Selectively starving cancer cells through dietary manipulation: methods and clinical implications.

As the link between obesity and metabolic syndrome and cancer becomes clearer, the need to determine the optimal way to incorporate dietary manipulation in the treatment of cancer patients becomes increasingly important. Metabolic-based therapies, such as caloric restriction, intermittent fasting and a ketogenic diet, have the ability to decrease the incidence of spontaneous tumors and slow the growth of primary tumors, and may have an effect on distant metastases in animal models. Despite the abundance of preclinical data demonstrating the benefit of dietary modification for cancer, to date there are few clinical trials targeting diet as an intervention for cancer patients. We hypothesize that this may be due, in part, to the fact that several different types of diet modification exist with no clear recommendations regarding the optimal method. This article will delineate three commonly used methods of dietary manipulation to assess the potential of each as a regimen for cancer therapy.

Low levels of Stat5a protein in breast cancer are associated with tumor progression and unfavorable clinical outcomes.

INTRODUCTION: Signal transducer and activator of transcripton-5a (Stat5a) and its close homologue, Stat5b, mediate key physiological effects of prolactin and growth hormone in mammary glands. In breast cancer, loss of nuclear localized and tyrosine phosphorylated Stat5a/b is associated with poor prognosis and increased risk of antiestrogen therapy failure. Here we quantify for the first time levels of Stat5a and Stat5b over breast cancer progression, and explore their potential association with clinical outcome. METHODS: Stat5a and Stat5b protein levels were quantified in situ in breast-cancer progression material. Stat5a and Stat5b transcript levels in breast cancer were correlated with clinical outcome in 936 patients. Stat5a protein was further quantified in four archival cohorts totaling 686 patients with clinical outcome data by using multivariate models. RESULTS: Protein levels of Stat5a but not Stat5b were reduced in primary breast cancer and lymph node metastases compared with normal epithelia. Low tumor levels of Stat5a but not Stat5b mRNA were associated with poor prognosis. Experimentally, only limited overlap between Stat5a- and Stat5b-modulated genes was found. In two cohorts of therapy-naïve, node-negative breast cancer patients, low nuclear Stat5a protein levels were an independent marker of poor prognosis. Multivariate analysis of two cohorts treated with antiestrogen monotherapy revealed that low nuclear Stat5a levels were associated with a more than fourfold risk of unfavorable outcome. CONCLUSIONS: Loss of Stat5a represents a new independent marker of poor prognosis in node-negative breast cancer and may be a predictor of response to antiestrogen therapy if validated in randomized clinical trials.

NSG-Pro mouse model for uncovering resistance mechanisms and unique vulnerabilities in human luminal breast cancers.

Most breast cancer deaths are caused by estrogen receptor-α­positive (ER+) disease. Preclinical progress is hampered by a shortage of therapy-naïve ER+ tumor models that recapitulate metastatic progression and clinically relevant therapy resistance. Human prolactin (hPRL) is a risk factor for primary and metastatic ER+ breast cancer. Because mouse prolactin fails to activate hPRL receptors, we developed a prolactin-humanized Nod-SCID-IL2Rγ (NSG) mouse (NSG-Pro) with physiological hPRL levels. Here, we show that NSG-Pro mice facilitate establishment of therapy-naïve, estrogen-dependent PDX tumors that progress to lethal metastatic disease. Preclinical trials provide first-in-mouse efficacy of pharmacological hPRL suppression on residual ER+ human breast cancer metastases and document divergent biology and drug responsiveness of tumors grown in NSG-Pro versus NSG mice. Oncogenomic analyses of PDX lines in NSG-Pro mice revealed clinically relevant therapy-resistance mechanisms and unexpected, potently actionable vulnerabilities such as DNA-repair aberrations. The NSG-Pro mouse unlocks previously inaccessible precision medicine approaches for ER+ breast cancers.

Idiopathic granulomatous mastitis masquerading as carcinoma of the breast: a case report and review of the literature.

BACKGROUND: Idiopathic granulomatous mastitis is an uncommon, benign entity with a diagnosis of exclusion. The typical clinical presentation of idiopathic granulomatous mastitis often mimics infection or malignancy. As a result, histopathological confirmation of idiopathic granulomatous mastitis combined with exclusion of infection, malignancy and other causes of granulomatous disease is absolutely necessary. CASE PRESENTATION: We present a case of a young woman with idiopathic granulomatous mastitis, initially mistaken for mastitis as well as breast carcinoma, and successfully treated with a course of corticosteroids. CONCLUSION: There is no clear clinical consensus regarding the ideal therapeutic management of idiopathic granulomatous mastitis. Treatment options include expectant management with spontaneous remission, corticosteroid therapy, immunosuppressive agents and extensive surgery for refractory cases.

Intraoperative radiotherapy for breast cancer: the lasting effects of a fleeting treatment.

