NCCTG trial participants were recruited from 125 academic and community NCCTG participating sites located throughout the United States and Canada. All studies were approved by Institutional Review Boards, and all study participants signed an informed consent document.
Figure 1 illustrates how data from four NCCTG studies were pooled based on whether the participants had received neurotoxic chemotherapy. Data obtained from patients recruited to two studies, N06CA (n = 203) and N08C1 (n = 173), who had received neurotoxic chemotherapy were pooled to form the “received neurotoxic chemotherapy” group (N = 376). In both studies, eligible patients were ≥18 years of age and did not have neuropathy due to other causes. N06CA was a randomized, double blind, placebo-controlled trial evaluating the efficacy of topical baclofen, amitriptyline, and ketamine (BAK) for the treatment for CIPN [16 (link)]. Participants had moderate-to-severe (≥4/10) CIPN-related numbness, tingling, and/or neuropathic pain for at least 1 month prior to study participation. N06CA baseline QLQ-CIPN20, BPI-SF, and NCI-CTCAE scores were used in the current analysis. N08C1 was a descriptive, longitudinal study designed to assess CIPN incidence and severity over time as patients received neurotoxic chemotherapy [6 (link), 17 (link)]. N08C1 QLQ-CIPN20 scores following 12 weeks of chemotherapy treatment were used in the current analysis.
Figure 1 also illustrates how samples from three studies were pooled to comprise the “no neurotoxic chemotherapy” group (N = 575). More specifically, the QLQ-CIPN-20 is currently being utilized in two additional ongoing prevention trials: N08CA (n = 134) and N08CB (n = 168). Baseline QLQ-CIPN20 scores obtained from patients participating in these two trials, plus baseline QLQ-CIPN20 scores from N08C1 obtained prior to patients starting chemotherapy (n = 273) were pooled. N08CA is a randomized, double blind, placebo-controlled trial designed to evaluate the efficacy of glutathione for the prevention of paclitaxel/carboplatin-induced CIPN. N08CB is a randomized, double blind, placebo-controlled trial evaluating the efficacy of intravenous calcium and magnesium for the prevention of oxaliplatin-induced neuropathy. Eligible participants for both studies were ≥18 years of age and did not have preexisting neuropathy.