By combining the results of 33 previous studies, Italian researchers found that current smokers were more than twice as likely as nonsmokers to develop cancer, either in the esophagus or part of the stomach called cardia.
In some studies, the risk of esophageal cancer remained high even when people had stopped smoking three decades earlier.
The two cancers, both known as adenocarcinomas, are relatively rare in Western countries. Rates elsewhere are much higher, especially in less developed countries. But in recent decades, cancer rates have risen in the U.S. and Europe - may be linked to rising obesity rates.
Smoking has long been considered a risk factor for both cancers.
But these results provide a "quantitative" risk, "said lead researcher Dr. Eva Negri, the" Mario Negri "Institute for Pharmacological Research in Milan.
Moreover, they suggest that the risks remain high as the average for some time after smokers quit.
"Stopping smoking is beneficial at any age, but it seems that for these cancer risk decreases only slowly," Negri said in an email.
For their study, published in the journal Epidemiology, Negri and his colleagues pooled the results of 33 previous studies. In most of them, the researchers compared a relatively small group of patients with tumors of the cardia or esophagus or stomach cancer against a group.
In three studies, researchers have followed large groups of adults over time, mapping of new cases of cancer of the cardia oesophageal or gastric.
Overall, the team found Negri, current smokers were more than double the chances of developing any cancer, compared with people who had never smoked.
0 Comments