Impact of hormone receptor status and tumor subtypes of breast cancer in young BRCA carriers.

BACKGROUND: Hormone receptor expression is a known positive prognostic and predictive factor in breast cancer; however, limited evidence exists on its prognostic impact on prognosis of young patients harboring a pathogenic variant (PV) in the BRCA1 and/or BRCA2 genes. PATIENTS AND METHODS: This international, multicenter, retrospective cohort study included young patients (aged ≤40 years) diagnosed with invasive breast cancer and harboring germline PVs in BRCA genes. We investigated the impact of hormone receptor status on clinical behavior and outcomes of breast cancer. Outcomes of interest [disease-free survival (DFS), breast cancer-specific survival (BCSS), and overall survival (OS)] were first investigated according to hormone receptor expression (positive versus negative), and then according to breast cancer subtype [luminal A-like versus luminal B-like versus triple-negative versus human epidermal growth factor receptor 2 (HER2)-positive breast cancer]. RESULTS: From 78 centers worldwide, 4709 BRCA carriers were included, of whom 2143 (45.5%) had hormone receptor-positive and 2566 (54.5%) hormone receptor-negative breast cancer. Median follow-up was 7.9 years. The rate of distant recurrences was higher in patients with hormone receptor-positive disease (13.1% versus 9.6%, P < 0.001), while the rate of second primary breast cancer was lower (9.1% versus 14.7%, P < 0.001) compared to patients with hormone receptor-negative disease. The 8-year DFS was 65.8% and 63.4% in patients with hormone receptor-positive and negative disease, respectively. The hazard ratio of hormone receptor-positive versus negative disease changed over time for DFS, BCSS, and OS (P < 0.05 for interaction of hormone receptor status and survival time). Patients with luminal A-like breast cancer had the worst long-term prognosis in terms of DFS compared to all the other subgroups (8-year DFS: 60.8% in luminal A-like versus 63.5% in triple-negative versus 65.5% in HER2-positive and 69.7% in luminal B-like subtype). CONCLUSIONS: In young BRCA carriers, differences in recurrence pattern and second primary breast cancer among hormone receptor-positive versus negative disease warrant consideration in counseling patients on treatment, follow-up, and risk-reducing surgery.

Circulating tumor DNA for predicting recurrence in patients with operable breast cancer: a systematic review and meta-analysis.

BACKGROUND: The incorporation of circulating tumor DNA (ctDNA) into the management of operable breast cancer (BC) has been hampered by the heterogeneous results from different studies. We aimed to assess the prognostic value of ctDNA in patients with operable (non metastatic) BC. MATERIALS AND METHODS: A systematic search of databases (PubMed/Medline, Embase, and CENTRAL) and conference proceedings was conducted to identify studies reporting the association of ctDNA detection with disease-free survival (DFS) and overall survival (OS) in patients with stage I-III BC. Log-hazard ratios (HRs) were pooled at each timepoint of ctDNA assessment (baseline, after neoadjuvant therapy, and follow-up). ctDNA assays were classified as primary tumor-informed and non tumor-informed. RESULTS: Of the 3174 records identified, 57 studies including 5779 patients were eligible. In univariate analyses, ctDNA detection was associated with worse DFS at baseline [HR 2.98, 95% confidence interval (CI) 1.92-4.63], after neoadjuvant therapy (HR 7.69, 95% CI 4.83-12.24), and during follow-up (HR 14.04, 95% CI 7.55-26.11). Similarly, ctDNA detection at all timepoints was associated with worse OS (at baseline: HR 2.76, 95% CI 1.60-4.77; after neoadjuvant therapy: HR 2.72, 95% CI 1.44-5.14; and during follow-up: HR 9.19, 95% CI 3.26-25.90). Similar DFS and OS results were observed in multivariate analyses. Pooled HRs were numerically higher when ctDNA was detected at the end of neoadjuvant therapy or during follow-up and for primary tumor-informed assays. ctDNA detection sensitivity and specificity for BC recurrence ranged from 0.31 to 1.0 and 0.7 to 1.0, respectively. The mean lead time from ctDNA detection to overt recurrence was 10.81 months (range 0-58.9 months). CONCLUSIONS: ctDNA detection was associated with worse DFS and OS in patients with operable BC, particularly when detected after treatment and using primary tumor-informed assays. ctDNA detection has a high specificity for anticipating BC relapse.

