AN ANALYSIS OF PROGNOSTIC FEATURES IN INFILTRATING LOBULAR CARCINOMA OF THE BREAST

To establish prognostically useful pathologic features for infiltratin g lobular carcinoma, histologic pattern, nuclear Grade 1 or 2, lymphat ic invasion, the presence and extent of lobular carcinoma in situ, est rogen and progesterone receptor status, axillary lymph node status, tu mor size, and pathologic stage were assessed as prognostic variables i n 92 cases of infiltrating lobular carcinoma. Clinical follow-up was o btained (mean duration, 5.2 yr), and patients were classified as alive with no evidence of disease, alive with disease, or dead of disease. Recurrence (alive with disease and dead of disease) was associated wit h axillary lymph node metastases (P = 0.04), tumors measuring >1.0 cm (P = 0.008), and pathologic Stage III/IV disease (P = 0.033). Survival (no evidence of disease and alive with disease) was associated with S tage I/II disease (P = 0.003). Statistically insignificant association s with disease recurrence or survival follow: infiltrative pattern (cl assical, alveolar, solid, mixed), nuclear grade, lymphatic vessel inva sion, presence of lobular carcinoma in situ, extent of lobular carcino ma in situ (<25% or greater than or equal to 25%), and hormone recepto r status. Many of the prognostic features used in ductal carcinoma do not appear to be applicable to infiltrating lobular carcinoma. However , tumor size, axillary node status, and pathologic stage are prognosti cally useful in infiltrating lobular carcinoma.