Three-dimensional volume imaging with electron microscopy toward connectome

Ultrastructural analyses with electron microscopy have provided indispensable information to understand physiology and pathology of the nervous system. Recent advancement in imaging methodology paved the way for complete reconstruction of the neuronal connection map in the central nervous system, which is termed 'connectome' and would provide key insights to understand the functions of the brain. The critical advancement includes serial ultrastructural observation with scanning electron microscopy (SEM) instead of conventional serial sectioning transmission electron microscopy along with specific tissue preparation methods to increase heavy metal deposition for efficient SEM imaging. The advanced imaging methods using SEM have distinct advantages and disadvantages in multiple aspects, such as resolution and imaging speed, and should be selected depending on the observation conditions, such as target tissue sizes, required spatial resolution and necessity for re-observation. Dealing with the huge dataset remained to be a major obstacle, and automation in segmentation and 3D reconstruction would be critical to understand neuronal circuits in a larger volume of the brain. Future improvement in acquisition and analyses of the morphological data obtained with the advanced SEM imaging is awaited to elucidate the significance of whole connectome as the structural basis of the consciousness, intelligence and memory of a subject.

MicroRNA-1246 expression associated with CCNG2-mediated chemoresistance and stemness in pancreatic cancer

Background:

Pancreatic cancer has a poor prognosis because of its high refractoriness to chemotherapy and tumour recurrence, and these properties have been attributed to cancer stem cells (CSCs). MicroRNA (miRNA) regulates various molecular mechanisms of cancer progression associated with CSCs. This study aimed to identify the candidate miRNA and to characterise the clinical significance.

Methods:

We established gemcitabine-resistant Panc1 cells, and induced CSC-like properties through sphere formation. Candidate miRNAs were selected through microarray analysis. The overexpression and knockdown experiments were performed by evaluating the in vitro cell growth and in vivo tumourigenicity. The expression was studied in 24 pancreatic cancer samples after laser captured microdissection and by immunohistochemical staining.

Results:

The in vitro drug sensitivity of pancreatic cancer cells was altered according to the miR-1246 expression via CCNG2. In vivo, we found that miR-1246 could increase tumour-initiating potential and induced drug resistance. A high expression level of miR-1246 was correlated with a worse prognosis and CCNG2 expression was significantly lower in those patients.

Conclusions:

miR-1246 expression was associated with chemoresistance and CSC-like properties via CCNG2, and could predict worse prognosis in pancreatic cancer patients.

Randomized trial of preoperative docetaxel with or without capecitabine after 4 cycles of 5-fluorouracil– epirubicin–cyclophosphamide (FEC) in early-stage breast cancer: exploratory analyses identify Ki67 as a predictive biomarker for response to neoadjuvant chemotherapy

This randomized, multicenter study compared the efficacy of docetaxel with or without capecitabine following fluorouracil/epirubicin/cyclophosphamide (FEC) therapy in operable breast cancer and investigated the role of Ki67 as a predictive biomarker. Patients were randomized to 4 cycles of docetaxel/capecitabine (docetaxel: 75 mg/m² on day 1; capecitabine: 1,650 mg/m² on days 1–14 every 3 weeks) or docetaxel alone (75 mg/m² on day 1 every 3 weeks) after completion of 4 cycles of FEC (5-fluorouracil 500 mg/m², epirubicin 100 mg/m² and cyclophosphamide 500 mg/m² on day 1 every 3 weeks). The primary endpoint was the pathological complete response (pCR) rate. Predictive factor analysis was conducted using clinicopathological markers, including hormone receptors and Ki67 labeling index (Ki67LI). A total of 477 patients were randomized; the overall response in the docetaxel/capecitabine and docetaxel groups was 88.3 and 87.4 %, respectively. There were no significant differences in the pCR rate (docetaxel/capecitabine: 23 %; docetaxel: 24 %; p = 0.748), disease-free survival, or overall survival. However, patients with mid-range Ki67LI (10–20 %) showed a trend towards improved pCR rate with docetaxel/capecitabine compared to docetaxel alone. Furthermore, multivariate logistic regression analysis showed pre-treatment Ki67LI (odds ratio 1.031; 95 % CI 1.014–1.048; p = 0.0004) to be a significant predictor of pCR in this neoadjuvant treatment setting. Docetaxel/capecitabine (after 4 cycles of FEC) did not generate significant improvement in pCR compared to docetaxel alone. However, exploratory analyses suggested that assessment of pre-treatment Ki67LI may be a useful tool in the identification of responders to preoperative docetaxel/capecitabine in early-stage breast cancer.