The long and winding road to biomarkers for immunotherapy: a retrospective analysis of samples from patients with triple-negative breast cancer treated with pembrolizumab.

BACKGROUND: Immune checkpoint blockade (ICB) in combination with chemotherapy improves outcome of patients with triple-negative breast cancer (TNBC) in metastatic and early settings. The identification of predictive biomarkers able to guide treatment decisions is challenging and currently limited to programmed death-ligand 1 (PD-L1) expression and high tumor mutational burden (TMB) in the advanced setting, with several limitations. MATERIALS AND METHODS: We carried out a retrospective analysis of clinical-pathological and molecular characteristics of tumor samples from 11 patients with advanced TNBC treated with single-agent pembrolizumab participating in two early-phase clinical trials: KEYNOTE-012 and KEYNOTE-086. Clinical, imaging, pathological [i.e. tumor-infiltrating lymphocytes (TILs), PD-L1 status], RNA sequencing, and whole-exome sequencing data were analyzed. We compared our results with publicly available transcriptomic data from TNBC cohorts from TCGA and METABRIC. RESULTS: Response to pembrolizumab was heterogeneous: two patients experienced exceptional long-lasting responses, six rapid progressions, and three relatively slower disease progression. Neither PD-L1 nor stromal TILs were significantly associated with response to treatment. Increased TMB values were observed in tumor samples from exceptional responders compared to the rest of the cohort (P = 3.4 × 10-4). Tumors from exceptional responders were enriched in adaptive and innate immune cell signatures. Expression of regulatory T-cell markers (FOXP3, CCR4, CCR8, TIGIT) was mainly observed in tumors from responders except for glycoprotein-A repetitions predominant (GARP), which was overexpressed in tumors from rapid progressors. GARP RNA expression in primary breast tumors from the public dataset was significantly associated with a worse prognosis. CONCLUSIONS: The wide spectrum of clinical responses to ICB supports that TNBC is a heterogeneous disease. Tumors with high TMB respond better to ICB. However, the optimal cut-off of 10 mutations (mut)/megabase (Mb) may not reflect the complexity of all tumor subtypes, despite its approval as a tumor-agnostic biomarker. Further studies are required to better elucidate the relevance of the tumor microenvironment and its components as potential predictive biomarkers in the context of ICB.

Characteristics and clinical outcomes of breast cancer in young BRCA carriers according to tumor histology.

BACKGROUND: Young women with breast cancer (BC) have an increased chance of carrying germline BRCA pathogenic variants (PVs). Limited data exist on the prognostic impact of tumor histology (i.e. ductal versus lobular) in hereditary breast cancer. METHODS: This multicenter retrospective cohort study included women aged ≤40 years with early-stage breast cancer diagnosed between January 2000 and December 2020 and known to carry germline PVs in BRCA1/2. Histology was locally assessed in each center. The Kaplan-Meier method and Cox regression analysis were used to assess disease-free survival and overall survival. RESULTS: Of 4628 patients included from 78 centers worldwide, 3969 (86%) had pure ductal, 135 (3%) pure lobular, and 524 (11%) other histologies. Compared with ductal tumors, lobular tumors were more often grade 1/2 (57.7% versus 22.1%), stage III (29.6% versus 18.5%), and luminal A-like (42.2% versus 12.2%). Lobular tumors were more often associated with BRCA2 PVs (71.1% BRCA2), while ductal tumors were more often associated with BRCA1 PVs (65.7% BRCA1). Patients with lobular tumors more often had mastectomy (68.9% versus 58.3%), and less often received chemotherapy (83.7% versus 92.9%). With a median follow-up of 7.8 years, no significant differences were observed in disease-free survival (adjusted hazard ratio 1.01, 95% confidence interval 0.74-1.37) or overall survival (hazard ratio 0.96, 95% confidence interval 0.62-1.50) between patients with ductal versus lobular tumors. No significant survival differences were observed according to specific BRCA gene, breast cancer subtype, or body mass index. CONCLUSIONS: In this large global cohort of young BRCA carriers with breast cancer, the incidence of pure lobular histology was low and associated with higher disease stage at diagnosis, luminal-like disease and BRCA2 PVs. Histology did not appear to impact prognosis.

