Births, breastfeeding rates may explain breast cancer disparities
August 16th, 2011
05:26 PM ET

Births, breastfeeding rates may explain breast cancer disparities

A new study may better explain why African American women have greater risk for developing more aggressive and difficult-to-treat forms of breast cancer, called estrogen and progesterone receptor negative cancers (ER-/PR-). The findings appear in the journal Cancer Epidemiology, Biomarkers and Prevention.

Breast cancer is the second-most common type of cancer among women, after skin cancer. While white women are slightly more likely to get breast cancer than African American women, African American women are more likely to die from breast cancer, according to the American Cancer Society, because they are more likely to develop more aggressive breast cancers. But why this happens has been less clear.

Researchers at Boston University’s Slone Epidemiology Center analyzed data from the Black Women’s Health Study, which began in 1995 and  follows 59,000 African American women who complete health questionnaires every two years.

From 1995 to 2009, 457 women developed estrogen and progesterone receptor positive cancers, ER+/PR+.

When a woman’s breast cancer cells are classified as hormone receptor positive it means they are more likely to respond to therapies that block the hormones from binding to receptors on cells. This is a less aggressive and more easily treated type of breast cancer.

During the same period, 318 cases of ER-/PR- cancers, the more aggressive and difficult-to-treat form of breast cancer, developed among the 59,000 women.

Women who gave birth to two or more children had a 50% associated increase in aggressive ER-/PR- cancer, but the association was not found when the women had breastfed. Other studies have also found an association between breastfeeding and decreased cancer risk.

The results were “strikingly different” when researchers compared the number of births and breastfeeding among women with hormone receptor positive cancers. Women who had two or more children had lower associations of ER+/PR+ cancers, and breastfeeding didn’t change that association.

The authors conclude that their findings suggest that more births among African American women are associated with greater risk for more aggressive ER-/PR- breast cancer, and “because African American women have had more births on average than U.S. white women, this association may” at least partially, explain the higher rates of those cancers among African American women. The authors suggest that efforts to encourage breastfeeding among African American women may help to reduce the number of these deadly types of cancers that disproportionately affect African American women.

soundoff (19 Responses)
  1. eliza

    I went fake tanning for a year when I was 17, and I am on birth control/estrogen pills. My chances of getting skin cancer and/or breast cancer are high. I'm scared.

    August 16, 2011 at 19:48 | Report abuse | Reply
    • Bobbe503

      I can't help you with the breast cancer. Maybe someone else can. But re the skin cancer, here is what you might want to do. Find yourself a dermatologist who is caring and thorough, explain everything, then do exactly what she says to do. It will be worth every penny you will have to pay for the peace of mind it will bring.

      August 18, 2011 at 08:50 | Report abuse |
    • LEB

      Just a year of tanning is unlikely to cause skin cancer by itself, because you've been exposed to more natural sunlight in your however many years than that single year of going to tanning booths. There is also evidence that long-term use of the pill can decrease the likelihood of other cancers. If you're really worried, there are tests that can be done to figure out your genetic predisposition to eventually developing breast cancer. It's not an end-all, be-all, but it can be good information to have.

      Regular self-exams and then mammograms when you're older and your doctor recommends them can catch cancer early, and breast cancer is very treatable if caught early enough. There is also a new test called NAF that is less invasive than biopsies, and considerably less uncomfortable than mammograms. In other words, MANY early diagnostic tests exist, and if you're really this worried, talk to your doctor about what tests are best for women your current age.

      August 22, 2011 at 15:29 | Report abuse |
  2. Lawrence

    Very hard to say. I support you either way.

    August 16, 2011 at 23:52 | Report abuse | Reply
  3. dainelle

    im a 14 year old who is an africian american. ive been healthy ever since but now that i think about it should still be safe but if its possible could i know what the symptoms off breast cancer is.

    August 17, 2011 at 02:17 | Report abuse | Reply
    • DKB

      Learn how to do a self exam, looking for unusual lumps. If you know your own body, then you'll be able to tell when something is "different". Also by the time you are 16 you should get a yearly well woman exam, during this the doctor will also check. At your age you shouldn't have much to worry about, but wanting to be educated is great! Good for you!

      August 17, 2011 at 10:17 | Report abuse |
    • CNNUser

      Dainelle, at 14 years old your chance of developing breast cancer is almost 0%. Your risk of breast cancer increases as you age.

