Taller women are at a greater risk for ovarian cancer, according to a new study.
The study, based on 47 previous studies that included 25,157 women with ovarian cancer and 81,311 women without, show for every 5 centimeters or about 2 inches taller in height, there is a 7 percent increase in a woman’s chances of developing the disease during their lifetime.
For example a 165 cm or 5.41 feet tall woman will have a 14 percent greater risk of ovarian cancer compared to those who are 155cm or 5.09 feet tall.
Researchers also found a similar link between weight and ovarian cancer risk only in women who have never used menopausal hormone replacement therapy.
“These results show that in women who are not taking HRT, ovarian cancer risk increases steadily with increasing BMI. These results relate only to the effect of body size on ovarian cancer risk and do not provide any relevant information about advice on HRT use,” one of the lead researchers Dr. Gillian Reeves of the Cancer Epidemiology Unit at Oxford University said in a statement released on Wednesday.
Researchers said that the average height and BMI of women in Western countries have been increasing by about 1 cm and 1 kg/m2 each decade, which suggest that the number of ovarian cancer cases are also rising by 3 percent ever decade, if all other factors involving ovarian cancer remained constant.
While scientists are still unsure as to why there is a link between disease risk to height and weight, they suggest that tall or heavier women have more cells in the body which can become cancerous, and that growth hormones may also play a role.
"The increase in ovarian cancer risk with increasing height and with increasing body mass index did not vary materially by women's age, year of birth, ethnicity, education, age at menarche, parity, family history of ovarian or breast cancer, use of oral contraceptives, menopausal status, hysterectomy, or consumption of alcohol and tobacco,” the authors wrote.
Researchers noted that while the increase in risk was found to be statistically significant, the likelihood of any particular person developing ovarian cancer is so low that their height will only make a marginal difference.
“The absolute risk is small. The shorter woman will have a lifetime risk of about 16 in 1000, which increases to 20 in 1000 for a taller woman,” Dr. Paul Pharoah, a cancer expert from Cambridge told the Telegraph.
“This study included as much evidence as possible to produce a clearer picture of the factors that can affect a woman's risk of developing ovarian cancer, and found that body size was important,” Sarah Williams, health information officer at Cancer Research UK, said in a news release.
“Women can reduce their risk of this and many other diseases by keeping to a healthy weight. For women trying to lose weight, the best method is to eat healthily, eat smaller amounts and be more physically active,” Williams added.
The study was published in the Public Library of Science Medicine journal.
According to the U.S. Centers for Disease Control and Prevention, ovarian cancer is the eighth most common cancer and the fifth leading cause of cancer death, among women in the United States. While ovarian cancer causes more deaths than any other cancer of the female reproductive system, the disease only accounts for about 3 percent of all cancers in women, and treatment is more effective the earlier it is detected.