Pathologic features related to local recurrence following lumpectomy and irradiation.

Breast conservation (lumpectomy and irradiation) has grown increasingly popular as a primary therapy for breast cancer. For the majority of patients whose breast cancers are now being detected at T1N0, both the expected cosmetic result and the survival are excellent. For this reason the possibility of local recurrences in the breast has a disproportionally larger impact on treatment planning for these patients. Although the majority of local recurrences occur in the vicinity of the primary tumor site within the initial 5 years of irradiation, local recurrences can be expected to occur well into the second decade as follow-up is continued. The majority of these late recurrences will not be in the immediate vicinity of the prior excision but represent de novo breast cancers developing in a multicentric fashion in other quadrants. Factors which influence recurrence per se include the size, grade, and stage (nodal status) of the tumor. Such factors influence local, locoregional, and distant metastases. A number of pathologic factors appear to affect only local recurrences. These, including positive margins, gross multicentricity, extensive intraductal carcinoma, and invasive lobular carcinoma, all share a common feature of a greater likelihood of local residual tumor burden. The increased risk of local recurrences related to positive surgical margins and extensive intraductal carcinoma can largely be eliminated by increasing the volume of tissue excised or the radiation dose. In summary, there are no absolute contraindications based on pathologic features of the tumor or the state of the resection margins which should preclude consideration of breast conservation for an individual patient.