Depending on their smoking history, a drug may have contrary effects on people suffering from diabetes — reducing lung cancer risk among non-smokers and increasing it among smokers.
Among non-smokers who had diabetes, those who took the diabetes drug Metformin had a decrease in lung cancer risk, findings showed.
“Our results suggest that risk might differ by smoking history, with metformin decreasing risk among nonsmokers and increasing risk among current smokers,†Lori Sakoda, a research scientist at Kaiser Permanente Division of Research in Oakland, California, said.
The study involved 47,351 diabetic patients — of which 54 % were men — 40 years or older, who completed a health-related survey between 1994 and 1996.
During 15 years of follow-up, 747 patients were diagnosed with lung cancer.
Metformin use was not associated with lower lung cancer risk overall; however, the risk was 43 % lower among diabetic patients who had never smoked, and the risk appeared to decrease with longer use.
Metformin use for five or more years was associated with a 31 % decrease in the risk for adenocarcinoma, the most common type of lung cancer diagnosed in nonsmokers, and an 82 % increase in the risk for small-cell carcinoma, a type of lung cancer often diagnosed in smokers.
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