Clinical factors associated with outcome in patients with metastatic clear-cell renal cell carcinoma treated with vascular endothelial growth factor-targeted therapy

BACKGROUND: Therapy targeted against the vascular endothelial growth factor (VEGF) pathway is a standard of care for patients with metastatic renal cell carcinoma (RCC). The identification of patients who are more likely to benefit from these agents is warranted. METHODS: In total, 120 patients with metastatic clear-cell RCC received bevacizumab, sorafenib, sunitinib, or axitinib on 1 of 9 prospective clinical trials at the Cleveland Clinic. Clinical features associated with outcome were identified by univariate analysis; then, a stepwise modeling approach based on Cox proportional hazards regression was used to identify independent prognostic factors and to form a model for progression-free survival (PFS). A bootstrap algorithm was used to provide internal validation. RESULTS: The overall median PFS was 13.8 months, and the objective response according to the Response Criteria in Solid Tumors was 34%. Multivariate analysis identified time from diagnosis to current treatment <2 years; baseline platelet and neutrophil counts >300 K/microL and >4.5 K/microL, respectively; baseline corrected serum calcium <8.5 mg/dL or >10 mg/dL; and initial Eastern Cooperative Oncology Group performance status >0 as independent, adverse prognostic factors (PF) for PFS. Three prognostic subgroups were formed based on the number of adverse prognostic factors present. The median PFS in patients with 0 or 1 adverse prognostic factor was 20.1 months compared with 13 months in patients with 2 adverse prognostic factors and 3.9 months in patients with >2 adverse prognostic factors. CONCLUSIONS: Five independent prognostic factors for predicting PFS were identified and were used to categorize patients with metastatic RCC who received VEGF-targeted therapies into 3 risk groups. These prognostic factors can be incorporated into patient care and clinical trials that use such novel, VEGF-targeted agents.     

Cessation of vascular endothelial growth factor-targeted therapy in patients with metastatic renal cell carcinoma: feasibility and clinical outcome

BACKGROUND:

The current treatment of metastatic renal cell carcinoma (mRCC) with vascular endothelial growth factor (VEGF)‐targeted agents is continuous therapy until progression of disease (PD) or unacceptable toxicity. Chronic mild to moderate toxicity and risk of long‐term toxicity ensue for some patients. It is hypothesized that patients with an initial response to treatment can maintain disease control off all therapy for a period of time.

METHODS:

A retrospective study of patients with mRCC who initiated VEGF‐targeted therapy between January 2004 and December 2009 at The Cleveland Clinic Foundation, Cleveland, Ohio, or Institut Gustave‐Roussy, Villejuif, France, was conducted. Patients had achieved RECIST (Response Evaluation Criteria in Solid Tumors)‐defined stable disease or better on therapy, and were then taken off all therapy for reasons not including disease progression. Patient, disease, and therapy characteristics were recorded. The primary objective was progression‐free survival (PFS), measured as the time from discontinuation of therapy to RECIST‐defined PD.

RESULTS:

Forty patients were identified. After a median follow‐up of 29.7 months (range, 4.2 to 84.7 months), 25 patients (63%) had PD off therapy (median PFS, 10.0 months; range, 1.4‐27.2 months). Among these patients, 8 (32%) had progression in sites that were not previously involved with disease. Heng risk group (hazard ratio, 2.49; 95% confidence interval, 1.19‐5.22; P = .011) and achievement of a complete response prior to discontinuing therapy (hazard ratio, 0.20; 95% confidence interval, 0.04‐0.86; P = .025) were independent predictors of PFS in a multivariable Cox proportional hazards model.

CONCLUSIONS:

A select subset of mRCC patients achieving stable disease or better on VEGF‐targeted therapy can be observed off all therapy. Further prospective investigation is warranted. Cancer 2011. © 2011 American Cancer Society.     