A phase II study of metronomic paclitaxel/cyclophosphamide/capecitabine followed by 5-fluorouracil/epirubicin/cyclophosphamide as preoperative chemotherapy for triple-negative or low hormone receptor expressing/HER2-negative primary breast cancer

PURPOSE

Better treatments for triple-negative breast cancer (TNBC) are needed. To address this need, we studied the effects of preoperative metronomic paclitaxel/cyclophosphamide/capecitabine (mPCX) followed by 5-fluorouracil (FU)/epirubicin/cyclophosphamide (FEC) as preoperative chemotherapy in TNBC patients.

METHODS

Forty primary TNBC patients received four cycles of metronomic paclitaxel (80 mg/m(2) on Days 1, 8, and 15), cyclophosphamide (50 mg/body daily), and capecitabine (1,200 mg/m(2) daily), followed by four cycles of 5-FU (500 mg/m(2)), epirubicin (100 mg/m(2)), and cyclophosphamide (500 mg/m(2)) every 3 weeks. The primary end point was the pathological complete response (pCR) rate.

RESULTS

Forty patients formed the intent-to-treat population. The median dose intensities of paclitaxel, cyclophosphamide, and capecitabine were 89.7, 92.1, and 89.8%, respectively. Five patients discontinued mPCX and two discontinued FEC, primarily because of adverse events, resulting in a per-protocol population (PPS) of 33 patients. The pCR (ypT0/Tis ypN0) rate was 47.5% (19/40) in the intent-to-treat population and 54.5% (18/33) in the PPS. The clinical response rates were 36/40 (90.0%) and 31/33 (93.9%) in the intent-to-treat and PPS, respectively. The breast conservation rate was 72.7% (24/33), and 5/13 patients underwent partial resection instead of pre-planned total mastectomy. Grade 3-4 adverse events included neutropenia (35%), leukopenia (25%), and hand-foot syndrome (8%).

CONCLUSIONS

Metronomic PCX followed by FEC chemotherapy was associated with a high pCR rate and low toxicity in TNBC patients. Further studies of this regimen in larger numbers of patients are warranted.

Distinct cell clusters touching islet cells induce islet cell replication in association with over-expression of Regenerating Gene (REG) protein in fulminant type 1 diabetes

BACKGROUND

Pancreatic islet endocrine cell-supporting architectures, including islet encapsulating basement membranes (BMs), extracellular matrix (ECM), and possible cell clusters, are unclear.

PROCEDURES

The architectures around islet cell clusters, including BMs, ECM, and pancreatic acinar-like cell clusters, were studied in the non-diabetic state and in the inflamed milieu of fulminant type 1 diabetes in humans.

RESULT

Immunohistochemical and electron microscopy analyses demonstrated that human islet cell clusters and acinar-like cell clusters adhere directly to each other with desmosomal structures and coated-pit-like structures between the two cell clusters. The two cell-clusters are encapsulated by a continuous capsule composed of common BMs/ECM. The acinar-like cell clusters have vesicles containing regenerating (REG) Iα protein. The vesicles containing REG Iα protein are directly secreted to islet cells. In the inflamed milieu of fulminant type 1 diabetes, the acinar-like cell clusters over-expressed REG Iα protein. Islet endocrine cells, including beta-cells and non-beta cells, which were packed with the acinar-like cell clusters, show self-replication with a markedly increased number of Ki67-positive cells.

