By A new study by the American Cancer Society has revealed a disturbing rise in a rare and often overlooked form of breast cancer. Experts warn that the disease, once considered uncommon, is now appearing more frequently — especially among younger women — raising urgent questions about lifestyle, hormones, and early detection.
Scientists have raised serious concerns after discovering that a rare yet deadly form of breast cancer is increasing in the United States at a rate nearly three times faster than other breast cancer types.
Surge in Invasive Lobular Carcinoma Cases
Between 2012 and 2021, cases of invasive lobular carcinoma (ILC) — a less common but aggressive type of breast cancer — rose by 2.8% annually among women aged 50 and older and 2.9% among women under 50.
By comparison, the rate for all other breast cancers combined grew by only 0.8% during the same period.
The most concerning phase occurred between 2016 and 2021, when annual ILC cases surged by 3.4%, highlighting a rapidly worsening trend. Experts believe this rise is primarily linked to lifestyle and hormonal factors, rather than genetic causes.
Sharpest Increase Seen in Asian American and Pacific Islander Women
According to new data released this week by the American Cancer Society (ACS), Asian American and Pacific Islander (AAPI) women showed the steepest increase in lobular breast cancer cases — with a 4.4% annual rise.
However, white women still report the highest overall rate, with 15 cases per 100,000 women, followed by Black women at 11 per 100,000, and AAPI women at nearly seven per 100,000.
“Although lobular breast cancer represents just over 10% of all breast cancers, the growing number of diagnoses makes it critical to understand,”
said Angela Giaquinto, Associate Scientist of Cancer Surveillance Research at the ACS.
How ILC Differs from Other Breast Cancers
Unlike most breast cancers that form a lump, lobular carcinoma spreads in scattered patterns, making detection more difficult.
While ILC is not necessarily more aggressive in terms of metastasis, it tends to spread to unusual locations in the body and may do so later, complicating diagnosis and treatment.
Researchers analyzed national cancer registries to compare invasive lobular carcinoma with other breast cancer types. Using advanced statistical models, they identified distinct growth trends and calculated long-term survival outcomes.
Lower Long-Term Survival Rates
Although the five-year survival rate for ILC is similar to other breast tumors, outcomes decline significantly over ten years.
Due to its unpredictable spread and potential for late recurrence, patients with ILC have poorer long-term prognoses.
- The 10-year survival rate for advanced-stage (distant) ILC is only 12.1%,
- compared to 19.6% for the more common ductal carcinoma.
This finding highlights a troubling reality: while early survival odds may seem similar, the long-term outlook for ILC patients is considerably worse.
“Preventive and early detection strategies targeting this subtype must be prioritized,” Giaquinto added.
“After seven years, survival rates for lobular breast cancer drop significantly compared to the most common forms.”
Chart: Diagnostic Rates of Lobular Breast Cancer in the U.S. (1975–2021)
This chart illustrates lobular breast cancer diagnosis rates by race and ethnicity across the U.S. over nearly five decades.
White women consistently exhibited the highest rates, with risk peaking between ages 70 and 79 before declining.
Researchers emphasized that the unique biology of ILC — which makes it harder to detect and potentially less responsive to chemotherapy — demands further investigation and targeted therapies.
“Invasive lobular breast cancer has been severely understudied, likely because its short-term outlook appears favorable.”
said Rebecca Siegel, Senior Scientific Director for Cancer Surveillance Research at the ACS.
However, she noted that metastatic ILC patients face half the survival rate at ten years compared to those with ductal carcinoma, underscoring the disease’s hidden severity.
Consistent Growth Across All Age Groups
Unlike many breast cancers that vary widely by age, ILC rates are rising steadily across both younger and older women.
Researchers attribute this steady increase primarily to lifestyle and hormonal influences rather than inherited mutations.
Hormonal Factors and Modern Lifestyle Risks
ILC is believed to have a stronger connection to female hormone exposure than other breast cancer types.
This link became clearer when cases dropped as menopausal hormone therapy usage declined in the past decades.
Other contributing factors include:
- Rising obesity rates
- Earlier menstruation
- Delayed childbirth or fewer pregnancies
- Later menopause
- Higher alcohol consumption
All these elements extend a woman’s lifetime exposure to estrogen, a hormone tied closely to ILC development.
Chart: Ten-Year Survival Rates for ILC (2007–2021)
The chart shows that early-stage ILC has better survival odds, but distant-stage disease survival plummets to just 12% — compared to 20% for ductal carcinoma.
Urgent Call for More Research
The full findings were published in the American Cancer Society’s journal, Cancer.
Experts agree that deeper genetic studies, improved screening tools, and dedicated clinical trials are essential to slow the growing toll of invasive lobular breast cancer.
Original Source: DailyMail.co.uk
Author: Cassidy Morrison, U.S. Senior Health Reporter
Contact: Cassidy.Morrison@mailonline.com
