Brazilian Breast Cancer Patients Research Articles

Interleukin-33 Expression on Treatment Outcomes and Prognosis in Brazilian Breast Cancer Patients Undergoing Neoadjuvant Chemotherapy.

Interleukin-33 (IL-33), a member of the interleukin-1(IL-1) family of cytokines, remains poorly understood in the context of human breast cancer and its impact on treatment outcomes. This study aimed to elucidate IL-33 expression patterns within tumor samples from a cohort of Brazilian female breast cancer patients undergoing neoadjuvant chemotherapy while exploring its correlation with clinicopathological markers. In total, 68 samples were meticulously evaluated, with IL-33 expression quantified through a quantitative polymerase chain reaction. The findings revealed a substantial upregulation of IL-33 expression in breast cancer patient samples, specifically within the Triple-negative and Luminal A and B subtypes, when compared to controls (healthy breast tissues). Notably, the Luminal B subtype displayed a marked elevation in IL-33 expression relative to the Luminal A subtype (p < 0.05). Moreover, a progressive surge in IL-33 expression was discerned among Luminal subtype patients with TNM 4 staging criteria, further underscoring its significance (p < 0.005). Furthermore, chemotherapy-naïve patients of Luminal A and B subtypes exhibited heightened IL-33 expression (p < 0.05). Collectively, our findings propose that chemotherapy could potentially mitigate tumor aggressiveness by suppressing IL-33 expression in breast cancer, thus warranting consideration as a prognostic marker for gauging chemotherapy response and predicting disease progression in Luminal subtype patients. This study not only sheds light on the intricate roles of IL-33 in breast cancer but also offers valuable insights for future IL-33-related research endeavors within this context.

Genetic Ancestry of 1127 Brazilian Breast Cancer Patients and Its Correlation With Molecular Subtype and Geographic Region

PurposeBreast cancer molecular subtypes show significant differences in different ethnic groups in the United States, but no study has evaluated genetic ancestry in breast cancer in Brazilian women. MethodsBreast cancer patients from distinct parts of Brazil were evaluated. Molecular subtypes were determined by immunohistochemistry. Genetic ancestry was evaluated using a panel of 46 AIMs (ancestry informative markers), which classified genetic ancestry as European, African, Asian, and Amerindian. PCR products were subjected to capillary electrophoresis and analyzed using GeneMapper 4.0 software. Ancestry was evaluated with Structure v.2.3.3 software. Ancestry was tested for correlations with geographic region and molecular subtype. The chi-square test and ANOVA with Bonferroni adjustment were applied. ResultsGenetic ancestry and clinical data were evaluated in 1127 patients. Higher rates of self-reported white ethnicity, European ancestry, and HER-2− luminal tumors were identified in the South region, which may influence age at diagnosis and result in a higher rate of early tumors. Conversely, higher rates of African ancestry in the North and Northeast regions, self-reported nonwhite ethnicity, HER-2+ tumors, and triple-negative tumors were noted. Triple-negative and HER-2+ tumors were associated with higher advanced and metastatic disease rates at diagnosis, with triple-negative tumors being more frequent in young women. ConclusionDifferences in genetic ancestry, self-reported ethnicity, and molecular subtype were found between Brazilian demographic regions. Knowledge of these features may contribute to a better understanding of age at diagnosis and the molecular distribution of breast cancer in Brazil.

Characterization of genetic predisposition to molecular subtypes of breast cancer in Brazilian patients.

Introduction BRCA1 and BRCA2 germline pathogenic variants (GPVs) account for most of the 5-10% of breast cancer (BC) that is attributable to inherited genetic variants. BRCA1 GPVs are associated with the triple negative subtype, whereas BRCA2 GPVs are likely to result in higher grade, estrogen-receptor positive BCs. The contribution of other genes of high and moderate risk for BC has not been well defined and risk estimates to specific BC subtypes is lacking, especially for an admixed population like Brazilian.ObjectiveThe aim of this study is to evaluate the value of a multigene panel in detecting germline mutations in cancer-predisposing genes for Brazilian BC patients and its relation with molecular subtypes and the predominant molecular ancestry.Patients and methodsA total of 321 unrelated BC patients who fulfilled NCCN criteria for BRCA1/2 testing between 2016-2018 were investigated with a 94-genes panel. Molecular subtypes were retrieved from medical records and ancestry-specific variants were obtained from off-target reads obtained from the sequencing data.ResultsWe detected 83 GPVs in 81 patients (positivity rate of 25.2%). Among GPVs, 47% (39/83) were identified in high-risk BC genes (BRCA1/2, PALB2 and TP53) and 18% (15/83) in moderate-penetrance genes (ATM, CHEK2 and RAD51C). The remainder of the GPVs (35% - 29/83), were identified in lower-risk genes. As for the molecular subtypes, triple negative BC had a mutation frequency of 31.6% (25/79), with predominance in BRCA1 (12.6%; 10/79). Among the luminal subtypes, except Luminal B HER2-positive, 18.7% (29/155) had GPV with BRCA1/2 genes contributing 7.1% (11/155) and non-BRCA1/2 genes, 12.9% (20/155). For Luminal B HER2-positive subtype, 40% (16/40) had GPVs, with a predominance of ATM gene (15% - 6/40) and BRCA2 with only 2.5% (1/40). Finally, HER2-enriched subtype presented a mutation rate of 30.8% (4/13) with contribution of BRCA2 of 7.5% (1/13) and non-BRCA1/2 of 23% (3/13). Variants of uncertain significance (VUS) were identified in 77.6% (249/321) of the patients and the number of VUS was increased in patients with Asian and Native American ancestry.ConclusionThe multigene panel contributed to identify GPVs in genes other than BRCA1/2, increasing the positivity of the genetic test from 9.6% (BRCA1/2) to 25.2% and, considering only the most clinically relevant BC predisposing genes, to 16.2%. These results indicate that women with clinical criteria for hereditary BC may benefit from a multigene panel testing, as it allows identifying GPVs in genes that directly impact the clinical management of these patients and family members.

