Emerging mutations in the ESR1 gene that encodes for the estrogen receptor (ER) are associated with resistance to endocrine therapy. ESR1 mutations rarely exist in primary tumors (~ 1%) but are ...relatively common (10-50%) in metastatic, endocrine therapy-resistant cancers and are associated with a shorter progression-free survival. Little is known about the incidence and clinical implication of these mutations in early recurrence events, such as local recurrences or newly diagnosed metastatic disease.
We collected 130 archival tumor samples from 103 breast cancer patients treated with endocrine therapy prior to their local/metastatic recurrence. The cohort consisted of 41 patients having at least 1 sample from local/loco-regional recurrence and 62 patients with metastatic disease (of whom 41 newly diagnosed and 28 with advanced disease). The 5 most common ESR1 hotspot mutations (D538G, L536R, Y537S/N/C) were analyzed either by targeted sequencing or by droplet digital PCR. Progression-free survival (PFS), disease-free survival (DFS), and distant recurrence-free survival (DRFS) were statistically tested by Kaplan-Meier analysis.
The prevalence of ESR1 mutations was 5/41 (12%) in newly diagnosed metastatic patients and 5/28 (18%) for advanced metastases, detected at allele frequency > 1%. All mutations in advanced metastases were detected in patients previously treated with both tamoxifen (TAM) and aromatase inhibitors (AI). However, in newly diagnosed metastatic patients, 4/5 mutations occurred in patients treated with TAM alone. PFS on AI treatment in metastatic patients was significantly shorter for ESR1 mutation carriers (p = 0.017). In the local recurrence cohort, ESR1 mutations were identified in 15/41 (36%) patients but only 4/41 (10%) were detected at allele frequency > 1%. Again, most mutations (3/4) were detected under TAM monotherapy. Notably, 1 patient developed ESR1 mutation while on neoadjuvant endocrine therapy. DFS and DRFS were significantly shorter (p = 0.04 and p = 0.017, respectively) in patients that had ESR1 mutations (> 1%) in their loco-regional recurrence tumor.
Clinically relevant ESR1 mutations are prevalent in newly diagnosed metastatic and local recurrence of endocrine-treated breast cancer. Since local recurrences are amenable to curative therapy, these mutations may inform the selection of subsequent endocrine therapies.
In view of the relatively limited efficacy of immunotherapies targeting the PD-1–PD-L1 axis in triple-negative breast cancer (TNBC) and of published reports on tumor-promoting roles of TNFR2+ ...tumor-infiltrating lymphocytes (TNFR2+ TILs), we determined the incidence of TNFR2+ TILs in TNBC patient tumors, their association with disease outcome and relations with PD-1+ TILs. Using a cohort of treatment-naïve TNBC patients with long follow-up (
n
= 70), we determined the presence of TNFR2+ TILs and PD-1+ TILs by immunohistochemistry. TILs (≥ 1% of cellular mass) and TNFR2+ TILs (≥ 1% of total TILs) were detected in 96% and 74% of tumors, respectively. The presence of TILs at > 5% of tumor cell mass (“Positive TILs”), as well as of positive TNFR2+ TILs (> 5%), was independently associated with good prognosis, and combination of both parameters demonstrated superior outcome relative to their lower levels. PD1+ TILs (> 5/hot spot) were detected in 63% of patients. High levels of PD-1+ TILs (> 20/hot spot) showed an unfavorable disease outcome, and in their presence, the favorable outcome of positive TNFR2+ TILs was ablated. Thus, TNFR2+ TILs are strongly connected to improved prognosis in TNBC; these findings suggest that TNFR2+ TILs have favorable effects in TNBC patients, unlike the tumor-promoting roles attributed to them in other cancer systems. Overall, our observations propose that the TNFR2+ TIL subset should not be targeted in the course of TNBC therapy; rather, its beneficial impacts may become into power when anti-PD-1 regimens—that may potentiate immune activities—are administered to TNBC patients.
After the publication of the original article 1, we were notified the upper panel of the Fig. 1, where the patients' codes are listed, was cropped by mistake so the patients 1-8 are repeated.
