• Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, 9609 Medical Center Dr., Rockville, MD 20850, USA.
• Department of Family Medicine and Public Health Sciences, Karmanos Cancer Institute, Wayne State University, 3939 Woodward Ave., Detroit, MI 48201, USA.
• Department of Urology, Yale School of Medicine, PO Box 208058, New Haven, CT 06520, USA.
• Biostatistics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, 9609 Medical Center Dr., Rockville, MD 20850, USA.
• Department of Human Genetics, University of Utah, 15 N 2030 E, Salt Lake City, UT 84112, USA.
• Laboratory of Environmental Precision Biosciences, Mailman School of Public Health, Columbia University, 722 West 168th St., New York, NY 10032, USA.
• Department of Epidemiology, Division of OVP, Cancer Prevention and Population Sciences, The University of Texas MD Anderson Cancer Center, Unit 1340 PO Box 301439, Houston, TX 77230-1439, USA.

BACKGROUND: Leukocyte telomere length (LTL) is a potential biomarker of cancer prognosis; however, evidence for renal cell carcinoma (RCC) is inconsistent.

METHODS: We investigated LTL and RCC-specific survival among 684 cases from the US kidney cancer study (USKC) and 241 cases from the prostate, lung, colorectal, and ovarian cancer screening trial (PLCO). Leukocyte telomere length was measured by quantitative polymerase chain reaction, and hazard ratios (HRs) and 95% confidence intervals (CIs) computed using multivariable Cox models.

RESULTS: Short LTL was associated with poorer disease-specific survival in both USKC (lowest vs highest quartile: HR: 2.3, 95% CI: 1.2-4.4; P for trend=0.02) and PLCO (HR: 2.4, 95% CI: 1.0-5.4; P=0.04). Among USKC cases, the association was strongest for stage-I RCC (HR: 5.5, 95% CI: 1.6-19.0; P=0.006).

CONCLUSIONS: Our findings suggest that shorter LTL is an independent marker of poor RCC prognosis, particularly for stage-I disease.