Genetic epidemiology of breast cancer (BC) risk genes from a diverse real-world oncology practice in Brazil.

10594 Background: As germline testing in BC is becoming more accessible, a large body of evidence from distinct populations is revealing different prevalence of affected genes or recurrent and founder mutations. We evaluated a series of Brazilian BC patients from diverse regions of the country that were studied in a single laboratory facility for likely pathogenic/pathogenic variants (PV) and variants of unknown significance (VUS) in BRCA1/2 and other BC susceptibility genes (ATM, BARD1, CDH1, CHEK2, PALB2, RAD51C, RAD51D and TP53). Methods: We used multi-gene NGS panels covering from 35 to 105 genes, including copy number alterations, to perform sequencing in patients with diagnosis of BC from 2016 to 2021. With patient consent, we extracted clinical and pathological data from curated Real-World Database of Oncoclínicas Group to classify tumors according to hormone receptor (HR) and HER2 status and assess family history of cancer. Primary endpoint was prevalence of PV and VUS in BRCA1/2 and other breast cancer risk genes. Results: In total, 1,520 patients with BC were included in the analysis, 99% were female, median age at genetic testing was 46 years and 84% had family history of cancer. BC subtype was available in 717 cases (43% HR+/HER2-, 26% HER2+, 31% triple negative). Median age at genetic testing in HR+/HER2- population was 49 years and 44 years in HER2+ and triple-negative cases. Overall, 11.7% (CI95% 10.1-13.4) of the population had at least one PV in any BC risk gene: 50 in BRCA1, 49 in BRCA2, 22 in TP53 (17 had Brazilian founder p.R337H haplotype), 19 in PALB2, 18 in CHEK2, 15 in ATM, 7 in other genes (BARD1, CDH1, RAD51C, RAD51D) and 4 patients had co-existing PV in 2 BC risk genes. BRCA1/2 PVs were found in 7% of BC patients and BRCA1/2 VUS in 3%, being higher in triple-negative cases (11% PVs) than HR+/HER2- (5% PVs) and HER2+ (3%). For other BC risk genes, 5% of the patients had a PV, without differences according to BC subtype, and the prevalence of VUS was 14%. The prevalence of TP53 Brazilian founder mutation in BC was 1.2%. Median age of genetic testing was younger in population with BRCA1 PV (43 years) than BRCA2 PV (47 years) and other genes PV (46 years). Conclusions: In this real-world cohort of BC patients enriched for high-risk features such as young age at diagnosis, positive family history and triple-negative disease, the prevalence of BRCA1 and BRCA2 PV was very similar and represented only 56% of all PV detected. Different from other studies, TP53 mutations are the third most common germline alteration in the Brazilian population, with close to 80% of the cases presenting the founder mutation p.R337H. BC with epidemiologic high-risk features should be offered a germline test in Brazilian patients due to the considerable chance of a PV detection.

Detection of germline variants in Brazilian breast cancer patients using multigene panel testing

Genetic diversity of germline variants in breast cancer (BC) predisposition genes is unexplored in miscegenated populations, such those living in Latin America. We evaluated 1663 Brazilian BC patients, who underwent hereditary multigene panel testing (20–38 cancer susceptibility genes), to determine the spectrum and prevalence of pathogenic/likely pathogenic (P/LP) variants and variants of uncertain significance (VUS). Associations between P/LP variants and BC risk were estimated in a case–control analysis of BC patients and 18,919 Brazilian reference controls (RC). In total, 335 (20.1%) participants carried germline P/LP variants: 167 (10.0%) in BRCA1/2, 122 (7.3%) in BC actionable non-BRCA genes and 47 (2.8%) in candidate genes or other cancer predisposition genes. Overall, 354 distinctive P/LP variants were identified in 23 genes. The most commonly mutated genes were: BRCA1 (27.4%), BRCA2 (20.3%), TP53 (10.5%), monoallelic MUTYH (9.9%), ATM (8.8%), CHEK2 (6.2%) and PALB2 (5.1%). The Brazilian variant TP53 R337H (c.1010G>A, p.Arg337His), detected in 1.6% of BC patients and 0.1% of RC, was strongly associated with risk of BC, OR = 17.4 (95% CI: 9.4–32.1; p < 0.0001); monoallelic MUTYH variants c.1187G>A and c.536A>G, detected in 1.2% (0.9% RC) and 0.8% (0.4% RC) of the patients, respectively, were not associated with the odds of BC, the former with OR = 1.4 (95% CI: 0.8–2.4; p = 0.29) and the latter with OR = 1.9 (95% CI: 0.9–3.9; p = 0.09). The overall VUS rate was 46.1% for the entire patient population. Concluding, the use of multigene panel testing almost doubled the identification of germline P/LP variants in clinically actionable predisposition genes in BC patients. In Brazil, special attention should be given to TP53 P/LP variants.

