Neurotoxicity (NT) in colon cancer (CC) survivors from NSABP Protocol C-07 comparing 5-FU + leucovorin (FULV) with the same regimen + oxaliplatin (FLOX): Preliminary results from NSABP Protocol LTS-01

Abstract

9575 Background: NT is an important acute toxicity associated with oxaliplatin therapy, yet little is known about NT in long term CC survivors treated with oxaliplatin as part of adjuvant therapy. NSABP LTS-01 is a comprehensive study examining patient reported outcomes (PROs) in long term survivors (LTS) of colon and rectal cancer previously treated on NSABP adjuvant trials. We report preliminary NT PRO results from LTS-01 for patients (pts) accrued to C-07 from 2000–2002. Methods: Eligible C-07 pts were recruited and consented by NSABP investigators providing regular follow-up. After consent, telephone interviews were used to collect PROs including NT by the validated FACT/GOG Oxaliplatin-Specific NT questionnaire (NTX-12). A subset of pts completed the NTX-12 as part of the original C-07 trial. Statistical comparisons of NT across treatments (TX) used the Wilcoxon test. Results: LTS-01 opened in Oct 06 and, as of Dec 07, NT PRO data are available from 280 pts (51% on FLOX). Characteristics were similar across TX with 50% of pts over age 65, 92% white, 96% non-Hispanic, 8% with CC recurrence, and 12% with new primary cancer. Median time from C-07 randomization to LTS-01 interview was 6 years. FLOX pts had more NT than FULV pts (p = 0.014), but the mean difference in NTX-12 score was 1.8, less than the 4 points considered clinically important. Individual item scores with significantly more NT on FLOX included: numbness/tingling in hands (31 v 44% with any severity, p = .017), numbness/tingling in feet (22 v 46%, p < 0.0001), and pain in hands/feet when exposed to cold (26 v 43%, p = 0.010). In the subset of 79 pts with baseline (BL) NTX-12 data (54% FLOX), the change from BL score was similar for both TX. In a subset of 34 FLOX pts with 18-month data, NT was similar at 18 months and the LTS assessment at 5–7 years. Conclusions: While small differences in oxaliplatin-induced NT persist to 6 years, they fail to reach clinical significance. Numbness, tingling, and cold-induced pain of the hands and feet remain a problem for some long term CC survivors treated with oxaliplatin. Supported by grants from the NCI and the American Cancer Society. No significant financial relationships to disclose.