CONCLUSION

The acinar-like cell clusters touching islet endocrine cells are distinct, because the cell clusters are packed with pancreatic islet clusters and surrounded by common BMs/ECM. Furthermore, the acinar-like cell clusters express REG Iα protein and secrete directly to neighboring islet endocrine cells in the non-diabetic state, and the cell clusters over-express REG Iα in the inflamed milieu of fulminant type 1 diabetes with marked self-replication of islet cells.

Survival of HER2-positive primary breast cancer patients treated by neoadjuvant chemotherapy plus trastuzumab: a multicenter retrospective observational study (JBCRG-C03 study)

We investigated the disease-free survival (DFS) of HER2-positive primary breast cancer patients treated with neoadjuvant chemotherapy plus trastuzumab, as well as predictive factors for DFS and pathologic response. Data from 829 female patients treated between 2001 and 2010 were collected from 38 institutions in Japan. Predictive factors were evaluated using multivariate analyses. The 3-year DFS rate was 87 % [95 % confidence interval (CI) 85-90]. The pathologic complete response (pCR: ypT0/is + ypN0) rate was 51 %. The pCR rate was higher in the ER/PgR-negative patients than in the ER/PgR-positive patients (64 vs. 36 %, P < 0.001). Patients with pCR showed a higher DFS rate than patients without pCR (93 vs. 82 %, P < 0.001). Multivariate analysis revealed three independent predictors for poorer DFS: advanced nodal stage [hazard ratio (HR) 2.63, 95 % CI 1.36-5.21, P = 0.004 for cN2-3 vs. cN0], histological/nuclear grade 3 (HR 1.81, 95 % CI 1.15-2.91, P = 0.011), and non-pCR (HR 1.98, 95 % CI 1.22-3.24, P = 0.005). In the ER/PgR-negative dataset, non-pCR (HR 2.63, 95 % CI 1.43-4.90, P = 0.002) and clinical tumor stage (HR 2.20, 95 % CI 1.16-4.20, P = 0.017 for cT3-4 vs. cT1-2) were independent predictors for DFS, and in the ER/PgR-positive dataset, histological grade of 3 (HR 3.09, 95 % CI 1.48-6.62, P = 0.003), clinical nodal stage (HR 4.26, 95 % CI 1.53-13.14, P = 0.005 for cN2-3 vs. cN0), and young age (HR 2.40, 95 % CI 1.12-4.94, P = 0.026 for ≤40 vs. >40) were negative predictors for DFS. Strict pCR (ypT0 + ypN0) was an independent predictor for DFS in both the ER/PgR-negative and -positive datasets (HR 2.66, 95 % CI 1.31-5.97, P = 0.006 and HR 3.86, 95 % CI 1.13-24.21, P = 0.029, respectively). These results may help assure a more accurate prognosis and personalized treatment for HER2-positive breast cancer patients.

Immunohistochemical study of mouse sciatic nerves under various stretching conditions with "in vivo cryotechnique"

BACKGROUND

In living animal bodies, some morphological changes of nerve fibers will probably occur when peripheral nerves are stretched or not stretched during various joint exercises. We aimed to capture the dynamic structures of nerves under various stretching conditions and to keep soluble serum proteins in their tissue sections.

NEW METHOD

Morphological changes of stretched or non-stretched sciatic nerve fibers were examined with "in vivo cryotechnique" (IVCT). Fibers were directly frozen with liquid isopentane-propane cryogen (-193°C). Immunolocalizations of protein 4.1G and albumin were also examined in the fibers.

RESULTS

The structures of IVCT-prepared sciatic nerves under the stretched condition showed a beaded appearance. By immunostaining for membrane skeletal protein 4.1G, Schmidt-Lanterman incisures (SLIs) were clearly identified, and the heights of their circular truncated cones were increased at narrow sites of the nerve fibers under the stretched condition, compared to those of non-stretched nerve fibers. Albumin was immunolocalized in blood vessels and also along endoneurium including regions near the node of Ranvier.

