Lymph node involvement in immunohistochemistry-based molecular classifications of breast cancer.

BACKGROUND: Prognosis and treatment options differ for each molecular subtype of breast cancer, but risk of regional lymph node (LN) metastasis for each subtype has not been well studied. Since LN status is the most important predictor for prognosis, the aim of this study is to investigate the propensity for LN metastasis in each of the five breast cancer molecular subtypes. METHODS: Under an institutional review board-approved protocol, we retrospectively reviewed the charts of all pathologically confirmed breast cancer cases from January 2004 to June 2012. Five subtypes were defined as luminal A (hormone receptor positive, Ki-67 low), luminal B (hormone receptor positive, Ki-67 high), luminal human epidermal growth factor receptor 2 (HER2), HER2-enriched (hormone receptor negative), and triple negative (TN). RESULTS: A total of 375 patients with complete data were classified by subtype: 95 (25.3%) luminal A, 120 (32%) luminal B, 69 (18.4%) luminal HER2, 26 (6.9%) HER2-enriched, and 65 (17.3%) TN. On univariate analysis, age (<50), higher tumor grade, HER2+ status, tumor size, and molecular subtype were significant for LN positivity. Molecular subtype correlated strongly with tumor size (χ(2); P = 0.0004); therefore, multivariable logistic regression did not identify molecular subtype as an independent variable to predict LN positivity. CONCLUSIONS: Luminal A tumors have the lowest risk of LN metastasis, whereas luminal HER2 subtype has the highest risk of LN metastasis. Immunohistochemical-based molecular classification can be readily performed and knowledge of the factors that affect LN status may help with treatment decisions.

Indications for sentinel lymph node biopsy in multifocal and multicentric breast cancer.

BACKGROUND: Multifocal and multicentric breast cancers have been regarded as relative contraindications for sentinel lymph node (SLN) biopsy, because initial validation studies noted an association with greater false-negative rates. The purpose of this study is to perform a meta-analysis of the literature evaluating the feasibility and accuracy of SLN biopsy in multifocal and multicentric breast cancer. METHODS: A PubMed search retrieved original articles published between 2000 and 2010 in which the authors evaluated the accuracy of SLN biopsy in multifocal and multicentric breast cancer. Sixteen original articles were included in our meta-analysis. RESULTS: Nine-hundred thirty-two patients with multifocal and multicentric breast cancer underwent SLN biopsy followed by axillary lymph node dissection. The overall accuracy rate and false-negative rate are 96% and 7.7%, respectively. Of the 37 false-negative biopsies, 7 patients had an additional relative contraindication for SLN biopsy. If we exclude these patients with additional known relative contraindication to SLN biopsy, the accuracy and false-negative rates are 96.7% and 6.3%, respectively. CONCLUSION: When a multifocal or multicentric breast cancer has an additional relative contraindication to performing SLN biopsy, such as neoadjuvant chemotherapy or T > 5 cm, the false-negative rate increases.

Chemoprevention of colorectal cancer by targeting APC-deficient cells for apoptosis.

Cancer chemoprevention uses natural, synthetic, or biological substances to reverse, suppress, or prevent either the initial phase of carcinogenesis or the progression of neoplastic cells to cancer. It holds promise for overcoming problems associated with the treatment of late-stage cancers. However, the broad application of chemoprevention is compromised at present by limited effectiveness and potential toxicity. To overcome these challenges, here we developed a new chemoprevention approach that specifically targets premalignant tumour cells for apoptosis. We show that a deficiency in the adenomatous polyposis coli (APC) gene and subsequent activation of beta-catenin lead to the repression of cellular caspase-8 inhibitor c-FLIP (also known as CFLAR) expression through activation of c-Myc, and that all-trans-retinyl acetate (RAc) independently upregulates tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) death receptors and suppresses decoy receptors. Thus, the combination of TRAIL and RAc induces apoptosis in APC-deficient premalignant cells without affecting normal cells in vitro. In addition, we show that short-term and non-continuous TRAIL and RAc treatment induce apoptosis specifically in intestinal polyps, strongly inhibit tumour growth, and prolong survival in multiple intestinal neoplasms C57BL/6J-Apc(Min)/J (Apc(Min)) mice. With our approach, we further demonstrate that TRAIL and RAc induce significant cell death in human colon polyps, providing a potentially selective approach for colorectal cancer chemoprevention by targeting APC-deficient cells for apoptosis.

Addition of adjuvant tamoxifen to cyclophosphamide, methotrexate and 5-fluorouracil for premenopausal women with oestrogen receptor-positive breast cancer.

