Abstract P5-08-22: Impact of delay neoadjuvant chemotherapy on pathologic complete response in locally advanced breast cancer evidence of the real world in Mexico

Background:

Several studies suggest that delay on initiation adjuvant systemic therapy has subtype specific effects on survival. Many patients need neoadjuvant chemotherapy (NAC) for locally advanced breast cancer (LABC) in middle income countries. The optimal timing from breast cancer (BC) diagnosis to initiation of NAC is unknown and is not known if this interval impacts in pathological complete response (pCR) and survival.

We evaluated the relationship between pCR (defined as no invasive disease in breast and lymph nodes) and the implications in survival outcomes from LABC diagnosis and initiation of NAC.

Methods:

Data were collected retrospectively from database on National Cancer Institute for locally advanced breast cáncer (II-III) treated with NAC within six months of their diagnosis and completed treatment between January 2007 to December 2015. We evaluated data´s of 934. Time between biopsy result and start of chemotherapy was calculated. Patients were grouped into those who had pCR vs. no pCR, those who started treatment within 28 days and those who started after 28 days and the expression of hormonal receptors and Her2 by immunohistochemistry. We evaluated the results with the Pearson´s X2 and Fisher´s exact test.

Results:

We evaluated data´s of 934 woman. Overall pCR rate for our population was (311) 33%. The patients who initiated their treatment before 28 days the pCR rate was 40% and in the group who initiated NAC after 28 days the pCR was 27% with p= 0.0001, independently of the immunohistochemistry pattern expression. The median overall survival for the patients who initiated NAC before 28 days is 111 months compare with the patients who initiated NAC after 28 days was 101 months with a p= 0.52. For disease free survival in patients who began NAC before 28 days and achieved pCR were 92.2 months and for the group after 28 days were 89.9 months (p=0.033)

If we divided the group in triple negative patients by immunohistochemistry (183) ER negative, PR negative, HER2 negative, the patients with less than 28 days have 49.5% of pCR and the patients who initiated NAC after 28 days have pCR 37% (p=0.044). In the group with triple positive 70 patients (ER positive, PR positive, HER2 positive) those who began the NAC before 28 days achieved pCR 45% and those after 28 days have pCR 39% (p=0.40). The patients with ER positive and HER2 negative 475, before 28 days achieved pCR 26% and those after 28 days pCR was 11% (p=0.0001). And finally the patients with ER negative and HER2 positive have a pCR of 64% if the NAC initiated before 28 days and the pCR was of 52% if the NAC started after 28 days (p=0.15).

Conclusions: As in the adjuvant treatment, the time between biopsy and initiation of neoadjuvant chemotherapy has an impact on the pCR rates and survival of patients with breast cancer locally advanced treated at National Cancer Institute of Mexico in the context of a real world scenario.

Citation Format: Cabrera P, Muñoz W, Gutierrez L, Ramirez MT, Albarado A, Lara F, Mohar A. Impact of delay neoadjuvant chemotherapy on pathologic complete response in locally advanced breast cancer evidence of the real world in Mexico [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-08-22.

Prognostic factors and recurrence in breast cancer: experience at the national cancer institute of Mexico

The purpose of this study was to analyze the prognostic and predictive factors that relate to locoregional or distant recurrences in breast cancer patients who have been treated at the National Cancer Institute of Mexico. Multivariate, time-dependent Cox regression analyses indicate that the pN status (positive versus negative lymph node; P = 0.003; HR (hazard ratio), 3.47; CI (confidence interval), 1.52-7.91) and the pathological complete response of the patient to neoadjuvant chemotherapy (yes versus no; P = 0.061; HR, 0.38; CI, 0.14-1.04) were important prognostic factors for recurrence.

Tumor HGF lacks prognostic significance in Mexican breast cancer patients

Hepatocyte growth factor-scatter factor (HGF-SF) is a pleiotropic protein implicated in tumor formation and metastasis. Since increased levels of HGF-SF were first identified in breast cancer tissue or patient serum, some evidence has suggested that tumor or serum HGF-SF concentration could be one of the most accurate prognostic factors for this disease. However, other recent investigations have not been able to corroborate this finding. The study aims to establish the prognostic significance of HGF-SF in Mexican breast cancer women. Surgical specimens were obtained from 67 incident breast cancer patients at the Mexican National Cancer Institute between 1994 and 1995. Primary breast cancer tissue HGF-SF was measured by quantitative sandwich enzyme immunoassay. Relapse-free and overall survival curves were generated using Kaplan-Meier method. Significance of survival differences was calculated by log-rank test. chi2 was used for the association analysis between prognostic variables. Disease-free survival and overall survival were similar between the high tumor HGF group of patients and the low HGF patients (p = 0.7 and p = 0.36 respectively). No association was found between HGF and other clinicopathological variables (age, menopause status, clinical tumor size, clinical node involvement, metastasis, tumor grade, Estrogen Receptor and Progesterone Receptor). We found no prognostic significance for HGF, nor did we find a clear association between HGF and other known prognostic factors. A firm conclusion cannot be established regarding the role of HGF as a prognostic tool in breast cancer patients.