Categories of response to first line vascular endothelial growth factor receptor targeted therapy and overall survival in patients with metastatic renal cell carcinoma

IntroductionSequential use of targeted therapy (TT) has improved overall survival (OS) of patients with metastatic renal cell carcinoma (mRCC). The value of objective response (OR) as compared to stable disease (SD) is unclear. We aimed to investigate OR of first-line TT and its impact on OS.Material and methodsRetrospective analysis of OS among 331 mRCC patients with a first-line assessment according to RECIST 1.0. Characteristics between objective responders (complete response [CR] or partial remission [PR]), patients with SD and non-responders (progressive disease [PD] and toxicity [Tox]) were compared with the Chi-square test and the Kruskal–Wallis test. Kaplan–Meier analysis of OS and progression-free survival (PFS). Cox model analysis of Predictors of OS .ResultsBest response was CR, PR, SD, PD and Tox in 9 (2.7%), 61 (18.4%), 167 (50.5%), 80 (24.2%) and 14 (4.2%) patients respectively resulting in an OR rate of 21%. Median OS in months: CR 63.2; PR 37.6; SD 35.9; PD 14.6; TOX 22.5 (p < 0.0001). Median PFS for responders was 14.8, 11.5 for patients with SD and 2.5 for non-responders (p < 0.0001). Similarly median OS was 38.7, 35.9 and 15.5 (p < 0.00001). Primary resistance and a first-line PFS <6 months were the strongest independent predictors of OS. The achievement of OR as compared to SD did not impact OS.ConclusionsIn our cohort of unselected patients OR was not associated with superior OS as compared to SD.     

The impact of kidney function on the outcome of metastatic renal cell carcinoma patients treated with vascular endothelial growth factor-targeted therapy

BACKGROUND:

A study was undertaken to investigate the effect of baseline renal function on treatment outcome in patients treated with vascular endothelial growth factor (VEGF)‐targeted therapy for metastatic renal cell carcinoma (mRCC).

METHODS:

Retrospective data from 6 North American cancer centers (3 US and 3 Canadian) were pooled to identify patients with mRCC treated with VEGF‐targeted therapy. Patient characteristics, response rate, time to treatment failure, and overall survival were collected. The Modification of Diet in Renal Disease formula was used at therapy initiation for calculation of glomerular filtration rate (GFR).

RESULTS:

Five hundred twenty‐nine patients with mRCC who received sunitinib (n = 323), sorafenib (n = 165), or bevacizumab (n = 41) were included in this analysis. Patient characteristics included: 74% male, median age 61 years, and median GFR 60.1 mL/min/1.73 m² (range, 6.5‐174.2). On univariate analysis, patients with a GFR <60 (n = 262) were more likely to have had a previous nephrectomy (P < .0001) and to be older (P < .0001), but were less likely to have poor prognostic features such as anemia (P = .041), hypercalcemia (P = .008), neutrophilia (P = .039), thrombocytosis (P < .0001), short diagnosis to treatment interval (P = .007), and low Karnofsky performance status (P = .051). GFR <60, when adjusted for poor risk factors, did not have an impact on type of objective response (odds ratio, 1.31; 95% confidence interval [CI], 0.74‐2.32; P = .359), time to treatment failure (hazard ratio [HR], 0.97; 95% CI, 0.79‐1.19; P = .772), or overall survival (HR, 0.90; 95% CI, 0.69‐1.17; P = .439).

CONCLUSIONS:

Renal function at therapy initiation does not adversely affect the efficacy of VEGF‐targeted therapy in mRCC. Clinicians should not avoid treating patients with impaired baseline renal function. Cancer 2011;. © 2011 American Cancer Society.     

Biology and clinical development of vascular endothelial growth factor-targeted therapy in renal cell carcinoma.

PURPOSE: To review the biology of renal cell carcinoma (RCC) leading to vascular endothelial growth factor (VEGF) overexpression and the clinical results of VEGF blockade in metastatic RCC. METHODS: A review of relevant published literature regarding VEGF, von Hippel-Lindau (VHL) gene inactivation and VEGF overexpression in RCC was performed. Further, a review of the mechanism, toxicity, and clinical development of VEGF-targeted therapy in metastatic RCC was undertaken. RESULTS: VEGF is the major proangiogenic protein that exerts a biologic effect through interaction with cellular receptors. The majority of sporadic clear-cell RCC tumors are characterized by VHL tumor suppressor gene inactivation. The resulting VHL gene silencing leads to VEGF overexpression. An antibody to VEGF (bevacizumab) has demonstrated a significant prolongation of time to disease progression compared with placebo in patients with metastatic RCC. Small molecules with inhibitory effects against the VEGF receptor have undergone initial clinical testing in metastatic RCC with substantial objective response rates. CONCLUSION: Therapeutic targeting of VEGF in RCC has strong biologic rationale and preliminary clinical efficacy. Further investigation will determine the optimal timing, sequence, and utility of these agents in RCC.     

