Immunotherapy: The end of the "dark age" for metastatic triple-negative breast cancer?

Histamine H4 Receptor Expression in Triple-negative Breast Cancer: An Exploratory Study

Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype. There are neither universally accepted prognostic markers nor molecular targets related to TNBC. The histamine H4 receptor (H4R) has been characterized in TNBC experimental models, demonstrating its critical role in tumor development and progression. In this study, H4R expression was compared in breast cancer subtypes and correlated with clinical features using The Cancer Genome Atlas data (Pan-Cancer Atlas). The H4R status was further evaluated by immunohistochemistry in 30 TNBC human samples in relation to clinicopathological parameters. Results indicate that H4R was downregulated in basal-like/TNBC compared with luminal A and normal breast-like tumors. The higher expression of H4R was associated with improved progression-free and overall survival outcomes in basal-like/TNBC. H4R immunoreactivity was detected in about 70% of tumors, and its expression was positively correlated with the levels in the histologically normal peritumoral tissue. High H4R expression in peritumoral tissue correlated with reduced number of lymph node involvement and unifocal TNBC, while it was associated with increased patient survival. In conclusion, the H4R might represent a potential prognostic biomarker in TNBC. Further studies in large cohorts are needed to better understand the significance of H4R in breast cancer biology.

Atezolizumab and pembrolizumab in triple-negative breast cancer: a meta-analysis

BACKGROUND

The approval of anti-PD-L1 drugs, including atezolizumab/pembrolizumab in triple-negative breast cancer (TNBC), offer potential improvement to current treatment regimens available for TNBC.

METHODS

We conducted a meta-analysis to review the efficacy of Atezolizumab/Pembrolizumab for the treatment of TNBC in both the adjuvant and neoadjuvant settings. We calculated standardized mean difference (SMD) for the associations of progression-free survival (PFS) and overall survival (OS) and odds ratios (ORs) to estimate the association between objective response rate (ORR) and pathological complete response (pCR), using 95% confidence intervals (CIs).

RESULTS

Six clinical trials comprising 3612 patients were identified. For adjuvant therapies, the ORR (OR=1.26, P=0.04) of atezolizumab/pembrolizumab plus chemotherapy was higher in the intention to treat (ITT) arms than the placebo groups in TNBC. The positive effect size was found for PFS in the ITT arms (Cohen's d=1.55, P<0.001). The atezolizumab plus chemotherapy group had a positive effect size for OS compared to the control groups (Cohen's d=0.52, P<0.001). In the neoadjuvant setting, patients in ITT arms had higher pCR rates than the control groups (OR=1.61, P=0.001).

CONCLUSION

We collate evidence of atezolizumab/pembrolizumab as viable therapeutics among patients with TNBC with PD-L1 subgroups deriving higher benefits.

Disparities in Guideline-Concordant Initial Systemic Treatment in Women with HER2-Negative Metastatic Breast Cancer: A SEER-Medicare Analysis

Background

Methods

Results

Conclusion

Plasmodium infection inhibits triple negative 4T1 breast cancer potentially through induction of CD8+ T cell-mediated antitumor responses in mice

We previously reported that Plasmodium infection promotes antitumor immunity in a murine Lewis lung cancer. In this study, we investigated the effects of Plasmodium infection on the tumor inhibition and antitumor CD8⁺ T cell responses in a murine triple negative breast cancer (TNBCA) model. The results showed that Plasmodium infection significantly inhibited tumor growth, and increased the survival rate of the tumor-bearing mice. Both effector and memory CD8⁺ T cells were increased in peripheral blood and tumor-draining lymph node (DLN) in the infected mice. The co-stimulatory (CD40L, GITR and OX-40) and co-inhibitory (PD-1, CTLA-4, TIM-3, LAG3) immune checkpoints were up-regulated on CD8⁺ T cells in infected mice. Importantly, Py induced remarkable effects on the infiltration of CD8⁺ T cells in the tumor and granzym B⁺ CD8⁺ T cells in tumor-bearing mice while not in tumor-free mice. In summary, the results suggested that the effects of Plasmodium infection on murine 4T1 breast cancer might be related to the induction of CD8⁺ T cell-mediated antitumor immune responses. This finding may provide a novel strategy for the treatment of triple negative breast cancer.

Are we ready to use TMB in breast cancer clinical practice?

We discussed the potentialities of tumor mutation burden (TMB) as a predictive marker for immunotherapy in breast cancer, also highlighting the limits that have hindered its introduction in the clinical practice. Although some studies have demonstrated the possibility to select patients more responsive to immune-checkpoint inhibitors by evaluating TMB, some issues emerged regarding the complexity of the methodologies for its determination, the costs of the analysis, and the necessity to improve the TMB determination with that of neoantigen identification.

