Status of Oxidative Stress and Antioxidant Levels in Smokers with Breast Cancer from Western Nepal

Abstract

Background: Research indicates that oxidative stress induced by smoking plays a role in breast cancer. In view of these reports, we aimed to study th relationship between smoking and oxidative stress in breast cancer patients from the western region of Nepal. Materials and Methods: The study included a control group of 42 females (non-smoking healthy women) and a test group sudivided into Group I consisting of 46 female breast cancer patients who were smokers and Group II consisting of 42 non-smoking breast cancer patients. Detailed history of the patients was collected with the help of pre-test proforma. Plasma levels of malondialdehyde (MDA), total antioxidant activity (TAA) which represents total dietary antioxidants, vitamin C and α-tocopherol were estimated by standard methods. Statistical analysis was done using SPSS version 16. Results: The plasma MDA, TAA, vitamin C and α-tocopherol were 1±1.4nmol/ml, 918±207µmol/L, 1±0.24mg/dL and 0.94±0.31mg/dL in controls, 5±1.2nmol/ml, 458±166 µmol/L, 0.64±0.32mg/dL and 0.5±0.3mg/dL in Group-I and 2.56±1.2nmol/ml, 663±178 µmol/L, 0.78±0.2mg/dL and 0.77±0.2mg/dL in Group-II, respectively. Vitamin C, α-tocopherol and TAA (p=0.001) were significantly reduced whereas MDA (p=0.001) was significantly raised in Group-I when compared to controls and Group-II. Conclusions: We observed a significant rise in oxidative stress and low levels of antioxidants in breast cancer patients with smoking habit. It is well known that free radicals facilitate the progression of breast cancer, possibly increasing the risk of progression to the next stage.

Activation of the hypoxia pathway in breast cancer tissue and patient survival are inversely associated with tumor ascorbate levels

“…SVCT-2 levels were shown to correlate with ascorbate uptake and to influence chemo-sensitivity in breast cancer cells in vitro [59]. Low plasma ascorbate levels have been documented in breast cancer patients, with levels as low as 15 μM [60] or 36 μM being reported [61–64]. In contrast, plasma levels in the general population average 50 μM, with levels above 70 μM being indicative of plasma saturation [65–68].…”

Potential Mechanisms of Action for Vitamin C in Cancer: Reviewing the Evidence

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Total Oxidant/Antioxidant Status in Sera of Patients with Esophageal Cancer

“…The relationship between oxidative stress parameters and a history of smoking and drinking is contradictory. A significant rise in oxidative stress and low levels of antioxidants has been observed in breast cancer patients with a smoking history [ 27 ]. However, smoking and alcohol consumption did not modify the effect of the oxidative stress-modifying genes in pancreatic cancer [ 28 ], and no significant interaction was observed between pack-years of smoking and oxidative stress-related genetic polymorphisms in colorectal cancer [ 29 ].…”