More and more women in the United States are becoming afflicted with endometrial cancer, with African-American women experiencing an increased risk to developing the most aggressive forms of the disease, according to a new study conducted by Wayne State University (WSU) researchers.
Michele Cote, a researcher at WSU's Karmanos Cancer Institute, led a team of scientists in examining data collected from cancer registries between 2000 and 2011. They discovered that cases of endometrial cancer in the U.S. increased among all ethnic and racial groups.
The researchers, however, noted that the increase in endometrial tumor cases among European-American women was one percent lower overall compared to the 2.5 percent increase for African-American and Asian-American women and the 1.8 percent increase for Hispanic-American women.
The findings also showed that the survival rate among African-American women with endometrial cancer was considerably lower compared to European-American women with similar age, type of cancer tumor and stage of the disease at diagnosis.
Cote and her colleagues found that these African-American women had a 6 percent lower chance to survive tumors that are low grade and a 59 percent lower chance to endure more aggressive forms of malignancies.
The researchers said that they have yet to determine the cause for this surprising and elevated risk of developing endometrial cancer among African-American women.
Cote explained that they have conducted studies over the past 10 years in order to determine the different factors linked to survival. She said that it is a complex area of research, with access to care and various socioeconomic factors most likely to play a role.
Cote added that there are certain differences in the biology of tumors that they still have to identify, which could cause the disease to be more aggressive in African-American women.
In their research, featured in the journal Cancer Epidemiology, Biomarkers & Prevention, Cote and her fellow investigators stated that endometrial cancer is the fourth most commonly occurring malignancy among women, with close to 50,000 cancer cases diagnosed in the United States alone in 2013.
Birth Control Pills for Cancer Prevention
Meanwhile, a review of previous research on endometrial cancer has found that women who take oral contraceptives during their reproductive years could receive long-term protection against the disease.
In a study published in the medical journal The Lancet Oncology, Oxford University researcher Valerie Beral and her team examined 36 studies including over 140,000 women from different parts of the world.
The researchers discovered that every five years of using contraceptive pills was associated with a reduction in endometrial cancer risk by as much as 24 percent. This was observed among women who had stopped taking birth control pills for over three decades.
"Our results show clearly, for the first time, that the protective effect of the pill on endometrial cancer lasts for over 30 years," Beral said.
Oral contraceptives most commonly prescribed by physicians feature man-made versions of progesterone and estrogen, two natural hormones produced by the female body.
While previous research has suggested that these birth control pills are potentially linked to a reduction in ovarian and endometrial tumor risk, the U.S. National Cancer Institute (NCI) said that these oral contraceptives can also cause an increased risk for other malignancies, such as liver, breast and cervical tumors.
The NCI explained that endometrial cancer typically afflicts 60-year-old women who are at the end of their years of reproduction. Risk factors associated with the disease include never having given birth, obesity, experiencing menstruation at a relatively young age, experiencing menopause at an older age and undertaking estrogen treatment to ease symptoms of menopause.
The researchers noted that since the introduction of the first birth control pills in the 1960s, around 400 million women living in high-income nations have depended on the use of these oral contraceptives alone.
Beral and her team studied medical data gathered from 27,276 women who developed endometrial tumors and an additional 115,743 who did not in order to determine the link between the cancer and the use of birth control pills. Half of the participants were at least 63 years old, while half of those who had endometrial cancer were diagnosed by 2001.
Among the number of endometrial cancer patients examined in the study, around one-third had taken oral contraceptives for close to three years. Around 40 percent of participants who did not have malignancies used the birth control pills and generally took them for over four years.
The reduction of risk to endometrial cancer linked to the use of oral contraceptives depended on the type of tumor. The use of birth control pills was linked to a 31 percent reduction of risk of developing common endometrial carcinomas. These contraceptives were also linked to a 17 percent risk reduction of developing sarcomas, which often begin in the patient's uterine muscle as well as the supportive tissue.
The use of oral contraceptives in high-income countries was associated with a lowering of endometrial cancer risk among women who were 75 years old. Among users of birth control pills, this meant that 1.3 women in every 100 would develop uterine cancer, compared to the 2.3 women in every 100 who did not use oral contraceptives, according to the estimation of the researchers.
Beral and her colleagues, however, note that further studies are needed to determine how oral contraceptives continue to provide protection against endometrial cancer to women who have stopped using them.
Photo: Manuel Medina | Flickr
