Deregulation of protein phosphatase 2A inhibitor SET is associated with malignant progression in breast cancer.

To understand the mechanism underlying metastasis, identification of a mechanism-based and common biomarker for circulating tumour cells (CTCs) in heterogenous breast cancer is needed. SET, an endogenous inhibitor of protein phosphatase 2A, was overexpressed in all subtypes of invasive breast carcinoma tissues. Treatment with SET-targeted siRNAs reduced the motility of MCF-7 and MDA-MB-231 cells in transwell assay. SET knockdown reduced the number of mammospheres by 60-70% in MCF-7 and MDA-MB-231 cells, which was associated with the downregulation of OCT4 and SLUG. Hence, we analysed the presence of SET-expressing CTCs (SET-CTCs) in 24 breast cancer patients. CTCs were enriched using a size-based method and then immunocytochemically analysed using an anti-SET antibody. SET-CTCs were detected in 6/6 (100%) patients with recurrent breast cancer with a median value of 12 (12 cells/3 mL blood), and in 13/18 (72.2%) patients with stage I-III breast cancer with a median value of 2.5, while the median value of healthy controls was 0. Importantly, high numbers of SET-CTCs were correlated with lymph node metastasis in patients with stage I-III disease. Our results indicate that SET contributes to breast cancer progression and can act as a potential biomarker of CTCs for the detection of metastasis.

Impact of combining the progesterone receptor and preoperative endocrine prognostic index (PEPI) as a prognostic factor after neoadjuvant endocrine therapy using aromatase inhibitors in postmenopausal ER positive and HER2 negative breast cancer.

The preoperative endocrine prognostic index (PEPI) predicts survival after neoadjuvant endocrine therapy (NAE) using aromatase inhibitors (AIs) for women with postmenopausal estrogen receptor (ER)-positive breast cancer irrespective of the human epidermal growth factor receptor 2 (HER2) status. Although the progesterone receptor (PgR) is also a prognostic factor for ER-positive breast cancer, the PgR status was not considered a prognostic factor in the original PEPI scoring system. In this study, we investigated the utility of a modified PEPI including the PgR status (PEPI-P) as a prognostic factor after NAE for postmenopausal patients with ER-positive and HER2-negative breast cancer. We enrolled 107 patients with invasive ER-positive and HER2-negative breast cancer treated with exemestane for ≥4 months as NAE. We initially assessed PEPI and compared survival between the groups. Additionally, we obtained an effective cutoff for PgR through survival analysis. Then, we assessed the survival significance of PEPI-P. A PgR staining rate of 50% was the most significant cutoff for predicting recurrence-free survival (RFS) and cancer-specific survival (CSS). PEPI was a significant prognostic factor; moreover, PEPI-P was the most significant prognostic indicator for RFS and CSS. PEPI-P is a potent prognostic indicator of survival after NAE using AIs for postmenopausal patients with ER-positive and HER2-negative breast cancer. This modified PEPI may be useful for therapeutic decision-making regarding postmenopausal ER-positive and HER2-negative breast cancer after NAE.

Power of PgR expression as a prognostic factor for ER-positive/HER2-negative breast cancer patients at intermediate risk classified by the Ki67 labeling index.

BACKGROUND: The Ki67 labeling index (LI) is regarded as a significant prognostic marker in ER-positive/HER2-negative breast cancer patients. The expression of PgR has recently been identified as another prognostic marker. In the present study, we investigated the prognostic utilities and most suitable cut-off values for Ki67 and PgR, and evaluated the relationship between Ki67 LI and PgR expression in ER-positive/HER2-negative breast cancer. PATIENTS AND METHODS: In the present study, 177 consecutive Japanese women with ER-positive/HER2-negative invasive carcinoma of no special type who were treated between 2000 and 2001 were enrolled. Recurrence-free survival (RFS) and cancer-specific survival (CSS) were analyzed according to Ki67 LI and PgR expression, and significant cut-off values for selecting patients with a poor prognosis were evaluated. RESULTS: The cut-off values for Ki67 LI as a prognostic marker plotted against P values showed bimodal peaks at 10% and 30%. Among the cut-off points examined for the PgR status, 20% PgR positivity was the most significant for predicting survival differences (RFS: P = 0.0003; CSS: P < 0.0001). A multivariate analysis showed that PgR (≥20%) was an independent prognostic marker (RFS: P = 0.0092; CSS: P = 0.00014). Furthermore, in the intermediate risk group with Ki67 LI of 10-30%, the low PgR <20% group had a markedly poorer prognosis for RFS and CSS (RFS: P < 0.0001; CSS: P < 0.0001). CONCLUSIONS: The expression of PgR is a potent prognostic indicator for evaluating the long-term prognosis of ER-positive/HER2-negative breast cancer, and the most suitable cut-off value was found to be 20%. Furthermore, the PgR status is a powerful method for selecting patients with a poor prognosis among ER-positive/HER2-negative patients at intermediate risk, as assessed using Ki67 LI.

