Public Release: 

Allina study shows patients with very small breast tumors may forgo lymph node biopsies

Study examined the outcomes of 294 patients, found only 1.5 percent had positive lymph nodes

Allina Health

How to treat patients who have microinvasive breast cancer - tumors that are 1 mm or less in size (the thickness of a dime) -- is somewhat controversial. Can these tiny tumors affect the lymph nodes and spread cancer to other areas of the body?

Physicians at the Virginia Piper Cancer Institute wanted to know if surgical procedures to test the lymph nodes for cancer were always necessary.

They examined the outcomes of 294 patients who were treated between 2001 and 2015. Only 1.5 percent had positive lymph nodes - indicating the rare possibility of metastatic cancer. And the only patients with positive lymph nodes had microinvasive tumors that were associated with relatively large non-invasive tumors (ductal carcinoma in situ or DCIS).

"These findings allow surgeons to select which patients with microinvasive tumors may actually benefit from lymph node sampling, while sparing other patients from this procedure," said Tamera Lillemoe, M.D, pathologist and a study co-author.


The study, funded by Engelsma Family Foundation and Abbott Northwestern Hospital Foundation, was published recently in The Breast Journal, the official journal of the National Consortium of Breast Cancers.

About Virginia Piper Cancer Institute® - Abbott Northwestern Hospital

The Virginia Piper Cancer Institute®, part of Allina Health, provides comprehensive care through all aspects of cancer prevention, early detection and treatment to help individuals maintain quality of life and find ways to live with and beyond cancer. The Institute was founded in 1990 at Abbott Northwestern Hospital.

In addition to retaining its first place ranking for the best hospital in the Twin Cities and second in the State of Minnesota in the U.S. News & World Report's 2016-17 best hospital rankings, Abbott Northwestern has received nursing magnet certification, a recognition earned by only five percent of hospitals nationwide.

Allina Health is dedicated to the prevention and treatment of illness and enhancing the greater health of individuals, families and communities throughout Minnesota and western Wisconsin. A not-for-profit health care system, Allina Health cares for patients from beginning to end-of-life through its 90+ clinics, 12 hospitals, 15 retail pharmacies, specialty care centers and specialty medical services, home care, home oxygen and medical equipment and emergency medical transportation services.

For more information, visit us at, Facebook, Twitter, YouTube or Healthy Set Go.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.