Abstract P5-07-06: Genomic characterization and tumor evolution in matched(primary-relapse)samplesof patients with METAPLASTIC breast cancer

Introduction and objectives. Metaplastic breast cancer is an heterogenous and infrequent disease (0.5-2%). Histologically, it is defined by differentiation of neoplastic epithelium into squamous or mesenchymal-like elements. Although they are mainly triple negative tumors, they present a more aggressive course with less response to chemotherapy and worse prognosis. The aim of our study was to characterize the molecular profile and tumor evolution in matched (primary-relapse) samples of patients (pts) with metaplastic breast cancer. Material and Methods. Genomic profiling of tumor biopsies from different time points in patients with early-stage metaplastic breast cancer who had disease recurrence/progression, and were treated at our institution between 2010 and 2020. Tumor samples were analyzed by DNA- Next Generation Sequencing (NGS; Illumina 2x75bp) using the ActionOncoKitDX panel (Imegen-Health in Code group). It allowed the study of point mutations in 50 genes, CNVs, fusion genes among 8 genes and pharmacogenetic SNPs associated with treatment efficacy or toxicity. It also determined MSI through 110 markers. The results were classified following the recommendations of the ACMG (American College of Medical Genetics). Only pathogenic and likely pathogenic variants were considered for analysis and afterwards we categorized them following the ComPerMed (The Personalized Medicine Commission) criteria. Results. We have analyzed 21 matched diagnosis-relapse tumor samples (8 primary tumor samples, and 13 loco-regional or metastatic disease) from 8 patients. In 4 patients, genomic characterization was performed at 3 different time points of their tumor evolution. Pathogenic alterations identified were mutations in TP53 (in 100% of the samples), TERT promoter (29%), and MYC amplifications (24% of samples, of which 75% were relapse/progression samples). We didn’t find any mutation in PI3KCA, but PTEN was found to have variations in 38% samples (10% mutations and 38% deletions). Amplification of FGFR1 was identified in 13% of the pts (only in the primary tumor). No ERBB2 or EGFR gene amplifications were detected, neither high grade MSI. We did not find a significant increase in point mutations between primary and relapse/progression samples, although gene amplifications were found more frequently in the former ones. Sixty three percent of the cases were Tier I and II category alterations, which could have future implications in the management of this neoplasia. Conclusion. In our series of metaplastic carcinoma, the most frequent pathogenic alterations occurred in cycle regulation’s genes, including TP53 and TERT promoter mutations, and MYC amplifications. Relapse/progression samples were enriched in MYC amplification and inTP53 allelic frequency. Larger studies are required to better characterize these tumors, and identify new strategies to improve the prognosis of these patients.

Citation Format: Mónica Cejuela, Agostina Stradella, Anna Petit, Pablo Gargallo, Jan Bosch, Paula Carbonell, Sabela Recalde, Andrea Vethencourt, Adela Fernández, Catalina Falo, Miguel Gil-Gil, Silvia Vazquez, Rafael Villanueva, Teresa Soler, Inés Calabria, Sonia Pernas. Genomic characterization and tumor evolution in matched(primary-relapse)samplesof patients with METAPLASTIC breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-07-06.

Adenoid cystic carcinoma and basaloid carcinoma of the breast: A clinicopathological study

Adenoid cystic carcinoma of the breast (ACCB) is a rare triple negative tumor (TNT) with an excellent prognosis in most cases. Three different histologic types are recognized: classic ACCB, solid basaloid ACCB (SB-ACCB), and ACCB with high-grade transformation. A majority of these tumors show characteristic molecular and immunohistochemical (IHC) features, with fusion of MYB and NFIB genes and overexpression of MYB, respectively. Basaloid carcinomas of the breast (BCB) are infrequently described. They resemble SB-ACCB and TNT of no special type (TNT-NST). We have studied the clinicopathological features of 17 ACCB and 9 BCB, investigating the expression of MYB by IHC and the rearrangements of MYB by fluorescence in situ hybridization (FISH). MYB was expressed by IHC in 15 ACCB and in 3 BCB. MYB FISH detected rearrangements in 11 ACCB and in 2 BCB. After a mean follow-up of 90 months, with a range of 12-204 months, 2 patients with ACCB with high-grade transformation and 1 patient with BCB developed metastases and died of disease. In summary, most ACCB have a good prognosis, but tumors with adverse histopathological features may metastasize. BCB may overlap with ACCB and TNT-NST, and their prognosis should be further studied.

Assessment of Tumor Cell Death After Percutaneous Ultrasound– Guided Radiofrequency Ablation of Breast Carcinoma: A Prospective Study

Background: Current trends in breast cancer treatment include the use of less aggressive surgeries to reduce morbidity, shorten hospital stays and improve cosmetic results. The aim of the study is to assess tumor cell viability after percutaneous ultrasound (US)-guided radiofrequency ablation (RFA) for small breast cancer by a combination of staining techniques. Methods: A prospective study was conducted at a single institution from 2013 to 2017. Twenty women with invasive ductal carcinoma of the breast measuring ≤ 20 mm were treated with US-guided RFA followed immediately by surgical resection. Tumor viability pre- and post-RFA was assessed with Hematoxylin and Eosin (H&E), Nicotinamide adenine dinucleotide (NADH), Succinate dehydrogenase (SDH), Cytochrome c oxidase (COX), Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and Cytokeratin 18 and 19 (CK18/CK19) staining techniques. Outcomes and correlation with the different techniques were evaluated with principal component analysis Cronbach’s alpha. Results: Oxidative enzymes in frozen sections showed loss of SDH and NADH in 13 of the 16 tumors (81%) and COX in 11 of the 13 tumors (84%). In paraffin-embedded tissues, CK18 was negative or markedly reduced in 98% and CK19 in 100% of the cases. Lack of evidence of cell death was seen in 3 cases where the maximum temperature achieved at the center of the tumor was ≤ 70ºC. The reliability and internal consistency between the different staining techniques was high (Cronbach’s alpha, 0.8), with concordance between the staining results of the oxidative enzymes and of CK18/CK19. Conclusion: Loss of tumor viability in small breast tumors after US-guided percutaneous RFA could be assessed in our series with different staining methods. CK18 and CK19 could be used in paraffin-embedded tissues as surrogate markers of tumor cell viability after immediate RFA.