Controversies in renal cell carcinoma: Treatment choice after progression on vascular endothelial growth factor-targeted therapy

The mammalian target of rapamycin inhibitor (mTORI) everolimus and the tyrosine kinase inhibitor (TKI) axitinib are the only two post-first-line treatment options for metastatic renal cell carcinoma (mRCC) licensed at present. Extrapolation of robust phase III studies suggests that median progression-free survival (PFS) is similar between agents. This presents a dilemma for the physician planning treatment for their patients with mRCC: should they be treated with a TKI–mTORI or a TKI–TKI sequence? The lack of direct comparison between axitinib and everolimus leaves the clinician without clear guidance on the optimal choice in second-line therapy. In phase III studies, both post first-line everolimus and axitinib have been shown to delay disease progression; however, cumulative toxicity with sequential use of TKIs may result in more treatment interruptions or dose reductions or increased likelihood of adverse events. While everolimus exerts a tolerability advantage, axitinib is associated with higher response rate and a similar PFS benefit. Proven superiority cannot be used to guide treatment sequence selection in mRCC. Instead, therapeutic planning requires us to take a long-term view of our patient’s treatment that includes quality of life and a balance between symptom control, adverse event management and avoidance of unnecessary drug interruptions or dose reductions. In the absence of curative therapies, sustaining a patient’s quality of life is a major goal throughout the course of treatment and choosing a second-line agent that is able to adequately achieve this by limiting adverse events should be a priority.     

Vascular endothelial growth factor-targeted therapy in renal cell carcinoma: current status and future directions.

Renal cell carcinoma is a highly vascular tumor associated with expression of vascular endothelial growth factor (VEGF). Recently, VEGF-targeted therapies have been identified as a promising therapeutic approach. Three agents targeting the VEGF pathway have shown clinical activity as monotherapy in metastatic renal cell carcinoma: the anti-VEGF monoclonal antibody, bevacizumab, and small-molecule VEGF receptor tyrosine kinase inhibitors, sorafenib and sunitinib. This article explores these agents in terms of their mechanisms of action, clinical efficacy, and toxicity profiles. This article also reviews future development strategies, including combination regimens and drug sequencing, trial design considerations, and patient selection opportunities.     

Thrombocytosis as a prognostic factor for survival in patients with metastatic renal cell carcinoma

BACKGROUND: It has been suggested that thrombocytosis, as defined by a platelet count >400,000/microL, is a negative predictor for survival among patients with metastatic renal cell carcinoma. However, this has not been a uniform finding. METHODS: To address this issue, retrospective analysis of 700 previously untreated patients entering on institution review board-approved phase 1, 2, or 3 clinical trials in the United States and Europe was conducted between 1982 and 2002. RESULTS: Thrombocytosis was present at study entry in 25% of patients. Median baseline platelet count was 304,000/microL (range, 86-1,420,000/microL). Eighty-seven percent of patients died with a median survival of 13.0 months. Median follow-up for patients not known to have died was 2.4 years. On univariate analysis, patients with elevated platelet counts had significantly shorter survival than patients with normal platelet counts; median survivals of 8.4 and 14.6 months, respectively, P < .001. However, platelet count was associated with several clinical and biochemical factors, including gender, age, performance status, time from diagnosis to study entry, prior radiotherapy or nephrectomy, presence of liver metastasis, number of metastatic sites, amount of hemoglobin, white blood cell count, amount of lactate dehydrogenase, and amount of serum alkaline phosphatase. Several of these factors have previously been reported as prognostic indicators for survival, and, therefore, multivariable analyses were conducted to determine whether thrombocytosis is an independent predictor of survival. After adjusting for multiple factors, thrombocytosis continued to impact negatively on survival, P < .001. CONCLUSIONS: Thrombocytosis was found to be an independent prognostic factor for survival in patients with metastatic renal cell carcinoma.     

Clinical activity of sorafenib and sunitinib in renal cell carcinoma refractory to previous vascular endothelial growth factor-targeted therapy: two case reports

Sunitinib and sorafenib are multitargeted receptor tyrosine kinase inhibitors of the vascular endothelial growth factor and platelet-derived growth factor receptor families with antiangiogenic and antitumor activity in metastatic renal cell carcinoma. The utility of these agents in patients refractory to previous treatment with the other agent is unknown. We report 2 cases highlighting that efficacy of these agents is possible after failure of the other agent. Further prospective study is needed.     

