Prabha Rajan

Cross-talk between Notch and the Estrogen Receptor in Breast Cancer Suggests Novel Therapeutic Approaches

High expression of Notch-1 and Jagged-1 mRNA correlates with poor prognosis in breast cancer. Elucidating the cross-talk between Notch and other major breast cancer pathways is necessary to determine which patients may benefit from Notch inhibitors, which agents should be combined with them, and which biomarkers indicate Notch activity in vivo. We explored expression of Notch receptors and ligands in clinical specimens, as well as activity, regulation, and effectors of Notch signaling using cell lines and xenografts. Ductal and lobular carcinomas commonly expressed Notch-1, Notch-4, and Jagged-1 at variable levels. However, in breast cancer cell lines, Notch-induced transcriptional activity did not correlate with Notch receptor levels and was highest in estrogen receptor alpha-negative (ERalpha(-)), Her2/Neu nonoverexpressing cells. In ERalpha(+) cells, estradiol inhibited Notch activity and Notch-1(IC) nuclear levels and affected Notch-1 cellular distribution. Tamoxifen and raloxifene blocked this effect, reactivating Notch. Notch-1 induced Notch-4. Notch-4 expression in clinical specimens correlated with proliferation (Ki67). In MDA-MB231 (ERalpha(-)) cells, Notch-1 knockdown or gamma-secretase inhibition decreased cyclins A and B1, causing G(2) arrest, p53-independent induction of NOXA, and death. In T47D:A18 (ERalpha(+)) cells, the same targets were affected, and Notch inhibition potentiated the effects of tamoxifen. In vivo, gamma-secretase inhibitor treatment arrested the growth of MDA-MB231 tumors and, in combination with tamoxifen, caused regression of T47D:A18 tumors. Our data indicate that combinations of antiestrogens and Notch inhibitors may be effective in ERalpha(+) breast cancers and that Notch signaling is a potential therapeutic target in ERalpha(-) breast cancers.

Cystosarcoma phyllodes in adolescent girls and young women: a study of 45 patients.

Cystosarcoma phyllodes (CP) is an uncommon tumor in adolescent girls and young women. This study seeks to define the clinical and pathologic features of CP in this unusual clinical setting. Forty-five CPs (34 benign and 11 malignant) in prepubertal and adolescent girls and young women were studied. Classification of the tumors was based on the following morphologic features: stromal cellularity, nuclear atypia, mitotic activity, necrosis, and the nature of tumor borders. Surgical therapy was local excision or mastectomy. The age of the patients ranged from 10 to 24 years (mean 17.7). The tumors measured 1.4 cm to 10.2 cm at their widest point (mean 4.6). Both breasts were affected equally. Thirty-two patients were treated by local excision with or without reexcision and four patients by mastectomy. Follow-up was available for 36 patients for a mean of 58.4 months. Local recurrence was reported in six of the 36 cases (16%) (four benign and two malignant). The six patients with recurrent disease had infiltrative tumor borders and positive surgical margins microscopically. There was a single instance of systemic metastases from a high-grade malignant tumor with rhabdomyosarcomatous stromal differentiation and a high mitotic rate. At last follow-up, 34 patients were alive with no evidence of disease, one patient was alive with pulmonary metastases, and one patient died of an unrelated cause. We concluded that CP in adolescent girls and young women is not more aggressive than in older patients. Infiltrative tumor borders and positive surgical margins are the best histologic predictors for local recurrence. Mitotic activity is the most important criterion for assessing the metastatic potential. CP in this age group should be treated to maximize breast conservation. Mastectomy may be required to obtain clear margins for CPs that cannot be managed by excision because of large tumor size relative to breast volume.

Notch-1 and Notch-4 Receptors as Prognostic Markers in Breast Cancer

Background: Studies looking at immunohistochemical (IHC) staining of Notch receptors in breast cancer and correlation with known prognostic factors are sparse. Methods: IHC staining for nuclear, cytoplasmic, and membrane Notch-1 (N1), Notch-4 (N4), and Jagged-1 (JAG1) was performed and correlated with known prognostic factors. Results: Of 48 breast cancers, 36 (67%) were invasive, mean age was 50 years (range 43-86 years), 37 (77%) were estrogen receptor (ERα) positive, and 13 (27%) node positive. There was significantly more marked N1 membranous staining in ERα-positive tumors (P < .05). On univariate analysis, cytoplasmic N1 was significantly correlated with node status and tumor grade (P < .05); both cytoplasmic and membranous N4 significantly correlated with Ki67 (P < .05); and membranous JAG1 significantly correlated with Ki67 (P < .05). On multivariate analysis, only cytoplasmic N1 significantly correlated with node status. Conclusion: IHC of Notch markers is feasible and correlates with known prognostic factors consistent with a biological role of Notch signaling in breast cancer progression.

