Distinct HR expression patterns significantly affect the clinical behavior of metastatic HER2+ breast cancer and degree of benefit from novel anti-HER2 agents in the real world setting.

We analyzed data from 738 HER2-positive metastatic breast cancer (mbc) patients treated with pertuzumab-based regimens and/or T-DM1 at 45 Italian centers. Outcomes were explored in relation to tumor subtype assessed by immunohistochemistry (IHC). The median progression-free survival at first-line (mPFS1) was 12 months. Pertuzumab as first-line conferred longer mPFS1 compared to other first-line treatments (16 vs. 9 months, p = 0.0001), regardless of IHC subtype. Median PFS in second-line (mPFS2) was 7 months, with no difference by IHC subtype, but it was more favorable with T-DM1 compared to other agents (7 vs. 6 months, p = 0.03). There was no PFS2 gain in patients with tumors expressing both hormonal receptors (HRs; p = 0.17), while a trend emerged for tumors with one HR (p = 0.05). Conversely, PFS2 gain was significant in HRs-negative tumors (p = 0.04). Median overall survival (mOS) was 74 months, with no significant differences by IHC subtypes. Survival rates at 2 and 3 years in patients treated with T-DM1 in second-line after pertuzumab were significantly lower compared to pertuzumab-naïve patients (p = 0.01). When analyzed by IHC subtype, the outcome was confirmed if both HRs or no HRs were expressed (p = 0.02 and p = 0.006, respectively). Our results confirm that HRs expression impacts the clinical behavior and novel treatment-related outcomes of HER2-positive tumors when treatment sequences are considered. Moreover, multivariate analysis showed that HRs expression had no effect on PFS and OS. Further studies are warranted to confirm our findings and clarify the interplay between HER2 and estrogen receptor pathways in HER2-positive (mbc) patients.

Epirubicin and docetaxel as first-line treatment for hormonal receptor positive metastatic breast cancer: the predictive value of luminal subtype: a retrospective cohort analysis.

BACKGROUND: We retrospectively evaluated the efficacy of first-line epirubicin and docetaxel in patients with metastatic, hormonal receptor (HR)-positive, and human epidermal growth factor receptor-2-negative breast cancer. A subgroup analysis evaluated the predictive value of immunohistochemistry-defined luminal subtype. METHODS: We included patients with at least one visceral and measurable site of metastatic disease. Patients were grouped as luminal A (HR(+) and Ki67<13%) or luminal B (HR(+) and Ki67>13%). RESULTS: Forty-four patients were entered and prognostic variables were similar between the subgroups. Luminal B patients achieved higher objective response rate than luminal A (69% versus 19%; P = 0.001), longer time to progression (12.2 months versus 8.6 months; P = 0.039), and longer overall survival (24.6 months versus 19.5 months; P = 0.041). The multivariate analysis confirmed the predictive value of luminal B subtype for longer time to progression. CONCLUSIONS: Identification by Ki67 labelling index of human epidermal growth factor receptor-2-negative luminal A could predict a substantial benefit from systemic chemotherapy. Endocrine therapy would be the most appropriate therapy for luminal A tumours.

Maintenance single-agent bevacizumab or observation after first-line chemotherapy in patients with metastatic colorectal cancer: a multicenter retrospective study.

The addition of bevacizumab to standard chemotherapy has improved progression-free survival (PFS) and overall survival (OS) in patients with metastatic colorectal cancer (mCRC) in both first- and second line treatment, but the role of maintenance bevacizumab remains controversial. The association of various clinical factor and survival was examined in this retrospective cohort analysis. The clinical data from 220 previously untreated patients with mCRC, not progressive at the end of standard chemotherapy plus bevacizumab, were collected and analyzed. Patients were classified into two subgroups: those given with maintenance bevacizumab: "maintenance bevacizumab cohort (n = 118; MB)", and those discontinuing bevacizumab as a result of physician's or patient's decision: "no maintenance bevacizumab cohort (n = 102; noMB)". The baseline factors were well balanced between the study subgroups. Median PFS and OS for the general population was 10 months (range 7-15) and 22.5 months (range 18-26), respectively. Median PFS was 13 and 8 months in the BM and noBM cohorts, respectively (p < 0.0001). In the multivariate analysis, maintenance therapy resulted independently associated with improved PFS (HR 1.73; p < 0.001), but only objective response (OR) after first-line chemotherapy was associated with improved OS. Maintenance chemotherapy cannot be considered a standard of care after induction chemotherapy for mCRC, because the optimal balance between efficacy and safety of maintenance therapy remains a significant challenge. The results of our retrospective study suggest that maintenance therapy with bevacizumab is a safe and valuable option, particularly in those patients achieving an objective response after first-line chemotherapy.