Statins and survival outcomes in patients with metastatic renal cell carcinoma

BackgroundA growing body of evidence has demonstrated the anti-neoplastic activity of statins. The objective of this study was to investigate the effect of statin use on survival in patients with metastatic renal cell carcinoma (mRCC) treated in the modern therapy era.Patients and methodsWe conducted a pooled analysis of mRCC patients treated on phase II and III clinical trials. Statistical analyses were performed using Cox regression and the Kaplan–Meier method.ResultsWe identified 4736 patients treated with sunitinib (n = 1059), sorafenib (n = 772), axitinib (n = 896), temsirolimus (n = 457), temsirolimus + interferon (IFN)-α (n = 208), bevacizumab + temsirolimus (n = 393), bevacizumab + IFN-α (n = 391) or IFN-α (n = 560), of whom 511 were statin users. Overall, statin users demonstrated an improved overall survival (OS) compared to non-users (25.6 versus 18.9 months, adjusted hazard ratio [aHR] 0.801, 95% confidence interval [CI] 0.659–0.972, p = 0.025). When stratified by therapy type, a benefit in OS was demonstrated in statin users compared to non-users in individuals receiving therapy targeting vascular endothelial growth factor (28.4 versus 22.2 months, aHR 0.749, 95% CI 0.584–0.961, p = 0.023) or mammalian target of rapamycin (18.6 versus 14.0 months, aHR 0.657, 95% CI 0.445–0.972, p = 0.035) but not in those receiving IFN-α (15.6 versus 14.8 months, aHR 1.292, 95% CI 0.703–2.275, p = 0.410). Adverse events were similar between users and non-users.ConclusionsWe demonstrate that statin use may be associated with improved survival in patients with mRCC treated in the targeted therapy era. Statins could represent an adjunct therapy for patients with mRCC; however, this is hypothesis generating and requires prospective evaluation.     

A new prognostic classification for overall survival in Asian patients with previously untreated metastatic renal cell carcinoma

The aims of the present study were to: (i) develop a clinically useful prognostic classification in Asian patients with metastatic renal cell carcinoma (RCC) by combining metastatic features with several pretreatment parameters; and (ii) evaluate the validity of this prognostic classification. Baseline characteristics and outcomes were collected for 361 patients who underwent interferon‐α‐based therapy between 1995 and 2005. Relationships between overall survival (OS) and potential prognostic factors were assessed using Cox's proportional hazard model. The predictive performance of the model was evaluated using bootstrap resampling procedures and by using an independent dataset obtained from randomly selected institutions. The predictive accuracy was measured using the concordance index (c‐index). Four factors were identified as independent prognostic factors: time from initial diagnosis to treatment, anemia, elevated lactate dehydrogenase (LDH), and poor prognostic metastatic group (liver only, bone only, or multiple organ metastases). Each patient was assigned to one of three risk groups: favorable risk (none or one factor; n = 120), in which median OS was 51 months; intermediate risk (two factors; n = 101), in which median OS was 21 months; and poor risk (three or four factors; n = 102), in which median OS was 10 months. The c‐index was 0.72 in the original dataset and 0.72 in 500 random bootstrap samples. In the independent dataset for external validation, the c‐index was 0.73. Thus, the new prognostic classification is easily applicable for Asian patients with previously untreated metastatic RCC and should be incorporated into patient care, as well as clinical trials performed in Asia.     

Prognostic factors for overall survival in patients with metastatic colorectal carcinoma treated with vascular endothelial growth factor-targeting agents

Objective: Angiogenesis represents a key element in the pathogenesis of malignancy. There are no robust data on prognostic factors for overall survival (OS) in patients with metastatic colorectal cancer treated with vascular endothelial growth factor (VEGF)-targeted therapy. The present study was conducted to establish a prognostic model for patients using an oxaliplatin-based or irinotecan-based chemotherapy plus bevacizumab in metastatic colorectal cancer. Methods: Baseline characteristics and outcomes on 170 patients treated with FOLFIRI or XELOX plus anti-VEGF therapy-naïve metastatic colorectal cancer were collected from three Turkey cancer centers. Cox proportional hazards regression was used to identify independent prognostic factors for OS. Results: The median OS for the whole cohort was 19 months (95% CI, 14.3 to 23.6 months). Three of the seven adverse prognostic factors according to the Anatolian Society of Medical Oncology (ASMO) were independent predictors of short survival: serum lactate dehydrogenase (LDH) greater than the upper limit of normal (ULN; p<0.001); neutrophils greater than the ULN (p<0.0014); and progression free survival (PFS) less than 6 months (p =0.001). Conclusion: Serum LDH and neutrophil levels were the main prognostic factors in predicting survival, followed by PFS. This model validates incorporation of components of the ASMO model into patient care and clinical trials that use VEGF-targeting agents.     

