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).
‘Small breast tumors that are 1 mm or less in size (the thickness of a dime) may not need lymph node biopsies.’
"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.