EXPERT ANALYSIS FROM ASBS 2017
LAS VEGAS (FRONTLINE MEDICAL NEWS) – Determination of whether excision of persistent breast cancer metastases can benefit the patient and even prolong survival depends on the location of the metastatic lesions, an investigator said at the annual meeting of the American Society of Breast Surgeons.
Before making the decision, it’s important to restage the patient’s disease and to recheck the receptor status if a biopsy is accessible, said Roshni Rao, MD , of the University of Texas Southwestern Medical Center.
Approximately 12% of patients present with the brain as the first site of metastasis, and 54% of patients have multiple brain metastases, most commonly at the cerebellum and frontal lobes.
Survival is worse when there are concurrent extracranial metastases or when brain metastases are greater than 5 cm, in patients with triple negative tumors, and in patients with a Karnofsky score of 70 or less, Dr. Rao said.
Surgery has the greatest benefit in patients with a single metastasis, with no extracranial disease, and who are able to undergo adjuvant whole brain radiation. In these cases, surgery improves survival, lowers recurrence rates, and reduces the risk of death neurological causes, she said.
Long-term survival is most common with continuous adjuvant therapy, either trastuzumab or hormonal, and in patients with a longer time interval to development of metastases. One series showed a 20-month survival increase.
Approximately 15% of patients with synchronous metastases will have liver metastases, and about half of stage IV patients will experience liver metastases at some point during treatment.
There is evidence from colorectal cancer that removing liver metastases is beneficial, and that has prompted interest in a similar approach in breast cancer. Liver resection has also become safer with new advances.
Dr. Rao discussed a single-institution study which took an aggressive approach to liver resection in 85 patients (Ann Surg. 2006;244:897-907 ). The researchers found that increased survival was associated with a good response to adjuvant chemotherapy, an r0 or r1 resection, and in patients who had a previous liver resection and were healthy enough to undergo another resection.
Overall, existing studies support liver resection if there are one to three lesions, if negative margins can be achieved, if the tumors are hormone receptor positive, and if the cancer is hormone positive and has good response to chemotherapy.
Dr. Rao emphasized that liver resections should be performed with a multidisciplinary team and should only be attempted at centers with low morbidity and where the doctors are experienced with liver resection.
When it’s possible, liver resection is beneficial. “There have been multiple reports of long-term survivors with no evidence of disease. There is likely a survival benefit with careful selection of these patients,” Dr. Rao said.
Lung surgeries are becoming safer, especially with the availability of video-assisted techniques, and pulmonary metastases are increasingly being spotted using more sensitive techniques such as higher resolution computed tomography.
A lung metastasis registry analysis showed three factors improved survival: prolonged disease-free survival, especially longer than 36 months; a complete resection; and a small number of metastases and success in resecting them all (Eur J Cardiothorac Surg. 2002;22:335-44 ). A more recent meta-analysis showed the same results (J Thorac Dis. 2015;7:1441-51 ).
Bone metastases remain rare choices for surgical treatment. Most of the time, morbidity will be too high, and there are good options for systemic treatment. That leaves surgery reserved mostly for stabilization or the treatment of fractures.
However, there are a couple of exceptions, according to Dr. Rao. One multi-institutional randomized trial looked at metastatic epidural spinal cord compression. Subjects either underwent decompressive surgery with stabilization and radiation or radiation alone. Patients in the surgical group had a longer ambulatory period and had a lower usage rate of steroids and opioids. Morbidity outcomes were similar in both groups. Patients whose primary tumor was in the breast seemed to benefit the most with respect to ambulatory time (Lancet. 2005;9486:643-8 ; J Neurosurg Spine. 2008;8:271-8 ).
Sternal metastases represent another special case. 70% of the time, patients with sternal metastases have it as their only metastatic site. A French series of 33 patients who underwent aggressive chest wall and rib resection reported a 36% complication rate, while another study of 28 patients showed a 21% complication rate. Those complications are a problem, “but if you’re able to perform this in a resected tumor, there are long term survivors. As usual, triple negative breast cancers predicted a worse prognosis,” said Dr. Rao.
Dr. Rao concluded that resection of metastatic sites has a role. “I think it’s our responsibility as breast surgeons who are many times continuously following these patients to consider appropriate operations,” said Dr. Rao.
However, she did sound one note of caution. Surgery can interrupt therapy that is helping a patient. “Let’s say you have someone get a big liver resection, and then they have a tough time with recovery. There could be a long period of time they can’t get the therapy that was keeping them alive. That’s the real concern,” she said.