What Data From the ‘Hair Straightener and Uterine Cancer’ Study Mean for Black Women.

A 2022 study published in the Journal of the National Cancer Institute has found a possible association between frequent use of chemical hair straightening products and developing uterine cancer. 

Researchers studied 33,947 women who participated in The Sister Study, a breast cancer research project conducted in the early 2000s. Participants had answered survey questions about their personal and family history of breast cancer, uterine cancer, and lifestyle behaviors, such as use of chemical hair straightener products.

Recent re-analysis of the data showed that women who used chemical hair straightening products frequently (more than 4 times) within the previous year were more than twice as likely to develop uterine cancer than women who had never used them. 

This is an alarming statistic. Moreover, it might be severely underestimating the true risk of those who are vulnerable—Black women. 

Black women comprise 60% of hair straightener product users in the US, yet the majority of patients in this study were actually white (85%). Only 7.4% of the patients in this study were Black. This is disheartening and unfortunately not surprising, as clinical research continues to under-represent non-white patient populations. 

So, what does this data mean for Black women? 

Since the relationship between hair straightener product use and uterine cancer was present for white women, we can assume it is there for Black women. But the patterns of use of chemical straightener and types of straighteners may be different by racial group. And this study, unfortunately, does not answer this question because of how few Black patients were included. 

We know that Black women are twice as likely to develop aggressive subtypes of uterine cancers, are more likely to be diagnosed at an advanced stage, and are nearly twice as likely to die from uterine cancer than non-Black women. Similar trends are seen in the Breast Cancer literature.  

I’m a Black woman, and I press my hair every month. Though I don't use relaxers or chemical products, hair care is an important part of my daily life and culture. Much of this is influenced by societal norms we place on women to have ‘good’ or ‘professional’ hair. Chemical hair straighteners may be associated with certain types of breast cancer—digging deeper into the data has potentially far-reaching impacts for me and my patients.

While the data are important and alarming, we cannot yet make a sweeping recommendation about whether women should immediately stop using chemical hair straighteners. This study demonstrates an association and not that these hair products directly cause cancers. We absolutely need more dedicated studies on chemical straightener use and endometrial cancer outcomes with a more representative patient population.

The best thing for Black women to do in the meantime is to control what we definitively know increase endometrial cancer risk.

Uterine cancer risk factors we can control.

Weight management.

Being overweight or obese increases a patient’s risk of endometrial cancer. According to the American Society of Clinical Oncology, approximately 70% of endometrial cancers can be linked with obesity. Every five-unit increase in body mass index increases the risk of endometrial cancer by 50%. Extra fatty tissue produces hormones that encourage overgrowth of the inner lining of the uterus (the endometrium), which can turn into cancer. 

While body positivity is important, there is not enough constructive discussion about the metabolic connection between obesity and cancer. In the U.S., nearly 42% of adults—including 49.9% of Black and 41.4% of non-Hispanic white adults—are obese. 

MedStar Washington Hospital Center is home to nationally recognized gynecologic oncology and bariatrics and weight management teams. Our metabolic specialists include experts in nutrition, exercise science, bariatric surgery, anti-obesity medication therapy, and women’s health. 

Self-advocacy.

If you know you have a family history of uterine cancer, talk with your doctor about how to reduce your personal risk. If you feel like you aren’t being heard, see a different doctor—advocating for yourself is key, and that means taking action when you have symptoms, rather than shrugging them off.

Research I'm doing right now in Black women with endometrial cancers shows that women consistently notice early symptoms, such as:

• Bleeding or spotting between periods or after menopause
• White or clear vaginal discharge
• Heavy or irregular periods
• Pain during sex
• Unexplained pelvic pain or cramping

However, I’m finding that some women think these changes are normal—THEY’RE NOT! And, more unfortunately, when they bring these issues up to their doctors, sometimes they don’t get listened to or they don’t get the correct studies or appropriate follow-up. Any bleeding after menopause is not normal, and even if an ultrasound looks OK, patients with bleeding still need an endometrial biopsy. If that is normal, they need a dilation and curettage.

These are the two extra steps you should ask the doctor to take if an initial exam comes back as inconclusive:

1. If you have vaginal bleeding (any bleeding after menopause or bleeding in between periods), you need a biopsy—when a doctor takes a sample of tissue from the endometrium (the lining of the uterus) and has it analyzed in a laboratory for signs of cancer. 
2. If the biopsy is clear, you need a dilation and curettage (D&C) procedure. The doctor removes a small sample of tissue from the uterus itself, which can help pinpoint the cause of abnormal bleeding. From a D&C, we can determine whether you have something that is common and highly treatable, such as non-cancerous polyps, or a more serious condition such as uterine cancer.

Doctors should be more aggressive in asking women about symptoms they might take as a normal part of having a uterus or aging. And patients should listen to their bodies and can be more vocal when their concerns aren’t addressed. These shifts could result in earlier detection of more cancers, saving lives and reducing the burden of uterine cancers on Black women and families.

Diverse enrollment in clinical trials.

Clinical studies offer an opportunity for patients to receive the best care and potentially a new, effective treatment option. However, patients can only enroll if they are alerted to new studies that are relevant to them—and limited access to healthcare among people of color makes this messaging more challenging.

Resolving this problem starts with patient-provider communication. Doctors should proactively ask about patients’ symptoms and conditions and offer patients opportunities to enroll in studies that make sense for present and future health. And patients should feel comfortable researching and asking about whether they are a fit for ongoing clinical studies. 

Depending on the study model, a patient may significantly benefit personally, contribute to diversifying the body of medical research, or both.