      You can reduce your risk of developing it by maintaining a healthy weight, not smoking, limiting the amount of fat in your diet, exercising regularly, and limiting your alchohol intake. Establishing these healthy habits now will reduce your risk of many illnesses not just breast cancer.

      You can increase your chance of survival should you get breast cancer through early detection. Do this by performing monthly breast self examinations. Talk to your doctor or nurse and ask them to show you how to do this. Get regular check ups and start getting annual mammograms when your doctor recommends. Establish a relationship with a doctor or nurse practioner who you trust and with whom you can discuss your questions and concerns. Then follow their recommendations.

      August 17, 2011 at 10:38 | Report abuse |
  4. Dr Bill Toth

    Are they more likely to die because they allegedly get "More agressive" cancers or because they are lessly likely to see a doctor or seek treatment?

    August 17, 2011 at 07:33 | Report abuse | Reply
    • Dr.Science

      Probably both! There are actually multiple reasons, such as lack of access to quality care, or simply lack of knowledge that contribute to this disparity (same goes for men too).

      August 17, 2011 at 09:33 | Report abuse |
  5. Dr.Science

    Please consult literature before making such statements! Hopefully you didn't just add Dr to your name to make yourself sound important!

    August 17, 2011 at 09:35 | Report abuse | Reply
  6. NM Bowman

    I disagree with you Dr Puttz. Research has indicated that Afr. Americans tend to mistrust doctors & the medical system due to medical experiments like the Tuskegee syphilis experiment. Also, as a married AA female, mother of three, I nurse my children b/c medical professionals have educated me on the benefits of breastfeeding.

    Also, AA women are not the only women having babies outside of marriage. In the past two decades white women have had a 69% increase in unwed birth.

    August 17, 2011 at 10:18 | Report abuse | Reply
  7. crystallla

    dick puttz needs speech lessons

    August 17, 2011 at 12:09 | Report abuse | Reply
  8. Ms. Fergy

    Pure ignorance DrWRONG – I truly hope you DON'T speak for a lot of people. First, as the person above pointed out "AA women are not the only women having babies outside of marriage. In the past two decades white women have had a 69% increase in unwed birth." Next, you assume that all black women are ONLY having children with black men. Check your facts before making such ignorant statements. You might want to do some research on the soaring rates of children out of wedlock in the U.S. as well as declining marriage rates. A lot of people, regardless of race, are just not getting married but the birth rate remains pretty stable. Although I will admit that African Americans rates of bearing children out of wedlock are higher, other races are not far behind....

    August 17, 2011 at 12:14 | Report abuse | Reply
  9. Dr Right

    Oh yeah my B. I forgot. Black wome are having to venture outside of black men for fathers since a LOT of black men prefer white women these days. I was wrong to assume that that all black women are ONLY having children with black men.

    August 17, 2011 at 12:36 | Report abuse | Reply
  10. Enough with the racist MEDICAL BS

    I was waiting for our weekly 'black people are inferior and this scientific study shows why' article from CNN. Reading this website for years and I have seen one EACH WEEK. Get off it already. I am a white woman and yet I am insulted this constant new form of racism. Using the guise of 'science' to support their prejudicial hate. I will say this once: COLOR HAS NOTHING TO DO WITH HEALTH CARE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Her brown skin has zero correlation to breast cancer or any other illness. If any pattern is seen, it is simply a SOCIAL / ECONOMIC ONE. Get it right.

    August 17, 2011 at 12:41 | Report abuse | Reply
    • You're Crazy

      And wrong.

      Have you ever heard of sickle cell anemia? The "Asian glow"? ..Certain genetic traits are more predominant in some races vs. others and to claim otherwise is ridiculous. Read a book.

      August 17, 2011 at 12:48 | Report abuse |
    • Renelda Moorehead


      August 17, 2011 at 12:58 | Report abuse |
    • Dr.Science

      You are obviously not a scientist or working in health care! There are genetic components that make some people more susceptible to developing cancer, and somethimes these genetic components are found in a particular race. African American men are more likely to develop prostate cancer than their white counterparts! It is a fact, but clearly you don't understand what that is. As this article states, African American women tend to develop a more agressive type of cancer. Even though they get diagnosed with breast cancer less than their white counterparts, they die more from it. Again, it is a fact! And no, I am not African American!

      Please get educated!

      August 17, 2011 at 14:25 | Report abuse |
  11. Renelda Moorehead


    August 17, 2011 at 12:55 | Report abuse | Reply

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