ASCO GU 2018: S-TRAC trial: Sensitivity Analyses of Disease-Free Survival

San Francisco, CA ( Disease free survival (DFS) has been frequently used as an endpoint in the adjuvant setting and was the primary basis of approval for adjuvant cancer therapies. In S-TRAC, adjuvant sunitinib demonstrated a significant improvement of DFS vs. placebo in patients with locoregional renal cell carcinoma (RCC) based on blinded independent central review.1 DFS was defined as time from randomization until recurrence or death from any cause or second cancer. In the absence of a standard definition of DFS in RCC, multiple sensitivity analyses were performed to confirm the robustness of the DFS results from S-TRAC.

Two analyses considered the time to recurrence including and excluding RCC specific deaths and contralateral kidney recurrence. Additional analyses used the same event and censoring rules as the primary analysis but considered earliest dates of relapse for equivocal new lesions, later determined to be unequivocal to align with RECIST 1.1 criteria for new lesions and some alternative dates for secondary malignancies. 

In the primary analyses, the median duration of DFS was 6.8 years in the sunitinib groups and 5.6 years in the placebo group. Results of these sensitivity analyses supported the robustness of the primary DFS analysis, through consistent hazard ratios (HRs (0.76-0.81) favoring sunitinib.

The HRs from select sensitivity analyses are presented in Table 1.
Table 1 – Hazard ratios from select sensitivity analyses:

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Results of sensitivity analyses with alternative definitions of DFS in S-TRAC demonstrated its robustness, with consistent HRs favoring sunitinib. Clinical trial information: NCT00375674

Presented by:  Daniel J. George, MD, Duke Cancer Institute, Durham NC 

Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre @GoldbergHanan, at the 2018 American Society of Clinical Oncology Genitourinary (ASCO GU) Cancers Symposium, February 8-10, 2018 - San Francisco, CA

1. Ravaud A, Motzer RJ, Pandha HS, et al. Adjuvant Sunitinib in High-Risk Renal-Cell Carcinoma after Nephrectomy. New England Journal of Medicine 2016; 375(23): 2246-54.