Determinants of Last-line Treatment in Metastatic Breast Cancer

In metastatic breast cancer (MBC) patients, the identification of factors helping clinicians in the choice between active therapy versus best supportive care is needed clinically. The aim of the present study was to identify the clinicopathologic factors that could improve the prognostic valuation of MBC patients and clinical decision-making at the end of life.

The present study analyzed data from a retrospective series of 522 MBC patients treated at the oncology department (University Hospital of Udine) from January 2004 to June 2014. The association between clinicopathologic features and death within 30 or 90 days since last-line treatment prescription was explored. Differences between lightly (≤ 3 lines) and heavily (> 3 lines) pretreated patients and the factors affecting treatment choice were investigated.

The event "death" occurred in 410 patients. The median last-line survival was 100 days. The median number of therapeutic lines was 3. On multivariate analysis, worse Eastern Cooperative Oncology Group performance status was significantly associated with death within 90 and 30 days since last-line treatment prescription. Among the heavily pretreated patients, liver function impairment and evaluation by a breast cancer specialist were significantly associated with a greater and lower risk of death within 30 days, respectively. Among the lightly pretreated patients with luminal disease, age < 70 years, luminal B-like disease, and number of previous lines were associated with a greater chance of receiving chemotherapy.

In the present study, the Eastern Cooperative Oncology Group performance status was the most robust independent factor driving the last-line therapeutic choice for MBC patients. In addition, the molecular subtype and oncologist subspecialization also influenced the decision-making process.