PP353 Patient-Reported Outcomes: What Matters For Brazilian Breast Cancer Patients?

IntroductionPatient-Reported Outcomes (PRO) are directly reported by the patient without interpretation of the patient's response by a clinician or anyone else and pertains to the patient's health, quality of life, or functional status associated with health care or treatment. It can provide patients’ perspectives regarding treatment benefit and harm, directly measure treatment benefit and harm beyond survival, and are often the outcomes of most importance to patients. This study aims to analyze outcomes reported by Brazilian women diagnosed with breast cancer and rank the most important attributes for these patients.MethodsObservational study composed of interviews and questionnaires applied to a convenience sample of women diagnosed with breast cancer. The instruments were developed taking into account the literature on the topic and the expertise of specialists. The questionnaire was built with close-ended questions using multiple-choice and a Likert scale, in order to rank the attributes and outcomes found in the interviews.ResultsThe total sample was composed of 65 women diagnosed with breast cancer. Twelve women were interviewed, in September 2020, to explore the main outcomes and preferences about their treatments, such as the most common side effects and the most impacted aspects of life after diagnosis and breast cancer treatment. Psychological, emotional, and sexual impacts were frequently described as aspects of life affected by the disease and its treatment. Fifty-three women, from all the five Brazilian regions, answered the survey applied in October and November 2020. Following an order of importance ranking, the following outcomes were chosen, respectively: overall survival, progression-free survival; and quality of life. The treatment effects that were considered less important, among this sample, were pain and adverse events.ConclusionsThinking about expanding the therapeutic quality of users, it is essential to take into account the experiences of patients. PRO is a trend in current research to achieve this goal, in order to influence the decisions of HTA agencies about the importance of valuing outcomes that affect patients' lives.

A novel lncRNA derived from an ultraconserved region: lnc-uc.147, a potential biomarker in luminal A breast cancer

ABSTRACT The human genome contains 481 ultraconserved regions (UCRs), which are genomic stretches of over 200 base pairs conserved among human, rat, and mouse. The majority of these regions are transcriptionally active (T-UCRs), and several have been found to be differentially expressed in tumours. Some T-UCRs have been functionally characterized, but of those few have been associated to breast cancer (BC). Using TCGA data, we found 302 T-UCRs related to clinical features in BC: 43% were associated with molecular subtypes, 36% with oestrogen-receptor positivity, 17% with HER2 expression, 12% with stage, and 10% with overall survival. The expression levels of 12 T-UCRs were further analysed in a cohort of 82 Brazilian BC patients using RT-qPCR. We found that uc.147 is high expressed in luminal A and B patients. For luminal A, a subtype usually associated with better prognosis, high uc.147 expression was associated with a poor prognosis and suggested as an independent prognostic factor. The lncRNA from uc.147 (lnc-uc.147) is located in the nucleus. Northern blotting results show that uc.147 is a 2,8 kb monoexonic trancript, and its sequence was confirmed by RACE. The silencing of uc.147 increases apoptosis, arrests cell cycle, and reduces cell viability and colony formation in BC cell lines. Additionally, we identifed 19 proteins that interact with lnc-uc.147 through mass spectrometry and demonstrated a high correlation of lnc-uc.147 with the neighbour gene expression and miR-18 and miR-190b. This is the first study to analyse the expression of all T-UCRs in BC and to functionally assess the lnc-uc.147.

Abstract PS9-27: Estimation of clinical benefit and economic burden for using a commercial 70-gene signature test for Brazilian breast cancer patients in the public health system

