Should a routine metastatic workup be performed for all patients with pathologic N2/N3 breast cancer?

Background: Node-positive breast cancer patients are at risk for metastatic disease. A routine metastatic workup might or might not be necessary for all patients with N2 or N3 diseases. The National Comprehensive Cancer Network guidelines recommend a metastatic workup for patients with T3N1 disease, yet no definitive recommendations are made for N2/N3 diseases. We hypothesized that for patients with operable pathologic N2/N3 diseases, a metastatic workup should only be considered for patients with T3/T4 lesions.

Study Design: Two hundred and fifty-six patients with pathologic N2/N3 diseases were identified from a prospective breast cancer database of 1,329 patients with stage 0 to III breast cancer. A metastatic workup included chest x-rays, bone scans, CT scans, and PET scans. Primary end point was incidence of stage IV disease at the time of diagnosis or within 1 month of definitive surgery. Statistical analysis included chi-square test, independent t-test, Kaplan-Meier Survival method, log-rank test, and Cox proportional hazard model. A p value ≤ 0.05 was considered statistically significant.

Results: There were 158 patients with N2 disease (62%) and 98 with N3 disease (38%). Overall, 16% had stage IV disease (N2 = 15%, N3 = 16%). There was no significant difference in age (p = 0.37), tumor size (p = 0.89), tumor grade (p = 0.09), estrogen-receptor status (p = 0.23), or progesterone-receptor status (p = 0.35) between the N2 and N3 groups. Incidences of stage IV disease were T0/T1, 0%; T2, 6%; T3, 22%; and T4, 36%. Multivariate analysis demonstrated that only T stage (p = 0.0006) and grade (p = 0.026) were independent predictors of overall survival.

Conclusions: A metastatic workup is only indicated for N2/N3 patients with T3 or T4 primary lesions.