A new study found that smoking cigarette increases the risk of breast cancer in young women by up to 60 percent.

The National Cancer Institute said that one out of eight American women is likely to develop breast cancer. However, only one out of 227 women aged 30 years will contract breast cancer before they reach the age of 40. Meaning to say, the risk of breast cancer is lower in younger women. Even so, smoking changes this, as this new study implied.

Researchers from the Fred Hutchinson Cancer Research Center led by epidemiologist Christopher Li discovered that there are some chemical components found in cigarette smoke that acts like estrogens which trigger breast cancer. However, they haven't fully determined yet if how smoking affects certain types of breast cancer.

They recruited women aged 20 to 44, who were diagnosed with cancer between 2004 and 2010. Among the group, 778 were diagnosed with estrogen receptor-positive type breast cancer, 182 were diagnosed with triple-negative type breast cancer, and 928 were cancer-free.

Each participant was asked about their smoking history. After reviewing the data collected, the researchers concluded that those who smoked a pack of cigarette a day for 10 years had increased their risk of developing estrogen receptor-positive breast cancer by 60 percent compared to those who smoked for less than a decade. Meanwhile, those who smoked less than a pack per day for at least 15 years were 50 percent at risk on developing the disease.

Participants who have smoked occasionally, on the other hand, were 30 percent at risk of having any type of breast cancer, compared with women who have never smoked.

However, it was found that women who smoke were not likely to develop triple-negative breast cancer, the more aggressive and more unusual type of breast cancer.

"I think there is a growing appreciation that breast cancer is not just one disease and there are many different subtypes. In this study, we were able to look at the different molecular subtypes and how smoking affects them," Li said to Tech Times.

This study was published in the Feb. 5 issue of Cancer.