapy with interferon (IFN) in metastatic disease produces response rates of around 10–20%, with median response durations of 3–16 months [8]. Retrospective data have also shown that patients with a performance status of 0 or 1 are more likely to gain benefit (i.e. increase in median survival) from immunotherapy than are patients with a performance status of 2 or worse [9]. Randomisedcontrolled trials have shown a survival advantage to IFN compared with non-immunotherapy. A randomised trial comparing IFN-a plus vinblastine (VLB) with VLB alone reported a median survival of about 16 months for the 79 patients receiving IFN plus VLB, and 9 months for the 81 patients treated with VLB (PZ 0.0049). Overall response rates were 16.5% for patients treated with IFN plus VLB and 2.5% for patients treated with VLB alone (PZ 0.0025) [10]. The