Figure 2

Stage II breast cancer incidence, US women 50–64-years old, 1992–2000, National Cancer Institute, Surveillance, Epidemiology, and End Results (SEER) data base. Stage II breast cancers are heterogeneous and include tumors larger than 2.0 cm with negative lymph nodes (Stage 2, N−) and tumors smaller than 2.0 cm with positive lymph nodes (Stage 2, N+). The sentinel lymph node biopsy (SLNB) technique for breast cancer rapidly disseminated after it was initially reported in the early 1990s. The steady rise in Stage II node positive breast cancer (solid diamonds) from 1995 to a new plateau in 1999 can be attributed to SLNB. These new Stage II breast cancers were recruited from Stage I node negative patients because of the more comprehensive evaluation of sentinel nodes and increased detection of nodal micrometastases. Note that the incidence of Stage II node negative breast cancer (open squares) has remained steady over the same time frame.