Women who smoke may have yet another reason to quit the habit, as a new study has found that there could be a link between smoking by women and the risk of developing breast cancer.
A research was conducted by the Hutchinson Cancer Research Center in Seattle, in which women of age between 20-44 diagnosed with cancer between 2004 and 2010, were studied. The study sample was composed of 778 women from the Greater Seattle area who were diagnosed with estrogen receptor-positive type breast cancer, and 182 with triple-negative type breast cancer. Their data was compared with those of 938 cancer-free women.
The study, headed by Dr. Christopher Li, has found that women aged between 20-44 who have been smoking a pack a day for at least a decade, were 60 percent more likely to develop estrogen receptor-positive breast cancer, when compared with those who have been smoking for less than ten years. Those who have been smoking less than a pack a day for at least 15 years had a 50 percent higher risk of contracting estrogen receptor-positive breast cancer. Those women who have smoked at some point in their lives had a 30 percent higher change of contracting any type of breast cancer, compared with women who have never smoked.
However, the smokers were not likely to develop the more aggressive and more rare type of breast cancer, which is the triple-negative breast cancer.
The researchers say it's possible that some of the chemicals found in cigarette smoke act like estrogens, which cause estrogen receptor-positive breast cancer. The study, however, have produced conflicting results, as questions still remain about how smoking causes certain types of breast cancers.
"I think there is a growing appreciation that breast cancer is not just one disease and there are many different subtypes," said Li. "In this study, we were able to look at the different molecular subtypes and how smoking affects them."
The National Cancer Institute says that one in every eight American women will have breast cancer. However, only one in every 227 women aged 30 years will develop breast cancer before they turn 40. This means that the risk of breast cancer is lower in younger women. However, smoking changes this, as this new study shows.
Geoffrey Kabat, an epidemiologist at the Albert Einstein College of Medicine of Yeshiva University in Bronx, New York, has researched the effects of smoking on the risk of breast cancer, and he says previous studies were still inconclusive.
"We know smoking is bad for you and the earlier you smoke and the more often you smoke the worse off you're going to be in terms of many outcomes, but the role of smoking in breast cancer is not clear," said Kabat. "There may be something going on and it may be a modest effect in some subgroups."
