Studies reveal disturbing trends in breast cancer in young women

Dawn Andersonby Dawn Anderson

Amanda was 36 when her employer announced they were hosting a mobile mammogram event she could take advantage of. Having read that a “baseline” mammogram was recommended for women between 35 and 40, she signed up. She was the mother of a one-year-old, trying to have a second child and didn’t have any health concerns – she was just doing what she had heard was a pro-active step in her breast health.

What she wound up with was the news that she had a stage 2 tumor in her breast that wasn’t even palpable. Her doctor told her that if she’d waited until she was 40 to have a mammogram, she probably wouldn’t have survived.

Heather knew she had a family history of breast cancer, so when – at age 36 – she felt 2 lumps in her breast, she went to her doctor with fear in her heart. It was August of 2019. Her doctor told her to monitor them and come back in a month. When she returned, a mammogram, ultrasound and biopsy all confirmed her worst fear. She was diagnosed with Her2+ breast cancer and by October began 6 months of chemotherapy – with surgery and more treatment continuing through the early months of the COVID pandemic.

We know that cancer risk increases the longer we live, for a variety of reasons. A recently published study, however, revealed a disturbing pattern of increased incidence of cancer in people younger than 50 years old (early onset cancer). As a breast cancer advocacy organization, we were particularly stricken by data that showed young women being the primary drivers of this increase.

The study was quite large – using data from 17 National Cancer Institute Surveillance, Epidemiology and End Results (SEER) registries from January 1, 2010 – December 31, 2019. It covered 562,145 patients with early onset cancer over those years, equaling a total of over 2 billion person years of observation.

It found that between 2010 and 2019, overall incidence rates of all early onset cancers increased “substantially.” And, while incidence in male individuals decreased by 4.91%, incidence in female individuals increased by 4.35%. In contrast, the incidence rates of cancers in individuals over 50 years old decreased during that time frame.

By age group, the incidence rate of early onset cancer in individuals 30-39 increased .91% per year, but remained stable in other age groups.

So what’s up with that increase in female early onset cases? The authors concluded that it is primarily due to cancer of the breast and uterus. Gastrointestinal (GI) cancers had the fastest growing incidence rates (2.16% average increase per year, with 7383 in 2019). But breast cancer accounted for the highest number of cases at the conclusion of the study period in 2019 (12,649), increasing 7.7% from 2010.

That rates of early onset breast cancer are increasing is alarming enough, but another recent study has even more disturbing news.

A 2021 study found that while breast cancer mortality rates have been declining since 1989 (primarily due to mammography screening programs and improved treatments), after 2010 those rates stopped declining for women younger than 40. The rates have continued to decline since 2010, by 1-2% per year for women 40-79, but not for younger women.

The study authors conclude this change in mortality rates in women younger than 40 is in part explained by a significant increase in the number of breast cancers diagnosed at a distant stage. In women 20-39 years old at diagnosis, distant stage incidence rates have increased by more than 4% per year since 2000. In women 40-69, distant stage rates increased by far less – 1.2% or less per year.

The study points out that screening guidelines in place in 2009 (prior to the study period) recommended against screening for women 40-49 and women over 74. They note there is also an increase of 1.85% per year in the rate of late stage disease in women 70-79.

It’s possible that the benefits of early detection contributing to lowered mortality rates for breast cancer are not benefiting young women.

The early-onset study didn’t speculate about the causes of the increase in incidence rates, other than evaluating patterns among 12 cancers known to be related to obesity. Breast cancer was not noted.

The 2021 study on mortality rates noted possible factors for the increase in breast cancer diagnoses in young women, but concluded there were “no clear explanations.” Possible known risk factors include genetics, delayed first pregnancy, dense breasts, early menarche and lifestyle factors such as diet, weight, alcohol use and environmental exposures. (WBCC has reported extensively on environmental exposures as a risk factor.)

We do know that young women diagnosed with breast cancer are more likely to be diagnosed with late stage disease (because they more often find their tumors themselves) and with more aggressive sub-types of breast cancer. Their recurrence risk is also increased.

Klara had recently weaned her daughter when she felt a lump. Like Heather, her doctor also told her to come back in a month. She was diagnosed two months later at age 28. That was in 2007. In May of 2021 she felt something that felt like she’d strained a muscle. It turned out she had a recurrence of her cancer in her chest wall.