Prognostic value of HER2-low status in breast cancer: a systematic review and meta-analysis.

BACKGROUND: Human epidermal growth factor receptor 2 (HER2)-low expression in breast cancer has been recently identified as a new therapeutic target. However, it is unclear if HER2-low status has an independent impact on prognosis. MATERIALS AND METHODS: A systematic literature research was carried out to identify studies comparing survival outcomes of patients affected by HER2-low versus HER2-zero breast cancer. Using random-effects models, pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for progression-free survival (PFS) and overall survival (OS) in the metastatic setting as well as disease-free survival (DFS), OS and pathological complete response (pCR) in the early setting. Subgroup analyses by hormone receptor (HoR) status were carried out. The study protocol is registered on PROSPERO (n.CRD42023390777). RESULTS: Among 1916 identified records, 42 studies including 1 797 175 patients were eligible. In the early setting, HER2-low status was associated with significant improved DFS (HR 0.86, 95% CI 0.79-0.92, P < 0.001) and OS (HR 0.90, 95% CI 0.85-0.95, P < 0.001) when compared to HER2-zero status. Improved OS was observed for both HoR-positive and HoR-negative HER2-low populations, while DFS improvement was observed only in the HoR-positive subgroup. HER2-low status was significantly associated with a lower rate of pCR as compared to HER2-zero status both in the overall population (OR 0.74, 95% CI 0.62-0.88, P = 0.001) and in the HoR-positive subgroup (OR 0.77, 95% CI 0.65-0.90, P = 0.001). In the metastatic setting, patients with HER2-low breast cancers showed better OS when compared with those with HER2-zero tumours in the overall population (HR 0.94, 95% CI 0.89-0.98, P = 0.008), regardless of HoR status. No significant PFS differences were found. CONCLUSIONS: Compared with HER2-zero status, HER2-low status appears to be associated with a slightly increased OS both in the advanced and early settings, regardless of HoR expression. In the early setting, HER2-low tumours seem to be associated to lower pCR rates, especially if HoR-positive.

The Future of Breast Cancer Research in the Survivorship Field.

Prevalence of survivors of breast cancer has been steadily increasing in the last 20 years. Currently, more than 90% of women diagnosed with early-stage breast cancer are expected to be alive at 5 years from diagnosis thanks to early detection and breakthrough innovations in multimodal treatment strategies. Alongside this advancement in clinical outcomes, survivors of breast cancer might experience several specific challenges and present with unique needs. Survivorship trajectories after diagnosis and treatment of breast cancer can be significantly impacted by long-lasting and severe treatment-related side effects, including physical problems, psychological distress, fertility issues in young women, and impaired social and work reintegration, which add up to patients' individual risk of cancer recurrence and second primary malignancies. Alongside cancer-specific sequelae, survivors still present with general health needs, including management of chronic preexisting or ensuing conditions. Survivorship care should implement high-quality, evidence-based strategies to promptly screen, identify, and address survivors' needs in a comprehensive way and minimize the impact of severe treatment sequelae, preexisting comorbidities, unhealthy lifestyles, and risk of recurrence on quality of life. This narrative review focuses on core areas of survivorship care and discuss the state of the art and future research perspectives in key domains including selected long-term side effects, surveillance for recurrences and second cancers, well-being promotion, and specific survivors' needs.

Cardiac safety of dual anti-HER2 blockade with pertuzumab plus trastuzumab in early HER2-positive breast cancer in the APHINITY trial.