The effect of omitting axillary dissection and the impact of radiotherapy on patients with breast cancer sentinel node macrometastases: a cohort study following the ACOSOG Z0011 and AMAROS trials

PURPOSE

To report the outcomes of implementing the ACOSOG Z0011 and AMAROS trials relevant to clinical practice, and to define target groups in whom to avoid or recommend axillary radiotherapy (ART). We also aimed to analyse the reduction in morbidity when axillary lymph node dissection (ALND) was omitted.

METHODS

A retrospective cohort study of T1-T2 patients with macrometastases at sentinel lymph node (SLN) who were treated between 2011 and 2020. Breast surgery included either lumpectomy or mastectomy. Patients with ≤ 2 positive SLN were divided into two cohorts by whether they received ART or not. Survival outcomes and morbidity were analysed by Kaplan-Meyer curves and Cox-regression, respectively.

RESULTS

260 pN1a patients were included and ALND was avoided in 167 (64.2%). According the Z0011 results, 72 (43.1%) received no further ART; and based on AMAROS criteria 95 (56.9%) received ART. Median follow-up was 54 months. The 5-year overall survival was 96.8% in the non-RT cohort and 93.4% in the RT cohort (p = 0.19), while the respective 5-year disease-free survivals were 100% and 92.3% (p = 1.06). Lymphedema developed in 3.6% of patients after SLNB versus 43% after ALND (OR 20.25; 95%CI 8.13-50.43). Decreased upper-extremity range of motion appeared in 8.4% of patients after SLNB versus 31.2% after ALND (OR 4.95; 95%CI 2.45-9.98%).

CONCLUSIONS

Our study confirms that omitting ALND is safe and has high survival rates in patients with T1-T2 tumours and ≤ 2 positive SLNs. Adding ART could be a treatment option for patients who present other risk factors. Avoiding ALND with or without ART was associated with significantly less arm morbidity.

Can we avoid axillary lymph node dissection in N2 breast cancer patients with chemo-sensitive tumours such as HER2 and TNBC?

PURPOSE

To find a group of cN2 patients or patients with high axillary burden who become ypN0 after neoadjuvant chemotherapy (NACT) and who may benefit from avoiding a lymphadenectomy.

METHODS

A retrospective observational cohort study was conducted with 221 clinically staged N2 patients or patients with at least 3 suspicious lymph nodes found by ultrasound at diagnosis. The predictive factors for ypN0 analysed were age, MRI-determined tumour size, histological subtype, the Nottingham histologic grade, surrogate molecular subtype, ki-67 and vascular invasion when present. Clinical and radiological responses after NACT were also evaluated. Univariate and multivariate analyses by logistic regression were performed. Distant disease-free survival (DDFS) was calculated in relation to the status of the axillary lymph nodes after NACT.

RESULTS

After NACT, 89 patients (40.3%) had axillary pathologic complete response (pCR) (ypN0) and 132 (59.7%) had residual axillary disease (ypN+). Molecular surrogate subtype, Ki-67 expression, and the clinical and radiological responses to NACT were the only independent factors associated with ypN0. Axillary pCR was observed more often in HER2-positive and triple-negative tumours than in luminal ones (OR 7.5 and 3.6, respectively). DDFS was 88.7% (95% CI 80.7-96.7%) for ypN0 and 56.2% (95% CI 32.1-80.3%) for ypN+ (p = 0.09).

CONCLUSIONS

In HER2-positive and triple-negative breast cancer patients staged as cN2 or with high axillary burden before NACT, a sentinel lymph node biopsy after NACT could be recommended if there is a clinical and radiological response.

Predictive factors for omitting lymphadenectomy in patients with node-positive breast cancer treated with neo-adjuvant systemic therapy

A pathologic complete response (pCR) in the axilla occurs in 30%-40% of patients with initially node-positive breast cancer after neo-adjuvant chemotherapy (NACT). Debate persists about whether to perform systematic axillary lymphadenectomy (ALND) in patients with initial node-positive disease and clinical complete response after NACT. We aimed to identify predictive factors of axillary pCR (ypN0) after NACT. This retrospective study analyzed data for all patients with initial biopsy-proven node-positive disease who underwent ALND after NACT between June 2008 and December 2016 at our institution. Clinical and pathologic features, recurrence and specific mortality rates were compared between patients who achieved an axillary pCR and those who did not (ypN0 vs ypN+, respectively). A total of 331 patients were included, of whom 128 (38.7%) became ypN0 after NACT. Among patients with >2 suspicious axillary lymph nodes before treatment, 54 (38%) achieved ypN0 status. The independent predictors of ypN0 were Ki-67 > 30 (OR 1.98; 95% CI, 1.146-3.381), HER2 positivity (OR 2.6; 95% CI, 1.354-5.108), nonluminal molecular-like subtype (OR 4.15; 95% CI, 2.068-5.108), and clinical complete response, defined as negative clinical and ultrasonographic findings (OR 2.8; 95% CI, 1.110-7.081). After a mean follow-up of 61 months, distant disease-free and overall survival rates were higher in patients with ypN0 disease (HR 4.14; 95% CI, 2.03-8.43) than ypN+ patients. Complete clinical response and the presence of nonluminal molecular-like subtypes independently predicted ypN0. Patients meeting these criteria might be suitable form omitting ALND and just performing targeted axillary procedures to patients meeting these criteria.

Abstract P5-15-09: Impact of oncotype dx genetic signature used in early breast cancer. Clinical and economic analisys of a 110 patient cohort treated in the Catalan Oncologic Institute (ICO), Spain

Introduction

Benefit from adjuvant chemotherapy (CT) is doubtful in a high percentage of patients with early breast cancer. The 21-gene recurrence-score (RS) assay (Oncotype DX, Genomic Health) is one gene-expression assay that provide prognostic and predictive information in hormone-receptor (RH) positive breast cancer. The results of the TAILORx study have confirmed that the majority of patients with tumors RH + and HER2 negative can avoid CT without increasing their risk of relapse. From 2012 to 2015 we used Mammaprint (MMP), in our institution and 60% of cases could avoided CT (communicated in SABCS 2015). Since 2017 we use RS for this purpose.

Primary Objective

To analyze the impact of using RS to change the indication of adjuvant CT.