Abstract Background The clinical benefit of adjuvant chemotherapy (CT) for breast cancer (BC) depends on several factors, like menopausal status, stage and molecular subtype. Commercial available gene signatures make possible a more accurate selection of the patients who could benefit more with adjuvant chemotherapy. In Brazil, gene signatures are not available to public health system users, nor even reimbursed for privately insured patients, making this matter a major cause of frustration for patients and oncologists. MINDACT trial evaluated 70-gene signature MammaPrint (70-GS) as predictive test for chemotherapy benefit. Long-term follow up showed premenopausal patients who had not received CT and were in in the high clinical risk/ low genomic risk group presented unfavorable outcomes. We aimed to estimate clinical impact and economic burden that a hypothetical access to 70-GS may result based on a Brazilian BC population treated in a university hospital. Methods Medical records from BC patients who received neo/adjuvant chemotherapy from January/2018 to June/2020 at the Hospital das Clínicas de Ribeirão Preto - USP (HCRP-USP) were retrospectively analyzed. The following inclusion criteria were considered to select patients who could benefit most with 70-GS: stage I or II invasive BC, tumors smaller than 5 cm, up to three positive lymph nodes (LN+), postmenopausal status and HR+/HER2- (hormone receptor-positive, HER2-negative) tumors. Online search for costs and reimbursed values. The Brazilian public health system reimburses clinics R$ 571 (US$ 107) (US$ 1=R$ 5.32; July 1, 2020) each month a patient receives adjuvant CT for stage I BC and R$ 800 (US$ 150) each month for stage II BC. The 70-GS test, purchased privately, costs R$ 15,000 (US$ 2,820). The study was approved by the local ethics committee (HCFMRPUSP no 4.078.614). Results From Jan/2018 to June/2020, 311 patients were treated with neo/adjuvant chemotherapy. Mainly 4 cycles of AC (doxorubicin-cyclophosphamide), 8 cycles of ACT (AC + docetaxel or paclitaxel) or 4 cycles of TC (docetaxel-cyclophosphamide) regimens were delivered, which lasted from 3 to 6 months. For an entire CT period, we estimate the maximum reimbursement amount of R$ 4,800 (US$ 752) (6 months for stage II BC). In our population, patient who received CT, according to subtypes, were 174 (56%) HR+/HER2-, 30 (10%) HR+/HER2+, 38 (12%) HR-/HER2+ and 69 (22%) triple-negative. Among RH+/HER2-, 96 (55%) were postmenopausal BC, 77 (44%) were premenopausal BC and one was male BC (1%). Taking in accountpostmenopausal stage I and II BC, tumors &amp;lt;5 cm and ≤3 LN+, a total of 54 patients who received CT (17%) would be candidates to 70-GS testing. For this group, the maximum reimbursement with CT would be R$ 259,200 (US$ 48,722) while the costs with 70-GS would be R$ 810,000 (US$ 152,280). Conclusions Among 311 patients who received CT at our institution, 54 met the inclusion criteria we chose as the most beneficial to perform 70-GS test. Considering that MINDACT trial found that 46% of high clinical risk may not require CT, approximately 25 patients (8%) could have avoided CT, saving R$ 120,000 (USS$ 22,556). The 70-GS test valuation for the public health system, considering only savings from chemotherapy, would be R$ 2,222 (US$ 418) and the current cost of 70-GS is 6.75 times higher than the money saved. Additional pharmacoeconomic analyses should include the estimated costs of early and late toxicities (i.e. febrile neutropenia, leukemia and cardiotoxicity) for this population, which can reduce the difference between the cost of 70-GS test and the amount saved. A national agreement between the company and the government could also contribute to increase access and make treatment de-escalation a reality also in lower-middle-income countries. Citation Format: Franklin F Pimentel, Isabela PC Buzatto, Tamara CGF Rodrigues, Jessica MC Borba, Karoline PI Peruchi, Jurandyr M de Andrade, Daniel G Tiezzi. Estimation of clinical benefit and economic burden for using a commercial 70-gene signature test for Brazilian breast cancer patients in the public health system [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS9-27.

MiRNA-195 expression in the tumor tissues of female Brazilian breast cancer patients with operable disease

OBJECTIVE:This study aimed to assess miRNA-195 expression in the tumor tissues from a cohort of Brazilian female breast cancer patients undergoing neoadjuvant chemotherapy (NAC) and evaluate its correlation with various clinicopathological markers.METHODS:Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to evaluate the miRNA-195 expression in tumor tissues from a cohort of female breast cancer patients undergoing NAC. This expression was then correlated with the occurrence of several distinct breast cancer molecular subtypes and other clinicopathological variables.RESULTS:A total of 55 patients were included in this study, 28 (50.9%) of whom were treated using NAC. Tumor miRNA-195 expression was suppressed in breast cancer patients, regardless of their exposure to systemic treatments, histological grade, size, nodal status, and tumor-node-metastasis (TNM) staging. This was more pronounced in luminal and triple-negative patients, and patient’s response to NAC was correlated with an increase in miRNA-195 expression.CONCLUSION:miRNA-195 is downregulated in the tumor tissues of Brazilian breast cancer patients regardless of NAC exposure; this reinforces its role as a tumor suppressor and a potential biomarker for chemotherapy response.

Germline and Somatic mutations in postmenopausal breast cancer patients

OBJECTIVES:In breast cancer (BC) patients, the frequency of germline BRCA mutations (gBRCA) may vary according to the ethnic background, age, and family history of cancer. Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) is the second most common somatic mutated gene in BC; however, the association of mutations in both genes with cancer has not been thoroughly investigated. Thus, our aims were to investigate gBRCA mutation frequency in a cohort of postmenopausal Brazilian BC patients and the association of gBRCA1/BRCA2 and PIK3CA somatic mutations.METHODS:Forty-nine postmenopausal (>55 years) and forty-one young (≤35 years) BC patients were included in this study. The postmenopausal group included patients who reported a positive family history of cancer. For these patients, gBRCA1/BRCA2 were sequenced using next-generation sequencing (NGS) or Sanger sequencing. Data for gBRCA in young patients were already available from a previous study. DNA from formalin-fixed, paraffin-embedded (FFPE) tumors was obtained from 27 postmenopausal and 41 young patients for analyzing exons 9 and 20 of PIK3CA. The association between gBRCA1/BRCA2 and somatic mutations in PIK3CA was investigated.RESULTS:The overall frequency of gBRCA1/BRCA2 among the 49 postmenopausal patients was 10.2%. The frequencies of somatic mutations in PIK3CA in the postmenopausal and young patients were 37% and 17%, respectively (ns). The most common PIK3CA mutation was found to be E454A. Nonsense and frameshift mutations, which may counteract the oncogenic potential of PIK3CA were also detected. Regardless of age, 25% of BRCA1/BRCA2 mutation carriers and non-carriers , each, had PIK3CA somatic mutations.CONCLUSIONS:Data obtained indicate that BRCA1/BRCA2 gene testing may be considered for postmenopausal patients with BC who have a family history of cancer. Although some of them are not considered pathogenic, somatic variants of PIK3CA are frequently observed in BC patients, especially in postmenopausal patients.

