No gold standard treatment exists for metastatic breast cancer (MBC). Clinical decision making is based on knowledge of prognostic and predictive factors that are extrapolated from clinical trials and, sometimes, are not reliably transferable to a real-world scenario. Moreover, misalignment between endpoints used in drug development and measures of outcome in clinical practice has been noted.The roles of overall survival (OS) and progression-free survival (PFS) as primary endpoints in the context of clinical trials are the subjects of lively debate. Information about these parameters in routine clinical practice is potentially useful to design new studies and/or to interpret the results of clinical research. This study analyzed the impact of patient and tumor characteristics on the major measures of outcome across different lines of treatment in a cohort of 472 patients treated for MBC. OS, PFS, and postprogression survival (PPS) were analyzed. The study showed how biological and clinical characteristics may have different prognostic value across different lines of therapy for MBC. After first-line treatment, the median PPS of luminal A, luminal B, and human epidermal growth factor receptor 2 (HER2)-positive groups was longer than 12 months. The choice of OS as a primary endpoint for clinical trials could not be appropriate with these subtypes. In contrast, OS could be an appropriate endpoint when PPS is expected to be low (e.g., triple-negative subtype after the first line; other subtypes after the third line). The potential implications of these findings are clinical and methodological. The Oncologist 2014;19:608-615 Implications for Practice: Although randomized clinical trials are recognized as the highest level of scientific evidence to demonstrate the efficacy of a treatment, sometimes they do not reflect the clinical circumstances faced in a real-world scenario. The present study provides data about outcomes of consecutive metastatic breast cancer patients treated at an academic hospital. The findings support the importance of considering breast cancer in distinct subgroups with the aim of obtaining more precise information about prognosis and expected benefit from treatment. The study also provides insights for future clinical trial design.

These findings indicate that a complete diagnostic work-up to detect metastases is unnecessary in the majority of patients with newly diagnosed breast cancer, whereas it may be indicated for specific patient categories such as those with stage III disease.

Results indicate that the aberrant gene expression of periostin in breast cancer cells is associated with an abnormal nuclear localisation of the protein. The nuclear localisation of periostin in breast cancer may induce significant biological effects.

See Appendix for individual names.Background: Pertuzumab combined with trastuzumab and docetaxel is the standard first-line therapy for HER2-positive metastatic breast cancer, based on results from the phase III CLEOPATRA trial. PERUSE was designed to assess the safety and efficacy of investigator-selected taxane with pertuzumab and trastuzumab in this setting. Patients and methods:In the ongoing multicentre single-arm phase IIIb PERUSE study, patients with inoperable HER2-positive advanced breast cancer (locally recurrent/metastatic) (LR/MBC) and no prior systemic therapy for LR/MBC (except endocrine therapy) received docetaxel, paclitaxel or nab-paclitaxel with trastuzumab [8 mg/kg loading dose, then 6 mg/kg every 3 weeks (q3w)] and pertuzumab (840 mg loading dose, then 420 mg q3w) until disease progression or unacceptable toxicity. The primary end point was safety. Secondary end points included overall response rate (ORR) and progression-free survival (PFS). Results:Overall, 1436 patients received at least one treatment dose (initially docetaxel in 775 patients, paclitaxel in 589, nabpaclitaxel in 65; 7 discontinued before starting taxane). Median age was 54 years; 29% had received prior trastuzumab. Median treatment duration was 16 months for pertuzumab and trastuzumab and 4 months for taxane. Compared with docetaxel-containing therapy, paclitaxel-containing therapy was associated with more neuropathy (all-grade peripheral neuropathy 31% versus 16%) but less febrile neutropenia (1% versus 11%) and mucositis (14% versus 25%). At this preliminary analysis (52 months' median follow-up), median PFS was 20.6 [95% confidence interval (CI) 18.9-22.7] months overall (19.6, 23.0 and 18.1 months with docetaxel, paclitaxel and nab-paclitaxel, respectively). ORR was 80% (95% CI 78%-82%) overall (docetaxel 79%, paclitaxel 83%, nab-paclitaxel 77%).Conclusions: Preliminary findings from PERUSE suggest that the safety and efficacy of first-line pertuzumab, trastuzumab and taxane for HER2-positive LR/MBC are consistent with results from CLEOPATRA. Paclitaxel appears to be a valid alternative taxane backbone to docetaxel, offering similar PFS and ORR with a predictable safety profile.ClinicalTrials.gov: NCT01572038.