COMPARISON WITH EXISTING METHODS

With the conventional perfusion-fixation method (PF), it was difficult to keep stable postures of living mouse limbs for tissue preparation. In nerve fibers after PF, the structures of SLI were easily modified, and albumin was heterogeneously immunolocalized due to diffusion artifacts.

CONCLUSIONS

IVCT revealed (1) the structures of peripheral nerve fibers under dynamically different conditions, indicating that the morphological changes of SLIs play a functional role as a bumper structure against mechanical forces, and (2) accurate immunolocalization of serum albumin in the sciatic nerve fibers.

Mosaic KCNJ2 mutation in Andersen-Tawil syndrome: targeted deep sequencing is useful for the detection of mosaicism

Andersen-Tawil syndrome (ATS) is an inherited disease characterized by ventricular arrhythmias, periodic paralysis, and dysmorphic features. It results from a heterozygous mutation of KCNJ2, but little is known about mosaicism in ATS. We performed genetic analysis of KCNJ2 in 32 ATS probands and their family members and identified KCNJ2 mutations in 25 probands, 20 families who underwent extensive genetic testing. These tests revealed that seven probands carried de novo mutations while 13 carried inherited mutations from their parents. We then specifically assessed a single proband and the respective family. The proband was a 9 year old girl who fulfilled the ATS triad and carried an insertion mutation (p.75_76insThr). We determined that the proband's mother carried a somatic mosaicism and that the proband's younger brother also carried the ATS phenotype with the same insertion mutation. The mother, who exhibited mosaicism, was asymptomatic, although she exhibited Q(T)U prolongation. Mutant allele frequency was 11% as per TA cloning and 17.3% as per targeted deep sequencing. Our observations suggest that targeted deep sequencing is useful for the detection of mosaicism and that the detection of mosaic mutations in parents of apparently sporadic ATS patients can help in the process of genetic counseling.

Bioimaging of fluorescence-labeled mitochondria in subcutaneously grafted murine melanoma cells by the "in vivo cryotechnique"

The microenvironments of organs with blood flow affect the metabolic profiles of cancer cells, which are influenced by mitochondrial functions. However, histopathological analyses of these aspects have been hampered by technical artifacts of conventional fixation and dehydration, including ischemia/anoxia. The purpose of this study was to combine the in vivo cryotechnique (IVCT) with fluorescent protein expression, and examine fluorescently labeled mitochondria in grafted melanoma tumors. The intensity of fluorescent proteins was maintained well in cultured B16-BL6 cells after cryotechniques followed by freeze-substitution (FS). In the subcutaneous tumors of mitochondria-targeted DsRed2 (mitoDsRed)-expressing cells, a higher number of cancer cells were found surrounding the widely opened blood vessels that contained numerous erythrocytes. Such blood vessels were immunostained positively for immunoglobulin M and ensheathed by basement membranes. MitoDsRed fluorescence was detected in scattering melanoma cells using the IVCT-FS method, and the total mitoDsRed volume in individual cancer cells was significantly decreased with the expression of markers of hypoxia. MitoDsRed was frequently distributed throughout the cytoplasm and in processes extending along basement membranes. IVCT combined with fluorescent protein expression is a useful tool to examine the behavior of fluorescently labeled cells and organelles. We propose that the mitochondrial volume is dynamically regulated in the hypoxic microenvironment and that mitochondrial distribution is modulated by cancer cell interactions with basement membranes.

Immuno- and Enzyme-histochemistry of HRP for Demonstration of Blood Vessel Permeability in Mouse Thymic Tissues by "In Vivo Cryotechnique"

