Detection of mammaglobin mRNA in peripheral blood is associated with high grade breast cancer: Interim results of a prospective cohort study

<p>Abstract</p> <p>Background</p> <p>We sought to examine the detection rate of cancer cells in peripheral blood (PBL) and in bone marrow (BM) using an established 7-gene marker panel and evaluated whether there were any definable associations of any individual gene with traditional predictors of prognosis.</p> <p>Methods</p> <p>Patients with T1-T3 primary breast cancer were enrolled into a prospective, multi-institutional cohort study. In this interim analysis 215 PBL and 177 BM samples were analyzed by multimarker, real-time RT-PCR analysis designed to detect circulating and disseminated breast cancer cells.</p> <p>Results</p> <p>At a threshold of three standard deviations from the mean expression level of normal controls, 63% (136/215) of PBL and 11% (19/177) of BM samples were positive for at least one cancer-associated marker. Marker positivity in PBL demonstrated a statistically significant association with grade II-III (vs. grade I; p = 0.0083). Overexpression of the mammaglobin (<it>mam</it>) gene alone had a statistically significant association with high tumor grade (p = 0.0315), and showed a trend towards ER-negative tumors and a high risk category. There was no association between marker positivity in PBL and the pathologic (H&E) and/or molecular (RT-PCR) status of the axillary lymph nodes (ALN).</p> <p>Conclusion</p> <p>This study suggests that molecular detection of circulating cancer cells in PBL detected by RT-PCR is associated with high tumor grade and specifically that overexpression of the <it>mam </it>gene in PBL may be a poor prognostic indicator. There was no statistically significant association between overexpression of cancer-associated genes in PBL and ALN status, supporting the concept of two potentially separate metastatic pathways.</p

Molecular detection of micrometastatic breast cancer in histopathology-negative axillary lymph nodes fails to predict breast cancer recurrence: A final analysis of a prospective multi-institutional cohort study

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. Seven breast cancer-associated genes (mam, mamB, PIP, CK19, muc1, PSE, and CEA) known to be overexpressed in metastatic breast cancer compared with control lymph nodes were used. Follow-up data were collected for 5 years. Results: Of the 501 breast cancer subjects enrolled, 348 were node negative and completed the 5-year follow-up. Of these patients (n = 94), 27% demonstrated evidence of molecular overexpression. The 5-year relapse-free survival rate was 95.4% (95% confidence interval [95% CI], 92.4-97.2%). No single gene or combination of study genes was predictive of recurrence. Conclusions: The genes in this study panel failed to be predictive of clinical relapse. This may be a function of several factors: the low event rate at 5 years, the particular gene set, the methodology used for detection/analysis or that our original hypothesis was wrong and that the presence of positive marker signal by real-time RT-PCR is not associated with a worsened clinical outcome. © 2010 Society of Surgical Oncology

Epidermal growth factor receptor signaling pathway is frequently altered in ampullary carcinoma at protein and genetic levels

Our objective was to explore alteration of the epidermal growth factor receptor signaling pathway in ampullary carcinoma. Immunohistochemical studies were employed to evaluate expression of amphiregulin as well as expression and activation of epidermal growth factor receptor. A lab developed assay was used to identify mutations in the epidermal growth factor receptor pathway genes, including KRAS, BRAF, PIK3CA, PTEN and AKT1. Fifty two ampullary carcinomas were identified, including 25 intestinal-type and 24 pancreatobiliary-type tumors with the intestinal type being associated with a younger age at diagnosis (p=0.03) and a better prognosis (p<0.01). Expression of amphiregulin correlated the better differentiation (p<0.01), but no difference was observed between two major histologic types. Expression and activation of epidermal growth factor receptor was more commonly seen in the pancreatobiliary type (p<0.01). Mutations were detected in 50% of the pancreatobiliary type and 60% of the intestinal type. KRAS was the most common gene mutated in the pancreatobiliary type (42%) as well as the intestinal type (52%). Other mutations detected included PIK3CA, and SMAD4 and BRAF. KRAS mutations at codons 12 and 13 did not impact adversely on overall survival. In conclusion, epidermal growth factor receptor expression and activation were different between intestinal- and pancreatobiliary-type ampullary carcinoma. KRAS mutation was common in both histologic types; however, the incidence appeared to be lower in the pancreatobiliary type compared to its pancreatic counterpart, pancreatic ductal adenocarcinoma. Mutational analysis of the epidermal growth factor receptor pathway genes may provide important insights into personalized treatment for patients with ampullary carcinoma