In well-selected patients who choose to pursue breast conservation therapy (BCT) for early-stage breast cancer, partial breast irradiation (PBI) delivered externally or intraoperatively, may be a viable alternative to conventional whole breast irradiation. Two large, contemporary randomized trials have demonstrated breast intraoperative radiotherapy (IORT) to be noninferior to whole breast external beam radiotherapy (EBRT) when assessing for ipsilateral breast tumor recurrence in select patients. Additionally, IORT and other PBI techniques are likely to be more widely adopted in the future because they improve patient convenience by offering an accelerated course of treatment. Coupled with these novel techniques for breast radiotherapy (RT) are distinct toxicity profiles and unique cosmetic alterations that differ from conventional breast EBRT and have the potential to impact disease surveillance and patient satisfaction. This paper will review the level-one evidence for treatment efficacy as well as important secondary endpoints like RT toxicity, breast cosmesis, quality of life, patient satisfaction, and surveillance mammography following BCT with IORT.

Pluripotent stem cell miRNAs and metastasis in invasive breast cancer.

BACKGROUND: The purpose of this study is to determine whether microRNA for pluripotent stem cells are also expressed in breast cancer and are associated with metastasis and outcome. METHODS: We studied global microRNA profiles during differentiation of human embryonic stem cells (n =26) and in breast cancer patients (n = 33) and human cell lines (n = 35). Using in situ hybridization, we then investigated MIR302 expression in 318 untreated breast cancer patients (test cohort, n = 22 and validation cohort, n = 296). In parallel, using next-generation sequencing data from breast cancer patients (n = 684), we assessed microRNA association with stem cell markers. All statistical tests were two-sided. RESULTS: In healthy tissues, the MIR302 (high)/MIR203 (low) asymmetry was exclusive for pluripotent stem cells. MIR302 was expressed in a small population of cancer cells within invasive ductal carcinoma, but not in normal breast (P < .001). Furthermore, MIR302 was expressed in the tumor cells together with stem cell markers, such as CD44 and BMI1. Conversely, MIR203 expression in 684 breast tumors negatively correlated with CD44 (Spearman correlation, Rho = -0.08, P = .04) and BMI1 (Rho = -0.11, P = .004), but positively correlated with differentiation marker CD24 (Rho = 0.15, P < .001). Primary tumors with lymph node metastasis had cancer cells showing scattered expression of MIR302 and widespread repression of MIR203. Finally, overall survival was statistically significantly shorter in patients with MIR302-positive cancer cells (P = .03). CONCLUSIONS: In healthy tissues the MIR302(high)/MIR203(low) asymmetry was characteristic of embryonic and induced pluripotency. In invasive ductal carcinoma, the MIR302/MIR203 asymmetry was associated with stem cell markers, metastasis, and shorter survival.

Loss of nuclear localized and tyrosine phosphorylated Stat5 in breast cancer predicts poor clinical outcome and increased risk of antiestrogen therapy failure.

PURPOSE: To investigate nuclear localized and tyrosine phosphorylated Stat5 (Nuc-pYStat5) as a marker of prognosis in node-negative breast cancer and as a predictor of response to antiestrogen therapy. PATIENTS AND METHODS: Levels of Nuc-pYStat5 were analyzed in five archival cohorts of breast cancer by traditional diaminobenzidine-chromogen immunostaining and pathologist scoring of whole tissue sections or by immunofluorescence and automated quantitative analysis (AQUA) of tissue microarrays. RESULTS: Nuc-pYStat5 was an independent prognostic marker as measured by cancer-specific survival (CSS) in patients with node-negative breast cancer who did not receive systemic adjuvant therapy, when adjusted for common pathology parameters in multivariate analyses both by standard chromogen detection with pathologist scoring of whole tissue sections (cohort I; n = 233) and quantitative immunofluorescence of a tissue microarray (cohort II; n = 291). Two distinct monoclonal antibodies gave concordant results. A progression array (cohort III; n = 180) revealed frequent loss of Nuc-pYStat5 in invasive carcinoma compared to normal breast epithelia or ductal carcinoma in situ, and general loss of Nuc-pYStat5 in lymph node metastases. In cohort IV (n = 221), loss of Nuc-pYStat5 was associated with increased risk of antiestrogen therapy failure as measured by univariate CSS and time to recurrence (TTR). More sensitive AQUA quantification of Nuc-pYStat5 in antiestrogen-treated patients (cohort V; n = 97) identified by multivariate analysis patients with low Nuc-pYStat5 at elevated risk for therapy failure (CSS hazard ratio [HR], 21.55; 95% CI, 5.61 to 82.77; P < .001; TTR HR, 7.30; 95% CI, 2.34 to 22.78; P = .001). CONCLUSION Nuc-pYStat5 is an independent prognostic marker in node-negative breast cancer. If confirmed in prospective studies, Nuc-pYStat5 may become a useful predictive marker of response to adjuvant hormone therapy.