It is difficult to understand the in vivo permeability of thymic blood vessels, but “in vivo cryotechnique” (IVCT) is useful to capture dynamic blood flow conditions. We injected various concentrations of horseradish peroxidase (HRP) with or without quantum dots into anesthetized mice via left ventricles to examine architectures of thymic blood vessels and their permeability at different time intervals. At 30 sec after HRP (100 mg/ml) injection, enzyme reaction products were weakly detected in interstitium around some thick blood vessels of corticomedullary boundary areas, but within capillaries of cortical areas. At 1 and 3 min, they were more widely detected in interstitium around all thick blood vessels of the boundary areas. At 10 min, they were diffusely detected throughout interstitium of cortical areas, and more densely seen in medullary areas. At 15 min, however, they were uniformly detected throughout interstitium outside blood vessels. At 30 min, phagocytosis of HRP by macrophages was scattered throughout the interstitium, which was accompanied by decrease of HRP reaction intensity in interstitial matrices. Thus, time-dependent HRP distributions in living mice indicate that molecular permeability and diffusion depend on different areas of thymic tissues, resulting from topographic variations of local interstitial flow starting from corticomedullary areas.

Abstract P1-13-15: Risk of late recurrence of hormone receptor positive breast cancer in cases with no recurrent disease at five years after surgery

Background: Among women who take 2-5 years of adjuvant endocrine therapy, more than half of all recurrences of hormone receptor (HR) positive breast cancer occur after the first 5 years. Data from large clinical trials including ATLAS, aTTom,MA17 and NSABP B-30 support extending tamoxifen or aromatase inhibitor beyond 5 year for women with HR positive breast cancer. For decision making according to extending endocrine therapy, the information of the risk of late recurrence is quietly important.

Patients and methods: In order to determine ten year disease free survival (DFS) rates, we reviewed medical records and database of patients who were treated at National Kyushu Cancer Center between 1990 and 2001. Among seven hundred fifty seven patients with HR positive breast cancer, 550 received tamoxifen for 2-5 years. Eighty eight patients had recurrence within five years after surgery, and 13 were not followed, with 83.5% of 5-year DFS after surgery. Remaining four hundred twenty six had no recurrence at the time of 5 years after surgery. To evaluate the risk of late recurrence, we analyzed the long-term results in association with clinicopathological factors for these 426 patients.

Results: Four hundred twenty six patients had 87.1% of 10-year DFS rate. According to lymph node metastasis (N), ten year DFS rates were 91.4% for 275 N-negative and 80.0% for 155 N-positive cases (P = 0.0037). As for the number of lymph node metastasis, 10-year DFS rates were 82.5%, 74.2%, and 79.1% for N1-3, N4-9, N&gt;9, respectively. Tumor size was correlated with the prognosis, and 10-year DFS rates were 91.5% for 167 T1 (≤2 cm), 86.9% for T2 (2-5 cm), and 67.9% for T3 (&gt;5cm) (P = 0.0334). There were no significant differences between grade and prognosis, and 10-year DFS rates of grade 1, 2 and 3 were 88.9%, 89.8%, and 96.8%, respectively (p = 0.3914). Considering the age at 5 years after surgery, no significant differences were observed as for late recurrence. Ten-year DFS rates of 96 cases of age under 50, 227 between 50 and 65, 113 over 65 was 89.4%, 85.1%, and 86.0%, respectively. Ten-year DFS rates of N-negative and N-positive were 94.3% and 81.2%, 88.1% and 80.1%, and 90.4% and 76.7% for these age criteria, respectively.

Conclusion: Patients with HR positive breast cancer require optimal information for decision making whether to receive extending endocrine therapy or not. Our data demonstrated the risk of late recurrence in relation to clinic-pathological factors, which may support the consideration about extending endocrine therapy. Relatively high risks of late recurrence with over 10% of 10 year DFS rates are there in cases with N-positive or T2-3 HR positive breast cancer.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-13-15.

Abstract P5-14-18: Indication of post-mastectomy radiation associated with risk of local recurrence in breast cancer patients with 1-3 lymph node metastasis

Objective: Post-mastectomy radiotherapy (PMRT) is strongly recommended for breast cancer patients with 1 to 3 axillary lymph node metastasis (N1-3) in NCCN guidelines Version 3.2013 (category 1), whereas the indication of that treatment should be considered individually according to the risk of local recurrence (St Gallen Consensus Meeting 2013). In order to support decision making of PMRT, we evaluated the risk factors of local recurrence after mastectomy.

