STOCKHOLM, Sweden, April 16 (UPI) — Girls who are relatively thin at age 7 may be at higher risk of breast cancer later in life while a large-body size may be protective, Swedish researchers said.
Jingmei Li and colleagues at the Karolinska Institutet in Stockholm, Sweden, said the study involved 2,818 Swedish breast cancer patients and 3,111 controls.
The study, published in the journal Breast Cancer Research, found a large-body type at age 7 was associated with a decreased risk of post-menopausal breast cancer.
“Although strongly associated with other known risk factors such as age of the first menstrual cycle, adult body mass index and breast density, size at age 7 remained a significant protective factor after adjustment for these other issues,” Li said in a statement.
In addition, large body size at age 7 was also found to be protective against estrogen receptor negative tumors, which generally fare worse, the researchers said.
“It appears counterintuitive that a large body size during childhood can reduce breast cancer risk, because a large birth weight and a high adult BMI have been shown to otherwise elevate breast cancer risk,” Li said in a statement. “There remain unanswered questions on mechanisms driving this protective effect.”
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