The influence of pathologic factors on breast cancer management.

The pathologist routinely provides to the therapist data which are used in the management of breast cancer patients. Clinical as well as gross and microscopic examination provides information used for staging and treatment selection. Biologic neoplasia precedes the usual morphologic and cytologic changes that characterize precancer and in situ carcinoma to the pathologist. Minimal breast cancer, including in situ carcinoma and small (0.5 cm) infiltrating cancers, is now a recognized entity separable from clinical cancer, although therapy is not yet uniform. The pathologist can routinely report the gross size and contour of the cancer; microscopic evaluation of the primary cancer adds information on the histologic type, differentiation (histologic or cytologic grade), and such other data as blood vessel invasion and cellular infiltration. One of the most useful bits of information is the status of axillary lymph nodes: whether or not there are metastases, the number of nodes with metastases, and whether they are micrometastases or macrometastases that extend through the capsule and involve pericapsular vessels. All of these data can be recorded routinely and are useful in developing management criteria. The pathologist, as any other consultant, reports to the attending physician who then uses these data with all other pertinent facts to formulate an individualized therapeutic program.