Patients and methods: We reviewed retrospectively 2422 cases with Stage I – III primary breast cancer receiving surgery at National Kyushu Cancer Center between 2000 and 2009. Seven hundred seventy six of them underwent mastectomy, and 547 of them received no PMRT. We analyzed the risk of local recurrence in relation to clinicopathologial factors, the status of hormone receptor and HER2, especially in cases with N1-3.

Results: Among 547 cases with no PMRT, there were 364 cases with no LN metastasis (N0), 146 N1-3, and 37 N≥4, and 5-year local disease free survival (DFS) rates were 97.0%, 91.2%, and 73.4%, respectively. In N1-3 (146) cases who underwent no post-operative regional radiotherapies, the 5-year DFS in extent of lymph vessel infiltration (ly) were: ly0 was 97.9% (50) and ly1-3 was 87.9% (92) (ly unknown were 4). In the ly0 cases, the 5-year local DFSs were 100% in grade 2 and 85.7% in grade 3; 100% in ER positive and 90.0% in ER negative; 90.9% in HER2 positive and 100% in HER2 negative. Those in the cases of ly1-3 were 94.5% and 73.4%, 88.7% and 76.6%, and 91.0% and 64.3%, respectively.

Conclusion: In patients with N1-3 breast cancer, the risk of local recurrence after mastectomy was significantly related to grade, extent of lymph vessel infiltration, ER and HER2. PMRT could be omitted in case with ly0,additionaly with grade 1-2, ER positive and HER2 negative. The remaining cases have the risk of local recurrence over 10%, if they don't receive PMRT, in which the indication of PMRT should be considered.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-14-18.

Abstract P3-12-03: Adjuvant capecitabine in breast cancer patients with pathologic residual disease after neoadjuvant chemotherapy: First safety analysis of CREATE-X (JBCRG-04)

Background

Patients (pts) without pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) have a poor prognosis compared with pts achieving a pCR with NAC. It is not clear whether further systemic chemotherapy is beneficial for pts with no pCR. CREATE-X (UMIN000000843) is an ongoing collaborative Korean (KRN)/Japanese (JPN) prospective multicenter open-label randomized phase III trial evaluating this clinical question using capecitabine (X) in pts with no pCR after NAC. We report first safety results, focusing on hand-foot syndrome (HFS), the timing of radiotherapy (RT) and hormone therapy (HT), and differences between KRN and JPN pts.

Methods

Pts with residual invasive cancer after anthracycline- and/or taxane-containing NAC were randomized to standard post-surgical treatment (RT, HT as appropriate) with or without 8 cycles of X (1250 mg/m2 bid, days 1–14 q3w). RT was given before or after X. Pts with hormone receptor (HR)-positive disease received HT either with or after X, according to each center's prespecified standard practice. After evaluation of the tolerability of 6 cycles of X in the first 50 pts, the independent data monitoring committee recommended extending X to 8 cycles.

Results

Between Feb 2007 and Jul 2012, 910 pts were enrolled (304 in Korea, 606 in Japan). At the time of data cut-off (May 20, 2013), data were available from 866 pts. Median age was 48 years in both arms. In the investigational arm, RT was given before X in 260 pts and after X in 33 pts; 73 pts received prophylactic vitamin B6 (VB6). In HR-positive pts HT was given with X in 200 pts and after X in 24 pts. The relative dose intensity of X was 85.7% in JPN pts and 95.2% in KRN pts. Grade (G) 3/4 neutropenia, HFS (G3 only), fatigue, and diarrhea were significantly (p&lt;0.05) more common with X than no X. G3 HFS occurred in 11.1% of pts receiving X, and was significantly more common in JPN vs KRN pts (p = 0.016). No significant difference in HFS was observed between pts who received vs did not receive VB6 (p = 0.392). G3/4 alanine aminotransferase (ALT) abnormalities were significantly more common in pts receiving RT after vs before X (p&lt;0.001) and in pts receiving HT after vs concurrently with X (p&lt;0.001).