BRCA1 alterations with additional defects in DNA damage response genes may confer chemoresistance to BRCA-like breast cancers treated with neoadjuvant chemotherapy.

The BRCA-like phenotype is a feature that some sporadic breast cancers share with those occurring in BRCA1 or BRCA2 mutation carriers. As tumors with the phenotype have defects in the DNA damage response pathway, which may increase sensitivity to drugs such as DNA cross-linking agents and PARP inhibitors, a method to identify this phenotype is important. The prediction of chemoresistance, which frequently develops in these tumors, is also crucial for improving therapy. We examined genomic aberrations and BRCA1 promoter methylation in tumors of 73 breast cancer (20 HR-/HER2- and 53 HR+/HER2-) patients, who received neoadjuvant chemotherapy with anthracycline, cyclophosphamide, and taxane, using SNP array CGH and quantitative PCR. The methylation and/or loss or uniparental disomy (UPD) of BRCA1 (BRCA1 alterations) and the loss or UPD of BRCA2 (BRCA2 alterations) were detected in 27 (37%) and 21 (29%), respectively, of the 73 tumors. Tumors with BRCA1 or BRCA2 alterations were associated with a higher number of genomic aberrations (P < 0.001 and P < 0.001) and higher percentage of TP53 alterations (P < 0.001 and P < 0.001) than those without. Overall survival (OS) rates were similar between patients with or without BRCA1 or BRCA2 alterations. However, when 27 patients with BRCA1-altered tumors were classified into those with or without the loss or UPD of PALB2, PAGR1, RAD51B, FANCM, MLL4, or ERCC1/2 in tumors, patients with additional defects in DNA damage response genes had worse OS (P = 0.037, 0.045, 0.038, 0.044, 0.041, or 0.019) than those without. These defects may confer chemoresistance and predict poor outcomes in patients with BRCA1-altered breast cancer.

Alterations of the genes involved in the PI3K and estrogen-receptor pathways influence outcome in human epidermal growth factor receptor 2-positive and hormone receptor-positive breast cancer patients treated with trastuzumab-containing neoadjuvant chemotherapy.

BACKGROUND: Chemotherapy with trastuzumab is widely used for patients with human epidermal growth factor receptor 2-positive (HER2+) breast cancer, but a significant number of patients with the tumor fail to respond, or relapse. The mechanisms of recurrence and biomarkers that indicate the response to the chemotherapy and outcome are not fully investigated. METHODS: Genomic alterations were analyzed using single-nucleotide polymorphism arrays in 46 HER2 immunohistochemistry (IHC) 3+ or 2+/fluorescent in situ hybridization (FISH)+ breast cancers that were treated with neoadjuvant chemotherapy with paclitaxel, cyclophosphamid, epirubicin, fluorouracil, and trastuzumab. Patients were classified into two groups based on presence or absence of alterations of 65 cancer-associated genes, and the two groups were further classified into four groups based on genomic HER2 copy numbers or hormone receptor status (HR+/-). Pathological complete response (pCR) and relapse-free survival (RFS) rates were compared between any two of the groups. RESULTS AND DISCUSSION: The pCR rate was 54% in 37 patients, and the RFS rate at 3 years was 72% (95% CI, 0.55-0.89) in 42 patients. The analysis disclosed 8 tumors with nonamplified HER2 and 38 tumors with HER2 amplification, indicating the presence of discordance in tumors diagnosed using current HER2 testing. The 8 patients showed more difficulty in achieving pCR (P=0.019), more frequent relapse (P=0.018), and more frequent alterations of genes in the PI3K pathway (P=0.009) than the patients with HER2 amplification. The alterations of the PI3K and estrogen receptor (ER) pathway genes generally indicated worse RFS rates. The prognostic significance of the alterations was shown in patients with a HR+ tumor, but not in patients with a HR- tumor when divided. Alterations of the PI3K and ER pathway genes found in patients with a HR+ tumor with poor outcome suggested that crosstalk between the two pathways may be involved in resistance to the current chemotherapy with trastuzumab. CONCLUSIONS: We recommend FISH analysis as a primary HER2 testing because patients with IHC 2+/3+ and nonamplified HER2 had poor outcome. We also support concurrent use of trastuzumab, lapatinib, and cytotoxic and anti-hormonal agents for patients having HR+ tumors with alterations of the PI3K and ER pathway genes.