Mouse Mammary Tumor Virus (MMTV)-Like env Sequence in Brazilian Breast Cancer Samples: Implications in Clinicopathological Parameters in Molecular Subtypes.

Background: Breast cancer (BC) is a complex disease in which susceptibility and clinical course depend on multiple factors. Evidence suggests that a mouse mammary tumor virus (MMTV)-homolog may be present in human BCs; however, little is known about its clinical implications. Methods: MMTV-like env nucleotide-sequence was searched in tumor and tumor-adjacent tissues from 217 Brazilian BC patients through nested-PCR and confirmed through PCR-sequencing. Blood samples were also tested for patients with MMTV-like env gene-positive tumors. Correlations with clinicopathological parameters were evaluated. Results: MMTV-like env sequence was detected in tumor and tumor-adjacent tissue samples from 41/217 and 30/196 patients, respectively. In blood, MMTV-like was detected in 17/32 patients. In Luminal-B tumors, MMTV-like in tumor tissue was negatively correlated with tumor size and disease stage, whereas in HER2 tumors it anti-correlated with lymph node metastasis (LNM) and disease stage. Considering blood, MMTV-like env gene positivity negatively correlated with age in general BC, while in Luminal-A tumors it positively correlated with Ki67 but negatively correlated with age and LNM. The associations with decreased LNM frequency were independent of other prognostic factors. Conclusion: MMTV-like env positivity is associated with better prognostic parameters in BC subtypes, which might be explainable by its anti-metastatic potential and by putative activation of immune milieu.

Abstract P2-08-31: Role of body mass index in Brazilian breast cancer patients: Clinical-pathological characteristics and outcome in a single-institution retrospective cohort

Abstract Background: Despite of several studies described body mass index (BMI) as a poor prognostic factor in breast cancer (BC) patients, the available data are still conflicting and the relation between obesity and BC remains unclear. In this study we evaluated the association of BMI at presentation with BC clinicopathological characteristics and outcomes in a Brazilian public hospital population. Methods: Retrospective review of all patients diagnosed and treated for breast cancer in a Brazilian public hospital, between 1999 and 2013 was performed. Pathological and clinical characteristics as well as survival was collected in the medical and electronic patients’ records. Bivariate and multivariate analyzes were done using SPSS version 20. It was considered to be obese women with BMI ≥ 30kg/m2. Results: Of 1,833 women included in this study, 620 (33.8%) was obese at presentation. When comparing age and menopause, obese women were slightly older and more related to postmenopausal status. (table 1). Correlation between clinicopathological characteristics and body mass index.BMI ≥ 30kg/m2BMI &amp;lt; 30kg/m2p valuen = 620n = 1211BMI, average (SD)35.0 (4.5)25.1 (3.1)0.01Age (years), median (range)56.2 (25.8 - 89.7)54.5 (22.6 - 93.9)0.03Size (mm), median (range)22 (0-154)20 (0-140)0.01n (%)n (%)Postmenopausal412 (66)722 (60)0.01HistologyDuctal531 (86)1007 (84)0.25Lobular26 (4)49 (4)Other57 (9)142 (12)Grade1125 (21)236 (21)2322 (54)623 (55)0.983145 (24)282 (25)Stage (TNM)030 (5)71 (6)I (A+B)110 (18)215 (18)II (A+B)227 (37)483 (40)0.43III (A+B+C)229 (37)399 (33)IV22 (4)42 (3)SubtypeLuminal375 (63)682 (59)Luminal/HER2+79 (13)173 (15)0.34Her2+53 (9)125 (11)Triple negative91 (15)184 (16)Estrogen receptor +459 (75)865 (74)0.23Progesterone receptor +396 (65)717 (60)0.06HER2+134 (22)303 (26)0.09Relapse (%)318/1211 (26,3%)164/620 (26,5%)0.930Time to recurrence (years) (range)2,40 (0,0-17,4)2,30 (0,20-16,6)0.821All cause mortality350/1211 (28,9%)350/1211 (28,9%)0.896Breast cancer specific Mortality273/1211 (22,5%)273/1211 (22,5%)0.752 There was no other significant association between BMI and tumor characteristics, recurrence or overall and specific survival. Conclusion: In our population, BMI was not a risk factor for more aggressive BC at presentation, neither for worse outcomes. BMI may not be so accurate to measure body fat content and the results of the studies may suffer influence of different populations. Otherwise the effects of obesity may be mitigated by the heterogeneous behavior of breast cancer and the current cancer therapies. Citation Format: Leonardo F Orlandini, Franklin F Pimentel, Hélio HA Carrara, Francisco JC dos Reis, Jurandyr M de Andrade, Daniel G Tiezzi. Role of body mass index in Brazilian breast cancer patients: Clinical-pathological characteristics and outcome in a single-institution retrospective cohort [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-08-31.