 n/N(%) Investigational armControl arm (n = 430)(n = 436)HR status Positive275/430(64)275/436(63)Negative141/430(33)143/436(33)Unknown14/430(3)18/436(4)G 3/4 toxicity Neutropenia36/385(9)5/326(2)Fatigue6/426(1)0/417(0)Diarrhea12/426(3)1/417(&lt;1)HFS(G3)47/424(11)0 JPN40/296(14)0 KRN7/128(5)0 VB66/73(8)- No VB641/351(12)-ALT abnormality10/409(2)3/391(&lt;1) with RT8/285(3)1/280(&lt;1) X → RT8/31(26)- RT → X0/254(0)- without RT2/124(2)2/111(2) with HT2/214(1)1/267(&lt;1) X + HT0/190(0)- X → HT2/24(8)- wothout HT8/195(4)2/124(2)

Conclusions

Addition of 8 cycles of X to standard adjuvant therapy is feasible and tolerable, resulting in a modest yet acceptable increase in toxicities. The timing of RT and HT administration relative to X influenced the incidence of adverse events. HFS was more common in JPN than KRN pts, although further investigation of the potential cause of this difference is required. These findings should be interpreted in light of efficacy data, expected in 2015.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-12-03.

Abstract P6-06-20: Predictive factors for pathologic complete response and disease-free survival after neoadjuvant chemotherapy with trastuzumab: A multicenter retrospective observational study in patients with HER2-positive primary breast cancer (JBCRG-C03 study)

BACKGROUND:

Addition of trastuzumab to neoadjuvant chemotherapy (NAC) improved pathologic complete response (pCR) rate in HER2-positive breast cancer. Although recent trials have shown favorable prognosis with NAC plus trastuzumab, clinicopathological factors to predict the outcome have not been fully understood. The aim of this study was to investigate the survival after NAC with trastuzumab and to explore the predictive factors.

PATIENTS AND METHODS:

This is a multicenter retrospective observational study. Patients with HER2-positive primary breast cancer treated with NAC plus trastuzumab from 2001 to 2010 were identified from the institutional database. Primary end point was disease-free survival (DFS). pCR was defined as ypT0/is+ypN0. Kaplan-Meier method was used to estimate DFS. Logistic regression and proportional hazard analysis were used to identify clinicopathological factors to predict pCR and DFS, respectively.

RESULTS:

733 patients were included in the analysis (whole dataset). 425 were ER/PgR-negative (HR- dataset) and 306 were ER/PgR-positive (HR+ dataset). Radiation therapy was performed in 90% of lumpectomy and 31% of mastectomy. Hormonal therapy was performed in 84% of HR+ dataset. pCR rate was 45% in whole dataset, 60% in HR- dataset, and 34% in HR+ dataset. Table 1 showed the result of multivariate analysis for pCR in whole dataset. When HR+ and HR- dataset were analyzed separately, no definitive predictors for pCR were identified in multivariate analysis. Although the patients with pCR showed a significantly favorable prognosis than those without pCR at 3 years DFS, in whole dataset (93% vs 83%, p&lt;0.0001) and HR- dataset (94% vs 80%, p&lt;0.0001), there was no significant difference in HR+ dataset (89% vs 86%, p = 0.10). Different predictors were selected for DFS when multivariate analysis was conducted separately between HR- and HR+ dataset (Table 2).

CONCLUSIONS:

In this observational study, we clarified predictors for pCR and DFS in HER2-positive patients treated with neoadjuvant trastuzumab containing therapy based on tumor subtype. Our results may help us to predict the prognosis more precisely and to simulate the disease course.

