A retrospective analysis of clinical outcome of patients with chemo-refractory metastatic breast cancer treated in a single institution phase I unit

Clinical outcomes of patients with metastatic breast cancer enrolled in phase I clinical trials

BACKGROUND

Next-generation phase I clinical trials (Ph1s) investigating targeted therapy (TT) and immunotherapy (IO) led to consistent improvements in outcomes of patients with cancer . Ph1s are mainly designed to enrol patients with different tumour types; hence, scant information on characteristics and outcomes of specific tumours is available. The aim of our study is to evaluate the outcomes of patients with metastatic breast cancer (BC) enrolled in Phs1 testing TT, IO and combinations.

MATERIAL AND METHODS

We retrospectively collected data on clinical characteristics and outcomes of all patients with metastatic BC treated in Ph1s from 2014 to 2019 at our Institution. The primary end-points were progression-free survival (PFS) and overall survival (OS). The secondary objectives were overall response rate (ORR), disease control rate (DCR) and 90-day mortality rate. Univariate and multivariate analyses were performed to assess the impact of different variables.

RESULTS

One hundred fifty-one patients with metastatic BC were treated, including 70 (46%) with hormone receptor-positive (HR+), 18 (12%) with HER2+ and 63 (42%) with triple-negative (TN) BC. The median age was 52.4 years (26.9-77.9). Patients with TNBC were less pretreated than patients with HR+ and HER2+ subtypes. Patients with HR+ tumours were preferentially included in TT rather than IO trials (97% vs. 2.9%, P < 0.001). In 148 patients evaluable for tumour response, DCR and ORR were 51.4% and 18.9%, respectively. Higher response rates have been observed in patients treated with TT (TT vs. IO: 23.5% vs. 3.0%, P = 0.008) and in the HER2+ or TN subtypes (HER2+ vs. TN vs. HR+: 33.3% vs. 24.2% vs. 10.3%, P = 0.032). Improved median PFS was observed in patients treated with TT (P < 0.001), aged ≥ 65 years (P = 0.001) and having fewer than 3 metastatic sites (P = 0.026). Patients with HR+ and HER2+ subtypes presented a numerically higher median PFS than those with TNBC (3.65 vs. 3.58 vs. 2.28 months, P = 0.053). Median OS was longer in HR+ and HER2+ subtypes than that in TNBC (20 vs. 16 vs. 10 months, P = 0.007). Variables independently associated with improved OS were fewer than three metastatic sites (P = 0.014) and a baseline lactate dehydrogenase lower than upper limit of normal (P < 0.001).

CONCLUSION

Our study provides novel insights on the landscape of metastatic breast cancer metasta treated in Ph1s. Patients with TNBC still have poor outcomes, reinforcing the need to better translate preclinical findings into the clinical context. TT-based trials-mainly biomarker-driven-are associated with improved outcomes, suggesting that future IO trials have to be guided by meaningful biomarkers. Finally, patients with low tumour burden can have significant benefit, underling the importance to enrol patients in earlier lines of treatment to maximise the benefit.

Prognostic significance of serum lactate dehydrogenase in patients with breast cancer: a meta-analysis

Background: Multiple studies have assessed the prognostic significance of serum lactate dehydrogenase (LDH) in patients with breast cancer, but their results remain controversial. This study aimed to evaluate the prognostic value of LDH in breast cancer by meta-analysis.

Methods: Electronic searches for relevant articles were conducted in PubMed, Embase and Web of Science databases. The HR and their 95% CI were used to assess the prognostic value of serum LDH. Stata Statistical Software 12.0 was applied for statistical analysis.

Results: A total of 11 studies involving 6,102 patients were subjected to final analysis. Our results showed that higher serum LDH had significant effect on poor overall survival (HR, 1.88; 95% CI, 1.68–2.11) and progression-free survival (HR, 1.98; 95% CI, 1.46–2.68). Moreover, the results of subgroup analyses were consistent with that of overall outcomes. No significant heterogeneity and publication bias were found in this study.

Conclusion: Serum LDH could act as a prognostic factor for patients with breast cancer. Future data are needed to validate and update our results.

Target-based therapeutic matching of phase I trials in patients with metastatic breast cancer in a tertiary referral centre

BACKGROUND

Greater understanding of the molecular classification of breast cancer has permitted the development of rational drug design strategies. In a phase I clinical trial setting, molecular profiling with next-generation sequencing of individual tumour samples has been employed to guide treatment.

METHODS

We conducted a retrospective evaluation of clinical outcomes of patients with metastatic breast cancer (MBC) treated in phase I clinical trials at our institution to assess the benefit of molecularly matched compared to non-matched treatments.

