A new study has reported that, in patients with triple negative breast cancer, once there is evidence of lymph node metastasis, prognosis may not be directly affected by the actual number of positive nodes. Triple negative breast cancer is a subtype of breast cancer that is estrogen receptor negative (ER-), progesterone receptor negative (PR-), and HER2 negative (HER2-).
The study was designed to investigate the relationships between tumor size, lymph node status, and prognosis in patients with triple negative breast cancer. To conduct the study, the authors reviewed medical records for 1,711 patients with confirmed triple negative breast cancer diagnosed during the period 1980 to 2009. Median age at diagnosis was 48 years. Data concerning tumor size and lymph node status was collected in addition to outcome statistics. The associations between tumor size and nodal status and survival outcomes were calculated after adjusting for certain relevant patient and disease characteristics.
There were 614 deaths and 747 breast cancer recurrences after a median follow-up period of 53 months. Survival appeared to be related to the number of positive lymph nodes: the five-year overall survival was 80% for lymph node negative patients (N0), 65% for those with one to three positive lymph nodes (N1), 48% for four to nine positive lymph nodes (N2), and 44% for 10 or more positive lymph nodes (N3). Similarly, the five-year relapse-free survival rates were 67% for N0, 52% for N1, 36% for N2, and 33% for N3. Comparison by nodal status showed that when comparing lymph node negative with lymph node positive disease, there was a statistically significant difference in overall survival and relapse-free survival.
However, when comparing outcomes among patients with lymph node positive disease (N1, N2 or N3) without regard to tumor size, no significant differences in overall survival or relapse-free survival were found. This suggests that tumor size is a more important prognostic indicator than the number of positive lymph nodes once it has been determined that a patient with triple negative breast cancer is lymph node positive.
However, the study results also indicate that any degree of lymph node involvement is a negative prognostic indicator among triple negative breast cancer patients.
Please see our articles on triple negative prognosis and what triple negative patients and survivors should eat for more information on triple negative breast cancer.