Comparing Two Weight Loss Programs for the Prevention of Kidney Cancer Progression Among Patients With Small Renal Masses on Active Surveillance

Development and Analysis of Weight Loss Programs for Renal Cell Carcinoma Patients on Active Surveillance

This clinical trial compares two different weight-loss programs, daily continuous calorie energy reduction (CER) versus (vs.) 5:2 intermittent fasting (IF), in preventing progression of kidney (renal) cancer among patients with one or more small renal masses (SRM) undergoing active surveillance (AS). Kidney cancer patients tend to have changes in metabolism that may increase body weight, but weight-loss strategies that work for best for these patients are unknown. The CER program requires a set daily limit for calories. The IF program requires fasting for 2 days a week and normal eating for the remaining 5 days. Both will include self-monitoring with interventionist feedback. This trial may help researchers determine whether the IF program works better than the CER program in improving weight loss, physical health, and/or reducing the risk of kidney cancer progression among patients with small renal masses undergoing AS

Study Overview

• Status: Recruiting
• Conditions: Renal Cell Carcinoma (RCC)
• Intervention / Treatment: Other: Continuous Energy Restriction (CER); Other: Intermittent Fasting

Detailed Description

PRIMARY OBJECTIVES:

I. Adapt two evidence-based behavioral weight loss intervention programs (IF and CER) with a goal to cause weight loss in SRM patients on AS.

II. Determine the feasibility of the two intervention programs (IF and CER).

SECONDARY OBJECTIVE:

I. Measure, compare and explore preliminary effect sizes of IF vs. CER on body weight, diet, body composition, tumor growth, and rates of clinical progression and invasive treatment conversion

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: ASK RPCI; Phone Number: 1-800-767-9355; Email: askroswell@roswellpark.org

Study Locations

• United States
  • New York
    • Buffalo, New York, United States, 14263
      • Recruiting
      • Roswell Park Comprehensive Cancer Center
      • Contact: ASK RPCI; Phone Number: 800-767-9355; Email: askrpci@roswellpark.org
      • Principal Investigator: Eric Kauffmann, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• English speaking
• SRM patient with biopsy-confirmed RCC who are initiating or already on AS
• Age 18 years or older
• Body mass index (BMI) ≥ 25 kg/m^2
• No medical problems that might contraindicate participation in a behavioral weight reduction program containing an exercise component
• No weight loss medication in the past 3 months
• Not pregnant or lactating
• No more than 5% body weight loss in the past 3 months
• No bariatric surgery in the last 10 years

Exclusion Criteria:

• Non-English speaking
• Less than 18 years old
• BMI < 25 kg/m^2
• Medical problems that might contraindicate participation in a behavioral weight reduction program containing an exercise component
• On weight loss medication in the past 3 months
• Pregnant or lactating
• More than 5% body weight loss in the past 3 months
• Bariatric surgery in the last 10 years
• Any condition which in the Investigator's opinion deems the participant an unsuitable candidate to receive study drug
• Unwilling or unable to follow protocol requirements
• Received an investigational agent within 30 days prior to enrollment

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Arm I - CER Program; Patients complete the CER program for 6 months. The CER intervention will be adapted to renal cell carcinoma patients on active surveillance	Other: Continuous Energy Restriction (CER); Lessons about lowering caloric intake each day and moderate physical activity with self-monitoring and interventionist feedback
Active Comparator: Arm II - IF Program; Patients will complete the IF program for 6 months. The IF arm will mirror the CER arm with the exception that IF additionally include 2 fasting days per week during which participants will be instructed to eat one 500-600kcal meal per fasting day.	Other: Intermittent Fasting; The IF intervention will instruct participants how to fast safely, how to conduct a 5:2 fast, and encourage moderate physical activity. Self-monitoring with interventionist feedback will also be included

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Participation Rate	This will assess the rate of eligible persons who enroll after invitation and the mean proportion of intervention components completed by arm and participant	At 6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in tumor size	Will be assessed based on radiologic imaging. Within-group differences between baseline and 6 months will be examined using paired t-tests or Wilcoxon signed-rank tests for continuous variables, and McNemar's test for categorical variables.	At baseline and at 6 months
Rate of clinical progression	defined based on radiologic tumor size (> 4 cm), stage (> cT1a) and growth rate (> 5 mm/year for < 3 cm size; > 3 mm/year for tumor size > 3 cm), in addition to biopsy histology (high grade or unclassified renal cell carcinoma histologic subtype) and patient symptomology (bleeding or paraneoplastic symptoms/signs attributable to the tumor), as per the International Consultation for Urologic Disease guidelines	Up to 6 months
Change in Body composition	Will be measured using a body composition monitor, which uses bioelectrical impedance analysis to measure whole body and segmental body composition, including trunk fat..	Baseline and at 6 months
Change in Dietary Intake	Participants will complete 3 recalls over the phone regarding dietary intake over a prior 24-hour period.	Baseline and 6 months

Collaborators and Investigators

• Sponsor: Roswell Park Cancer Institute
• Investigators: Principal Investigator: Eric Kaufmann, Roswell Park Comprehensive Cancer Center

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): September 1, 2027
• Study Completion (Estimated): September 1, 2028

Study Registration Dates

• First Submitted: July 15, 2026
• First Submitted That Met QC Criteria: July 15, 2026
• First Posted (Actual): July 20, 2026

Study Record Updates

• Last Update Posted (Actual): August 20, 2026
• Last Update Submitted That Met QC Criteria: August 18, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urogenital Diseases; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Male Urogenital Diseases; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Neoplasms by Histologic Type; Neoplasms, Glandular and Epithelial; Adenocarcinoma; Urologic Neoplasms; Carcinoma; Kidney Neoplasms; Carcinoma, Renal Cell
• Other Study ID Numbers: I-4928826

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No