Secondary Objectives

To analyze the association between different clinical pathological factors and the RS value, and calculate the difference between the cost of all RS test and the cost in direct expense of the treatment with CT of all patients who could avoid it thanks to the RS

Material and methods

We analyzed all RS test performed in the three ICO centers during 2017. We sent 112 tumor samples; in 2 samples adequated RNA for RS was not obtained. We compared the adjuvant treatment initially planned according to institutional treatment protocol with the treatment given after RS. We compared the direct economic costs of CT with the costs of the diagnostic test, and performed a logistic regression analysis of some pathological factors and RS value.

Results

The RS could be determined in 110 of 112 cases, in which there was indication of adjuvant CT. Only 14 patients received CT (12,72%) with the RS value, so CT was avoided in 96 patients (87,28%).

The clinical-pathological characteristics of the series are summarized in the table 1. Of the risk factors analyzed, only grade 3 (p 0.001) and PR <20% (p<0.002) showed a statistically significant relationship with a higher probability of RS> 25. No association was found between age, nodal status, tumor diameter, Ki67, Infiltrating Ductal Carcinoma vs neither Infiltrating Lobular Carcinoma nor Lympho-Vascular invasion.

The cost of the genetic studies was 180000€ (1636€ each). The cost of each CT schedule (EC x 4 followed by paclitaxel x 12) was 7214€ and the total cost of 96 cases 692590€. Direct costs savings estimated from the reduction in CT treatment were 512590€

Conclusion: Our series shows that RS avoided unnecessary CT in 87% of cases and was more cost-effective than a previous series with MMP. G3 and RP <20 were the only pathological factors associated with an increased risk of RS> 25.

Table 1.Patients characteristics and clinical-pathological details from the analyzed tumorsPatient characteristicsAge, mean (range)53,76 (19 – 75)≥50y72 (65.5%)<50y38 (34.5%)HistologyInfiltrating ductal carcinoma88 (80%)Infiltrating lobular carcinoma20 (18,2%)Others2 (1,8%)TNMTumor diameter (mm), mean (range)19,25 (1 – 160)pN058 (52,7%)pN1mic21 (19%)pN131 (28,3%)Hormone receptorsRE 2-100%110 (100%)RP <20%22 (20%)RP ≥20%88 (80%)Ki67 median, mean (range)20, 21 (2-75)Lymphovascular invasionyes9 (8%)no101 (92%)Adjuvant treatmentCT14 (12,72%)Hormonotherapy96 (87,28%)

Citation Format: Ferrer M, Dorcas J, Quiroga V, Margelí M, del Barco S, Stradella A, Petit A, Falo C, Viñas G, Romeo M, Villanueva R, Cirauqui B, Vázquez S, Fernández A, Recalde S, Vethencourt A, Soler T, Pérez-Martín X, Gil-Gil M. Impact of oncotype dx genetic signature used in early breast cancer. Clinical and economic analisys of a 110 patient cohort treated in the Catalan Oncologic Institute (ICO), Spain [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-15-09.

Abstract P6-09-04: Predictive factors for considering to avoid axillar lymphadenectomy in selected node positive breast cancer patients after neoadjuvant chemotherapy

Background:

To perform a systematic axillar lymphadenectomy (ALND) in clinical node positive (N+) patients after neoadjuvant chemotherapy (NACT) is currently under discussion. We aimed to study which factors are related to a pathological complete axillar response (ypN0) after NACT in order to select which patients could benefit from a sentinel lymph node biopsy without interfering with survival.

Material and methods

N+ patients who underwent ALND after NACT between June 2008 and December 2016 were retrospectively analyzed. Clinical features, molecular and histological factors, recurrence and specific mortality rates were compared between patients achieving a complete pathological axillary response vs not (ypN0 vs ypN+).

Results

345 N+ patients were reviewed. After NACT, 137 (39.6%) become ypN0[CF1] , 9 (2.6%) ypN1 mic, 113 (32.7%) ypN1, 60 (17.3%) ypN2 and 22 (6.4%) N3. Univariate analysis results regarding the predictive factors for ypN0 are detailed in [table 1]. Multivariate analyses showed molecular subtype (TN and Her2+) and clinical response as independent predictors of ypN0 [table 2]. After a mean follow-up of 58 months, overall survival was statistically superior in ypN0 vs ypN1 (p= 0.001).

Table 1.Predictive factors for ypN0 YpN0 (n = 137)YpN+ (n = 208)pAge (mean, years)58.3 ± 13.2758.59 ± 12.340.799BMI (mean)27.8±5.4927.8±5.360.973Dosis of QT (median)(%)  0.575IIA6 (31.6)13 (68.4) IIB71 (39.3)110 (60.8) IIIA28 (36.8)48 (63.2) IIIB24 (43.6)31 (56.4) IIIC7 (58.3)5 (41.7) Radiological image(%)  0.930Nodule77 (38.1)125 (61.9) Non-mass distortion10 (43.5)13 (56.5) Radiological size (median)32 (0-115)29 (0-130)0.246Suspicious a-LN by US(%)  0.486130 (30.9)37 (24.3) 25 (5.2)14 (9.2) >257 (58.8)91 (59.9) Histological subtype(%)  0.093Invasive Ductal Carcinoma133 (40.9)192 (59.1) Invasive Lobular Carcinoma2 (20)8 (80) Others2 (22.2)7 (78.8) Nottingham grade(%)  <0.001G11 (6.2)15 (93.8) G244 (28.6)110 (71.4) G386 (53.4)75 (46.6) Molecular-like subtype(%)  <0.001Luminal A-like2 (5.3)36 (94.7) Luminal B-like (Her2 -)21(18.1)95 (81.9) Luminal B-like (Her2 +)40 (63.5)23 (36.5) HER-2 enriched (non luminal)43 (74.1)15 (25.9) Triple Negative31 (44.9)38 (55.1) Vascular invasion19 (42.2)26 (57.8)0.889Clinical Response(%)  <0.001Complete61 (75.3)20 (24.7) Partial69 (31.8)148 (68.2) No response6 (20.7)23 (79.3) Progression1 (10)9 (90) Percentage are given per row.

