As the Canadian Task Force on Preventive Health Care prepares to release its anticipated updated guidelines on breast cancer screening, University of Ottawa researchers are sounding an alarm: Breast cancer cases in young Canadian women, especially women in their 20s, have risen by as much as 45.5% in recent years.
Study findings, which were published on April 25 in the Canadian Association of Radiologists Journal also highlighted an increase in cases among women in their 30s and 40s by as much as 12.5% and 9.1%, respectively. These statistics raise the question of whether Canadian women younger than 50 years (for whom mammography screening has not been routinely recommended) should be screened.
“We should be doing a better job at identifying people who are more likely to get breast cancer in their 20s and 30s,” lead study investigator Jean Seely, MD, head of breast imaging at The Ottawa Hospital and professor of radiology at the University of Ottawa, Ottawa, Ontario, Canada, told Medscape Medical News. “By age 25 or 30 at the latest, any woman should undergo a risk assessment for breast cancer to learn if she would benefit from early screening,” she added.
Need for Vigilance
Seely and her team evaluated breast cancer incidence trends in women younger than 50 years in Canada and compared them with corresponding trends in women aged 50-54 years. Case data were obtained from the National Cancer Incidence Reporting System (1984-1991) and the Canadian Cancer Registry (1992-2019) and population data from Statistics Canada.
“One of the significant differences in this study was that we examined age-specific incidence rates, looking at them in age groups by decade (ie, 20-29 years, 30-39 years, 40-49 years), and then even divided the [latter group] into 40-44 years and 45-49 years,” said Seely. “We really saw a dramatic change starting around the year 2000 for women in their 20s, with an annual percent increase of 3.06% per year, and it steadily increased from there.”
For women in their 30s, annual rates increased by 1.25% from 2009 onward. For women in their 40s, an increase of 0.26% was observed between 1984 and 2019; in women between ages 40 and 44 years, the increase was 0.19%. Rates in women aged 50-54 years were not as dramatic; they appeared to decline significantly between 1999 and 2005 but rose in 2005 and 2015, likely because of inconsistent screening recommendations for women in their 40s during those years, according to the researchers.
The findings are useful for informing screening recommendations for women in their 40s (who are currently advised to weigh screening pros and cons with their doctors), said Seely. They also highlighted an important and currently underrecognized need in Canada: Early detection in younger women to avert unnecessary morbidity and mortality.
Role of Risk Assessment
The study did not include 2020 data because including them might have resulted in a downward bias on incidence trends, according to the researchers. Moreover, it did not assess ductal carcinoma in situ. Nevertheless, “it’s a well-designed study, and I think that it’s providing us with some valuable information, most notably that women are being diagnosed at younger ages with breast cancers,” said Ruth Heisey, MD, head of family and community medicine and primary care at Women’s College Hospital in Toronto, Ontario, Canada.
“It’s really important for us as clinicians to be vigilant, especially in young women presenting with breast symptoms,” added Heisey, who was not involved in the study. “We can’t fall into the trap of assuming that because a woman is young, it’s likely a benign disease or just prominent breast tissue that will resolve after their next period,” she said.
It’s well established in the literature that younger women who present with breast cancer tend to be diagnosed with later stage, aggressive disease. Seely and Heisey emphasized the importance of taking a thorough family history for identifying high-risk patients, who represent about 5% of the population, said Seely.
“We should risk stratify them and look closely for clues,” said Heisey, adding that “the most accurate risk assessment tools that we have, the CanRisk or the IBIS risk tool, are readily available.” Discussing a genetic testing option also provides an opportunity to maintain a high index of suspicion. “Anybody we think may carry the risk of cancer presenting at young ages and multiple predominantly first-, second-, or even third-degree relatives, we need to be paying attention,” she said.
Finally, Heisey advised that clinicians be mindful of less apparent clues. “Women will sometimes indirectly communicate their breast symptoms. If someone says, ‘Do I need a mammogram?’ they may actually be saying that they have a breast concern,” she said.
The study was partially funded by Women and Gender Equality Canada. Seely and Heisey reported no relevant financial relationships.
Liz Scherer is an independent health and science journalist based in the United States.