Publications by authors named "Robert L DeWitty"

A high-throughput multiconstriction microfluidic channels device can distinguish human breast cancer cell lines (MDA-MB-231, HCC-1806, MCF-7) from immortalized breast cells (MCF-10A) with a confidence level of ∼81-85% at a rate of 50-70 cells/min based on velocity increment differences through multiconstriction channels aligned in series. The results are likely related to the deformability differences between nonmalignant and malignant breast cells. The data were analyzed by the methods/algorithms of Ridge, nonnegative garrote on kernel machine (NGK), and Lasso using high-dimensional variables, including the cell sizes, velocities, and velocity increments.

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Background: MYC overexpression is associated with poor prognosis in breast tumors (BCa). The objective of this study was to determine the prevalence of MYC amplification and associated markers in BCa tumors from African American (AA) women and determine the associations between MYC amplification and clinico-pathological characteristics.

Methods: We analyzed 70 cases of well characterized archival breast ductal carcinoma specimens from AA women for MYC oncogene amplification.

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Background/aims: Breast cancer (BCa) prognostication is a vital element for providing effective treatment for patients with BCa. Studies suggest that ethnicity plays a greater role in the incidence and poor prognosis of BCa in younger women than in their older counterparts. Therefore, the goal of this study was to assess the association between age and ethnicity on the overall final prognosis.

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Expression of estrogen receptor (ER), progesterone receptor (PR), and the human epidermal growth factor receptor 2 (HER2) can subdivide breast carcinomas into clinically meaningful classes. Cancers lacking expression of all three of these receptors (triple-negative breast cancer; TNBC) is of particular interest for molecular research because these tumors currently have no effective targets for therapy. Furthermore, TNBCs are relatively more prevalent among African-American women and can account for some of the health disparities associated with breast cancer.

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Background: Fascin, an actin bundling protein, plays a critical role in cell motility due to formation of actin rich protrusions called filopodia, important in cell migration, invasion and metastatic spread. Fascin overexpression has been associated with epithelial to mesenchymal transition and correlates with progression and unfavourable prognosis in breast carcinoma.

Objective: To evaluate fascin expression by immunohistochemistry and correlate the expression pattern with clinicopathological parameters in breast cancer in African-American (AA) women, in whom triple negative breast cancer (TNBC), an aggressive subtype, is more prevalent.

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Introduction: Due to increased awareness of breast cancer resulting in early detection, there is a decreased incidence nationwide of late-stage breast cancer, including that which presents with skin involvement (T4b).

Methods: A retrospective analysis of a 10-month period from August 2007 to May 2008 at Howard University Hospital (HUH), Washington, DC, revealed 12 patients diagnosed with T4b breast cancer and compared to similarly staged patients in the Surveillance, Epidemiology, and End Results (SEER) database. Finally, a logistic regression for the likelihood of T4b diagnosis was performed patients in the SEER database.

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Background: To address the clinical relevance of molecular detection of occult breast cancer in sentinel lymph nodes and nonsentinel axillary lymph nodes (ALN), we initiated the Minimally Invasive Molecular Staging of Breast Cancer (MIMS) trial, a multi-institutional prospective cohort study. This trial represents the first prospective cohort study in which a multimarker, real-time reverse transcription polymerase chain reaction (RT-PCR) analysis was applied to the detection of breast cancer micrometastases in ALN.

Materials And Methods: Sentinel and/or nonsentinel ALN from 501 breast cancer subjects with T1-T3 primary tumors were analyzed by standard histopathology and multimarker, real-time RT-PCR analysis.

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The Gail model has been used to predict invasive breast cancer risk in women using risk factors of age, age at menarche, age at first live birth, number of first-degree relatives with breast cancer, and number of previous benign breast biopsies. However, this model underestimates breast cancer risk in African-American women. The Contraceptive and Reproductive Experience (CARE) model has been developed to replace the Gail model in predicting breast cancer risk in African-American women.

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With the current classification of breast carcinoma into molecular subtypes with distinct prognosis and response to therapy, we sort to assess the clinical significance of p53 and bcl-2 coexpression phenotypes in invasive breast tumors and correlate this to the different molecular breast cancer subtypes in African-American women. We performed a retrospective analysis of data on p53 and bcl-2 expression. Results were correlated to molecular breast cancer subtypes, and clinicopathologic variables of prognostic significance.

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In the current study we tested if highest incidence of benign as well as cancer growths in breast tissue is due to constitutive molecular composition of this tissue. To delineate the molecular basis, we compared the expression of nine functional gene modules (total 578 genes) that regulate major positive growth and negative inhibitory signals in normal breast with two other reproductive tissues, ovary and uterus. We present data to demonstrate that breast tissues constitutively have very highly elevated levels of several growth promoting molecules and diminished levels of inhibitory molecules which may, in part, contribute for highest incidence of tumor growths in this tissue.