Table 2.Multivariate analysis logistic regression of clinical predictive factors of ypN0. OR95% Confidence Intervalp valueMolecular subtype   No-luminal vs Luminal7,7483,913-15,343<0,001Clinical response   Response vs not response6,8491,834-25,5710,04OR: Odd ratio. No-luminal includes: luminal B (HER2 +), HER2 Henriched and triple negative. Luminal includes: Luminal A and Luminal B (HER2 -).

Conclusions

A remarkable percentage of N+ became ypN0 after NATC. Molecular subtype and complete clinical response were independent predictive factors of ypN0. We propose to offer the benefit of a targeted axillary procedure in those patients.

Citation Format: Fernandez-Gonzalez S, Falo Zamora C, Nuñez D, Vethencourt A, Pla MJ, Soler T, Guma A, Perez X, Gil M, Ponce J, Garcia A. Predictive factors for considering to avoid axillar lymphadenectomy in selected node positive breast cancer patients after neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-09-04.

Abstract P3-13-07: Is radiofrequency ablation better than lumpectomy for margin status in breast cancer? Results of a randomized clinical trial

PURPOSE: To study the safety and efficacy of ultrasound-guided percutaneous radiofrequency ablation (RFA) as local treatment for breast cancer and to intraoperatively evaluate the margin status after RFA in comparison with lumpectomy.

MATERIAL and METHODS: Preliminary in vitro RF ablation experimentation with two mastectomy specimens was performed to test the electrode, practice the ultrasound technique and evaluate the macroscopic and microscopic effects of RF. Then, aprospective, randomized open-label phase II clinical trial (NCT02281812) was conducted in a single institution from 2013-2017. Forty subjects, mean age 64 (range 46-86), with ductal infiltrating carcinoma of the breast ≤2 cm were randomly assigned to RFA plus lumpectomy or lumpectomy alone. Margin status, tumor cell viability (TCV) after RFA (by nicotinamide adenine dinucleotide (NADH) and Cytokeratin 18 (CK18) staining), adverse events and local recurrences were evaluated by univariable and multivariable analyses (SPSS statistical software).

RESULTS: In the experimental design with mastectomies, the only procedural complication was a skin burn at the entrance site of the electrodes. We learned that the tip of the electrodes should cut cross the tumor by at least 10mm.

The clinical trial includes two groups: study group (n=20) and control group (n=20). NADH and CK18 staining demonstrated absence of TCV after RFA with at least one of the two techniques. The percentage of intraoperatively affected surgical margins was higher in the control group although local adverse effects after surgery was higher in the RFA treatment arm. Three study subjects presented local infection (two had partial irradiation of the breast) and none in the control group. Median follow up was 25 months (range 1–83). No recurrence or second surgery was required during the study period.

Outcomes RFA group (n = 20)Control group (n=20)p valueSpecimen weight (median, gr)42 (24-80)27 (11-60)0.004Specimen volume (median, ml)369 (259-847)201 (100-602)0.004Positive margin (intraoperative)4/20 (20%)11/20 (55%)0.022Pathological size (median, mm)11.5 (5-20)10.5 (6-16)0.07Local Adverse effect8/20 (40%)1/20 (5%)0.01Breast Inflammation5/20 (25%)1/20 (5%)0.182Breast Infection3/20 (15%)0/20 (0%)0.23RFA: radiofrequency ablation. n=number of subjects

CONCLUSION: RFA seems effective in the cases considered and could be more accurate than lumpectomy in terms of obtaining more free margins. Surgical excision associated with RFA leads to a higher amount of local adverse effects, especially if combined with partial irradiation of the breast. RFA could be considered as a less invasive treatment in tumors smaller than 20 mm; however, this warrants further investigation.

Citation Format: Garcia-Tejedor A, Guma A, Soler T, Valdivieso A, Petit A, Contreras N, Chappuis CG, Falo C, Pernas S, Anselem A, Fernandez-Montoli E, Pla MJ, Burdio F, Ponce J. Is radiofrequency ablation better than lumpectomy for margin status in breast cancer? Results of a randomized clinical trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-13-07.

Tumor xenograft modeling identifies an association between TCF4 loss and breast cancer chemoresistance

Understanding the mechanisms of cancer therapeutic resistance is fundamental to improving cancer care. There is clear benefit from chemotherapy in different breast cancer settings; however, knowledge of the mutations and genes that mediate resistance is incomplete. In this study, by modeling chemoresistance in patient-derived xenografts (PDXs), we show that adaptation to therapy is genetically complex and identify that loss of transcription factor 4 (TCF4; also known as ITF2) is associated with this process. A triple-negative BRCA1-mutated PDX was used to study the genetics of chemoresistance. The PDX was treated in parallel with four chemotherapies for five iterative cycles. Exome sequencing identified few genes with de novo or enriched mutations in common among the different therapies, whereas many common depleted mutations/genes were observed. Analysis of somatic mutations from The Cancer Genome Atlas (TCGA) supported the prognostic relevance of the identified genes. A mutation in TCF4 was found de novo in all treatments, and analysis of drug sensitivity profiles across cancer cell lines supported the link to chemoresistance. Loss of TCF4 conferred chemoresistance in breast cancer cell models, possibly by altering cell cycle regulation. Targeted sequencing in chemoresistant tumors identified an intronic variant of TCF4 that may represent an expression quantitative trait locus associated with relapse outcome in TCGA. Immunohistochemical studies suggest a common loss of nuclear TCF4 expression post-chemotherapy. Together, these results from tumor xenograft modeling depict a link between altered TCF4 expression and breast cancer chemoresistance.

Summary: By modeling chemoresistance in patient-derived breast cancer xenografts, this study shows that adaptation to therapy is genetically complex and that loss of transcription factor 4 (TCF4) is associated with this process.

Abstract P4-08-08: Biomarkers to predict distant recurrence free survival after neoadjuvant endocrine therapy in breast cancer. A long follow up retrospective study

Background:

Neoadjuvant endocrine therapy (NET) is gaining more acceptances for the management of estrogen receptor (ER) positive breast cancer (BC). Rate of patients achieving pathological complete response is very low and Ki67 suppression and PEPI score are the only prognostic factors associated with relapse free survival.