Triple-negative breast cancer (TNBC) is primarily treated via chemotherapy; in parallel, efforts are made to introduce immunotherapies into TNBC treatment. CD4+ TNFR2+ lymphocytes were reported as ...Tregs that contribute to tumor progression. However, our published study indicated that TNFR2+ tumor-infiltrating lymphocytes (TNFR2+ TILs) were associated with improved survival in TNBC patient tumors. Based on our analyses of the contents of CD4+ and CD8+ TILs in TNBC patient tumors, in the current study, we determined the impact of chemotherapy on CD4+ and CD8+ TIL subsets in TNBC mouse tumors. We found that chemotherapy led to (1) a reduction in CD4+ TNFR2+ FOXP3+ TILs, indicating that chemotherapy decreased the content of CD4+ TNFR2+ Tregs, and (2) an elevation in CD8+ TNFR2+ and CD8+ TNFR2+ PD-1+ TILs; high levels of these two subsets were significantly associated with reduced tumor growth. In spleens of tumor-bearing mice, chemotherapy down-regulated CD4+ TNFR2+ FOXP3+ cells but the subset of CD8+ TNFR2+ PD-1+ was not present prior to chemotherapy and was not increased by the treatment. Thus, our data suggest that chemotherapy promotes the proportion of protective CD8+ TNFR2+ TILs and that, unlike other cancer types, therapeutic strategies directed against TNFR2 may be detrimental in TNBC.
Abnormal molecular processes occurring throughout the genome leave distinct somatic mutational patterns termed mutational signatures. Exploring the associations between mutational signatures and ...clinicopathological features can unravel potential mechanisms driving tumorigenic processes.
We analyzed whole genome sequencing (WGS) data of tumor and peripheral blood samples from 37 primary breast cancer (BC) patients receiving neoadjuvant chemotherapy. Comprehensive clinico‐pathologic features were correlated with genomic profiles and mutational signatures.
Somatic mutational landscapes were highly concordant with known BC data sets. Remarkably, we observed a divergence of dominant mutational signatures in association with BC subtype. Signature 5 was overrepresented in hormone receptor positive (HR+) patients, whereas triple‐negative tumors mostly lacked Signature 5, but expectedly overrepresented Signature 3. We validated these findings in a large WGS data set of BC, demonstrating dominance of Signature 5 in HR+ patients, mostly in luminal A subtype. We further investigated the association between Signature 5 and gene expression signatures, and identified potential networks, likely related to estrogen regulation.
Our results suggest that the yet elusive Signature 5 represents an alternative mechanism for mutation accumulation in HR+ BC, independent of the homologous recombination repair machinery related to Signature 3. This study provides theoretical basis for further elucidating the processes promoting hormonal breast carcinogenesis.
Abstract
Tumor heterogeneity frequently develops through the course of disease, therapy and metastasis. This molecular evolution is a major challenge in the clinical setting and is the main reason ...for resistance to therapy. Although metastatic disease is the cause of death in breast cancer, most studies involve primary tumors compared to normal breast. An alternative approach of serial assessments can add an informative value and highlight important molecular players that may be otherwise underestimated.
We sought to explore alterations through the course of disease by profiling serial samples from individual breast cancer cases followed from diagnosis to recurrence. We have assembled a unique cohort of patients having matched samples from pre-treatment, post-treatment and recurrent events. We collected paraffin-embedded samples and profiled miRNA expression across all samples for each patient using NanoString analysis.
We hypothesized that expression modulations in individual patients through their course of disease can target miRNAs sets that differentially function at the various stages of the disease. We therefore used an innovative approach for analysis, identifying modulation patterns as opposed to differential absolute expression. We defined all the 8 possible patterns of expression modulations in 3 time points across the course of disease. For each pattern, we identified a set of miRNAs that are shared between patients by limiting the search algorithm to find modulations of at least 1.5 fold in at least 3 patients. Each miRNA set was examined for enrichments in known miRNAs datasets (METABRIC), for target predictions and for literature evidences.
We found an agreement between the predicted pattern of each assigned miRNAs and the observed trend. For example, miRNAs assigned to a pattern of an increased expression post-treatment and a decrease at recurrence were found to be down-regulated in breast cancer and negatively correlated with the cell cycle pathway. Interestingly, we found that this miRNAs set can differentiate between individual patients, based on their response to therapy. All patients sharing the same pattern for its assigned set of miRNAs had a partial response to therapy. In contrast, patients that showed the opposite pattern demonstrated a minimal response to therapy. Finally, although this miRNA set were identified by the pattern dynamics, we found a significant difference in its average absolute expression level between patients having recurrence and patients that are recurrence free, suggesting that the identified miRNA set may have a prognostic value.
In summary, examining serial assessments enabled us to identify significant molecular signatures characterizing breast cancer progression based on expression patterns through the course of disease. This longitudinal approach of profiling individual patients may have important consequences for personalized medicine.
Citation Format: Maya Dadiani, Noa Bossel, Shani Paluch-Shimon, Gili Peri, Anya Pavlovski, Smadar Kahana-Edwin, Nora Balint, Adi Yosepovich, Adi Zundelevich, Einav Gal-Yam, Raanan Berger, Iris Barshack, Eytan Domany, Bella Kaufman. Tumor evolution inferred by patterns of miRNA expression through the course of disease, therapy and recurrence in breast cancer. abstract. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4011. doi:10.1158/1538-7445.AM2015-4011
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