A new study led by an international consortium of breast cancer experts, including senior author Paul Romitti, University of Iowa Distinguished Chair and professor of epidemiology, sheds light on how advanced breast cancer is changing—and what that means for patient care.

The research was developed by the Breast International Group and the National Clinical Trials Network Node-Positive Luminal Disease Working Group. Investigators analyzed U.S. Surveillance, Epidemiology, and End Results Program cancer data from 2010 through 2021 to understand trends in breast cancers that are still operable but carry a heavy disease burden. These include cancers with multiple lymph nodes involved or large tumors, which historically required aggressive treatment.

Key findings:

• Cases with extensive lymph node involvement have declined, likely due to less aggressive surgery and more pre-surgery treatments.
• Large tumors with limited node involvement have increased among hormone receptor-positive, HER2-negative cancers.
• Invasive lobular cancer appears more often in these advanced cases.

“This work provides contemporary insights into how locally advanced breast cancer is evolving amid changes in surgery and systemic therapy,” says Romitti. “It helps guide more precise treatment and informs strategies to improve care for patients with substantial disease burden.”

Romitti noted that genetic and biologic testing is already changing treatment for early-stage breast cancer and will soon extend to higher stages. “Our study helps define the profile of these patients and informed a National Cancer Institute-funded trial exploring how biological tools can guide therapy for operable, high-risk breast cancers.”

The findings underscore the need for future clinical trials to tailor treatment to tumor biology, reduce use of chemotherapy when there is limited benefit, and improve outcomes for patients facing these challenging diagnoses.