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Objective: To analyze whether the local-regional surgical treatments (breast-conserving therapy, mastectomy) resulted in different overall survival, distant metastasis-free survival, and locoregional recurrence-free survival rates for the various molecular breast cancer subtypes.

Summary Background Data: Molecular gene expression profiling has been proposed as a new classification and prognostication system for breast cancer. Current recommendation for local-regional treatment of breast cancer is based on traditional clinicopathologic variables.

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Purpose: It has been reported that approximately a million women are diagnosed with benign breast lesions that include ductal hyperplasias per year in the United States. Recent studies that followed women with benign lesions have established that about 8% to 9% of them will subsequently develop invasive breast cancer (IBC). However, currently, there are no means of identifying a subclass of "true precancerous tissues" in women with ductal hyperplasias who will subsequently develop cancer.

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Background: GPR30 is a cell surface estrogen receptor that has been shown to mediate a number of non-genomic rapid effects of estrogen and appear to balance the signaling of estrogen and growth factors. In addition, progestins appear to use GPR30 for their actions. Therefore, GPR30 could play a critical role in hormonal regulation of breast epithelial cell integrity.

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Background: The aim of this study was to evaluate the prognostic significance of the basal cell-like molecular breast cancer subtype with respect to locoregional recurrence and distant metastasis in African American women treated for breast cancer.

Methods: A retrospective analysis was performed of the tumor registry database for all African American women diagnosed and treated for breast cancer from 1998 to 2005 who had assessable data for all 3 markers: estrogen, progesterone, and Her-2/neu.

Results: A total of 372 patients were included in our study sample.

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Background: Breast cancer is currently regarded as a heterogeneous disease classified into various molecular subtypes using gene expression analysis. These molecular subtypes include: basal cell-like, Her-2/neu, luminal A, and luminal B.

Objectives: To analyze the prevalence and clinicopathologic associations for molecular breast cancer subtypes in premenopausal and postmenopausal African-American women.

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Introduction: Breast cancer is currently viewed as a heterogeneous disease made up of various subtypes, with distinct differences in prognosis. Our goal was to study the distribution and to characterize the clinical and biological factors that influence the behavior and clinical management of the different molecular breast cancer subtypes in premenopausal African-American women.

Methods: A retrospective analysis of Howard University Hospital tumor registry, for all premenopausal African-American women aged less than 50 years, diagnosed with breast cancer from 1998-2005, was performed.

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Background: Epidemiologic studies have established that women with prior atypical ductal hyperplastic (ADH) lesions have a 5-fold increased risk of developing invasive breast cancer (IBC). However, there is currently no means of identifying a subclass of ADH from women who will most likely develop cancer. The purpose of this study is to investigate whether elevated expression of carcinoembryonic antigen cell adhesion molecule 6 (CEACAM6) in ADH tissues is associated with the development of IBC.

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Breast cancer is the second leading cause of cancer death for women in the United States. In 2005, about 215,000 cases of invasive breast cancer (IBC) and 50,000 cases of ductal carcinoma in situ will be diagnosed and 40,000 women will die of IBC in the US. Yet there is presently no molecular marker that can be used to detect a precancerous state or identify which premalignant lesions will develop into invasive breast cancer.

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Objective: We sought to establish the clinical relevance of micrometastatic disease detected by reverse transcription polymerase chain reaction (RT-PCR) in axillary lymph nodes (ALN) of breast cancer patients.

Background: The presence of ALN metastases remains one of the most valuable prognostic indicators in women with breast cancer. However, the clinical relevance of molecular detection of micrometastatic breast cancer in sentinel lymph nodes (SLN) and nonsentinel ALN has not been established.

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Purpose: African Americans have the highest cancer mortality rates and poorest survival and are more often uninsured and underinsured compared with other ethnic groups. Minority participation in clinical trials has traditionally been low, with reports ranging from 3% to 20%. The present study systematically assesses 235 consecutively diagnosed African American cancer patients regarding recruitment onto cancer treatment clinical trials at Howard University Cancer Center between January 1, 2001, and December 31, 2002.

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Incidence of breast cancer (BC) varies among ethnic groups, with higher rates in white than in African-American women. Until now, most epidemiological and genetic studies have been carried out in white women. To investigate whether interactions between genetic and reproductive risk factors may explain part of the ethnic disparity in BC incidence, a genetic epidemiology study was conducted, between 1989 and 1994, at the Howard University Cancer Center (Washington, DC), which led to the recruitment of 245 African-American families.

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