Does dihydropyrimidine dehydrogenase level modify plasma antioxidant capacity in colorectal cancer patients treated with fluoropyrimidines?  oleh Velko Minchev, Nadya Hristova-Avakumova, Kalina Kamenova, Liliya Atanasova, Marin Angelov, Lozan Todorov, Slavina Surcheva, Rumen Nikolov