Stage II breast cancer is not simply a late stage I.

Conventional wisdom holds that stage II breast cancer (with positive axillary nodes) is a late stage I (with negative axillary nodes). The use of direct (e.g., 5-year) survival analysis, has led to the concept that these stages reflect a "delay" in diagnosis. Controlled clinical trials and demographic cancer registries, in which life table analysis of survival is used, provide data that require that this concept be reconsidered and perhaps discarded. Survival data published by NSABP B04 and the Connecticut Tumor Registry show that deaths in both stages start shortly after diagnosis but show different annual rates of dying. The anticipated "delay" (lead time bias) is not seen. These rates are permanently and consistently different. The local recurrence rates occurring in the two stages are different. The clinical response to tamoxifen citrate in postmenopausal women and chemotherapy in premenopausal women has been shown to be different between the two stages. Histopathologic examination of the primary tumor shows the two stages to be different with respect to size of tumor at time of diagnosis and the presence of lymphatic and vascular invasion. The conclusion must be reached that the two stages represent variants of breast cancer disease; stage II is not simply a late diagnosis of stage I.