The aim of our study was to identify biomarkers of prediction of distant relapse risk that could help clinicians in the decision-making of systemic adjuvant treatment in patients previously treated with NET

Material & Methods:

Retrospective study of 119 postmenopausal women with ER or progesterone receptor (PR) positive BC treated with NET in ICO-HUB from 1997 to 2009. Clinical-pathological data and treatments administered were reviewed. IHC expression of ER, PR, Ki67, Androgen receptor (AR), BCL-2, Cyclin D1 (CD1), p16, p53, CD 44 and synaptophysin were analyzed in post-NET surgical formalin-fixed paraffin-embedded tumor samples through a tissue microarray. Survival was calculated by Kaplan-Meier method. Univariate and multivariate analysis of variables associated with distant relapse free survival (DRFS) was evaluated by Cox proportional hazard model.

Results:

Mean age was 74 (63-88). cT: T2 5%, T3 6.5%, T4 43.5%. cN: N0 59%, N1 25%, N2-3 16%. Stage: I 21%, II 49.5%, III 29.5%. Histological subtype: ductal 84%, lobular 6%, others 10%. Histological grade: G1 20%, G2 55%, G3 25%.

Vascular invasion 15%. NET: Aromatase Inhibitors 64%, SERM 36%. Median duration of NET 8.5 months. Clinical Response: Complete 4%, Partial 55%, Stable 37%, Progression 4%. Surgery: Lumpectomy 72%, Mastectomy 28%;Lymphadenectomy 70.5%, Sentinel lymph node biopsy 6%, No surgical approach of axilla 23.5%. Surgical specimen: ypT1 36%, ypT2 54%, ypT3 6%, ypT4 4%; ypN0 28%, ypN1 22%, ypN2 13.5%, ypN3 12% ypNx 23.5%. Surgical margins: Negative 89% Positive 11%. Median fibrosis rate 20% (0-95). PR and Ki67 showed a statistically significant decrease after NET(p<0,05) but no ER (p=0,29).

Adjuvant treatment: chemotherapy 7%, radiotherapy 76%, endocrine therapy 96%. Median follow-up: 104 months. Only 21 patients developed distance relapse. Median OS was 139 months [95% CI = 98-181]. Univariate analysis for DRFS showed statistically significant differences in cN (HR=3), histological grade 3 (HR=3.61), ypN (HR=3.62), p16 (HR=6.1) and p53 (HR=2.79). Multivariate analysis of post-NET biomarkers showed that negative nuclear p16 expression (HR=4.79)and positive p53 (HR=2.83)were independently associated with worse DRFS. In multivariate analysis of all clinico-pathological and molecular factors, histological grade 3 (HR=2.82) was the sole DRFS independent factor.

Conclusions:

Negative nuclear p16 expression and positive p53 post-NET were associated with worseDRFS. Whenall clinico-pathological and molecular factors were analysed, G3 was the sole DRFS independent factor. Patients with G3, negative p16 or positive p53 after NET could probably benefit from adjuvant chemotherapy or CDK 4-6 inhibitors treatment. In our series, we did not find usefulness in analysing ER, PR and Ki67 post-NET changes to predict DRFS.

Citation Format: Gil-Gil M, Morilla I, Petit A, Soler T, Perez-Martin X, Guma A, Pla MJ, Ortega R, Garcia-Tejedor A, Falo C, Montal R, Perez-Casanova L, Loayza C, Pernas S. Biomarkers to predict distant recurrence free survival after neoadjuvant endocrine therapy in breast cancer. A long follow up retrospective study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-08-08.

Abstract P6-15-06: SOLTI-0702 CAPRICE: Final results of a phase II study of pegylated liposomal doxorubicin plus cyclophosphamide followed by paclitaxel as neoadjuvant chemotherapy in elderly or cardiotoxicity-prone patients with high-risk breast cancer: 5-year overall survival disease free survival and late cardiac safety

Background:

Anthracycline and taxane-based chemotherapy is the standard treatment for high-risk breast cancer. However, conventional anthracyclines are not commonly used in elderly patients or those patients prone to cardiotoxicity and there is a potential risk leaving them undertreated. Pegylated liposomal doxorubicin (PLD) has comparable efficacy, but significantly less cardiotoxicity than conventional anthracyclines. We conducted a phase II trial to assess the efficacy and safety of a neoadjuvant chemotherapy (NC) based on PLD and paclitaxel (PTX) in this group of patients. The pathological complete response, breast conservative surgery (BCS) and safety data at a 35-month follow-up were published (Gil-Gil et al. Breast Cancer Res Treat 2015). Here we present the final analysis of 5-year overall survival (OS) and 5-year disease-free survival (DFS) and cardiac safety after 60 months of follow-up.

Methods:

Fifty patients with stage II (48%) and III (52%) breast cancer (seven cases were T4d) and with at least one risk factor for developing cardiotoxicity were included. NC schedule: PLD 35 mg/m2 plus cyclophosphamide 600 mg/m2 every 4 weeks for four cycles, followed by 80 mg/m2 weekly PTX for 12. Median age was 73 years old (84% were older than 65 years). Forty-eight (96%) of tumors were triple negative (TN). Secondary objectives included 5-year DFS, 5year OS and cardiac safety measured by a decrease in left ventricular ejection fraction (LVEF), electrocardiogram (ECG) anda cardiac questionnaire performed every 3 months during the first year, every 6 months year 2-3 and every 12 months year 4-5 of follow-up.

Results: Forty-eight patients (96%) completed the 4 cycles of PLD plus CPM, while only 26 patients (52%) could complete the 12 weeks of PTX. Forty-six patients (92%) underwent surgery. After surgery: 27 patients received radiotherapy, 2 letrozole and 1 trastuzumab. The 5-year OS was 56% (95% CI 41.2-68.4) and the 5-year DFS was 54.4% [95% CI: 38.3-67.9].No significant decrease in LVEF was seen (mean baseline LVEF was 66.6 (52-86) and mean LVEF after 60 months was 66 (54.5-73). Four patients (8%) developed cardiotoxicity (in 2 cases G3). There were 5 non-cancer deaths (10%): 3 during treatment (all in patients > 80 years: a sudden death one month after surgery, a haemorrhagic stroke 30 days after completing chemotherapy and a non-neutropenic pneumonia); and 2 during follow-up (1 Amyotrophic Lateral Sclerosis and 1 intestinal ischemia).

