Abstract 3906
Background
Anti-HER2 agents were a breakthrough in the treatment of HER2-enriched breast cancer (BC). In this study, we aimed to describe the real-life efficacy and safety of pertuzumab-trastuzumab-taxane (PTT) combination in BC patients.
Methods
This study was conducted by the Turkish Oncology Group and reached 35 centers nationwide. 309 visceral metastatic, and trastuzumab naive patients who received first line PTT were included.
Results
Patients' characteristics and treatment details are summarized in the table. Median progression-free survival (PFS) was 28.5 months (95% CI:15.6-41.4), while median overall survival (OS) was 40.3 months (95%CI: 26.9-53.7). Brain metastatic patients (n = 13, 4.2%) had worse PFS (16.8m vs. 28.5m; HR:3.9, 95% CI:1.7-9.2, p = 0.002) and OS (26.7m vs. 40.3m; HR:3.2, 95% CI:1.3-7.6, p = 0.009). Elderly patients (>65y) had significantly lower OS results (19.8m vs. 40.3m; HR:0.4, %95 CI:0.2-0.8, p = 0.01). Docetaxel was the choice in 268 patients (86.7%), while 41 patients (13.3%) received paclitaxel. There was no statistically significant difference in PFS (28.5 m vs. 24.1 m; p = 0.61) and OS (40.3 m vs. NR; p = 0.17) between taxane groups. Additionally, ≥10 cycles of docetaxel were not associated with improvement in outcomes compared with 6-10 cycles. One treatment-related death due to sepsis was noted. In 8 patients (2.6%), 5-40% ejection fraction decrease from baseline was detected without any sign of heart failure.Table: 325P
Demographic characteristics and treatment details
| N = 309 | % | |
|---|---|---|
| Median age (year, range) | 51 (22-82) | |
| >65 years-old patients | 39 | 12.6 |
| De-novo metastatic patients | 258 | 83.5 |
| Histopathology | ||
| IDC | 290 | 93.9 |
| ILC | 3 | 1 |
| Mixt | 5 | 1.6 |
| Others | 11 | 3.5 |
| Hormone receptor status | ||
| ER and/or PR positive | 170 | 55.2 |
| ER/PR negative | 138 | 44.8 |
| Unknown | 1 | 0.3 |
| Metastatic site distribution | ||
| Liver ± LN/skeletal | 112 | 36.3 |
| Lung ± LN/skeletal | 120 | 38.8 |
| Brain only | 6 | 1.9 |
| Brain + liver + lung | 7 | 2.3 |
| Liver + lung | 16 | 5.2 |
| Other | 48 | 15.5 |
| Only skeletal or only LN | - | - |
| Prior therapies | ||
| Prior anthracyclines | 51 | 16.5 |
| Prior trastuzumab | NA | NA |
| Treatment details | ||
| Median number of cycle (range) | ||
| Pertuzumab-trastuzumab | 10 (1-75) | |
| Docetaxel | 6 (1-23) | |
| Paclitaxel | 3 (1- 26) |
IDC: Invasive Ductal Carcinoma ILC: Invasive lobular carcinoma LN: Lymph Node
Conclusions
This real-life practice population differs from the CLEOPATRA study in terms of visceral only metastatic disease, and inclusion of brain metastatic patients. Regardless of these negative prognostic characteristics, results are concordant with the pivotal study. Elderly patients had overall lower PFS, which necessitates further investigation of pertuzumab-trastuzumab combination with cytotoxic/antihormonal therapies. To our knowledge, this is the largest scale real-life clinical practice study of PTT to date.
Clinical trial identification
Legal entity responsible for the study
Ece ESIN, on behalf of Turkish Oncology Group.
Funding
Has not received any funding.
Editorial Acknowledgement
Disclosure
All authors have declared no conflicts of interest.