Increased serum levels of vascular endothelial growth factor in patients with renal cell carcinoma.

Neovascularization, an essential event for the growth of solid tumors, is regulated by a number of angiogenic factors. One such factor, vascular endothelial growth factor (VEGF), is considered to exert a potent angiogenic activity, as indicated by immunohistochemical and molecular evidence. In this study we investigated the serum VEGF level (s-VEGF) in patients with renal cell carcinoma (RCC). s-VEGF in peripheral blood samples was analyzed in 40 RCC patients and 40 patients without cancer (controls) using a sandwich enzyme-linked immunoassay. In 20 RCC patients, serum samples were obtained separately from the bilateral renal veins. s-VEGF was also measured before, 4 and 8 weeks after nephrectomy in 11 patients. There were significant differences in s-VEGF between the RCC patients and the controls (207.3+/-32.9 vs. 71.5+/-9.1 pg/ml, mean+/-SE) (P<0.005), between the tumor-bearing renal veins and the contralateral ones (P<0.01), between the pre- and post-nephrectomy situations (P<0.01) and among the various parameters of tumor status such as tumor extent (P<0.001) and existence of metastasis (P<0.001). s-VEGF significantly correlated with the tumor volume obtained by a three-dimensional measurement (r=0.802, P<0.0001). The sensitivity and specificity of s-VEGF at the cut-off level of 100 pg/ml, as determined by the receiver-operating-characteristics curve, were 80.0% and 72.5%, respectively. The results indicate that tumor tissue of RCC liberates VEGF into the systemic blood flow and that s-VEGF is a possible marker for RCC.     

Improvement in survival end points of patients with metastatic renal cell carcinoma through sequential targeted therapy

Survival of patients with metastatic renal cell carcinoma (mRCC) has improved since the advent of targeted therapy. Approved agents include the multi-targeted tyrosine kinase inhibitors (TKIs) sunitinib, sorafenib, axitinib, pazopanib, cabozantinib, and lenvatinib (approved in combination with everolimus), the anti-VEGF monoclonal antibody bevacizumab, the mammalian target of rapamycin (mTOR) inhibitors everolimus and temsirolimus, and the programmed death-1 (PD-1) targeted immune checkpoint inhibitor nivolumab. The identification of predictive and prognostic factors of survival is increasing, and both clinical predictive factors and pathology-related prognostic factors are being evaluated. Serum-based biomarkers and certain histologic subtypes of RCC, as well as clinical factors such as dose intensity and the development of some class effect adverse events, have been identified as predictors of survival. Expression levels of microRNAs, expression of chemokine receptor 4, hypermethylation of certain genes, VEGF polymorphisms, and elevation of plasma fibrinogen or d-dimer have been shown to be prognostic indicators of survival. In the future, prognosis and treatment of patients with mRCC might be based on genomic classification, especially of the 4 most commonly mutated genes in RCC (VHL, PBRM1, BAP1, and SETD2). Median overall survival has improved for patients treated with a first-line targeted agent compared with survival of patients treated with first-line interferon-α, and results of clinical trials have shown a survival benefit of sequential treatment with targeted agents. Prognosis of patients with mRCC will likely improve with optimization and individualization of current sequential treatment with targeted agents.     

Pretherapeutic gamma-glutamyltransferase is an independent prognostic factor for patients with renal cell carcinoma

Background:

Gamma-glutamyltransferase (GGT) regulates apoptotic balance and promotes cancer progression and invasion. Higher pretherapeutic GGT serum levels have been associated with worse outcomes in various malignancies, but there are no data for renal cell carcinoma (RCC).

Methods:

Pretherapeutic GGT serum levels and clinicopathological parameters were retrospectively evaluated in 921 consecutive RCC patients treated with nephrectomy at a single institution between 1998 and 2013. Gamma-glutamyltransferase was analysed as continuous and categorical variable. Associations with RCC-specific survival were assessed with Cox proportional hazards models. Discrimination was measured with the C-index. Decision-curve analysis was used to evaluate the clinical net benefit. The median postoperative follow-up was 45 months.