Collagen gel droplet-embedded culture-drug sensitivity test and Ki67 expression in estrogen receptor-positive and HER2-negative breast cancer.

Anthracyclines and taxanes are standard anticancer drugs used in breast cancer chemotherapy. In general, the efficacy of chemotherapy is lower in patients with estrogen receptor (ER)-positive tumors compared to patients with ER-negative tumors. Although less chemosensitive, ER-positive disease includes a subset of patients who significantly benefit from adjuvant chemotherapy. The collagen gel droplet-embedded culture-drug sensitivity test (CD-DST) is an in vitro chemosensitivity test that has several advantages over conventional tests. The aim of the present study was to examine the correlation between CD-DST and the expression of Ki67, an indicator of tumor proliferation, to evaluate the efficacy of anthracyclines and taxanes in patients with ER-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer. CD-DST was performed in 68 patients with ER-positive and HER2-negative breast cancer between August 2001 and November 2006. The specimens obtained during surgery were used for the CD-DST and immunohistological examination of Ki67 expression. Chemosensitivity to the anticancer drugs adriamycin (ADM), epirubicin (EPI), docetaxel (DOC) and paclitaxel (PTX) was estimated using CD-DST. Results obtained from the CD-DST showed the chemosensitivity to each anticancer drug to be ADM, 23.7%; EPI, 75.0%; DOC, 69.2% and PTX, 43.6%. Ki67 expression was significantly higher in the group that was sensitive to DOC compared to the group that was resistant to DOC (P=0.048) and PTX (P=0.036). In addition, a significant correlation was observed between a Ki67 labeling index (LI) of >30% and chemosensitivity to PTX. In conclusion, results obtained from CD-DST and Ki67 expression levels are able to identify a subset of patients with ER-positive and HER2-negative breast cancer who exhibit sensitivity to chemotherapy, particularly to taxane therapy.

Topoisomerase II alpha expression and the Ki-67 labeling index correlate with prognostic factors in estrogen receptor-positive and human epidermal growth factor type-2-negative breast cancer.

BACKGROUND: Topoisomerase II alpha (Topo IIa) is involved in DNA replication and is a molecular target for anthracycline-based chemotherapy. The Ki-67 labeling index (LI) is an evaluation of tumor cell proliferation. The objective of this study was to evaluate relationships among Topo IIa expression, the Ki-67 LI, and prognostic factors in estrogen receptor (ER)-positive, human epidermal growth factor type-2 (HER2)-negative breast cancer. MATERIALS AND METHODS: Seventy-one patients were diagnosed with ER-positive, HER2-negative breast cancer between July 2003 and December 2004. Formalin-fixed, paraffin-embedded tumor specimens were stained for Topo IIa expression and Ki-67 LI. We investigated the correlation of the level of Topo IIa expression and the Ki-67 LI with clinical factors such as age, tumor size, progesterone receptor status, nodal status, nuclear grade, and lymphovascular invasion (LVI). RESULTS: Statistically significant differences were observed between Topo IIa overexpression, nuclear grade (p = 0.036), and LVI (p = 0.029). Topo IIa overexpression was statistically correlated with the Ki-67 LI (p < 0.0001). A statistically significant difference was observed between the Ki-67 LI and nuclear grade (p = 0.01). Survival analysis revealed the significant prognostic value of Ki-67 LI in patients with ER-positive, HER2-negative breast cancer (p = 0.003). CONCLUSIONS: Ki-67 LI is a strong prognostic factor in ER-positive HER2-negative breast cancer. Topo IIa overexpression was significantly correlated with the Ki-67 LI, nuclear grade, and LVI. These findings suggest use of Topo IIa expression as a proliferation marker and a prognostic factor in ER-positive, HER2-negative breast cancer.

Pathological complete response and prognosis in patients receiving neoadjuvant paclitaxel and trastuzumab with and without anthracyclines for stage II and III, HER2-positive operable breast cancer: a single-institute experience.