For young breast cancer patients, their experience with the disease can have different impacts than in an older woman. A study on breast cancer in adolescents and young adults found they more frequently report quality of life issues than older breast cancer patients.

They are at higher risk for psychosocial issues including “depression, anxiety, sense of isolation, poor body image, disruptions in relationships, occupational difficulties, and financial toxicity.” Physical side effects from treatment may follow them throughout their lives – such as cardiac dysfunction from chemotherapy, or bone density loss from ovarian suppression. Fertility preservation is a big concern not present for older breast cancer patients.

Their first hurdle, though, may simply be getting a doctor to believe them and take action when they say something is wrong. If a 50-year-old woman presented at her physician’s office saying she’d felt a lump, she would be examined and most likely sent promptly for diagnostic tests. That is often not the case for young women.

Rose was diagnosed 3 weeks after the birth of her fifth child, but she first pointed out the lump she and her husband felt when she was 15 weeks pregnant. At 20 weeks, her OB “brushed it off” as likely a clogged milk duct. Finally, after delivery, with her husband acting as advocate, they were able to get an exam. She was diagnosed with stage 2 breast cancer.

Young women are less likely to be as financially secure as older women and while a cancer diagnosis is often financially devastating for anyone, for young adults it can be catastrophic. One of the young survivors with whom I spoke for this article shared with me that she and her husband lost their home and had to file for bankruptcy. Rose shared that her fellow employees donated hundreds of hours of PTO to help cover her insurance costs, her husband was fortunate to have flexibility in his job to join her for appointments, and her mother moved in to help out, but said “We would have never been able to afford to live without the support system around us and understanding jobs.”

Young women with families bear the burden of having to share their diagnosis with young children.

Heather shared with me that while her 9-year-old son was very brave, one day she decided to change from a brunette wig to a blond one. He became very emotional driving to school because he was afraid “everyone would know.” She describes trying to juggle working, parenting and treatment: “Some days were definitely harder than others to remain strong and not show him I was feeling defeated. There were a lot of days when I would feel like a terrible mom because I was just tired and needed to sleep and couldn’t play outside with him.” 

Rose says telling her children (four under the age of 10) was the hardest part. She and her husband immediately contacted their school counselor for guidance. Almost one year later, as she’s now healing from radiation and planning for two more surgeries, her kids are having a hard time grasping what a long process this is. “So when I’m sick or down, I can really see the worry in my kids eyes.”

Data is important. Emerging trends can be like the proverbial “canary in a coal mine.” And while science progresses based on data, not anecdotal stories, these stories are vital. It’s important that they’re shared.

I’d like to thank these young survivors who chose to share their stories with me for this article and encourage anyone else with a story to find ways to share it with health policy makers or through advocacy organizations like WBCC – we can help be your bullhorn.

The reality in all of this, as we embark on an October full of breast cancer awareness messaging, is that we are far from done in our work. Celebrating survivorship is wonderful and we share in that joy all year round. But something is amiss, and we should be paying attention to the trend of increasing incidence of breast cancer in young women AND a coinciding lack of decrease in mortality rates in that age group.

As the authors of the early onset study concluded, health care professionals need to be educated about the increase in early onset cancer and investigation of possible tumors needs to be considered in all patients, not just those over 50. The data should be a “call to action for further research into the various environmental factors that may be associated with this concerning pattern.”

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If you have been diagnosed with early onset breast cancer, you can find a supportive community in The Young Survival Coalition.

Sources:

R. Edward Hendrick, Mark A. Helvie and Debra L. Monticciolo. “Breast Cancer Mortality Rates Have Stopped Declining in U.S. Women Younger than 40 Years.” Radiology 2021 299:1, 143-149. https://pubs.rsna.org/doi/full/10.1148/radiol.2021203476.

Benjamin Koh, Darren Jun Hao Tan, Cheng Han Ng, et al. “Patterns in Cancer Incidence Among People Younger Than 50 Years in the US, 2010 to 2019.” JAMA Netw Open 2023 6:8. https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2808381

Elizabeth J. Cathcart-Rake, Kathryn J. Ruddy, Archie Bleyer, and Rebecca H. Johnson. “Breast Cancer in Adolescent and Young Adult Women Under the Age of 40 Years.” JCO Oncology Practice 2021 17:6, 305-313. https://ascopubs.org/doi/10.1200/OP.20.00793