Plasma micronutrient antioxidants in cancer patients

The distribution of breast, colon, gastric, thyroid, oral, rectal, pancreat ic and renal cancers were determined in 71 Kuwaitis, 45 other Arabs, and 26 Indians. Plasma levels of micronutrient antioxidants, retinol, alpha -toco pherol, lycopene, and alpha -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 occurre d exclusively in Kuwaitis, while breast and colon cancers were disproportio nately higher in Kuwaitis than in the other groups. Micronutrient antioxida nt levels were similar in the groups, except for higher lycopene levels in Kuwaitis. In most instances, the micronutrient antioxidants, except beta -c arotene, decreased significantly in levels in patients than in controls. Lo w levels of retinol, lycopene, and beta -carotene were strongly associated with pancreatic cancer. Compared to controls, significantly increased level s of beta -carotene occurred in breast, colon, thyroid, and renal cancers; increased lycopene occurred in oral cancer, and increased alpha -tocopherol occurred in pancreatic cancer. Alpha-tocopherol strongly correlated with c holesterol. Generally, changes in alpha -tocopherol/cholesterol ratios mimi cked those of alpha -tocopherol levels. Micronutrient antioxidant levels we re significantly lower in male patients than female patients. Age showed a negative but statistically insignificant relationship with micronutrient an tioxidants. Lycopene strongly correlated with beta -carotene and alpha -toc opherol with retinol. Among the patients, all micronutrient antioxidants ex cept 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 impl y tumor utilization or antioxidant burden in oxidative stress or both. Furt hermore, the incidence of pancreatic, colon and breast cancers among Kuwait is warrants further study.