Conclusions:

PLD followed by PTX as NC was feasible in a fragile population of patients who were not candidates for conventional doxorubicin. The 5 year DFS and 5 year OS in elderly patients with bulky TN tumors were similar tothe reported in the literature. This regimen could be an option for the neoadjuvant treatment of cardiotoxicity-prone patients or elderly patients who present high-risk breast cancer.

Citation Format: Gil-Gil M, Bellet M, Morales S, Barnadas A, Manso L, Morilla Ruiz I, Azaro A, Ciruelos Gil E, Garcia Martínez E, Marínez N, Melé M, Soler T, Villagrasa P, Pernas S. SOLTI-0702 CAPRICE: Final results of a phase II study of pegylated liposomal doxorubicin plus cyclophosphamide followed by paclitaxel as neoadjuvant chemotherapy in elderly or cardiotoxicity-prone patients with high-risk breast cancer: 5-year overall survival disease free survival and late cardiac safety [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-15-06.

Attenuation of RNA polymerase II pausing mitigates BRCA1-associated R-loop accumulation and tumorigenesis

Most BRCA1-associated breast tumours are basal-like yet originate from luminal progenitors. BRCA1 is best known for its functions in double-strand break repair and resolution of DNA replication stress. However, it is unclear whether loss of these ubiquitously important functions fully explains the cell lineage-specific tumorigenesis. In vitro studies implicate BRCA1 in elimination of R-loops, DNA-RNA hybrid structures involved in transcription and genetic instability. Here we show that R-loops accumulate preferentially in breast luminal epithelial cells, not in basal epithelial or stromal cells, of BRCA1 mutation carriers. Furthermore, R-loops are enriched at the 5' end of those genes with promoter-proximal RNA polymerase II (Pol II) pausing. Genetic ablation of Cobra1, which encodes a Pol II-pausing and BRCA1-binding protein, ameliorates R-loop accumulation and reduces tumorigenesis in Brca1-knockout mouse mammary epithelium. Our studies show that Pol II pausing is an important contributor to BRCA1-associated R-loop accumulation and breast cancer development.

Stem cell-like transcriptional reprogramming mediates metastatic resistance to mTOR inhibition

Inhibitors of the mechanistic target of rapamycin (mTOR) are currently used to treat advanced metastatic breast cancer. However, whether an aggressive phenotype is sustained through adaptation or resistance to mTOR inhibition remains unknown. Here, complementary studies in human tumors, cancer models and cell lines reveal transcriptional reprogramming that supports metastasis in response to mTOR inhibition. This cancer feature is driven by EVI1 and SOX9. EVI1 functionally cooperates with and positively regulates SOX9, and promotes the transcriptional upregulation of key mTOR pathway components (REHB and RAPTOR) and of lung metastasis mediators (FSCN1 and SPARC). The expression of EVI1 and SOX9 is associated with stem cell-like and metastasis signatures, and their depletion impairs the metastatic potential of breast cancer cells. These results establish the mechanistic link between resistance to mTOR inhibition and cancer metastatic potential, thus enhancing our understanding of mTOR targeting failure.

Study of breast cancer incidence in patients of lymphangioleiomyomatosis

Molecular evidence has linked the pathophysiology of lymphangioleiomyomatosis (LAM) to that of metastatic breast cancer. Following on this observation, we assessed the association between LAM and subsequent breast cancer. An epidemiological study was carried out using three LAM country cohorts, from Japan, Spain, and the United Kingdom. The number of incident breast cancer cases observed in these cohorts was compared with the number expected on the basis of the country-specific incidence rates for the period 2000–2014. Immunohistochemical studies and exome sequence analysis were performed in two and one tumors, respectively. All cohorts revealed breast cancer standardized incidence ratios (SIRs) ≥ 2.25. The combined analysis of all cases or restricted to pre-menopausal age groups revealed significantly higher incidence of breast cancer: SIR = 2.81, 95 % confidence interval (CI) = 1.32–5.57, P = 0.009; and SIR = 4.88, 95 % CI = 2.29–9.99, P = 0.0007, respectively. Immunohistochemical analyses showed positivity for known markers of lung metastatic potential. This study suggests the existence of increased breast cancer risk among LAM patients. Prospective studies may be warranted to corroborate this result, which may be particularly relevant for pre-menopausal women with LAM.

[Positive sentinel node risk in relation to oestrogen receptors in breast cancer in premenopausal and postmenopausal women]

OBJECTIVE

The influence of the relationship between pre- and post-menopausal stage of patients with breast cancer (BC) and the risk of sentinel lymph node (SLN) metastasis as well as the influence of oestrogen receptor (ER) status within each one of these groups were analyzed.

METHODS

A BC database with 1,388 patients was analysed. Three age groups were studied: A, elderly postmenopausal, 200 patients, ≥ 70 years old; B, younger postmenopausal, 89 patients, 55-69 years old; C, premenopausal, 85 patients, <55 years old. In each group 2 subgroups were analyzed: positive ER and negative ER tumours. Data analysed: SLN-positive patients, non-sentinel node (NSN)-positive patients, non-surgical detections (NSD) and non disease-free (NDF) patients after a follow-up of 52 months.

STATISTICAL ANALYSIS

chi-squared test, significance: P ≤ 0.05.

RESULTS

SLN metastasis was significantly (P<0.025) more common in premenopausal than in postmenopausal patients, and within those, mainly in negative ER tumours. Positive-NSN increases slightly in premenopausal patients (exclusively in negative ER tumours). NDF patients are similar in the 3 groups and in all of them it is much more frequent in negative ER tumours.

CONCLUSION

SLN metastasis varies significantly according to hormonal state and not according to age, being more frequent in premenopausal patients and mainly in ER negative tumours.

p53 and p21 Expression levels predict organ preservation and survival in invasive bladder carcinoma treated with a combined-modality approach

BACKGROUND

The purpose of the current study was to evaluate the expression levels of p53, p21 and pRB as predictors of for long-term organ preservation and survival in patients with bladder carcinoma who were treated with bladder-sparing intent using a combined-modality approach.

METHODS

Tumor samples from 82 consecutive patients with localized invasive bladder carcinoma treated on 3 different bladder-sparing studies were examined for p53, p21, and pRB expression by immunohistochemical methods. Treatment consisted of transurethral resection, platinum-based neoadjuvant chemotherapy, and, according to response, either radiotherapy or radical cystectomy. The median follow-up duration was 55 months.

