Treatment of Metastatic Breast Cancer in a Real-World Scenario: Is Progression-Free Survival With First Line Predictive of Benefit From Second and Later Lines?

Oncologist. 2015 Jul;20(7):719-24. doi: 10.1634/theoncologist.2015-0002. Epub 2015 May 27.

Abstract

Introduction: Despite the availability of several therapeutic options for metastatic breast cancer (MBC), no robust predictive factors are available to help clinical decision making. Nevertheless, a decreasing benefit from first line to subsequent lines of treatment is commonly observed. The aim of this study was to assess the impact of benefit from first-line therapy on outcome with subsequent lines.

Methods: We analyzed a consecutive series of 472 MBC patients treated with chemotherapy (CT) and/or endocrine therapy (ET) between 2004 and 2012. We evaluated progression-free survival (PFS) at first (PFS1), second, third, and fourth therapeutic lines, according to treatment (ET and/or CT) and tumor subtypes.

Results: In the whole cohort, median overall survival was 34 months, and median PFS1 was 9 months. A 6-month benefit was shown by 289 patients (63.5%) at first line, 128 (40.5%) at second line, 76 (33.8%) at third line, and 34 (23.3%) at fourth line. Not having a 6-month benefit at PFS1 was associated with less chance of benefit at second line (odds ratio [OR]: 0.48; 95% confidence interval [CI]: 0.29-0.77, p = .0026) and at any line beyond first (OR: 0.39; 95% CI: 0.24-0.62, p < .0001). In the total series, after stratification for tumor subtypes, a strong predictive effect was observed among HER2-positive tumors (OR: 0.2; 95% CI: 0.05-0.73, p = .0152).

Conclusion: Our results suggest that the absence of at least a 6-month benefit in terms of PFS with first-line therapy predicts a reduced probability of benefit from subsequent therapeutic lines, especially in HER2-positive disease.

Implications for practice: This study supports evidence showing that the absence of a 6-month benefit in terms of progression-free survival with first-line therapy predicts a lack of benefit from subsequent therapeutic lines in metastatic breast cancer. The random distribution of benefit experienced by a subset of the cohort further spurs an interest in identifying predictive factors capable of identifying the most appropriate therapeutic strategy.

Keywords: Breast neoplasms; Decision making; Overall survival; Treatment outcome.

Publication types

  • Clinical Study

MeSH terms

  • Aged
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / mortality*
  • Breast Neoplasms / pathology
  • Disease-Free Survival
  • Female
  • Humans
  • Middle Aged
  • Triple Negative Breast Neoplasms / drug therapy
  • Triple Negative Breast Neoplasms / metabolism
  • Triple Negative Breast Neoplasms / mortality
  • Triple Negative Breast Neoplasms / pathology