Special ACS Report: Lesser-Known Lobular Breast Cancer on the Rise in U.S. Women

ATLANTA, October 7, 2025 - Today, the American Cancer Society released Lobular Breast Cancer Statistics, 2025, a report on occurrence and outcomes in the United States for this subtype of breast cancer. Findings show an estimated 33,600 women will be diagnosed with lobular breast cancer or invasive lobular carcinoma (ILC) this year. Ranked separately, the disease would be the seventh most common cancer among women in the U.S. The report also finds that incidence rates for ILC have increased more steeply (2.8% per year) than all other breast cancers combined (0.8% per year) from 2012 to 2021. The report is to be published in the journal Cancer, an international, interdisciplinary journal of the American Cancer Society.

"Although lobular breast cancer accounts for a little over 10% of all breast cancers, the sheer number of new diagnoses each year makes this disease important to understand," said Angela Giaquinto, MSPH, associate scientist, cancer surveillance research at the American Cancer Society, and lead author of the report. "Also, survival rates beyond seven years are significantly lower for ILC than the most common type of breast cancer, highlighting the pressing need for prevention and early detection strategies targeting this subtype to be brought to the forefront."

ILC originates in the lobules, the milk-producing glands in the breast. According to study authors, the disease is typically combined with the most common subtype - invasive ductal carcinoma - in research and clinical trials, masking many unique and important characteristics, including how the cancer appears and grows. For example, ILC tumors grow in a linear or dispersed pattern, instead of forming a lump typical of other breast cancers. This can contribute to delayed detection by patients and doctors, treatment challenges, and poorer long-term prognosis for advanced disease.

For the report, researchers used data from the North American Association of Central Cancer Registries (NAACCR) and the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program to analyze incidence and outcomes of ILC by age, race, and ethnicity among women.

Other key findings from the report include:

• Similar to other breast cancers, the steepest rise in ILC incidence is among Asian American/Pacific Islander women, with an increase of 4.4% per year from 2012 to 2021.
• White women have the highest incidence rate of ILC (14.7 per 100,000 women), with Black women ranking second (11 per 100,000).
• Survival for women diagnosed with ILC is slightly higher than that for ductal breast cancer in the first seven years after diagnosis and for localized-stage disease, but lower for both regional (78.2% versus 76.4%) and distant-stage disease (19.6% versus 12.1%) at 10 years after diagnosis.

"Invasive lobular breast cancer is very understudied, probably because of a very good short-term prognosis. But at 10 years, these women with metastatic disease are half as likely to be alive as their counterparts with ductal cancer, probably because of the unique spread and resistance to therapy," said Rebecca Siegel, MPH, senior scientific director, cancer surveillance research at the American Cancer Society and senior author of the study. "Our study underscores the need for much more information on lobular cancers across the board, from genetic studies to clinical trial data, so we can improve outcomes for the increasing number of women affected with this cancer."

ACS researcher Dr. Ahmedin Jemal also contributed to this report.

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