Breast Cancer (4)

Treatment

For most patients, primary treatment is surgery, often with radiation therapy. Chemotherapy, hormone therapy, or both may also be used, depending on tumor and patient characteristics. For inflammatory or advanced breast cancer, primary treatment is systemic therapy, which, for inflammatory breast cancer, is followed by surgery and radiation therapy; surgery is usually not helpful for advanced cancer. Paget's disease of the nipple is treated as for other forms of breast cancer, although a very few patients can be treated successfully with local excision only.

Surgery: Most patients with DCIS are cured by simple mastectomy. However, more patients are being treated with wide excision alone, especially when the lesion is < 2.5 cm and histologic characteristics are favorable, or with wide excision plus radiation therapy when size and histologic characteristics are less favorable.

For patients with invasive cancer, survival rates do not differ significantly whether modified radical mastectomy (simple mastectomy plus lymph node dissection) or breast-conserving surgery (lumpectomy, wide excision, partial mastectomy, or quadrantectomy) plus radiation therapy is used. Thus, patient preference can guide choice of treatment within limits. The main advantage of breast-conserving surgery plus radiation therapy is cosmetic. In 15% of patients treated with breast-conserving surgery and radiation therapy, cosmetic results are excellent. However, need for total removal of the tumor with a tumor-free margin overrides cosmetic considerations. With both types of surgery, a lymph node dissection or node sampling should be done. Routine use of extensive procedures is not justified because the main value of lymph node removal is diagnostic, not therapeutic. However, results of frozen section analysis may change the extent of surgery needed. Some surgeons get prior agreement for more invasive surgery in case nodes are positive; others wake the patient and do a 2nd procedure if needed.

Some physicians use preoperative chemotherapy to shrink the tumor before removing it and applying radiation therapy; thus some patients who might otherwise have required mastectomy can have breast-conserving surgery. Early data suggest that this approach does not affect survival. Radiation therapy after mastectomy significantly reduces incidence of local recurrence on the chest wall and in regional lymph nodes and may improve overall survival in patients with primary tumors > 5 cm or with involvement of ≥ 4 axillary nodes. Adverse effects of radiation therapy are usually transient and mild.

Procedures for reconstruction include submuscular or subcutaneous (less common) placement of a silicone or saline implant, use of a tissue expander with delayed placement of the implant, muscle flap transfer using the latissimus dorsi or the lower rectus abdominis, and creation of a free flap by anastomosing the gluteus maximus to the internal mammary vessels. Free flap transfer is being increasingly used for DCIS.

After axillary dissection or radiation therapy, lymphatic drainage of the ipsilateral arm can be impaired, sometimes resulting in significant swelling due to lymphedema; magnitude of the effect is roughly proportional to the number of nodes removed. Venipuncture, BP measurement, and IV infusions are avoided on the affected side. A specially trained therapist must treat lymphedema. Special massage techniques once or twice daily may help drain fluid from congested areas toward functioning lymph basins; low-stretch bandaging is applied immediately after manual drainage, and patients should exercise daily as prescribed. After the lymphedema resolves, typically in 1 to 4 wk, patients continue daily exercise and overnight bandaging of the affected limb indefinitely.

Adjuvant systemic therapy: Patients with LCIS are treated with daily oral tamoxifen. If tamoxifen is unsuitable or refused, bilateral mastectomy may be considered.


For patients with invasive cancer, chemotherapy or hormone therapy is usually begun soon after surgery and continued for months or years; these therapies delay or prevent recurrence in almost all patients and prolong survival in some. However, some experts believe that these therapies are not necessary for tumors < 1 cm (particularly in postmenopausal patients) if lymph nodes are not involved because the prognosis is already excellent. Some experts begin adjuvant systemic therapy before surgery if tumors are > 5 cm.

Relative reduction in risk of recurrence and death associated with chemotherapy or hormone therapy is the same regardless of the clinical-pathologic stage of the cancer. Thus, absolute benefit is greater for patients with a greater risk of recurrence or death (ie, a 20% reduction reduces a 10% recurrence rate to 8% but a 50% rate to 40%). Adjuvant chemotherapy reduces annual odds of death on average by 25 to 35% for premenopausal patients; for postmenopausal patients, the reduction is about 1⁄2 of that (9 to 19%), and the absolute benefit in 10-yr survival is much smaller. Postmenopausal patients with ER– tumors benefit the most from adjuvant chemotherapy (see Table 3: Breast Disorders: Preferred Breast Cancer Adjuvant Systemic Therapy).

Combination chemotherapy regimens (eg, cyclophosphamide, methotrexate, plus 5-fluorouracil; doxorubicin plus cyclophosphamide) are more effective than a single drug. Regimens given for 4 to 6 mo are preferred; they are as effective as regimens given for 6 to 24 mo. Acute adverse effects depend on the regimen but usually include nausea, vomiting, mucositis, fatigue, alopecia, myelosuppression, and thrombocytopenia. Long-term adverse effects are infrequent with most regimens; death due to infection or bleeding is rare (< 0.2%). Whether increasing dose density (giving treatments more frequently) or adding a taxane (eg, docetaxel, paclitaxel) improves response or survival is uncertain.

High-dose chemotherapy plus bone marrow or stem cell transplantation offers no therapeutic advantage over standard therapy and should not be used.