Published in Cancer Detection and Prevention 2001; 25(3):309-317.

Plasma Micronutrient Antioxidants in Cancer Patients

Clifford D. Abiaka, PhD,a Farida M. Al-Awadi, PhD,b Hilal Al-Sayer, MC, FRCS,c Sima Gulshan, PhD,b Abdulla Behbehani, PhD, FRCS,c and Medhat Farghaly, MC, FRCSc

Departments of aMedical Laboratory Science, bBiochemistry, and cSurgery, Kuwait University, Sulaibikhat, Kuwait.

Address all correspondence and reprint requests to: Clifford D. Abaika, PhD, Department of Medical Laboratory Science, Faculty of Allied Health Sciences, Kuwait University, P.O. Box 31470, Sulaibikhat 90805, Kuwait.

ABSTRACT: The distribution of breast, colon, gastric, thyroid, oral, rectal, pancreatic and renal cancers were determined in 71 Kuwaitis, 45 other Arabs, and 26 Indians. Plasma levels of micronutrient antioxidants, retinol, α-tocopherol, lycopene, and β-carotene were measured in the groups and in 90 matched controls for comparison. Cholesterol was measured to determine its association with the micronutrient antioxidants. Pancreatic cancer ocurred exclusively in Kuwaitis, while breast and colon cancers were disproportionately higher in Kuwaitis than in the other groups. Micronutrient antioxidant levels were similar in the groups, except for higher lycopene levels in Kuwaitis. In most instances, the micronutrient antioxidants, except β-carotene, were significantly lower in cases than in controls. Low levels of retinol, lycopene, and β-carotene were strongly associated with pancreatic cancer. Compared to controls, significantly increased levels of β-carotene ocurred in breast, colon, thyroid, and renal cancers; increased lycopene ocurred in oral cancer, and increased α-tocopherol occurred in pancreatic cancer. Alph-tocopherol strongly correlated with cholesterol. Generally, changes in α-tocopherol/cholesterol ratios mimicked those of α-tocopherol levels. Micronutrient antioxidant levels were significantly lower in male patients than female patients. Age showed a negative but statistically insignificant relationship with micronutrient antioxidants. Lycopene strongly correlated with β-carotene and α-tocopherol with retinol. Among the patients, all micronutrient antioxidants except retinol decreased significantly in levels in smokers than nonsmokers, suggesting susceptibility to cigarette smoke oxidative stress. We conclude that micronutrient antioxidant depletions and altered associations may imply tumor utilization or antioxidant burden in oxidative stress or both. Furthermore, the incidence of pancreatic, colon and breast cancers among Kuwaitis warrants further study.

KEY WORDS: micronutrient antioxidants, retinol, &alpha, -tocopherol, lycopene, &beta, -carotene, cancer.