Abstract P2-11-12: The influences of adherence to tamoxifen and CYP2D6 pharmacogenetics on plasma concentrations of the active metabolite (Z)-endoxifen in breast cancer

Abstract One-third of early breast cancer patients with estrogen receptor (ER) positive tumors treated with the selective estrogen receptor modulator tamoxifen either relapse or die from the disease in the following decade. Improvement of tamoxifen efficacy requires a better knowledge of factors determining outcome of which the medication-taking behavior, i.e. adherence, is a strong suspect. Discontinuation and non-adherence to tamoxifen are frequent and result in increased mortality. Commonly used methods to assess drug adherence such as prescription-refill patterns infer that the medication is taken exactly as prescribed yet, partial adherence or actual use of the medication cannot be controlled. An objective surrogate of tamoxifen adherence is the monitoring of drug concentrations in the patients’ plasma including the parent drug and its active metabolite (Z)-endoxifen (endoxifen), however individual concentrations depend on pharmacogene polymorphisms particularly those of the liver enzyme cytochrome P450 2D6 (CYP2D6). Patients without CYP2D6 variants have normal enzyme function (extensive metabolizer, EM) and achieve high endoxifen concentrations compared to patients with variants conferring absent activity (poor metabolizer, PM) or reduced activity (intermediate metabolizer, IM) who have significantly lower plasma concentrations of the active metabolite. A putative threshold of 5.9 ng/mL endoxifen has been proposed suggesting that patients with endoxifen concentration above or below threshold have lower or higher risk for recurrence, assuming that low endoxifen exposure in the tumor likely results in incomplete inhibition of ER-dependent growth signaling. During tamoxifen treatment it is therefore important that patients achieve clinically relevant endoxifen levels while at the same time avoid confounders of which adherence is a prime candidate. To this end, we investigated patients’ ability to achieve relevant plasma concentrations during tamoxifen treatment in relation to their CYP2D6 metabolizer status and their tamoxifen adherence behavior. Our prospective study included 192 Brazilian breast cancer patients treated with 20 mg tamoxifen daily. Two-thirds of the patients were premenopausal. Plasma levels of tamoxifen and its metabolites were measured by LC-MS/MS at 3, 6 and 12 months of treatment. Adherence to tamoxifen was evaluated by the questionnaire-based Morisky medication adherence scale. CYP2D6 polymorphisms were determined by MALDI-TOF mass spectrometry and real-time PCR. Adherence to tamoxifen decreased from 74% at month 3 to 64% at month 12, and explained 47% of the variability of tamoxifen plasma concentrations (P&amp;lt;.001). Accordingly, plasma monitoring of tamoxifen is useful to inform on tamoxifen adherence. Endoxifen concentrations were associated with CYP2D6 status and adherence. While CYP2D6 explained 26.4% of endoxifen variability at 12 months, the combination with adherence explained 40% (P&amp;lt;.001). The influence of low adherence to not achieving therapeutic endoxifen levels was highest in patients with non-compromised CYP2D6 function (EM phenotype, RR 3.65; 95% CI: 1.48-8.99). we conclude that for patients with intact CYP2D6 function adherence to tamoxifen is critical to achieve therapeutic endoxifen plasma levels. CYP2D6 phenotyping and endoxifen plasma monitoring may help to guide EM (and IM) patients to adhere to tamoxifen which is particularly relevant for premenopausal women who are at higher risk to not adhere to tamoxifen. Citation Format: Jose Claudio Casali da Rocha, Jeanine M Nardin, Werner Schroth, Thais A Almeida, Thomas Mürdter, Solange Picolotto, Evelyn CL Vendramini, Reiner Hoppe, Jenifer P Kogin, Diandra Miqueleto, Silvia DR Moraes, Matthias Schwab, Roberto F Pecoits-Filho, Hiltrud Brauch. The influences of adherence to tamoxifen and CYP2D6 pharmacogenetics on plasma concentrations of the active metabolite (Z)-endoxifen in breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-11-12.

Prevalence and clinical implications of the TP53 p.R337H mutation in Brazilian breast cancer patients: a systematic literature review

Prevalence and clinical implications of the TP53 p.R337H mutation in Brazilian breast cancer patients: a systematic literature review

Post-marketing assessment of generic tamoxifen in Brazilian breast cancer patients.

Generic formulations of tamoxifen are commonly prescribed to oestrogen receptor-positive breast cancer patients at the Brazilian National Cancer Institute (INCA). We carried out a post-marketing surveillance of the generic tamoxifen formulation in current use at INCA, by comparing plasma concentrations of the parent drug and metabolites obtained with the generic vs the reference formulation. Thirty patients participated in an open-label, bracketed protocol, comprising 3 successive phases of 30-32days each: the generic formulation was used in phases 1 and 3 and the reference formulation in phase 2. Two blood samples were collected in the last 4days of each phase, for LC-MS/MS quantification of tamoxifen and metabolites in plasma. The median plasma concentrations (ng/mL) for the reference formulation were as follows: tamoxifen, 135.0 (CI 95% 114.2-155.8); endoxifen, 35.3 (30.0-40.8); and 4-hydroxytamoxifen, 4.8 (4.2-5.4). The endoxifen/tamoxifen plasma concentration ratio was 0.27 (0.21-0.25). ANOVA detected no statistically significant difference in plasma concentrations of tamoxifen, metabolites or the endoxifen/tamoxifen ratio among the three phases. The genetic component (rGC) of the CYP2D6-mediated conversion of tamoxifen into endoxifen, estimated using the repeated drug administration procedure across the three phases, was 0.87, pointing to an important component of genetic variability. In conclusion, this first post-marketing surveillance trial of oncologic generic drugs carried out in Brazilian patients verified the switchability between the reference and the generic tamoxifen formulation currently used at our institution. The adopted bracketed protocol adds confidence to this conclusion and may serve as a frame for future trials of post-marketing assessment of other generic drug products.

