Stage I, II, IIIA, and operable IIIC breast cancer often requires a multimodality approach to treatment. Irrespective of the eventual procedure selected, the diagnostic biopsy and surgical procedure that will be used as primary treatment should be performed as two separate procedures. In many cases, the diagnosis of breast carcinoma is made by core needle biopsy. After the presence of a malignancy is confirmed, treatment options should be discussed with the patient before a therapeutic procedure is selected. Estrogen-receptor (ER) and progesterone-receptor (PR) protein status and human epidermal growth factor receptor 2 (HER2/neu) status should be determined for the primary tumor. Additional pathologic characteristics, including grade and proliferative activity may also be of value.[2,3,4,5]
Options for surgical management of the primary tumor include breast-conserving surgery plus radiation therapy, mastectomy plus reconstruction, and mastectomy alone. Surgical staging of the axilla should also be performed. Survival is equivalent with any of these options as documented in randomized prospective trials (including the European Organization for Research and Treatment of Cancer's trial [EORTC-10801]).[6,7,8,9,10,11,12,13] Selection of a local therapeutic approach depends on the location and size of the lesion, analysis of the mammogram, breast size, and the patient's attitude toward preserving the breast. The presence of multifocal disease in the breast or a history of collagen vascular disease are relative contraindications to breast-conserving therapy. A retrospective study of 753 patients who were divided into three groups based on receptor status (ER- or PR-positive; ER- and PR-negative but HER2/neu -positive; and ER-, PR-, and HER2/neu -negative [triple-negative]) found no differences in disease control within the breast in patients treated with standard breast-conserving surgery; however, there are not yet substantive data to support this finding.
All histologic types of invasive breast cancer may be treated with breast-conserving surgery plus radiation therapy. The rate of local recurrence in the breast with conservative treatment is low and varies slightly with the surgical technique used (e.g., lumpectomy, quadrantectomy, segmental mastectomy, and others). Whether completely clear microscopic margins are necessary is debatable.[17,18,19]
Retrospective studies have shown the following examples of tumor characteristics to correlate with a greater likelihood of finding persistent tumor on re-excision:
- Large tumors (T2 lesions).
- Positive axillary nodes.
- Tumors with an extensive intraductal component.
- Palpable tumors.
- Lobular histology.
Patients whose tumors have these characteristics may benefit from a more generous initial excision to avoid the need for a re-excision.[21,22]
Radiation therapy (as part of breast-conserving local therapy) consists of postoperative external-beam radiation therapy (EBRT) to the entire breast with doses of 45 Gy to 50 Gy, in 1.8 Gy to 2.0 Gy daily fractions over a 5-week period. Shorter hypofractionation schemes achieve comparable results.[23,24,25] A further radiation boost is commonly given to the tumor bed. Two randomized trials conducted in Europe have shown that using boosts of 10 Gy to 16 Gy reduces the risk of local recurrence from 4.6% to 3.6% at 3 years (P = .044),[Level of evidence: 1iiDiii] and from 7.3% to 4.3% at 5 years (P < .001), respectively.[Level of evidence: 1iiDiii] If a boost is used, it can be delivered either by EBRT, generally with electrons, or by using an interstitial radioactive implant.