Histological Toxicity of Grepafloxacin after Intravitreal Injection

PURPOSE

To determine the intravitreal levels of grepafloxacin after intravitreal injection of 80 microg and to evaluate the retinal toxicity after intravitreal injection of different doses of grepafloxacin in rabbit eyes.

METHODS

Fifteen female New Zealand white rabbits and 15 female pigmented 'Gigantes de España' rabbits were injected with 80 microg of grepafloxacin into the vitreous cavity. The grepafloxacin concentration was determined with HPLC after 2, 4, 8, 12 and 24 h. Eighteen female rabbits (9 New Zealand white rabbits and 9 pigmented 'Gigantes de España' rabbits) were used for a study of toxicity. The rabbits were divided into 6 treatment groups: group 1 (3 pigmented rabbits) received an intravitreal injection of 80 microg of grepafloxacin in 0.1 ml of saline solution, group 2 (3 white rabbits) 80 microg of grepafloxacin in 0.1 ml, group 3 (3 pigmented rabbits) 800 microg of grepafloxacin, group 4 (3 white rabbits) 800 microg of grepafloxacin, group 5 (3 pigmented rabbits) and group 6 (3 white rabbits) 0.1 ml of saline solution. Clinical examination was performed prior to injection and 24 h and 10 days after surgery. The animals were sacrificed 10 days after the injection, and the eyes were enucleated and fixed for histopathology. The specimens were stained with hematoxylin-eosin and toluidine blue.

RESULTS

No relevant complications were found during the clinical follow-up. All the eyes showed no abnormalities in the histologic evaluation.

CONCLUSION

Grepafloxacin can be considered as a safe alternative for intravitreal injection for the treatment of intraocular infections.

The nuclear deltaB isoform of Ca2+/calmodulin-dependent protein kinase II regulates atrial natriuretic factor gene expression in ventricular myocytes

Cultured neonatal ventricular myocytes display features of myocardial hypertrophy including increased cell size, myofilament organization, and reexpression of the embryonic gene for atrial natriuretic factor (ANF). KN-93, an inhibitor of multifunctional Ca2+/calmodulin-dependent protein kinase (CaM kinase II), blocked the induction of these responses by the alpha1-adrenergic receptor agonist phenylephrine, whereas its inactive analog KN-92 did not. To directly determine whether CaM kinase II could regulate ANF gene expression, we transiently expressed each of three isoforms of CaM kinase II (alpha, deltaB, and deltaC) along with an ANF promoter/luciferase reporter gene. The deltaB isoform markedly increased luciferase gene expression, whereas comparable levels of the deltaC and alpha isoforms were ineffective. Expression of deltaB-CaM kinase II also potentiated phenylephrine-mediated ANF gene expression, and this effect was blocked by KN-93 but not by KN-92. The ability of deltaB-CaM kinase II to transactivate a truncated ANF promoter, containing a serum response element (SRE) required for phenylephrine-inducible gene expression, was lost when this SRE was mutated. The deltaB isoform of CaM kinase II has been shown to exhibit nuclear localization. Coexpression of the non-nuclear deltaC or alpha isoforms, which can form multimers with the deltaB isoform, prevented the nuclear localization of deltaB-CaM kinase II and also blocked its effects on ANF reporter gene and protein expression. In addition, a chimeric alpha-CaM kinase II which contains the nuclear localization signal of the deltaB isoform was able to induce ANF reporter gene expression, albeit to a lesser extent than deltaB-CaM kinase II. These data are the first to assign a function to the deltaB isoform of CaM kinase II and to link its nuclear localization to subsequent activation of cardiac gene expression.