Transforming growth factor beta receptor II (TGFBR2) promoter region polymorphism in Brazilian breast cancer patients: association with susceptibility, clinicopathological features, and interaction with TGFB1 haplotypes.

Transforming growth factor beta (TGFβ) has paradoxical effects in breast cancer (BC), inhibiting initial tumors while promoting aggressive ones. A polymorphism onTGFBR2promoter region (G-875A, rs3087465) increases TGFβ type II receptor expression and is protective against cancer. Previously, we have shown thatTGFB1variants have subtype-specific roles in BC. This work sought to investigate the association betweenTGFBR2and susceptibility and clinicopathological features in BC subgroups. TGFBR2G-875A was analyzed through PCR-RFLP in 388 BC patients and 405 neoplasia-free women. Case-control analyses as well as interaction withTGFB1haplotypes previously associated with BC were tested through age-adjusted logistic regression. Correlations between G-875A and clinicopathological parameters were assessed through Kendall's Tau-b test. All statistical tests were two-tailed (α = 0.05). TGFBR2G-875A was protective against BC in additive, genotypic, and dominant models. In subgroup-stratified analyses, these effects were greater in hormonal receptor-positive and luminal-A tumors, but were not significant in other subgroups. Logistic models includingTGFB1variants showed that in luminal-A tumors, G-875A retained its significance whileTGFB1haplotype showed a trend towards significance; otherwise, in HER2+tumorsTGFB1variants remained significant whileTGFBR2showed a trend for association. There was no interaction between these genes. In correlation analyses, G-875A positively correlated with histopathological grade in total sample, and a trend towards significance was observed in triple-negative BCs. These results indicate that G-875A is a protective factor against BC, especially from luminal-A subtype, but may promote anaplasia in established tumors, consistent with TGFβ signaling roles in BC.

Reduction of Breast Cancer Treatment Delay as a Result of Efforts Carried Out by Two Brazilian NGOs

Background: Brazilian breast cancer patients present disease often at advanced stages (III, IV). Previous studies indicated that system delay is a causal factor of bad prognosis and increased mortality rate. In the state of Paraíba, northeast of Brazil, two non-governmental organizations (NGOs) Américas Amigas and Mulheres de Peito de Campina Grande (MLDP), promote faster access to treatment by donating diagnostic mammography and biopsies as well as anatomo-histopathological and immunohistochemical analysis. Aim: The current study aimed at evaluating the effectiveness of the assistance provided by both NGOs and comparing patient flow between HNL and FAP, two reference cancer centers in João Pessoa and Campina Grande, respectively. Methods: Time-to-treatment was analyzed for different time intervals between first medical consultation and initiation of treatment. Comparison was performed between three groups of patients: 40 patients from Hospital Napoleão Laureano (HNL) in João Pessoa; 80 patients from Fundação Assistencial da Paraíba (FAP) in Campina Grande and 15 patients from FAP, who received support from the NGOs. Kaplan-Meier analysis was performed to compare time-intervals among the groups. To estimate the impact of socioeconomic variables Cox regression analysis was performed. Results: Mean time-interval between first medical consultation and hospital admission was 135 (SD=21.0), 370 (SD=73.7) and 515 (SD=36.6) days, for patients of HNL, MLDP and FAP, respectively ( P = 0.0021). Time intervals analyzed for patients within the FAP hospital, between first medical consultation and hospital admission, tended to be shorter for patients who were assisted by the NGOs, compared with those who did not receive any assistance from the NGOs. Patients who had consulted specialized oncological health services beforehand had an increased chance (HZ=2.32; 95% CI: 1.17-4.60; P = 0.016) of being admitted at the reference hospital within 90 days after the first medical consultation, compared with those who had not consulted such specialized services. There were no significant differences between HNL and FAP, regarding the time interval between hospital admission and treatment initiation ( P = 0.21). Conclusion: The assistance to patients provided by the two NGOs, aimed at speeding up the diagnosis process, accelerated patient flow between first medical consultation and admission at the hospitals. Regarding HNL, patients from the inland had been sent by primary health units in their municipalities, directly to the cancer reference hospital in João Pessoa, without being referred to an in-between health service. Such procedure explains the variation of time intervals when admissions at FAP and HNL are compared. The results of the current study indicate that by providing faster breast cancer diagnosis, the NGOs’ mediation can significantly improve patient flow.

Detection of inherited mutations in Brazilian breast cancer patients using multi-gene panel testing.

e13610Background: Genetic diversity among populations in the spectrum and frequency of germline variants in BRCA1/2 genes has been well documented. It is unclear whether this extends to other breas...

PTGS2 polymorphism rs689466 favors breast cancer recurrence in obese patients.