BACKGROUND: Trastuzumab increases the incidence of cardiac events (CEs) in patients with breast cancer (BC). Dual blockade with pertuzumab (P) and trastuzumab (T) improves BC outcomes and is the standard of care for high-risk human epidermal growth factor receptor 2 (HER2)-positive early BC patients. We analyzed the cardiac safety of P and T in the phase III APHINITY trial. PATIENTS AND METHODS: Left ventricular ejection fraction (LVEF) ≥ 55% was required at study entry. LVEF assessment was carried out every 3 months during treatment, every 6 months up to month 36, and yearly up to 10 years. Primary CE was defined as heart failure class III/IV and a significant decrease in LVEF (defined as ≥10% from baseline and to <50%), or cardiac death. Secondary CE was defined as a confirmed significant decrease in LVEF, or CEs confirmed by the cardiac advisory board. RESULTS: The safety analysis population consisted of 4769 patients. With 74 months of median follow-up, CEs were observed in 159 patients (3.3%): 83 (3.5%) in P + T and 76 (3.2%) in T arms, respectively. Most CEs occurred during anti-HER2 therapy (123; 77.4%) and were asymptomatic or mildly symptomatic decreases in LVEF (133; 83.6%). There were two cardiac deaths in each arm (0.1%). Cardiac risk factors indicated were age > 65 years, body mass index ≥ 25 kg/m2, baseline LVEF between 55% and <60%, and use of an anthracycline-containing chemotherapy regimen. Acute recovery from a CE based on subsequent LVEF values was observed in 127/155 patients (81.9%). CONCLUSIONS: Dual blockade with P + T does not increase the risk of CEs compared with T alone. The use of anthracycline-based chemotherapy increases the risk of a CE; hence, non-anthracycline chemotherapy may be considered, particularly in patients with cardiovascular risk factors.

Efficacy of tyrosine kinase inhibitors for the treatment of patients with HER2-positive breast cancer with brain metastases: a systematic review and meta-analysis.

BACKGROUND: Brain metastases (BMs) are frequent events in patients with HER2-positive metastatic breast cancer (MBC) and are associated with poor prognosis. Small-molecule anti-HER2 tyrosine kinase inhibitors (TKIs) are promising agents for the treatment of BM. In this study, we assess the clinical outcomes of patients with HER2-positive MBC and BM treated with TKI-containing regimens compared with those treated with non-TKI-containing regimens. MATERIALS AND METHODS: PubMed, Embase, Cochrane Library, and conference proceedings (ASCO, SABCS, ESMO, and ESMO Breast) were searched up to June 2021. The primary endpoint was progression-free survival (PFS) in patients with BM. Secondary endpoints included PFS in patients without BM and overall survival (OS). The study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Overall effects were pooled using random-effects models. RESULTS: This systematic review and meta-analysis included data from 2437 patients (490 with and 1947 without BM at baseline) enrolled in five trials assessing tucatinib-, lapatinib-, pyrotinib-, or afatinib-based combinations. A nonstatistically significant PFS benefit favoring TKI-containing regimens was observed in both patients with BM [hazard ratio (HR) 0.67, 95% confidence interval (CI) 0.41-1.12; P = 0.13] and without BM (HR 0.55, 95% CI 0.24-1.26; P = 0.16). Sensitivity analysis, excluding each study singly, demonstrated a significant PFS benefit favoring TKI-containing regimens in patients with BM after the exclusion of afatinib from the analysis (HR 0.56, 95% CI 0.35-0.90; P = 0.016). No statistically significant differences in OS were observed between the comparison groups. CONCLUSIONS: A trend in PFS favoring TKI-containing regimens was observed in patients with BM. Sensitivity analysis including only trials that evaluated regimens containing tucatinib, lapatinib, or pyrotinib demonstrated a significant PFS benefit favoring TKI-containing regimens in patients with BM.

CDK4/6 inhibitors as adjuvant treatment for hormone receptor-positive, HER2-negative early breast cancer: a systematic review and meta-analysis.

