2.1. Patients:
In our study, 236 patients who referred to the outpatient oncology department of Emam Hospital, affiliated to Mazandaran University of Medical Sciences were screened for enrollment. Eighty patients were eligible for the study. Inclusion criteria were a histologically confirmed diagnosis of cancer, at least 18 years of age, and occurrence of CIPN.
Exclusion criteria were 1) any underlying diseases with manifestation of neuropathy symptoms including diabetes, neuromuscular disease, vitamin B12 deficiency, amyloidosis, and connective tissue disease, 2) patients with a history of neurological diseases such as hereditary and acquired neuropathies, 3) taking any antioxidant supplement in the last two months, 4) pregnancy or breastfeeding, 4) known hypersensitivity to silymarin. All participants gave their written informed consent. Eligible patients were randomly assigned to treatment arms on a 1:1 basis.
The study was approved by the ethics committee of Mazandaran University of Medical Sciences (IR.MAZUMS.IMAMHOSPITAL.REC.1398.6176) and registered in Iranian Registry of Clinical Trials (IRCT20201128049515N1). The trial was conducted according to the guidelines of the Declaration of Helsinki for Research on Human Subjects 1989. Considering the effect size of 0.6, 95% confidence level and test power of 80%, sample size was calculated 80 patients (40 cases in each group) by G-Power software.