Surgery in metastatic breast cancer: Patients with a favorable profile seem to have the most benefit from surgery

Abstract

Introduction

About 3–10% of breast cancer patients have distant metastases (Stage IV) at initial presentation; standard treatment (in the Netherlands) of these patients consists of palliative systemic therapy. However, retrospective studies have shown an improved survival in patients who received surgery for their primary tumor. The aim of this study was to assess characteristics associated with surgical treatment and to determine the impact on survival in women with stage IV breast cancer.

Methods

A cohort of women with a diagnosis of breast cancer and concomitant distant metastases was retrospectively studied. Patient characteristics, treatment and survival distilled from medical files were evaluated using univariate and multivariable analysis.

Results

Of 171 patients included in this analysis, 59 underwent surgery. In multivariable analysis lower age, no medication use, lower clinical T-stage and lower grade were associated with receiving surgery. In 21 of the 59 patients (35%) who received surgery it was unknown at the time of surgery that the patient had metastatic disease. Stratified survival analyses showed an association between surgery and improved survival for young patients (HR 0.3; p = 0.02), without comorbidity (HR 0.4; p = 0.002), with no medication use (HR 0.5; p = 0.009), with a small tumor (HR 0.4; p = 0.01), no regional lymph node involvement (HR 0.4; p = 0.01), with positive Estrogen (HR 0.6; p = 0.02) or Progesterone receptor (HR 0.4; p = 0.03) and with only visceral metastases (HR 0.5; p = 0.03). In multivariable analyses, younger patients and patients without comorbidity that received surgery had an increased survival (HR 0.3; p = 0.03 and HR 0.5; p = 0.03, respectively).

Conclusion

This study showed that patients with the most favorable profile receive local surgery and that a survival gain for operated patients was seen in young patients and in patients without comorbidity.

Introduction

With an increasing incidence, breast cancer is still the number one cancer affecting women in the western world. In 2008, 13,097 women were diagnosed with invasive breast cancer in the Netherlands.¹ Of all these women, 3–10% had distant metastases at initial presentation. The median survival of these patients is 18–24 months.² Standard treatment in the Netherlands for metastatic breast cancer consists of palliative systemic therapy with hormonal therapy, chemotherapy and biological therapy. Tumor resection in the breast or axilla is, according to guidelines, only indicated in the palliative setting to prevent skin ulceration, infection or bleeding and to improve quality of life. Recent retrospective studies, however, have shown improved survival in patients who received surgery of the primary tumor, with a hazard ratio ranging from 0.47 to 0.71. Even after adjustment for (among others) age, number of metastatic sites, systemic treatment and receptor status, survival advantages were present.3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 A meta-analysis performed in 2010 showed a pooled hazard ratio for overall mortality of 0.65 (95%CI 0.59–0.72) in favor of the patients undergoing surgery.¹⁸

These surgery-favoring results in stage IV disease are not fully understood. One hypothesis is that resection of the primary tumor will result in restoration of the immune system with eradication of cancer stem cells, that are believed to be responsible for the initiation of tumor development, growth, metastatic properties and tumor recurrence. Most retrospective studies, however, do not give detailed information about the timing of surgery and presence of comorbidity. Therefore, the aim of this study was to assess characteristics associated with receiving surgery and to determine the impact of surgery on survival in women with stage IV breast cancer.