Prolactin inhibits BCL6 expression in breast cancer through a Stat5a-dependent mechanism.

BCL6 is a transcriptional repressor that recognizes DNA target sequences similar to those recognized by signal transducer and activator of transcriptions 5 (Stat5). BCL6 disrupts differentiation of breast epithelia, is downregulated during lactation, and is upregulated in poorly differentiated breast cancer. In contrast, Stat5a mediates prolactin-induced differentiation of mammary epithelia, and loss of Stat5 signaling in human breast cancer is associated with undifferentiated histology and poor prognosis. Here, we identify the mammary cell growth factor prolactin as a potent suppressor of BCL6 protein expression in human breast cancer through a mechanism that requires Stat5a, but not prolactin-activated Stat5b, MEK-ERK, or PI3K-AKT pathways. Prolactin rapidly suppressed BCL6 mRNA in T47D, MCF7, ZR75.1, and SKBr3 breast cancer cell lines, followed by prolonged reduction of BCL6 protein levels within 3 hours. Prolactin suppression of BCL6 was enhanced by overexpression of Stat5a but not Stat5b, was mimicked by constitutively active Stat5a, but did not require the transactivation domain of Stat5a. Stat5 chromatin immunoprecipitation demonstrated physical interaction with a BCL6 gene regulatory region, and BCL6 transcript repression required histone deacetylase activity based on sensitivity to trichostatin A. Functionally, BCL6 overexpression disrupted prolactin induction of Stat5 reporter genes. Prolactin suppression of BCL6 was extended to xenotransplant tumors in nude mice in vivo and to freshly isolated human breast cancer explants ex vivo. Quantitative immunohistochemistry revealed elevated BCL6 in high-grade and metastatic breast cancer compared with ductal carcinoma in situ and nonmalignant breast, and cellular BCL6 protein levels correlated negatively with nuclear Stat5a (r = -0.52; P < 0.001) but not with Stat5b. Loss of prolactin-Stat5a signaling and concomitant upregulation of BCL6 may represent a regulatory switch facilitating undifferentiated histology and poor prognosis of breast cancer.

Prognostic indicators following ipsilateral tumor recurrence in patients treated with breast-conserving therapy.

BACKGROUND: We attempt to determine significant predictors of systemic recurrence following ipsilateral breast tumor recurrence (IBTR). METHODS: A retrospective single-institution chart review of all newly diagnosed breast cancer patients was conducted to identify women treated with breast-conserving therapy (BCT) who developed IBTR. Charts were reviewed for demographics, clinical presentation, method of detection, stage, type of therapy, histopathology, and margin status for both the primary and recurrent tumors. RESULTS: Of 1,733 patients who were treated with BCT, 157 experienced IBTR. Multivariate Cox regression showed that time to recurrence and method of detection of local recurrence remained significant predictors of distant metastases-free survival (DMFS). Median DMFS times for clinically and radiographically detected IBTRs were 54 months and 231 months, respectively. Adjusted relative risk for clinically detected IBTRs was 2.2. CONCLUSIONS: Given the prognostic significance of post-treatment mammography in our study, combined with median time to recurrence of 44 months, we believe that routine long-term mammographic surveillance is indicated following BCT.

Human breast cancer-associated fibroblasts (CAFs) show caveolin-1 downregulation and RB tumor suppressor functional inactivation: Implications for the response to hormonal therapy.

It is becoming increasingly apparent that the tumor microenvironment plays a critical role in human breast cancer onset and progression. Therefore, we isolated cancer-associated fibroblasts (CAFs) from human breast cancer lesions and studied their properties, as compared with normal mammary fibroblasts (NFs) isolated from the same patient. Here, we demonstrate that 8 out of 11 CAFs show dramatic downregulation of caveolin-1 (Cav-1) protein expression; Cav-1 is a well-established marker that is normally decreased during the oncogenic transformation of fibroblasts. Next, we performed gene expression profiling studies (DNA microarray) and established a CAF gene expression signature. Interestingly, the expression signature associated with CAFs encompasses a large number of genes that are regulated via the RB-pathway. The CAF gene signature is also predictive of poor clinical outcome in breast cancer patients that were treated with tamoxifen mono-therapy, indicating that CAFs may be useful for predicting the response to hormonal therapy. Finally, we show that replacement of Cav-1 expression in CAFs (using a cell-permeable peptide approach) is sufficient to revert their hyper-proliferative phenotype and prevent RB hyper-phosphorylation. Taken together, these studies highlight the critical role of Cav-1 downregulation in maintaining the abnormal phenotype of human breast cancer-associated fibroblasts.

Timing of sentinel lymph node biopsy and reconstruction for patients undergoing mastectomy.

