Among the non -smokers with diabetes who participated in a study, those who took metformin had a decrease in the risk of lung cancer, according to the conclusions of the investigation, published in 'Cancer Prevention Research', a magazine of the American Association for theCancer research, by researcher Lori Sakoda, of the Kaiser Permanent Research Division in Oakland, California, United States.
Some laboratory studies and a series of observation analysis suggest that metformin can prevent cancer, but human test data, however, are in conflict, explains Sakoda.The researchers of this work conducted the study to further clarify the link between the use of metformin and the risk of lung cancer.
Sakoda and his colleagues did a retrospective cohort study of 47,351 diabetic patients (54 percent men), 40 years or older, who completed a health -related survey between 1994 and 1996. Information about their diabetes medications was collectedof electronic pharmacy records, with about 46 percent "users" of metformin.
For 15 years of tracking, 747 patients were diagnosed with lung cancer, of which 80 were non -smokers and 203 smoked today.The use of metformin was not associated with a lower risk of lung cancer in general, but the risk was 43 percent lower among diabetic patients who had never smoked and the risk seems to decrease with prolonged consumption.
Non -smokers who took metformin for five years or more had a 52 percent reduction in the risk of lung cancer, but this result was not statistically significant.The use of metformin for five or more years was associated with a 31 percent decrease in the risk of adenocarcinoma, the most common type of lung cancer diagnosed in non -smokers, although it was not statistically significant.
But metformin consumption for five or more years was also linked to an 82 percent increase in the risk of small cell carcinoma, a type of lung cancer frequently diagnosed in smokers, results that were not statistically significant.
In an interview, Sakoda underlines: "The use of metformin was not associated with the risk of lung cancer when we look at all diabetes patients. However, our results suggest that the risk may be different according to the history of smoking habit,with metformin reducing the risk among non -smokers and raising it among smokers. "
"Our results that suggest that the risk linked to metformin could differ by the history of smoking were unexpected. Great additional studies are needed well done to clarify whether metformin can be used to prevent lung cancer or other types, especially in subpopulationsSpecific, such as non -smokers, "he concludes.