Notch-1 and Notch-4 biomarker expression in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) demonstrates lack of expression of hormone receptors and human epidermal growth factor receptor. However, there is no targeted therapy for TNBC. The authors analyzed 29 TNBC cases for Notch-1 and Notch-4 biomarker expression and subcellular location, Ki67 proliferation rate, and relevant clinical/survival data. Results demonstrated an unfavorable Ki67 rate in 90% of cases, Notch-1 expression in tumor and endothelial cells in 100% of cases, and Notch-4 expression in tumor cells in 73% of cases and endothelial cells in 100% of cases. Additionally, subcellular localization of Notch-1 and Notch-4 was predominantly nuclear and cytoplasmic. In conclusion, (a) the majority of TNBCs are high-grade infiltrating ductal carcinomas with high Ki67 proliferation rate and (b) both Notch-1 and Notch-4 receptors are overexpressed in tumor and vascular endothelial cells with subcellular localization different from that of hormone-positive breast cancer. Targeting Notch signaling with gamma secretase inhibitors should to be explored to further improve the survival rate of TNBC patients.

Predicting cancer on excision of atypical ductal hyperplasia

BACKGROUND There are no specific histopathologic factors that allow identification of patients with atypical ductal hyperplasia (ADH) who will have cancer on final excision. METHODS This was a retrospective study of all patients who had ADH on biopsy followed by excision from 1999 to 2006. RESULTS Fifty-one patients were found to have ADH on core biopsy. Eight (15.7%) patients had invasive carcinoma on surgical excision, 9 (17.5%) had ductal carcinoma-in-situ (DCIS), 21 (41.5%) had ADH, 4 (8%) patients had atypical lobular hyperplasia, and 9 (17.5%) had benign tumors. The grade of atypia on the core biopsy was mild in 13 (25%) patients, moderate in 22 (43%), and marked in 16 (32%). On multivariate analysis of histopathologic factors, the grade of atypia was the only significant variable that predicted a diagnosis of cancer on final surgical excision (P = .001). CONCLUSIONS The grade of atypia correlated with the presence of cancer on surgical excision.

Pseudoangiomatous stromal hyperplasia of the breast: A contemporary approach to its clinical and radiologic features and ideal management

BACKGROUND Pseudoangiomatous stromal hyperplasia (PASH) is a benign, proliferative lesion of the breast whose clinical relevance, presentation, and optimal treatment remains described incompletely. The purpose of this study is to review the clinical, radiologic, and histopathologic features and appropriate management. METHODS Patients diagnosed with PASH were identified from our pathology database between 2000 and 2009. Clinicopathologic data including presentation, diagnosis, imaging, and histology were reviewed. All specimens were confirmed by a single pathologist. RESULTS We identified PASH in 80 patients. Median follow-up was 3.71 years (range, 0.45-9.42). Age ranged from 12 to 65 (median, 45) and 95% were female. Lesions were palpable in 56% and found on imaging in the remainder. Core biopsy was performed in 65 of 80 patients (81%), which confirmed a diagnosis of PASH in 65%. The other 23 of 65 patients (35%) required operative excision for diagnosis. There was a progression rate of 26% in the observation arm versus 13% in the excision arm. A diagnosis of cancer or carcinoma in situ was seen in 30% at or before the diagnosis of PASH. CONCLUSION PASH may present as a mass, radiologic lesion, or incidentally in pathology specimens. It may be associated with cancerous or precancerous lesions. A diagnosis on core biopsy in the absence of suspicious radiologic features may be managed with follow-up and imaging at a 6-month interval. In this series, 35% of patients with PASH had a negative core biopsy. Growth, suspicious radiologic findings, or inconclusive biopsy warrants surgical excision. Close surveillance is necessary given its recurrence rate of 13-26%.

Pseudoangiomatous Stromal Hyperplasia (PASH) of the Breast: A Clinicopathological Study of 79 Cases

Background. Pseudoangiomatous stromal hyperplasia (PASH) of the breast is a benign lesion that can present as a palpable nodule or as an incidental finding in breast biopsies. Design. The study comprised 79 cases diagnosed at Loyola University Medical Center from 2002 to 2009. The pathology slides were reviewed to document the distribution, type, and association with preneoplastic or neoplastic epithelial lesions. Z-test for independent proportions is used for analysis. Results. A total of 76 patients were female and 3 were male. In all, 59.8% of patients presented with a breast mass and in 40.2% the lesion was an incidental finding. Classical PASH morphology was seen in 97.6% and proliferative PASH in 2.4%. Associated epithelial lesions were benign proliferative changes in 60.4%, atypical ductal and atypical lobular hyperplasia in 25.6% and infiltrating carcinoma in 11% of cases. Conclusions. Based on these results, extensive sampling of biopsy specimen with PASH and appropriate clinical and radiologic follow-up is recommended.