Impact of histamine H4 receptor deficiency on the modulation of T cells in a murine breast cancer model

BACKGROUND

The histamine H4 receptor (H4R) is preferentially expressed in immune cells and is a potential therapeutic target for inflammatory and autoimmune diseases. This study aimed at further exploring the role of H4R in the immunobiology of breast cancer.

METHODS

We used wild type (WT) and H4R deficient mice (KO) to evaluate whether H4R genotypes show a different distribution of T cell subsets in spleens, tumours and tumour draining lymph nodes (TDLN) in a syngeneic ErbB2-positive breast cancer model developed orthotopically with LM3 cells and its impact on tumour growth.

RESULTS

The presence of tumours had a differential impact on the distribution of T cells in TDLN from KO mice compared to WT ones. At day 21 post-inoculation (p.i.) of cells, despite no significant changes in the tumour weight, TDLN from KO mice showed a significantly increased proportion of CD8⁺ T cells compared to WT mice. At day 38 p.i. of cells a reduced tumour weight was evident in KO mice. This was accompanied by a decreased proportion of CD4⁺CD25⁺FoxP3⁺ regulatory T cells in TDLN of KO compared to WT mice. Tumour-bearing KO mice showed a better survival compared to WT mice.

CONCLUSIONS

H4R-mediated mechanisms may modulate the immune tumour microenvironment, promoting an immunosuppressive milieu. Results suggest that H4R could be explored as an immunotherapeutic target with potential benefit in combination with immunotherapy. Further preclinical and clinical studies are necessary to confirm this hypothesis.

When Something Seems Amiss: Radiology-Pathology Correlation of Metaplastic Breast Cancer

Metaplastic breast cancer is difficult to diagnose, resistant to conventional treatment, and biologically aggressive. A suspicious timeline and discordance between imaging findings and histopathologic tissue diagnosis should trigger additional workup. New, large lesions or rapidly growing lesions with complex echogenicity on ultrasound warrant correlation with image-guided biopsy for a definitive diagnosis. Lesions that appear aggressive on imaging, with negative biopsy findings, may represent false negatives due to sampling bias from intratumoral heterogeneity. In such cases, it may be advisable to obtain an excisional biopsy. These tumors are known to progress even with neoadjuvant chemotherapy. Immunotherapy, however, may be effective even for metastatic disease. A multidisciplinary approach and a high index of suspicion may, therefore, confer survival benefits in circumstances where the imaging phenotype does not fit with the timeline or pathologic diagnosis. This report describes five cases of metaplastic breast cancer diagnosed at our institution to highlight the importance of a timely and accurate diagnosis of this rare but aggressive breast malignancy.

Older age and comorbidity in breast cancer: is RT alone the new therapeutic frontier?

AIM

To assess the impact of age, comorbidities and endocrine therapy (ET) in older breast cancer (BC) patients treated with hypofractionated radiotherapy (Hypo-RT).

METHODS

From June 2009 to December 2017, we enrolled in this study 735 ER-positive BC patients (stage pT1-T2, pNx-1, M0 and age ≥ 65 years) receiving hypo-RT and followed them until September 2019. Baseline comorbidities included in the hypertension-augmented Charlson Comorbidity Index were retrospectively retrieved. Logistic regression model estimated adjusted-odds ratios (ORs) of ET prescription in relation to baseline patient and tumor characteristics. Competing risk analysis estimated 5-year cumulative incidence function (CIF) of ET discontinuation due to side effects (with BC progression or death as competing events), and its effect on locoregional recurrence (LRR) and distant metastasis (DM) (with death as competing event).

RESULTS

ET has been prescribed in 89% patients. In multivariable analysis, the odds of ET prescription was significantly reduced in older patients (≥ 80 years, OR 0.08, 95% CI 0.03-0.20) and significantly increased in patients with moderate comorbidity. Patients ≥ 80 years discontinued the prescribed therapy earlier and more frequently than younger (65-69 years) patients (p = 0.060). Five-year CIF of LLR, DM and death from causes other that BC were 1.7%, 2.2% and 7.5%, respectively. Patients who discontinued ET had higher chance of LRR (p = 0.004). ET use did not impact on OS in any of the analyzed groups.

CONCLUSIONS

In older patients, ET did not show a benefit in terms of overall survival. Further studies focusing on tailored treatment approaches are warranted to offer the best care in terms of adjuvant treatment to these patients.