Second-line Eribulin in Triple Negative Metastatic Breast Cancer patients. Multicentre Retrospective Study: The TETRIS Trial.

Introduction: Large and consistent evidence supports the use of eribulin mesylate in clinical practice in third or later line treatment of metastatic triple negative breast cancer (mTNBC). Conversely, there is paucity of data on eribulin efficacy in second line treatment. Methods: We investigated outcomes of 44 mTNBC patients treated from 2013 through 2019 with second line eribulin mesylate in a multicentre retrospective study involving 14 Italian oncologic centres. Results: Median age was 51 years, with 11.4% of these patients being metastatic at diagnosis. Median overall survival (OS) and progression free survival (PFS) from eribulin starting were 11.9 (95%CI: 8.4-15.5) and 3.5 months (95%CI: 1.7-5.3), respectively. We observed 8 (18.2%) partial responses and 10 (22.7%) patients had stable disease as best response. A longer PFS on previous first line treatment predicted a better OS (HR=0.87, 95%CI: 0.77-0.99, p= 0.038) and a longer PFS on eribulin treatment (HR=0.92, 95%CI: 0.85-0.98, p=0.018). Progression free survival to eribulin was also favorably influenced by prior adjuvant chemotherapy (HR=0.44, 95%CI: 0.22-0.88, p=0.02). Eribulin was generally well tolerated, with grade 3-4 adverse events being recorded in 15.9% of patients. Conclusions: The outcomes described for our cohort are consistent with those reported in the pivotal Study301 and subsequent observational studies. Further data from adequately-sized, ad hoc trials on eribulin use in second line for mTNBC are warranted to confirm our findings.

Adjuvant capecitabine in triple negative breast cancer patients with residual disease after neoadjuvant treatment: real-world evidence from CaRe, a multicentric, observational study.

Background: In triple negative breast cancer patients treated with neoadjuvant chemotherapy, residual disease at surgery is the most relevant unfavorable prognostic factor. Current guidelines consider the use of adjuvant capecitabine, based on the results of the randomized CREATE-X study, carried out in Asian patients and including a small subset of triple negative tumors. Thus far, evidence on Caucasian patients is limited, and no real-world data are available. Methods: We carried out a multicenter, observational study, involving 44 oncologic centres. Triple negative breast cancer patients with residual disease, treated with adjuvant capecitabine from January 2017 through June 2021, were recruited. We primarily focused on treatment tolerability, with toxicity being reported as potential cause of treatment discontinuation. Secondarily, we assessed effectiveness in the overall study population and in a subset having a minimum follow-up of 2 years. Results: Overall, 270 patients were retrospectively identified. The 50.4% of the patients had residual node positive disease, 7.8% and 81.9% had large or G3 residual tumor, respectively, and 80.4% a Ki-67 >20%. Toxicity-related treatment discontinuation was observed only in 10.4% of the patients. In the whole population, at a median follow-up of 15 months, 2-year disease-free survival was 62%, 2 and 3-year overall survival 84.0% and 76.2%, respectively. In 129 patients with a median follow-up of 25 months, 2-year disease-free survival was 43.4%, 2 and 3-year overall survival 78.0% and 70.8%, respectively. Six or more cycles of capecitabine were associated with more favourable outcomes compared with less than six cycles. Conclusion: The CaRe study shows an unexpectedly good tolerance of adjuvant capecitabine in a real-world setting, although effectiveness appears to be lower than that observed in the CREATE-X study. Methodological differences between the two studies impose significant limits to comparability concerning effectiveness, and strongly invite further research.

PANHER study: a 20-year treatment outcome analysis from a multicentre observational study of HER2-positive advanced breast cancer patients from the real-world setting.

BACKGROUND: The evolution of therapeutic landscape of human epidermal growth factor receptor-2 (HER2)-positive breast cancer (BC) has led to an unprecedented outcome improvement, even if the optimal sequence strategy is still debated. To address this issue and to provide a picture of the advancement of anti-HER2 treatments, we performed a large, multicenter, retrospective study of HER2-positive BC patients. METHODS: The observational PANHER study included 1,328 HER2-positive advanced BC patients treated with HER2 blocking agents since June 2000 throughout July 2020. Endpoints of efficacy were progression-free survival (PFS) and overall survival (OS). RESULTS: Patients who received a first-line pertuzumab-based regimen showed better PFS (p < 0.0001) and OS (p = 0.004) than those receiving other treatments. Median PFS and mOS from second-line starting were 8 and 28 months, without significant differences among various regimens. Pertuzumab-pretreated patients showed a mPFS and a mOS from second-line starting not significantly affected by type of second line, that is, T-DM1 or lapatinib/capecitabine (p = 0.80 and p = 0.45, respectively). Conversely, pertuzumab-naïve patients receiving second-line T-DM1 showed a significantly higher mPFS compared with that of patients treated with lapatinib/capecitabine (p = 0.004). Median OS from metastatic disease diagnosis was higher in patients treated with trastuzumab-based first line followed by second-line T-DM1 in comparison to pertuzumab-based first-line and second-line T-DM1 (p = 0.003), although these data might be partially influenced by more favorable prognostic characteristics of patients in the pre-pertuzumab era. No significant differences emerged when comparing patients treated with 'old' or 'new' drugs (p = 0.43), even though differences in the length of the follow-up between the two cohorts should be taken into account. CONCLUSION: Our results confirmed a relevant impact of first-line pertuzumab-based treatment and showed lower efficacy of second-line T-DM1 in trastuzumab/pertuzumab pretreated, as compared with pertuzumab-naïve patients. Our findings may help delineate a more appropriate therapeutic strategy in HER2-positive metastatic BC. Prospective randomized trials addressing this topic are awaited.