RESULTS

A total of 97 consecutive patients with MBC were enrolled onto ≥1 trial between 2009 and 2015. Fourteen patients participated in multiple trials, and a total of 113 trial encounters were reviewed in this retrospective study. Eighty-three percent of patients with molecular data available were able to participate in trials matched to molecular aberrations. Patients who were treated on matched studies had improved clinical benefit (RR: 1.80, p = 0.005), progression-free (HR: 0.52, p = 0.003) and overall survival (HR: 0.54, p < 0.001). Treatment was well tolerated with low rates of treatment discontinuation for toxicity (8% overall) that did not differ between groups. No toxicity-related deaths were observed.

CONCLUSIONS

Molecular profiling for MBC patients in a phase I setting is feasible and aids therapeutic decisions with improved patient outcomes.

Long-term survivor characteristics in HER2-positive metastatic breast cancer from registHER

Background:

Data characterising long-term survivors (LTS) with human epidermal growth factor receptor 2 (HER2)–positive metastatic breast cancer (MBC) are limited. This analysis describes LTS using registHER observational study data.

Methods:

A latent class modelling (LCM) approach was used to identify distinct homogenous patient groups (or classes) based on progression-free survival (PFS), overall survival, and complete response. Demographics, clinicopathologic factors, first-line treatment patterns, and clinical outcomes were described for each class. Class-associated factors were evaluated using logistic regression analysis.

Results:

LCM identified two survivor groups labelled as LTS (n=244) and short-term survivors (STS; n=757). Baseline characteristics were similar between groups, although LTS were more likely to be white (83.6% vs 77.8%) with oestrogen receptor–positive (ER+) or progesterone receptor–positive (PgR+) disease (59.4% vs 50.9%). Median PFS in LTS was 37.2 (95% confidence interval (CI): 32.9–40.5) vs 7.3 months (95% CI: 6.8–8.0) in STS. Factors associated with long-term survival included ER+ or PgR+ disease, metastasis to node/local sites, first-line trastuzumab use, and first-line taxane use.

Conclusions:

Prognostic variables identified by LCM define a HER2-positive MBC patient profile and therapies that may be associated with more favourable long-term outcomes, enabling treatment selection appropriate to the patient's disease characteristics.

Phosphanegold(I) dithiocarbamates, R3PAu[SC(=S)N((i)Pr)CH2CH2OH] for R = Ph, Cy and Et: role of phosphane-bound R substituents upon in vitro cytotoxicity against MCF-7R breast cancer cells and cell death pathways

The synthesis and characterisation of R3PAu[S2CN((i)Pr)CH2CH2OH], for R = Ph (1), Cy (2) and Et (3)4, is reported. Compounds 1-3 are cytotoxic against the doxorubicin-resistant breast cancer cell line, MCF-7R, with 1 exhibiting greater potency and cytotoxicity than either of doxorubicin and cisplatin. Based on human apoptosis PCR-array analysis, caspase activities, DNA fragmentation, cell apoptotic assays, intracellular reactive oxygen species (ROS) measurements and human topoisomerase I inhibition, induction of apoptosis by 1, and necrosis by 2 and 3, are demonstrated, by both extrinsic and intrinsic pathways. Compound 1 activates the p53 gene, 2 activates only the p73 gene, whereas 3 activates both the p53 and p73 genes. Compounds 1 and 3 activate NF-κB, and each inhibits topoisomerase I.

ABCB1/MDR1 contributes to the anticancer drug-resistant phenotype of IPH-926 human lobular breast cancer cells

Contribution of the ABCB1/MDR1/P-glycoprotein drug transporter to breast cancer resistance has been controversial. One issue is that ABCB1-dependent drug-resistance has primarily been investigated in mammary epithelial cell models technically manipulated to overexpress ABCB1, either by gene transfer using appropriate expression vectors or by chronic anticancer drug-selection. However, an unmodified human breast cancer cell line with an endogenous overexpression of ABCB1 has not been described thus far. Using Affymetrix microarray analyses, we identified an endogenous overexpression of several tumor-biologically relevant transcripts including ABCB1, BCAR4, CCL28, SCGB2A2 and PIP in IPH-926, an anticancer drug-resistant human lobular breast cancer cell line derived from a chemo-refractory mammary carcinoma patient. In a panel of twenty breast cancer cell lines examined, overexpression of ABCB1 mRNA and protein was exclusively detected in IPH-926. This was further validated using chronically in vitro drug-selected KB-V-1 cells as a widely used reference model to accurately define an ABCB1 overexpression. IPH-926 and KB-V-1 displayed a similar overexpression of ABCB1. Flow cytometric analyses showed that IPH-926 but not ABCB1-negative breast cancer cells extruded the anticancer agent doxorubicin, a classical substrate of the ABCB1 drug transporter. PSC-833 (valspodar), a selective ABCB1 inhibitor, blocked this efflux, restored apoptotic PARP cleavage and increased doxorubicin sensitivity in IPH-926 and KB-V-1. To our knowledge, IPH-926 represents the first human breast cancer cell line with a genuine, endogenous overexpression of ABCB1. IPH-926 provides evidence that ABCB1 can occasionally cause anticancer drug-resistance in breast cancer patients and offers a new tool for the evaluation of compounds to overcome drug-resistance.