OBJECTIVE: To study the value of adjuvant tamoxifen (TAM) in premenopausal women with oestrogen receptor (ER)-positive breast cancer who received adjuvant cyclophosphamide, methotrexate and 5-fluorouracil (CMF) polychemotherapy. METHODS: Four hundred and two premenopausal ER-positive breast cancer patients who received CMF chemotherapy between January 1990 and December 1999 were retrospectively studied. Disease-free survival (DFS) and overall survival (OS) were used to evaluate the clinical value of TAM therapy. The relationships between nodal status and TAM were also analysed. RESULTS: After a mean of 41 months of follow-up, 43 (13.7%) patients died of breast cancer and 68 (19.9%) patients suffered recurrence. There was a significant difference between TAM and non-TAM treatment groups for DFS (p=0.0058), but no significant difference for OS. For node-negative patients, there was no significant difference between the TAM and non-TAM treatment groups for either DFS or OS. For node-positive patients, the difference between TAM and non-TAM treatment groups was significant for both DFS and OS (p=0.0497 and p=0.0285, respectively). CONCLUSION: TAM resulted in additional benefit to premenopausal patients with node-positive ER-positive breast cancer who received the CMF polychemotherapy regimen.

The expression of ER beta protein correlates with vascular endothelial growth factor and its prognostic significance in human breast cancer.

Although cloning of ER beta has prompted a reevaluation of the role of ERs in human breast cancer and there have been many studies focusing on the clinical value of ER beta detection, however, few reports evaluated the prognostic significance of ER beta based on follow-up data. The VEGF gene transcription may be mediated by different ER subtypes directly. The aim of this study was to evaluate the relationship of angiogenesis factor VEGF with different ER subtypes and the prognostic value of ER beta and VEGF in 116 human breast cancer patients. Of these patients, 40 (34.5%) were ER beta protein high expressed and 76 (65.5%) were ER beta protein low expressed. When correlated the ER beta protein levels with other clinical characteristics, statistical significance (p<0.05) was found between ER beta protein expression and menopausal status, and tumor grade. No significance was found between ER beta protein level and node status, stage, or tumor size. Inverse relationship was found between ER beta protein expression and PR status (p<0.05). When comparing the VEGF levels with different ER subtypes a significant difference between ERs and VEGF was found. In ER beta protein high expression group, the VEGF protein was highly expressed (p<0.01), inverse relationship was also found between ER alpha and VEGF. In univariate analysis ER alpha, ER beta and VEGF levels had prognostic value for both relapse-free survival and overall survival (p<0.05). However, in a multivariate study, ER beta and ER alpha protein levels lost the prognostic value either to relapse-free survival or to overall survival. Only VEGF levels acted as an independent prognostic factor to disease-free survival. The result suggested that ER beta protein may have important prognostic value in human breast cancer patients. VEGF expression may be mediated through different ER subtypes.

The tumor suppressor gene LKB1 is associated with prognosis in human breast carcinoma.

PURPOSE: LKB1 (also called STK11) is a recently identified tumor suppressor gene in which its mutation can lead to Peutz-Jeghers syndrome, characterized by gastrointestinal polyps and cancers of different organ systems. Weak expression of this gene does occur at a certain frequency in sporadic breast cancer. This indicates that LKB1 gene may relate to the tumorigenesis of breast cancer. EXPERIMENTAL DESIGN: To investigate the function of the LKB1 gene in sporadic breast cancer, we reintroduced LKB1 into breast cancer cell lines which lack the LKB1 gene. Also, we examined the LKB1 protein expression in human breast cancer samples. RESULTS: We found that reintroducing LKB1 into breast cancer cell lines suppresses cell growth by G(1) cell cycle block. The LKB1-mediated G(1) cell cycle arrest is caused by up-regulation of the expression of p21(WAF1/CIP1) in breast cancer MDA-MB-435 cells. We also demonstrated that low LKB1 protein expression correlates with higher histological grade (P = 0.013), larger tumor size (P = 0.001), progesterone receptor status (P = 0.048), and presence of lymph node metastasis (P = 0.003). Furthermore, LKB1 low expression was associated with a higher relapse rate (P = 0.002) and a worse OS (P = 0.008). CONCLUSIONS: LKB1 plays a role in tumor suppressor function in human breast cancer. LKB1 expression may be a useful prognostic marker in human breast cancer.

[Effect of different estrogen receptor subtypes on vascular endothelial growth factor protein expression in human breast cancer samples].

OBJECTIVES: To evaluate the relationship of vascular endothelial growth factor expression with estrogen receptor (ER) subtypes in fresh human breast cancer samples, and study the potential effect of ER subtypes on tumor angiogenesis. METHODS: Western blot was used to detect the VEGF and ERbeta protein expression in 86 fresh samples of human breast cancer. ERalpha was analyzed by immunohistochemistry routinely. RESULTS: Among 86 samples, 42 (48.8%) showed low expressed VEGF and 44 (51.2%) high expressed VEGF. The level of VEGF protein was correlated with ERbeta. In high expressed VEGF group, ERbeta was also highly expressed (chi(2) = 7.36, P < 0.01). But there was no significant difference between VEGF protein level and ERalpha (P > 0.05). CONCLUSION: In human breast cancer samples, VEGF may be related to ERbeta protein expression.