RESULTS

Positive immunoreactivity for p53, p21, and pRB was observed in 47%, 52%, and 67% of patients, respectively. Positive p53 immunoreactivity and positive p21 immunoreactivity were independent predictors of decreased survival with bladder preservation (P = 0.02 and P = 0.02, respectively) and disease-free survival (DFS; P = 0.005 and P = 0.009, respectively) in a multivariate analysis adjusting for clinical stage, ureteral obstruction, and age. Regarding overall survival (OS), p53 overexpression was associated with poor outcome (P = 0.03), whereas the association of poor outcome with p21 expression did not reach statistical significance (P = 0.07). No association between pRB immunoreactivity and outcome was found. When the combined expression of p53 and p21 was assessed, the positive expression of both markers was a strong and unfavorable prognostic factor for survival with bladder preservation (P = 0.006), DFS (P = 0.003), and OS (P = 0.02).

CONCLUSIONS

Expression levels of p53 and p21, especially when simultaneously assessed, exhibit independent predictive value for long-term bladder preservation and survival in patients with bladder carcinoma treated with combined-modality therapy. These determinations could be useful in the selection of candidates for bladder-preserving treatment.

Adaptation and standardization of the geriatric evaluation of relative's rating instrument (GERRI) for Spain

BACKGROUND

The Geriatric Evaluation of Relative's Rating Instrument (GERRI) is a scale that evaluates the frequencies of alterations in behavior and functional capacity over a two-week period prior to exploration. The scale depends on the observations done by a relative o first caregiver of the studied subject.

AIM

To adapt and standardize the GERRI for the use in the Spanish population as a part of a general project to standardized cognitive and functional tests.

METHOD

The scale was administered to 444 subjects: 249 controls, 85 mild memory-cognitive disorders without dementia subjects (DWD) and 110 patients with Alzheimer-type dementia (ATD). An across-sectional statistical study was conducted in our samples stratified by age, gender and education. We evaluated the reliability of repeatability of the test, the internal reliability and the age, sex and education effects on the score of the different subscales. We also took into account the diagnostical validity in the Alzheimer disease and finally we correlated this test results with Mini mental test.

RESULTS

The demographic variables age and schooling were found to affect the GERRI subscales differently. Gender did not reach significance. Internal consistency for the GERRI-Social, -Mood and -Cognitive were 0.8620, 0.7647 and 0.9259, respectively.

CONCLUSION

The Spanish version of the GERRI may be applied to Spanish clinical series because of its reliable internal consistency and reproducibility.

[Pulmonary thromboembolism associated with antiphospholipid syndrome and systemic lupus erythematosus]

The association between systemic lupus erythematosus and antiphospholipid syndrome can cause several complications. We report a 45 years old woman, treated with steroids for a systemic lupus erythematosus. She presented with a clinical picture of a lupus pneumonitis and, subsequently, with the picture of a pulmonary thromboembolism. The diagnosis was confirmed by helicoidal computed axial tomography. The patient was treated with anticoagulants, with a favourable outcome.

Molecular characterization of the leucine plasmid from Buchnera aphidicola, primary endosymbiont of the aphid Acyrthosiphon pisum

The complete sequence of the leucine plasmid of Buchnera aphidicola from the aphid Acyrthosiphon pisum (pLeu-BAp) is reported. Its gene organization was concordant with those of other leucine plasmids of Buchnera from aphids of the Aphidini and Macrosiphini tribes. Three inverted repeats are present in pLeu-BAp. Two of them are also present in pLeu from the family Aphididae: (i) SIR1, located downstream the leucine operon, resembles a rho-independent terminator of transcription, and (ii) LIR1, located upstream of the leucine operon, is suggested to be involved in transcription termination or messenger stability. The third, located near the putative ATGC repeats involved in the origin of replication, is specific in aphids of the Macrosiphini tribe. Phylogenetic analyses based on sequences of leuA, leuB, leuC, leuD, repA1 and ORF1 showed a closer relationship between Buchnera (A. pisum) and Buchnera (Diuraphis noxia). However, tree topologies indicate that the split between both aphid species took place soon after the formation of the Macrosiphini lineage.

The prevalence of spondylolysis in the Spanish elite athlete

The diagnosis of spondylolysis is a major cause of concern for patients and their families, especially when the patients are young athletes with promising futures in their sports. In this study, 3152 case histories of high-level athletes were evaluated to determine which sports had a higher prevalence of spondylolysis. The overall percentage of spondylolysis among athletes in this study (8.02%) was not very much higher than that among the general population, which varies between 3% and 7%. However, when each sport was considered separately we found much higher values for some sports, with the highest percentages occurring in throwing sports (26.67%), artistic gymnastics (16.96%), and rowing (16.88%). The analysis of the biomechanical movements involved in the sports with greater prevalence of spondylolysis has led us to include the element of torsion against resistance as another possible causative factor for spondylolysis that should be added to the already known causative mechanisms, lumbar hyperextension and rotation. We have divided the sports into three risk groups according to the prevalence of spondylolysis shown and the characteristics of the sample, and we recommend systematic radiological examination of the lumbar spine in athletes considered to be at greater risk of developing spondylolysis.

Upper digestive tract dyspepsia and early gastric cancer

AIM

The study of the frequency and evolution of upper digestive tract dyspepsia in a group of patients operated for early gastric cancer (EGC) and to perform a strategy of diagnosis for the patients with long term upper digestive tract dyspepsia.

METHODS

Clinical data of 35 patients operated for EGC were retrospectively evaluated. The frequency, characteristics and evolution time of upper digestive tract dyspepsia, main when it began more than 6 months before surgery, were analyzed. Radiologic and endoscopic exams carried out for diagnosis were also evaluated. Histological diagnosis of surgical specimens were considered, looking for the presence of chronic atrophic gastritis, intestinal metaplasia, and peptic gastric ulcer.

RESULTS

Long-term upper digestive tract dyspepsia was present in 27 patients (mean evolution time of 43.4 months). Clinical changes of previous symptoms that suggested gastric carcinoma were not found in 15 patients. Concurrent peptic gastric carcinoma were not found in 15 patients. Concurrent peptic gastric ulcer along with EGC was diagnosed by histology in 11 patients, and chronic atrophic gastritis and intestinal metaplasia were both present in the non-tumoral gastric mucosa in all cases.

