Many women with breast cancer lack basic knowledge about their disease, such as their cancer stage and other characteristics, according to a new study.
The lack of knowledge was even more pronounced among minority women, the study authors found.
This finding is worrisome because knowing about a health condition can help people understand why treatment is important to follow, experts say.
"We certainly were surprised at the number of women who knew very little about their disease," said Dr. Rachel Freedman, assistant professor of medicine at Harvard Medical School and a medical oncologist specialising in breast cancer at the Dana-Farber Cancer Institute.
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Although the study didn't specifically look at the reasons behind the lack of knowledge, Freedman suspects that women may be overwhelmed when they're initially diagnosed. In addition, she said, individual doctors vary in how much information they give and how well they explain the cancer characteristics.
The study is published online in Cancer.
Kimlin Tam Ashing, a professor at the Beckman Research Institute at the City of Hope Cancer Centre in Duarte, California, reviewed the study's findings, and said that quick appointments may also be to blame for the knowledge gap.
What is cancer 'stage'?
In the survey, Freedman and her team asked 500 women four questions about their cancer including questions about tumour stage, grade, and hormone receptor status.
Overall, 32 percent to 82 percent of women reported that they knew the answers to these questions. But only 20 percent to 58 percent were actually correct, depending on the characteristics, the investigators found.
Just 10 percent of white women and 6 percent of black and Hispanic women knew all of their cancer characteristics correctly, according to the study.
Cancer "stage" describes the extent of the cancer, whether it is invasive or not and if lymph nodes are involved (stages 0 through IV). Two-thirds of white women and about half of black and Hispanic women were able to correctly identify their cancer's stage, the researchers found.
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Cancer "grade" describes how the cancer cells look under the microscope and can help predict its aggressiveness. Just 24 percent of white women, 15 percent of black women and 19 percent of Hispanic women knew what their cancer grade was, according to the study.
Two other questions asked about hormone receptor status. One asked about whether or not a cancer was HER2 positive. HER2-positive tumours test positive for a protein (human epidermal growth factor receptor 2) that promotes cancer cell growth. Almost two-thirds of white women, and just over half of black and Hispanic women were able to answer this question accurately, the researchers found.
Racial and ethnic differences
The other question about hormone receptor status was whether or not the cancer was oestrogen receptor-positive. Oestrogen receptor-positive cancers need oestrogen to grow. Other cancers are progesterone receptor-positive. Seventy percent of white women knew their oestrogen receptor status, but fewer than half of the black and Hispanic women did, the study revealed.
Black and Hispanic women were less likely than white women to know and have correct responses in each measure. Even after the researchers took into account women's education and their health literacy, there were still racial and ethnic differences.
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While the results were disappointing, Freedman added, hopefully, "this is a modifiable problem."
Doctors and other health care professionals can address the knowledge gap in clinics and in practices, she said. She recommends that breast cancer patients bring along a partner, friend or other family members. "When patients come with people, it always helps," she said, as they can take notes for the patient or think of questions that haven't occurred to the patient.
"I wasn't surprised, unfortunately," Ashing said of the current study.
The danger of not knowing information about your breast cancer, she said, is that it "might influence women's decision about treatment adherence." It might also affect how well they stick to schedules recommended for follow-up care and testing.
Along with having someone accompany you to a medical visit, she recommended that breast cancer patients ask if they can talk to another patient with the same diagnosis. She has studied this approach, known as "peer navigation", and found it to be helpful.
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