Do B vitamins reduce lung cancer risk?

Smoking is the major risk factor for lung cancer, according to a new study published in JAMA, higher levels of vitamin B6 and methionine in the blood was associated with lower risk of lung cancer.

This was a large scale IARC study with 520,000 volunteers across Europe, part of the EPIC cohort. Blood samples were taken from both the case group and the control group and the amount of B6 and methionine measured.

The researchers found that there was a lower risk of lung cancer with a higher level of B6 and methionine whether they were smokers or non-smokers. Overall, people with above average levels of B6 and methionine had 50% reduction in the risk of developing lung cancer than those with below average levels.

Critics say that the blood samples were taken on only one occasion and a cohort study cannot prove a cause and effect for a reduced risk of lung cancer for B6. Furthermore, B6 and methionine are found in meat and potatoes, but it was unknown whether eating more of this food would make a difference to the risk of developing lung cancer because a lower level of these substances in the blood may be due to poor absorption.

Source: Johansson M, Relton C, Magne Ueland P, et al. "Serum B Vitamin Levels and Risk of Lung Cancer". JAMA 2010; 303: 2377-2385

Racial gaps in lung cancer surgery

A new study published in JAMA found that black patients newly diagnosed with lung cancer were less inclined to have surgery than whites because they did not connect well with their doctors.

Researchers analysed data from 386 lung cancer patients in Carolina and found that only 55% of black patients had surgery compared to 66% of white patients. They found that many black patients misunderstood their prognosis or did not feel comfortable enough to discuss with their doctors treatment options and outcomes. Black patients were also less likely to have other sources of support.

The authors said that there are many barriers to improving the disparities but doctors and hospitals can work on the negative perceptions of patient-physician communications and spend more time with patients about their treatment options.

Source: "Factors Associated With Decisions to Undergo Surgery Among Patients With Newly Diagnosed Early-Stage Lung Cancer". JAMA, 2010; 303 (23): 2368-2376

Lack of sunlight may increase lung cancer risk

US researchers examined data from 111 countries to study the association between latitude, exposure to UVB light ( principal source of vitamin D) and rates of lung cancer.

Analysis of data showed that lung cancer rates were highest in those countries furthest from the equator where exposure to sunlight is lowest and lowest in those nearest. The researchers believed that vitamin D can halt tumor growth by promoting the factors responsible for cell death in the body. They found smoking accounted for up to 85% of all cases of lung cancer but exposure to UVB light in particular had an impact.

Experts warn that exposure to sunlight is the major cause of skin cancer and the link between vitamin D and lung cancer is still unclear. Source : "Could ultraviolet B irradiance and vitamin D be associated with lower incidence rates of lung cancer?" Journal of Epidemiology and Community Health 2008;62:69-74