CONCLUSIONS

1) Unspecific upper digestive tract dyspepsia is frequently found in patients with EGC. 2) Endoscopy should be the first exam performed in patients with upper digestive tract dyspepsia. 3) The patients with gastric ulcer, chronic atrophic gastritis or intestinal metaplasia must be submitted to sequential endoscopic follow-up.

Lipoma arborescens of the knee: MR characteristics in 13 joints

Lipoma arborescens (LA) is a rare, poorly understood intraarticular lesion, with few cases reported in the imaging literature. Our purpose was to describe on MR the different morphologic appearances of LA of the knee and to investigate the incidence of associated anomalies.

METHOD

The medical records and MR findings of 12 patients with proven LA in 13 knee joints were retrospectively reviewed with particular emphasis on the shape of the lesion, location, signal intensity, and past clinical history.

RESULTS

We found three common morphological patterns of presentation: multiple villous lipomatous synovial proliferations (n = 6), isolated frond-like fat subsynovial mass (n = 2), and mixed pattern (n = 5). Multiple villous lipomatous synovial proliferations and mixed pattern were usually associated with a history of trauma and/or chronic inflammatory diseases. However, the least frequent isolated frond-like fat subsynovial mass appears to originate without antecedent. The durations of symptoms were 1-7 months (multiple villous lipomatous synovial proliferations), 1-20 years (mixed pattern) and 6-7 years (isolated frond-like subsynovial fat mass).

CONCLUSION

Our study suggest that LA can present with a variety of morphological appearances on MR that may depend on the previous clinical history and duration of the disease.

[Molecular changes in adenocarcinoma of the small intestine associated with Peutz-Jeghers syndrome]

The presence of molecular alterations in the c-K-ras and p53 genes in a small bowel adenocarcinoma arising in a case of Peutz-Jeghers syndrome is reported. The absence of mutations at codon 12 and 13 of the c-K-ras gene in the hamartoma and carcinoma indicates that this oncogene does not contribute to its development. On the other hand, p53 protein overexpression was detected in a small proportion (5-10%) of adenocarcinoma cells. Our findings suggest that p53 inactivation occur in late stages of tumour progression.

[Changes in the cellular proliferation of the healthy mucosa in patients with colorectal cancer]

AIM

To analyze differences in the proliferative pattern of normal mucosa between patients with colorectal cancer and healthy subjects.

PATIENTS AND METHODS

By using flow cytometry we examined the proliferative pattern (Proliferative Index and S-Phase) in samples of normal mucosa from 34 patients operated on for colorectal cancer at our hospital and from 14 healthy subjects as a control group.

RESULTS

All examined samples were diploid. The Proliferative Index and S-Phase in the Cancer Group were significantly higher than in the Control Group (16.7 +/- 5.9 vs 11.4 +/- 4, p < 0.003, and 11.9 +/- 3.9 us 6.6 +/- 3 p < 0.0004).

CONCLUSIONS

These findings provide evidence for an altered proliferative pattern in the healthy colonic mucosa of patients with colorectal cancer.

Cyclic changes in pulmonary wedge v waves in dilated cardiomyopathy

Right and left cardiac catheterization was performed in a 29-year-old male with dilated cardiomyopathy. During the procedure, prominent v waves appeared spontaneously in the pulmonary capillary wedge pressure recording with a simultaneous decrease in left ventricular systolic pressure. Left ventricular angiography showed moderate to severe mitral regurgitation and an ejection fraction of 22%. The right ventricular endomyocardial biopsy revealed histological findings consistent with dilated cardiomyopathy. Cardiac catheterization was repeated 9 months later, after a period of clinical improvement and a reduction in the right and left ventricular filling pressures was documented. The cyclic swings in the pulmonary capillary wedge pressure and in the left ventricular systolic pressure were not observed. Left ventriculography showed mild mitral regurgitation with an ejection fraction of 37%. Right ventricular endomyocardial biopsy documented a reduction in myofibrillar and nuclear hypertrophy. Thus, cyclic changes in pulmonary wedge v waves may be observed in dilated cardiomyopathy. This finding is consistent with cyclic variations in the degree of mitral regurgitation. Disappearance of this factor seems to be related to improvement in left ventricular contractility.

Risk of thrombosis during coronary angioplasty with low osmolality contrast media

Studies in vitro have suggested that nonionic low osmolar contrast agents produce an increase in thrombogenicity. To determine the incidence of thrombi related to the use of nonionic low osmolar contrast media during coronary angioplasty, a double-blind randomized study was performed in 100 patients. Medication before angioplasty included oral aspirin (250 mg/day) in all cases. At the beginning of the procedure, aspirin (250 mg) and heparin (10,000 U) were intravenously administered. During the procedure patients were randomly assigned to receive either an ionic low osmolar contrast agent ioxaglate (n = 50), or a nonionic low osmolar contrast media iohexol (n = 50). The presence of thrombus was evaluated on the angiogram and on the guidewire immediately after its retrieval from the patients. Clinical, angiographic and procedural variables were similar in the 2 randomized groups. Angiographic evidence of thrombus was observed in 1 patient (2%) assigned to ioxaglate and in 11 patients (22%) assigned to iohexol (p less than 0.005). One patient (2%) from the ioxaglate group and 6 patients (12%) from the iohexol group showed thrombotic residues on the guidewire (p = not significant). Three patients had acute myocardial infarction, 1 patient (2%) receiving ioxaglate and 2 patients (4%) iohexol (p = not significant). There were no deaths. Thus, compared with an ionic low osmolar contrast media ioxaglate, the nonionic low osmolar contrast agent iohexol increases the incidence of thrombus during coronary angioplasty.

Structure of an isolated cerebellum and related nuclei developed within the matrix of a mature ovarian teratoma

The distribution and organization of nerve cells in a microcerebellum and cerebellar stalk, developed within the matrix of a mature ovarian teratoma, were analyzed with respect to recent data on cerebellar histogenesis. It is postulated that a neuroectodermal germinal locus with proliferation capability similar to that found in the alar plates of the normal embryonic rhombencephalon was responsible for the formation of this highly organized neural tissue.