BACKGROUND: Trastuzumab and various chemotherapy combinations have shown superior results in patients with primary and metastatic breast cancer. However, cardiotoxicity becomes a major adverse event when trastuzumab is used with anthracycline-containing regimens. The purpose of this study was to determine the clinical and pathological efficacy of neoadjuvant chemotherapy (NAC), using trastuzumab and chemotherapy, with or without anthracyclines, for patients with primary breast cancer and human epidermal growth factor receptor 2 (HER2-)-positive tumors. PATIENTS AND METHODS: A retrospective analysis of 41 patients with stage II and III primary breast cancer and HER2-positive tumors treated with NAC was performed. NAC consisted of weekly paclitaxel plus trastuzumab with (PTA group, n=21) or without anthracycline (PT group, n=20). Patients in the PTA group received four courses of 5-fluorouracil, epirubicin, and cyclophosphamide every 3 weeks followed by concomitant 80 mg/m² paclitaxel and trastuzumab weekly for 12 weeks, and those in the PT group received four courses of 80 mg/m² paclitaxel weekly (days 1, 8, and 15) followed by a 1-week break and trastuzumab weekly (days 1, 8, 15, and 29). RESULTS: The median age of the patients was 50 years. Of 41 patients, 21 (51%) had a pathological complete response (pCR). Patients with clinical stage II cancer had a higher pCR rate compared with those with clinical stage III. Patients with estrogen receptor (ER)-negative tumors showed a trend toward a higher pCR rate. No significant difference was observed according age, clinical stage, ER status, clinical response, or pathological response between the PTA and the PT groups. The pCR rate of the PTA and the PT groups was 47.6% and 55.0%, respectively. No significant difference in disease-free survival was observed between the two groups at a median follow-up of 32 months. CONCLUSION: Trastuzumab-containing NAC is effective irrespective of anthracycline use for treating patients with primary breast cancer and HER2-positive tumors.

Papillary lesions of the breast diagnosed using core needle biopsies.

Papillary lesions of the breast include a broad spectrum of lesions, from benign papillomas to papillary carcinomas. It is difficult to determine whether a lesion is benign or malignant based on the fragmented material of a core needle biopsy (CNB). This study evaluated patients with papillary lesions examined using CNB. We retrospectively reviewed 31 papillary lesions diagnosed using CNB between 2004 and 2007. The clinical findings of benign and malignant papillary lesions were compared. The average patient age was 48.9 years. Twelve patients presented with a discharge and 10 patients presented with a lump. Eight patients were asymptomatic. The initial diagnoses by CNB of the 31 lesions were 25 intraductal papillomas, 4 intracystic papillomas and 2 adenomas. After CNB, excisional biopsies were performed in 23 patients and biopsies with a Mammotome(®) in 2 patients. Seven patients underwent regular follow-up. Five (16%) of the 31 patients with papillary lesions were ultimately diagnosed with breast cancer. The average distance from the nipple to a tumor diagnosed as malignant was 2.46 cm, which was longer than for a tumor diagnosed as benign. Ultimately, 5 papillary lesions (16%) were diagnosed as breast cancer. To avoid overlooking a malignancy, surgical excision is advantageous for papillary lesions, particularly those located far from the nipple.

Axillary lymph node dissection can be avoided in women with breast cancer with intraoperative, false-negative sentinel lymph node biopsies.

BACKGROUND: It is currently unclear which patients with breast cancer with sentinel lymph node (SLN) metastases do not need axillary lymph node dissection (ALND). PATIENTS AND METHODS: A cohort of 1,132 women who had unilateral invasive breast cancer with clinically negative nodes or nodes suspicious for metastasis, were intraoperatively diagnosed as having negative SLNs, and did not undergo an immediate ALND. Our intraoperative histological investigation uses H&E staining of a frozen section from a maximum cut surface of each SLN. Of these 1,132 women, 132 (11.7%) were postoperatively diagnosed as having positive SLNs, which classifies them as having an intraoperative, false-negative SLN biopsy (SLNB). Patient and tumor characteristics, treatment methods, and the prognoses of these patients were investigated and compared with the remaining 1,000 patients who were negative for SLNB. RESULTS: Of the 132 patients with intraoperative, false-negative SLNB, none underwent a further ALND. With a median follow-up period of 58.1 months, none of these patients exhibited recurrence in the axillary nodes. Their recurrence-free survival rates were not statistically different from those of patients with negative SLNB. CONCLUSIONS: ALND can be avoided in most patients with breast cancer with intraoperative, false-negative SLNB.

True recurrences and new primary tumors have different clinical features in invasive breast cancer patients with ipsilateral breast tumor relapse after breast-conserving treatment.

