Prognostic Factors Associated With Long-Term Survival In Previously Untreated Metastatic Renal Cell Carcinoma

Patients with metastatic renal cell carcinoma (mRCC) overall have a poor prognosis, with median survival in the range of one year. However, there remains a subset of patients (around 10%) who, despite having metastatic disease, demonstrate a prolonged survival, sometimes in excess of 5 years. In this study by Choueiri and colleagues out of the Cleveland Clinic, they evaluated their experience with mRCC patients to identify clinical parameters associated with long-term survival.

In this study, the authors evaluated 358 patients with untreated metastatic RCC, enrolled in phase I/II studies over a 15 year period to identify clinical parameters associated with long-term survival. They defined long-term survival as patients with an overall survival (OS) > 5 years, and defined short-term survival as patients with an OS < 2 years. In their series they identified 226 patients with short-term survival and compared them to 31 patients with long-term survival. One hundred one patients were eliminated from the analysis due to incomplete follow-up, or those that had an OS between 2 and 5 years. While patients received a variety of systemic therapies, the type of therapy received did not influence outcome (p=0.55). In their multivariate analysis, the factors that predicted against long-term OS (> 5 years) included haemoglobin less than the lower limit of normal (p<0.001), more than 2 sites of metastatic disease (p=0.006), involvement of the left kidney (versus right) (p=0.003), and ECOG performance status of 1 (versus 0) (p=0.03). Improved response to therapy was noted in the long-term survivors (30% partial/complete response) when compared to short-term survivors (6% partial/complete response) (p<0.001). The authors then used the 4 clinical parameters that predicted outcome to group patients into 3 specific risk subsets. Thirty-two percent of patients with 0 or 1 risk factors had an OS of > 5 years, 9% of patients with 2 risk factors had an OS of > 5 years, and only 1% of patients with more than 2 risk factors had an OS of > 5 years. The authors conclude that haemoglobin levels, ECOG performance status, sites of metastases, and laterality of the primary tumour (left versus right) are predictive of long-term survival in patients with untreated mRCC. These factors should be considered in counselling patients regarding outcomes, but await further prospective validation before prior to widespread implementation in prognostic nomograms.(Source: Annals of Oncology : Cleveland Clinic : February 2007.)