The link between smoking and kidney cancer may be stronger than experts have appreciated. Pulling together data from 24 studies conducted since the 1960s, an international research team found that the risk of kidney cancer was 38 percent higher among people who had ever smoked versus those who had never picked up the habit. And the more smokers had puffed over a lifetime, the greater the risk to their kidneys a so-called dose-response relationship that supports a direct link between smoking and kidney cancer.

Smoking is responsible for most cases of lung cancer, as well as cancers of the throat, mouth and bladder; it also contributes to a number of other cancers, including tumors of the pancreas and cervix. It’s only in recent years, however, that the habit has been acknowledged as a risk factor for kidney cancer, and the extent of the risk has not been clear.

“This study actually quantifies the risk,” said lead author Dr. Jay D. Hunt, a researcher at the Louisiana State University Health Sciences Center in New Orleans. “And we found that the risk is larger than we’d thought.” In fact, Hunt told, before conducting this study, he had been skeptical that the relationship between smoking and kidney cancer was real in part because past studies have yielded conflicting results.

Even when an association has been found in individual studies, he noted, it has generally been “modest.” The new findings, according to Hunt, indicate that, compared with certain other cancers particularly lung cancer the kidney cancer risk associated with smoking is indeed modest. But it may be a bigger risk than generally appreciated, he said, with even light to moderate smoking boosting a person’s chances of developing the disease.

Source: PakTribune