Ipsilateral breast tumor relapse (IBTR) after breast-conserving treatment (BCT) may represent two distinct types of lesion, including a true recurrence (TR) or a new primary tumor (NPT). The aim of this study was to ascertain the difference between TRs and NPTs and to show the clinical significance of classifying IBTR into these two types of recurrence. Patients (n = 2,075) with unilateral invasive breast cancer who underwent BCT between 1987 and 2005 at Saitama Cancer Center were analyzed. IBTR was classified into TR and NPT, which was based on all clinical and pathological features of both a primary tumor and IBTR that can be evaluated. IBTR-free survival and the risk factors were analyzed in order to compare the findings for TR and NPT. In addition, the salvage surgical methods for IBTR and overall survival after IBTR were analyzed. Sixty patients with IBTR were classified into 52 with TR and eight with NPT. IBTR-free survival was significantly shorter in the patients with TR than those with NPT. Young age, tumor size, a positive surgical margin, and omission of radiation therapy (RT) were significant risk factors for TR. Omission of RT was the only significant risk factor for NPT. In 27 patients who underwent a repeat lumpectomy for TR, four had a second IBTR. The overall survival after IBTR was worse in patients with TR than NPT. TR and NPT show quite different clinical features. Classifying IBTR into TR or NPT can therefore help to select the most appropriate treatment for IBTR.

Ipsilateral breast tumor relapse after breast conserving surgery in women with breast cancer.

Ipsilateral breast tumor relapse (IBTR) is a potentially a significant problem after breast conserving surgery (BCS). With a median follow-up period of 64.7 months, IBTR occurred as a first relapse in 67 (3.0%) of a total of 2243 patients and distant recurrence occurred in 167 (7.4%). A positive surgical margin and the omission of radiotherapy (RT) were independently associated with IBTR. The five-year cumulative IBTR rates were 5.1% in patients with positive margins and 2.0% in the patients with negative margins. The five-year cumulative IBTR rates were 1.8% in patients with RT and 8.1% in patients without RT. IBTR was independently associated with distant-recurrence-free survival rates as well as age, nodal metastasis, lymphovascular invasion and progesterone receptor status. The five-year distant-recurrence-free survival rates were 81.9% in patients with IBTR and 93.2% in patients without IBTR. In order to prevent IBTR, a negative margin and the administration of RT are therefore considered to be important in patients who undergo BCS.

Positive sentinel lymph node biopsy predicts the number of metastatic axillary nodes of breast cancer.

It remains to be clarified whether a positive sentinel lymph node biopsy (SLNB) can predict the number of metastatic axillary nodes. This study examined a consecutive series of women with unilateral invasive breast cancer who underwent axillary lymph node dissection after an intra-operative positive SLNB. The numbers of positive and negative sentinel lymph nodes (SLNs) were analyzed for a likelihood of pN1a, pN2a, and pN3a diseases as per the UICC TNM classification. Of the 368 study patients, 165 (45%) had one positive SLN and one or more negative SLNs. This result represented the most common combination of positive and negative SLNs. It was also the most predictive indicator (93%) of pN1a disease and the least predictive indicator (7% or 0%) of pN2a or pN3a disease, respectively. The numbers of positive and negative SLNs can predict the number of metastatic axillary nodes in breast cancer patients.

Current trends of sentinel lymph node biopsy for breast cancer--a surgeon's perspective.

Sentinel lymph node biopsy (SLNB) is standard care for patients with early-stage breast cancer, and axillary lymph node dissection (ALND) is considered unnecessary when sentinel lymph nodes (SLNs) are tumor-free. Additional non-SLN metastasis in patients with positive SLNs can be estimated using several risk factors such as primary tumor size, metastatic tumor size in SLNs, lymphatic vessel invasion, and so on. All patients with positive SLNs may be treated with further ALND based on their own risk for non-SLN metastasis. Recent randomized clinical trials have already proved less surgical morbidity and better QOL for SLNB alone compared with ALND. However, trials concerning the efficacy of ALND in positive SLNB patients in preventing local regional recurrence and improving overall survival compared with no ALND, and also, concerning the effectiveness of ALND compared with axillary radiation therapy (RT), have not yielded clear results. The prognostic significance of micrometastasis in SLNs or bone marrow also remains to be determined. So far SLNB is not acceptable for patients with positive nodes in the axilla at initial diagnosis even if their axillary metastases are down-staged to negative by neoadjuvant chemotherapy. Although basically SLNB does not need to be performed for patients with pure ductal carcinoma in situ (DCIS), it is recommended for patients with an initial diagnosis of DCIS which is large, palpable, high grade, or found in younger patients. Because these types of DCIS have higher incidences of accompanying invasive lesions. In addition if patients will undergo mastectomy, SLNB is recommended because of the inability to perform SLNB after mastectomy. SLNB may be acceptable for patients with T3 or T4b tumors, even though SLN identification is lower yet SLN involvement is higher compared with T1 or T2 tumors, and systemic adjuvant therapy is more important for patients with T3 or T4b tumors. SLNB is a bridge to further axillary treatment such as ALND or axillary RT, and which strategy, including no further treatment, is best considered individually based on recurrence risk, treatment responsiveness and use or non-use of systemic therapy.