Breast cancer is the leading cancer among women, and its increasing incidence is a challenge worldwide. Estrogen exposure is the main risk factor, but obesity among postmenopausal women has been shown to favor disease onset and progression. The link between obesity and mammary carcinogenesis involves elevated estrogen production and proinflammatory stimuli within the adipose tissue, with activation of the cyclooxygenase-2 pathway. Here, we evaluate the impact of the four most common cyclooxygenase-2 gene polymorphisms (rs689465, rs689466, rs20417 and rs20417), in combination with obesity, on the risk of breast cancer progression in a cohort of Brazilian breast cancer patients (N = 1038). Disease-free survival was evaluated using Kaplan-Meier curves, with multivariate Cox proportional hazards regression models for calculation of adjusted hazard ratios (HRadj). Obesity did not affect disease progression, whereas rs689466 variant genotypes increased the recurrence risk among obese patients (HRadj = 2.5; 95% CI = 1.4-4.3), either for luminal (HRadj = 2.2; 95% CI = 1.1-4.2) or HER2-like and triple-negative tumors (HRadj = 3.2; 95% CI = 1.2-8.5). Likewise, the haplotype *4, which contains variant rs689466, was associated with shorter disease-free survival among obese patients (HRadj = 3.3; 95% CI = 1.8-6.0), either in luminal (HRadj = 3.5; 95% CI = 1.6-7.3) or HER2-like and triple-negative (HRadj = 3.1; 95% CI = 1.1-8.9) tumors. Such deleterious impact of variant rs689466 on disease-free survival of obese breast cancer patients was restricted to postmenopausal women. In conclusion, cyclooxygenase-2 genotyping may add to the prognostic evaluation of obese breast cancer patients.

Abstract A23: Germline BRCA1 and BRCA2 mutations in Brazilian ovarian and breast cancer patients

Abstract Background: Approximately 5-10% of epithelial ovarian and breast cancer cases are hereditary and germline mutations in BRCA1 and BRCA2 genes are the most common in these patients. Prevalence of clinically relevant mutations in BRCA1/2 differs among different populations, and specifically in Brazil, a country with great ethnic diversity and miscegenation, and only limited data are available to the present moment. In our country, the public health system (SUS) is responsible for the health care of almost 75% of the population; however, genetic tests are not yet covered. Our aim was to evaluate the complete coding sequence of BRCA1/2 genes and large rearrangements in patients diagnosed with epithelial ovarian and breast cancer in the largest cancer hospital from the Brazilian public health system. Methodology: The complete coding sequence of BRCA1/2 genes were evaluated through next-generation or capillary sequencing, and large deletions were investigated through multiplex ligation-dependent probe amplification (MLPA) in four cohorts of patients: 102 unrelated patients diagnosed with epithelial ovarian cancer unselected for family history of breast and/or ovarian cancer; 89 unrelated early-onset breast cancer patients (&amp;lt;35 years); 42 unrelated postmenopausal breast cancer patients (&amp;gt; 55 years) reporting positive breast and ovarian family history; and 49 unrelated breast cancer patients selected through Frank, BRCApro, and Evans algorithms (risk &amp;gt; 10%). Results: Pathogenic mutation in BRCA1/2 genes was detected in 44 patients (44/282: 15.6%; BRCA1, n=27; BRCA2, n=17) featuring 33 different mutations (16 in BRCA1 and 17 in BRCA2), including two large deletions in BRCA1 (exon 1-2 deleted and exon 5-7 deleted). Five mutations were detected more than once in BRCA1 gene (c.211A&amp;gt;G, c.3331_3334delCAAG, c.4484G&amp;gt;T, c.5074+2T&amp;gt;C, and c.5266dupC); however, all mutations in BRCA2 gene were detected only once. Only three ovarian cancer patients had a mutation localized in an ovarian cancer cluster region (OCCR) of BRCA1 and two breast cancer patients in BRCA1 breast cancer cluster regions (BCCR). Ovarian cancer patents most commonly presented BRCA1 mutations and young breast cancer mainly presented BRCA2 mutation. In this series of patients, 24 missense variants of uncertain significance were detected (BRCA1: n=6 and BRCA2: n=18). Considering distribution of pathogenic mutation among the patient groups, a high frequency was observed in two groups: patients diagnosed with epithelial ovarian cancer (18.36%) and breast cancer patients selected by Frank, BRCApro, and Evans algorithms (18.6%). Conclusion: The chance of carrying a BRCA1/2 germline mutation in Brazilian high-risk ovarian and breast cancer patients is 15.6%. The entire gene should be analyzed as mutations are detected in various regions. Financial support: FAPESP, CNPq. Citation Format: Simone Maistro, Giselly Encinas, Tauana Nagy, Natalia Teixeira, Maria Lucia H. Katayama, Ana Carolina R. C. Gouvêa, Maria del Pilar E. Diz, Roger Chammas, Geertruida H. de Boch, Maria Aparecida A. K. Folgueira. Germline BRCA1 and BRCA2 mutations in Brazilian ovarian and breast cancer patients [abstract]. In: Proceedings of the AACR International Conference held in cooperation with the Latin American Cooperative Oncology Group (LACOG) on Translational Cancer Medicine; May 4-6, 2017; São Paulo, Brazil. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(1_Suppl):Abstract nr A23.