Small breast tumours may not need biopsy

Turns out, patients with very small breast tumours can forgo lymph node biopsies.

A new study conducted by Allina Health explored the treatment options for patients with microinvasive breast cancer - tumours that are one mm or less in size (the thickness of a dime).

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, a study co-author.

The study appears in The Breast Journal.