Options for immediate breast reconstruction after mastectomy are directly affected by nodal status. Historically, axillary dissection has been performed simultaneously with mastectomy. The advent of sentinel lymph node biopsy (SLNB) drastically changed the trends in breast cancer surgery. SLNB is often performed at the time of mastectomy and may negate the need for a formal axillary dissection. The algorithm presented here outlines an approach where SLNB is performed as a separate outpatient operation several days prior to mastectomy when immediate reconstruction is planned. While this approach requires a separate procedure, SLNB can be performed with minimal morbidity with monitored anesthesia care and local anesthesia. The significance of this algorithm is that it allows time for complete pathologic evaluation prior to definitive surgery, eliminating the dependency on frozen section diagnosis. This method also decreases the possibility of irradiating a fresh autologous flap if radiation therapy is deemed necessary after further pathology review of the sentinel node specimen. We endorse SLNB as a separate outpatient procedure prior to definitive surgery with reconstruction, particularly latissimus dorsi myocutaneous flap. This method involves a close team approach between the breast and plastic surgeons.

Differences in breast carcinoma characteristics in newly diagnosed African-American and Caucasian patients: a single-institution compilation compared with the National Cancer Institute's Surveillance, Epidemiology, and End Results database.

BACKGROUND: Breast carcinomas in African-American patients appear to be more aggressive than in Caucasian patients due to multifactorial differences. METHODS: The authors compiled pathology data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database regarding stage, histologic grade, and estrogen receptor (ER) expression in breast carcinomas diagnosed in 197,274 African-American and Caucasian patients between 1990 and 2000, and the same information, along with nuclear grade, Ki-67, c-erb-B2, and p53 expression, in 2230 African-American and Caucasian patients diagnosed at Thomas Jefferson University Hospital between 1995 and 2002. Immunohistochemical markers were assayed in paraffin-embedded, formalin-fixed tissue stained with hematoxylin and eosin using antibodies to these proteins, with differences in expression analyzed by the chisquare test. RESULTS: In both databases, more African-American patients presented with advanced stage tumors and higher histologic (P < .001) and nuclear grade (P < .001) than Caucasian patients. African-American patients had less ER positivity (51.9% vs 63.1%; P < .001) but significantly higher Ki-67 (42.4% vs 28.7%; P < .001) and p53 expression (19.4% vs 13.1%; P < .05) than Caucasian patients with all stages of disease. In addition, the basal or "triple-negative" breast cancer phenotype was more common in African-American patients than in Caucasian patients (20.8% vs 10.4%; P < .0001), and was associated with higher histologic and nuclear grade (P < .0001). CONCLUSIONS: African-American patients with breast carcinomas are more likely than Caucasian patients to present with tumors that are of a later stage and higher grade, with higher Ki-67 expression and more ER negativity, thereby highlighting a greater need for early screening among African-American women. Molecular studies that may explain these differences, and correlations with survival, have been proposed to identify therapeutic targets.

Diagnosis, treatment, and management of breast cancer in previously augmented women.

Augmentation mammaplasty is rapidly becoming one of the most frequently performed cosmetic surgeries. However, as the augmented patient population ages, major concerns associated with the screening, diagnosis and treatment of breast cancer are being realized. Although current evidence convincingly indicates that breast implants do not play a role in inducing localized or systemic disease, particularly breast cancer, recent studies have shown implants not only reduce the sensitivity of mammography, but interfere with mammographic detection, possibly leading to delayed breast cancer diagnosis. In addition, the risk for local recurrence, as well as unfavorable cosmetic results, breast fibrosis, and capsular contracture following radiation therapy as part of breast-conserving therapy in previously augmented patients are of great concern. Given the overall lack of treatment consensus, paucity of literature, and increasing number of augmented breast cancer patients, we provide a retrospective review of the diagnosis, treatment, and follow-up of 12 augmented patients from 1998 to 2004 who developed breast cancer. Eight of 12 augmented patients presented with a palpable mass on physical examination, which prompted further mammographic evaluation. Abnormalities in the remaining four individuals were detected on routine mammographic screening. Pathology staging results were available for all 12 patients. Breast-conserving therapy was used to treat six patients and adequate negative pathologic margins were obtained in all patients. The remaining six patients were treated with mastectomy due to multifocal disease, inadequate margins, or proximity to the implant capsule. Thus far, one patient has had local recurrence and one patient has had distant recurrence after initial surgery. No evidence of local or systemic recurrence, infection, contracture, poor cosmetic outcome, or other complications has been detected in the remaining 10 patients as of the most recent follow-up. Based on this small cohort of augmented women, the presence of implants led to an increased proportion of palpable tumors, in spite of routine screening mammography. Consistent with other studies, although our results suggest a tendency toward delayed diagnosis in augmented women relative to age-matched controls, this did not appear to influence the overall prognosis.