Women with breast cancer aged 35 and under are at a higher risk of the disease spreading to other parts of the body, according to an alarming new report.
Doctors believe this may be due to the fact that young women are less likely to have regular breast exams, and thus may allow the cancer to go undetected until it’s reached more aggressive stages, The Guardian reported on Tuesday.
Approximately one in eight women in the US — about 13% — will develop “invasive” breast cancer during their lifetime, according to the American Cancer Society. Globally, some 2.3 million women will be diagnosed with the disease, per World Health Organization statistics.
Survival rates trend towards positive outcomes if detected during its early stages, but a new review of more than 400 breast cancer studies indicates that the overall risk of the cancer metastasizing — or, spreading to other parts of the body — ranges relatively widely, between 6% and 22%.
The new study indicated specific risk factors for metastatic breast cancer, including those diagnosed under age 35; who develop large tumors prior to initial diagnosis; or have been diagnosed with particularly aggressive forms of the disease, such as subtype Luminal B breast cancer.
Results of the review, which incorporated data of tens of thousands of women throughout the six habitable continents, was presented at the sixth International Consensus Conference for Advanced Breast Cancer, to be held virtually from Nov. 4 to Nov. 6.
“Secondary breast cancer can develop many years after an initial cancer diagnosis, so it’s vital that we understand it better and find new ways to prevent it,” said Kotryna Temcinaite, a spokesperson at UK-based advocacy group Breast Cancer Now, in a statement.
A patient’s likelihood of cancer metastasis varies between those aforementioned risk factors.
Women aged 35 and under with the diagnosis face a 12.7% to 38% risk of seeing their cancer return elsewhere in the body. Compare that to breast cancer patients aged age 50 and up, whose risk of secondary breast cancer is 3.7% to 28.6%.
Meanwhile, the risk of metastasis for those diagnosed with Luminal B subtype was 4.2% to 35.5%; less aggressive form, Luminal A, suggested half the risk, between 2.3% to 11.8%.
“This may be because younger women have a more aggressive form of breast cancer or because they are being diagnosed at a later stage,” said Dr Eileen Morgan, of the International Agency for Research on Cancer (IARC), who will present the study at the upcoming conference.
Once the cancer has returned, it “becomes much harder to treat and the risk of dying is higher,” said Morgan.
“However, we don’t really know how many people develop metastatic breast cancer because cancer registries have not been routinely collecting this data,” she added.