Background: Isolated tumor cells (ITCs), often detectable only with immunohistochemical techniques, have an unknown significance in the prognosis of breast cancer. The American Joint Committee on Cancer guidelines classify such patients as N0 (immunohistochemistry +), staging them with node-negative patients. We sought to further elucidate the impact of ITCs on survival.
Methods: We conducted a retrospective review of all women at our institution with breast cancer from 1996 to 2005. Of 514 patients, 16 had isolated tumor cells detected only with immunohistochemical staining. Survival then was compared with historical survival rates for women with node-free disease.
Results: The 16 women with N0 (i+) disease had stage I or II disease. There was no documented recurrence among these women, with an average follow-up period of 2.5 years.
Conclusions: Our data suggest that ITCs detected in lymph nodes do not adversely impact survival or disease-free survival compared with women with node-negative disease. Larger studies will be required to confirm these findings.