A novel interaction between adrenergic receptors and the alpha-subunit of eukaryotic initiation factor 2B

The alpha-subunit of eukaryotic initiation factor 2B (eIF-2B), a guanine nucleotide exchange protein that functions in regulation of translation, was observed to associate with the carboxyl-terminal cytoplasmic domains of the alpha2A- and alpha2B-adrenergic receptors in a yeast two-hybrid screen of a cDNA library prepared from 293 cells. This protein association was confirmed in vitro by affinity chromatography and was shown to be specific for a subset of G protein-coupled receptors, including the alpha2A-, alpha2B-, alpha2C-, and beta2-adrenergic receptors, but not the vasopressin (V2) receptor. Association of these proteins in vivo was confirmed by specific co-immunoprecipitation of eIF-2Balpha with full-length beta2-adrenergic receptors expressed in transfected 293 cells and by fluorescence microscopy showing co-localization of these proteins in intact cells. Remarkably, eIF-2Balpha co-localized with receptors exclusively in regions of the plasma membrane that are in contact with the extracellular medium, but failed to associate with membranes making cell-cell contacts. Overexpression of eIF-2Balpha in 293 cells caused a small (approximately 15%) but significant enhancement of beta2-adrenergic receptor-mediated activation of adenylyl cyclase, without affecting forskolin or V2 receptor-mediated activation. These observations suggest a new role for a previously identified guanine nucleotide exchange protein in membrane biology and cell signaling.

The MEKK-JNK pathway is stimulated by alpha1-adrenergic receptor and ras activation and is associated with in vitro and in vivo cardiac hypertrophy

In neonatal rat ventricular myocytes, stimulation of the alpha1-adrenergic receptor (alpha1-AdrR) activates a program of genetic and morphological changes characterized by transcriptional activation of the atrial natriuretic factor (ANF) gene and enlargement (hypertrophy) of the cells. The low molecular weight GTPase Ras has been established as an important regulator of hypertrophy both in vitro and in vivo. Ras activates a kinase cascade involving Raf, the mitogen-activated protein kinase kinase (MEK), and the extracellular signal-regulated protein kinase (ERK). However, the extent of involvement of this pathway in regulating hypertrophic responses is controversial. We demonstrate here that both alpha1-AdrR stimulation and Ras can also activate the c-Jun NH2-terminal kinase (JNK) in cardiomyocytes. The alpha1-AdrR effect on JNK occurs through a pathway requiring Ras and MEK kinase (MEKK). A constitutively activated mutant of MEKK that preferentially activates JNK, stimulates ANF reporter gene expression, while a dominant negative MEKK mutant inhibits ANF expression induced by PE. Furthermore, JNK activity is increased in the ventricles of mice overexpressing oncogenic Ras, whereas ERK activity is not. These results suggest that the alpha1-AdrR mediates ANF gene expression through a Ras-MEKK-JNK pathway and that activation of this pathway is associated with in vitro and in vivo hypertrophy.

Endothelin ETA receptor regulates signaling and ANF gene expression via multiple G protein-linked pathways

We have characterized the interaction of endothelin (ET) with cultured neonatal rat ventricular myocytes. Binding studies indicate a single population of ETA receptors [53,000 sites/cell, apparent dissociation constant (Kd) for ET-1 approximately 0.07 nM]. Analysis of mRNA levels for ET receptors using 35 cycles of reverse transcriptase-polymerase chain reaction demonstrates the presence of only ETA-receptor message. Studies with ET-1 and a variety of congeners and antagonists indicate that ETA receptors couple to both the stimulation of phosphoinositide turnover and the inhibition of adenylyl cyclase. In myocytes transfected with an atrial natriuretic factor (ANF) promoter linked to a luciferase reporter gene, ET-1 stimulates luciferase expression through an ETA receptor. These data indicate that the ETA receptor is the exclusive receptor on neonatal ventricular myocytes and that this receptor couples to both phosphoinositide hydrolysis and adenylyl cyclase. ET-1 also induces a threefold increase in mitogen-activated protein kinase (MAPK) activity, an effect that is not sensitive to pertussis toxin (PTx). By contrast, ET-stimulated ANF-luciferase expression is partially inhibited by treatment of cells with PTx, suggesting that both PTx-sensitive (Gi) and PTx-insensitive (Gq) pathways mediate the effects of ET-1 on ANF gene expression in neonatal myocytes and that hormonal regulation of ANF expression may utilize pathways in addition to the activation of MAPK.

M1 muscarinic receptors heterologously expressed in cardiac myocytes mediate Ras-dependent changes in gene expression