BACKGROUND: The combination of cyclin-dependent kinases 4/6 inhibitors (CDK4/6is) and endocrine therapy (ET) is standard of care for patients with hormone receptor-positive (HR+), HER2-negative (HER2-) advanced breast cancer (BC). However, studies evaluating adjuvant CDK4/6is provided contradictory results thus far. MATERIALS AND METHODS: We conducted a systematic review and meta-analysis to assess if the addition of CDK4/6is to adjuvant ET impacts on survival's outcomes and safety of patients with HR+/HER2- early BC (EBC). This study was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines and was registered in the PROSPERO database (ID: CRD42020218597). A systematic review of PubMed, Cochrane and EMBASE databases and major conference proceedings was performed up to 15 December 2020. All randomized controlled trials including patients with HR+/HER2- EBC treated with CDK4/6is plus ET versus ET alone in the adjuvant setting were included. Pooled hazard ratios (HRs) and odds ratios (ORs) for survival and safety outcomes, respectively, were calculated with 95% confidence intervals (95% CIs) using random effect models. RESULTS: With data available from three studies (N = 12 647), the addition of CDK4/6is to adjuvant ET showed a trend for a benefit in terms of invasive disease-free survival (IDFS; HR 0.85, 95% CI 0.71-1.01; P = 0.071). No significant improvement in distant relapse-free survival was observed (HR 0.83, 95% CI 0.58-1.19; P = 0.311). The risk of all-grade toxicities and early treatment discontinuation increased significantly with the addition of CDK4/6is to ET (OR 9.36, 95% CI 3.46-25.33, P < 0.001, and OR 22.11, 95% CI 9.45-51.69, P < 0.001, respectively). CONCLUSION: The administration of adjuvant CDK4/6is to patients with HR+/HER2- EBC showed a trend for an IDFS benefit and an increase in the risk of toxicities and treatment discontinuation. The role of adjuvant CDK4/6is remains controversial and a longer follow-up of these randomized controlled trials is needed before supporting a straightforward change in clinical practice.

Beta-blockers in early-stage breast cancer: a systematic review and meta-analysis.

BACKGROUND: Preclinical and retrospective studies suggest that beta-blockers are active against breast cancer. We carried out a systematic review and meta-analysis to assess the impact of beta-blockers on the outcomes of patients with early-stage breast cancer. METHODS: A systematic literature search was performed to identify studies comparing outcomes of patients with early-stage breast cancer according to beta-blocker use (yes versus no). The primary endpoint was recurrence-free survival (RFS), defined as the occurrence of breast cancer recurrence or death. Secondary objectives were pathologic complete response (pCR), breast cancer recurrence, breast cancer-specific mortality and overall survival (OS). Hazard ratios (HRs) or odds ratios (ORs) and 95% confidence intervals (CIs) were extracted from each study and a pooled analysis with the random-effect model was conducted. The Higgins' I-squared test was used to quantify heterogeneity. Egger's test was applied to assess publication bias. All P values were two-sided and considered significant if ≤0.05. RESULTS: Overall, 13 studies were included as follows: RFS (6), pCR (2), breast cancer recurrence (6), breast cancer-specific mortality (7) and OS (5). The use of beta-blockers was associated with a significant RFS improvement in the overall population (N = 21 570; HR 0.73; 95% CI, 0.56-0.96; P = 0.025) and in patients with triple-negative disease (N = 1212; HR 0.53; 95% CI, 0.35-0.81; P = 0.003). No significant differences in terms of pCR (N = 1554; OR 0.77; 95% CI, 0.44-1.36; P = 0.371), breast cancer recurrence (N = 37 957; OR 0.66; 95% CI, 0.42-1.03; P = 0.065), breast cancer-specific mortality (N = 64 830; HR 0.77; 95% CI, 0.56-1.08; P = 0.130) or OS (N = 103 065; HR 1.03; 95% CI, 0.87-1.23; P = 0.692) were observed according to beta-blocker use. DISCUSSION: In this meta-analysis, beta-blocker use was associated with a longer RFS in patients with early-stage breast cancer, with a more pronounced effect observed in those with triple-negative disease. Beta-blockers arise as an interesting option to be explored in prospective studies for patients with early-stage breast cancer.

Do platinum salts fit all triple negative breast cancers?

Triple-negative breast cancer (TNBC) is an aggressive disease with limited treatment options and poor prognosis once metastatic. Pre-clinical and clinical data suggest that TNBC could be more sensitive to platinum-based chemotherapy, especially among BRCA1/2-mutated patients. In recent years, several randomised trials have been conducted to evaluate platinum efficacy in both early-stage and advanced TNBC, with conflicting results especially for long-term outcomes. Experimental studies are now focusing on identifying biomarkers of response to help selecting patients who may benefit most from platinum-based therapies, including BRCA1/2 mutational status and genomic instability signatures (such as HRD-LOH or HRD-LST scores). A standard therapy for TNBC is still missing and platinum-based regimens represent an emerging therapeutic option for selected patients with a defect in the homologous recombination repair system. The identification of these patients through validated biomarker assays will be crucial to optimize the use of currently approved agents in TNBC.