Results:

Median pretherapeutic serum GGT level was 25 U l⁻¹. Gamma-glutamyltransferase levels increased with advancing T (P<0.001), N (P=0.006) and M stages (P<0.001), higher grades (P<0.001), and presence of tumour necrosis (P<0.001). An increase of GGT by 10 U l⁻¹ was associated with an increase in the risk of death from RCC by 4% (HR 1.04, P<0.001). Based on recursive partitioning-based survival tree analysis, we defined four prognostic categories of GGT: normal low (<17.5 U l⁻¹), normal high (17.5 to <34.5 U l⁻¹), elevated (34.5 to <181.5 U l⁻¹), and highly elevated (⩾181.5 U l⁻¹). In multivariable analyses that adjusted for the effect of standard features, both continuously and categorically coded GGT were independent prognostic factors. Adding GGT to a model that included standard features increased the discrimination by 0.9% to 1.8% and improved the clinical net benefit.

Conclusions:

Pretherapeutic serum GGT is a novel and independent prognostic factor for patients with RCC. Stratifying patients into prognostic subgroups according to GGT may be used for patient counselling, tailoring surveillance, individualised treatment planning, and clinical trial design.     

Vascular endothelial growth factor-D expression is an independent prognostic marker for survival in colorectal carcinoma

The angiogenic factor vascular endothelial growth factor-D (VEGF-D) isa ligand for VEGF receptor-3 (VEGFR-3/Flt-4) and receptor-2 (VEGFR-2/KDR)and is implicated in the development of lymphatic vessels and promotion of lymphatic metastases. We assessed the expression of VEGF-D and VEGFR-3 in relation to microvessel density (MVD) in colorectal carcinomas (CRC), adenomas, and adjacent normal tissue by immunohistochemistry on consecutive archival sections. VEGF-D was detected in malignant and benign epithelium and in some smooth muscle of the colorectum. High-grade VEGF-D expression was observed frequently (74%) in CRC compared with adenomas (0%) and adjacent normal mucosa (22%). High-grade VEGF-D expression was not correlated with MVD, Dukes' stage (A to C), or tumor differentiation, but was associated with lymphatic involvement and patient survival. By multivariate analysis, VEGF-D expression was found to be an independent prognostic factor for both disease-free and overall survival. VEGFR-3 expression was detected in a subset of vessels, typically thin-walled and devoid of RBCs, in 89% of CRC cases examined. VEGFR-3-positive vessel densities increased progressively from normal mucosa to adenomas and carcinomas and were correlated with MVD, but not with Dukes' stage (A to C), tumor differentiation, or VEGF-D expression. VEGFR-3 expression was spatially associated with macrophage-rich inflammatory infiltrates, which were significantly more frequent among VEGFR-3-positive cases. We conclude that VEGF-D expression, but not that of its receptor VEGFR-3, is an independent prognostic indicator in CRC. VEGF-D expression may be associated with disease outcome through the promotion of lymphatic involvement/metastases.     

Infusional floxuridine-based therapy for patients with metastatic renal cell carcinoma

BACKGROUND: The treatment of patients with metastatic renal cell carcinoma (RCC) continues to pose a major clinical challenge. Previous studies have suggested that infusional floxuridine (FUDR) has antitumor efficacy and is well tolerated. To the authors knowledge the combination of infusional FUDR with biologic response modifiers (BRMs) has not been evaluated extensively in patients with metastatic RCC. METHODS: Thirty-nine previously untreated patients with metastatic RCC were treated with infusional FUDR at 0.075 mg/kg/day for 14 days of a 28-day cycle. Beginning with the second cycle of FUDR, 24 patients received subcutaneous interferon-alpha-2b (3 million U 3 times a week for Weeks 1 and 2) and 15 received subcutaneous interleukin-2 (IL-2) (5 million U/m(2) 5 days a week for 3 weeks, followed by 1 week off). The dose of FUDR was increased by 0.025 mg/kg each cycle until the maximum tolerated dose for each patient was reached. RESULTS: Five patients receiving FUDR plus interferon achieved a partial response and 1 achieved a complete response whereas 3 patients receiving FUDR plus IL-2 achieved a partial response, for an overall response rate of 23%. The median survival for all patients was 21 months, and 8 patients still were alive 6-57+ months after the initiation of therapy. Toxicity was mild to moderate, and was comprised primarily of fatigue, diarrhea, dacryocystitis, and fluid retention (in the IL-2 cohort). CONCLUSIONS: FUDR in conjunction with IL-2 or interferon appears to produce response rates comparable to those observed with other programs utilizing BRMs and generally is well tolerated. FUDR regimens may be useful in the treatment of metastatic RCC in the outpatient community setting.