Stimulation of alpha 1-adrenergic receptors in neonatal ventricular cardiomyocytes induces hypertrophic changes including activation of the atrial natriuretic factor (ANF) gene. This receptor couples to Gq to activate phospholipase C (PLC) and protein kinase C, which have been implicated as mediators of the hypertrophic response. To directly determine whether receptor coupling to Gq/PLC is sufficient to induce ANF expression, we expressed wild-type and chimeric muscarinic cholinergic receptors (mAChRs) with altered G-protein coupling properties in cardiac myocytes and examined their ability to activate an ANF promoter/luciferase reporter gene. The cholinergic agonist carbachol failed to induce transcriptional activation of the ANF reporter gene through endogenous Gi-linked M2mAChRs or in cells transfected with M2mAChRs. In contrast, in cells transfected with M1mAChRs, which effectively couple to Gq/PLC, carbachol increased ANF reporter gene expression 10-fold and also increased ANF protein, as determined by immunofluorescence. Carbachol-mediated ANF gene expression was inhibited by the mAChR antagonist pirenzepine with a Ki value characteristic of an M1mAChR. Studies using chimeric M1- and M2mAChRs demonstrated that the N-terminal 21 amino acids of the third intracellular loop of the M1mAChR were required for receptor coupling to ANF gene expression. This region, previously shown to specify receptor coupling to Gq/PLC, also conferred partial activity to a chimeric M2 receptor. We further demonstrated that M1mAChR coupling to ANF gene expression was Ras-dependent since co-expression of dominant-interfering Ala-15 Ras inhibited M1mAChR-induced ANF expression by 60%. In contrast, ANF expression induced by the chimeric M2 receptor was not blocked by dominant-interfering Ras. We suggest that receptor coupling to Gq/PLC is sufficient to induce ANF expression and that a Ras-dependent pathway contributes additional signals required for maximal M1mAChR-mediated ANF gene expression.

HIV screening of newborns

Iowa has participated in the national survey for the prevalence of HIV infection in childbearing women since July of 1989. As of February 1992, blinded testing for antibodies to HIV has been performed on blood spot specimens from 100,717 newborns. Of this number, 14 were confirmed as positive by Western blot. In the Iowa survey the prevalence of HIV infection in childbearing women was 0.14/1000 or 1/7000. This is similar to the prevalence that was observed for PKU in newborns during this time period. However, assuming only 30% of mothers transmit HIV to their babies, the predicted prevalence of HIV infection in Iowa newborns is 1/23,000. Certainly HIV disease is a public health concern with a frequency in Iowa mothers similar to that of other diseases screened for in the Iowa program. HIV meets the remaining WHO criteria for newborn screening, as well: the HIV screening test is simple and reliable and has a low incidence of false-positive and false-negative results; confirmatory testing, counseling, and medical care are available; the quality and length of life of affected individuals are improved by treatment; and data show that early diagnosis and treatment result in a cost advantage to society. The major obstacle to the addition of HIV testing to a newborn screening program is obtaining informed consent without jeopardizing program effectiveness.

Effect of a benzodiazepine derivate Ro 15-4513 on ethanol-free selection and CNS mitochondrial energetics in rats

1) Females are higher EtOH drinkers than males in E.F.S. experiments in rats. 2) Ro 15-4513 inhibited intake of EtOH. 3) Hypothalamus mitochondrial energetics, studied at Sites I and II, showed Ro 15-4513 inhibition of these parameters at different doses by sex: effects were seen in females at 15 mg and in males at 10 mg/kg rat/24 h. An uncoupled effect between electron transport and ADP/O was found.

Investigation of atypical western blot (immunoblot) reactivity involving core proteins of human immunodeficiency virus type

Serum specimens which originally exhibited a narrow (indeterminate) 24-kilodalton core protein (p24) or p24/p55 pattern of reactivity with human immunodeficiency virus (HIV) in the Western blot (immunoblot) test were studied to gather information on antibody specificity. A total of 12 specimens were initially reevaluated with an indirect immunofluorescence assay (IFA), three enzyme-linked immunosorbent assays (ELISAs), and Western blot analyses. Five of the specimens were IFA positive and contained anti-gp160/gp120 antibodies which were observed only when an HIV Western blot antigen rich in gp160 and gp120 was used. The remaining seven serum specimens were nonreactive by IFA and showed variable reactivity in HIV antibody ELISAs. The specimens did not cross-react with core antigens for human T-cell leukemia virus types 1 and 2 or contain detectable levels of HIV p24 antigen. The p24/p55 reactivity of six of the seven indeterminate specimens could be reduced or eliminated by preincubating the specimens with disrupted, HIV-infected H9 cells but not with uninfected H9 cells. The six specimens also exhibited discernible reactivity with recombinant HIV p24 antigen. When an additional 23 indeterminate specimens were assayed, all of the serum specimens were nonreactive by IFA while 65% (15 of 23) showed various degrees of reactivity with the recombinant p24 protein. There was no indication that any of the HIV core antibody reactivity was caused by HIV infection. Indeterminate results for five patients with specific p24 reactivity, who were retested after a period of weeks or months, remained indeterminate for HIV antibody with no significant change in ELISA or Western blot reactivity.