LOCOREGIONAL TREATMENT FOR METASTATIC BREAST CANCER

Question
How would you treat a postmenopausal patient with a T2 N1 M1 (bone) estrogen receptor- and progesterone receptor-positive carcinoma in the left breast? As per National Comprehensive Cancer Network guidelines,^[1] she would receive only hormonal therapy. But would she also benefit from either a simple mastectomy or lumpectomy, or induction chemotherapy and lumpectomy?

Response from Thomas A. Buchholz, MD Professor of Radiation Oncology; Chair, Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas

How to incorporate local-regional treatments into therapy for patients with metastatic breast cancer is a controversial topic. When considering such interventions, the associated morbidities of local-regional treatments must be weighed against the potential benefits. For most patients with metastatic disease, there are no clear benefits to be gained from local therapies. However, there are 2 situations in which local-regional therapies may be indicated:

When they have the potential to improve a patient's quality of life by palliating symptoms associated with uncontrolled growth of primary or regional disease; and In situations where aggressive interventions may prolong the life of a patient.

A number of studies have explored whether mastectomy improves survival compared with systemic treatments alone for patients with metastatic disease. These studies were nicely reviewed in a recent article published in Oncology by Seema Kahn, MD, of the Department of Surgery at Northwestern School of Medicine.^[2] Many retrospective studies comparing the outcomes of patients treated with surgery plus systemic treatments vs those treated with systemic treatments alone have reported a better progression-free or overall survival for those patients treated with surgery. However, selection biases have a significant influence on such studies, in that clinicians tend to offer surgery to those patients who are doing very well and not offer surgery to those patients with rapid progression of their disease.

In my own opinion, surgery and adjuvant radiation treatments of the primary and regional lymph nodes may be appropriately considered for highly selected patients who are first treated with systemic therapy and demonstrate a complete response at the sites of the metastatic disease. At MD Anderson Cancer Center, we also consider aggressive approaches for patients with few sites of visceral disease (oligometastases) that are amenable to local interventions in addition to the treatment of the primary and regional disease. The goal of treatments for such patients is to prolong life; accordingly, such patients should receive the optimal combination of surgery and radiation. We have adopted this strategy for highly selected patients at MD Anderson and have achieved a 5-year progression-free survival rate of 42% in the patients treated with surgery and radiation when they have first achieved an excellent response to systemic treatment.^[3]

For the patient presented, I would favor initial treatment with hormonal therapy, and I would monitor her response. Local-regional treatments should be considered only if an excellent and prolonged response is achieved.