Histopathologic characteristics of the primary tumor in breast cancer patients with isolated tumor cells of the sentinel node

BACKGROUND Clinicians often rely on primary tumor characteristics to decide on adjuvant treatment for patients with breast cancer with isolated tumor cells (ITC) in the sentinel lymph node. The purpose of this study was to determine if there is a significant difference in primary tumor characteristics between ITC and other nodal groups. METHODS Patients undergoing sentinel lymphadenectomy were divided into 3 groups: N0, no metastases; ITC, metastasis less than 0.2 mm; and micro- or macrometastases (MM), metastasis greater than 0.2 mm. The chi-square test and analysis of variance were used. RESULTS A total of 552 patients underwent sentinel lymphadenectomy; 197 (36%) had tumor-positive sentinel lymph nodes. Of these, 35 (18%) were classified as ITC and 162 (82%) as MM. When primary tumor characteristics were compared, the ITC group had significantly more lymphovascular invasion and higher proliferative rate than the N0 group (P < .05) and significantly less lymphovascular invasion, lower proliferative rate, and smaller tumor size (P < .05) than the MM group. There were no significant differences in the age, hormone receptor status, histologic type, or tumor grade among the patient groups. CONCLUSIONS Proliferation and lymphovascular invasion of the primary tumor are significantly different between the ITC, N0, and MM groups suggesting that ITC tumors may have different biology than the N0 or MM tumors.

Abstract P1-02-01: Flat epithelial atypia diagnosed on breast core biopsy: what next?

Background: Historically, atypical ductal hyperplasia (ADH) identified on breast core biopsy has been associated with a 20% upgrade to malignancy at surgical excision. Recent literature has suggested a downward trend in such upgrade rates, possibly related to the use of larger gauge core biopsy devices. It is still unclear if this applies to other high-risk lesions, such as flat epithelial atypia (FEA). As core biopsy techniques and imaging have improved, it is critical to review the correlation between FEA diagnosed on core biopsy and malignancy at final surgical excision. Methods: We performed a retrospective chart review of our institution9s medical record from 2009 to 2011 to identify all patients who (1) underwent breast core biopsy, (2) were initially diagnosed with FEA without malignancy (in situ or invasive carcinoma), and (3) proceeded with surgical excision at our institution. Results: Of the 726 breast core biopsies performed between 2009 and 2011, we identified 14 patients who met our inclusion criteria. Three patients were upgraded to malignancy following surgical excision (21%). The median age was 53.5 years, and the average breast cancer risk assessment scores were 3.5% 5-year and 18.9% lifetime. All patients underwent pre-biopsy mammogram, and four were further evaluated with ultrasound; no patients underwent a breast MRI. All of the imaging abnormalities were initially classified as BI-RADS 4, including five masses/densities and nine with suspicious calcifications. Only one patient reported the lesion as palpable on presentation and this was eventually upgraded to malignancy. All patients underwent image-guided core biopsies, including 13 stereotactic, vacuum-assisted and one ultrasound-guided, vacuum-assisted. Nine patients had 9-gauge core needle biopsies, while the remaining four patients had 11, 12, or 14-gauge needle biopsies, and this did not vary between years. Following surgical excision, three of the 14 patients (21%) were upgraded pathologically to ductal carcinoma in situ (DCIS; n=1) or invasive ductal carcinoma (n = 2). All three of these patients had 9-gauge core biopsies prior to surgical excision. Of note, four patients also had concurrent ADH on initial biopsy, although none of these were pathologically upgraded to malignancy. Of the upgrades, one patient proceeded with a definitive lumpectomy (negative sentinel lymph node biopsy) and one underwent bilateral mastectomy. The third patient is planning to undergo ipsilateral mastectomy for a subsequent diagnosis of multi-centric breast disease, including identification of an ipsilateral DCIS lesion distant from the primary lesion. Conclusions: The use of a larger gauge core biopsy needle (e.g. 9-gauge) may yield superior tissue sampling and should likely be considered as the standard of care in the evaluation of image-detected breast abnormalities. In addition, biopsy results should not be considered definitively non-malignant when a high-risk lesion is identified. While there may be a trend towards not excising some of these high-risk lesions, we believe that a core biopsy demonstrating FEA still warrants surgical excision. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-02-01.