Table 1) Multivariate logistic regression analysis for pCR in whole datasetFactorsOR95%CIp-valuePost- vs Pre-menopause1.50(1.05-2.15)0.026*cT1-2 vs cT3-41.72(1.16-2.59)0.008*ER/PgR-negative vs ER/PgR-positive3.32(2.30-4.82)&lt;0.0001*Grade 3 vs 1-21.28(0.89-1.84)0.183

Table 2) Multivariate proportional hazard analysis for DFSFactors†HR95%CIp-valueWhole dataset   Pre- vs Post-menopause1.61(1.04-2.52)0.033*cN2-3 vs cN03.06(1.58-6.24)0.001*cN1 vs cN02.26(1.23-4.41)0.007*Grade 3 vs 1-21.87(1.20-2.97)0.006*non-pCR vs pCR1.90(1.18-3.13)0.008*HR- dataset   Pre- vs Post-menopause1.70(1.01-2.85)0.046*cT3-4 vs cT1-21.86(1.09-3.17)0.024*non-pCR vs pCR3.28(1.90-5.87)&lt;0.0001*HR+ dataset   cN2-3 vs cN05.01(1.79-16.19)0.002*cN1 vs cN03.50(1.40-10.61)0.006*Grade 3 vs 1-22.95(1.52-5.87)0.001*†Only factors with statistical significance

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-06-20.

Abstract P2-18-03: Feasibility of sentinel node biopsy following neoadjuvant chemotherapy in cytology-proven node positive breast cancer before chemotherapy

BACKGROUND: Sentinel node biopsy (SNB) for the node negative breast cancer is standard treatment as an accurate assessment of axillary lymph node status; however, axillary node dissection is a standard procedure for the node positive breast cancer. Neoadjuvant chemotherapy (NAC) has become the standard of care for patients with locally advanced breast cancer. It is reported that 40% of node positive disease convert to node negative after NAC. It remains controversial whether SLB could be applied to patients who present with node-positive disease before neoadjuvant chemotherapy. In this study, we evaluated the accuracy of SNB following NAC in breast cancer patients presenting with cytology-proven axillary node metastasis before chemotherapy.

METHODS: A multicenter prospective study was performed from September 2011 to April 2013 in 101 breast cancer patients with positive axillary nodes, proven by ultrasound-guided fine-needle aspiration at initial diagnosis (T1-3, N1, M0). After the confirmation of patients as clinically node-negative by preoperative imaging following NAC, all patients underwent breast surgery, with SNB and complete axillary lymph node dissection. The sentinel nodes were examined by hematoxylin-eosin staining, immunohistochemical analysis or one-step nucleic acid amplification assay (OSNA).The false negative rate and detection rate were analyzed.

RESULTS: Among the 101 patients analyzed, all cases presented with invasive ductal carcinoma. with a mean tumor size of 3.4cm. Thirty-six cases were hormone receptor (HR) positive and HER2 negative (Lum), 14 cases were HR positive and HER2 positive (Triple-Positive), 27 cases were positive for HER2 (HER2-enriched), and 24 cases were Triple-Negative. After neoadjuvant chemotherapy, a complete clinical response in the primary tumor was seen in 24.8%(25/101), a partial response in 66.3%(67/101), and no response in 7.9%(8/101). Pathological complete response of primary tumor was 39.6%. The pathological complete nodal response rate was 42.2%. The sentinel lymph node could be identified in 91 of 101 cases (90.1%); 88.9% (32/36) of patients with Lum, 100%(14/14)of those with Triple-Positive, 85.2% (23/27) of those with HER2-enriched, and 91.7% (22/24)% of those with Triple-Negative breast cancer subtype. The false negative rate was 12.7%; 35.7 (5/14) for Lum, 0% (0/8) for Triple-Positive, 5.0% (1/20) for HER2-enriched, and 7.7% (1/13) for Triple-Negative subtype (P = 0.03).

CONCLUSION: SNB following NAC in patients with node-positive breast cancer was found to be technically feasible, but is not recommended for the Lum subtype. However, it might be safely considered in selected patients, those with Triple-Positive, HER2-enrich and Triple-Negative subtype breast cancers.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-18-03.

Abstract P3-14-05: Randomized phase II study of preoperative docetaxel and cyclophosphamide-containing chemotherapy for luminal-type breast cancer

Background: We compared and evaluated three 6-cycle, docetaxel and cyclophosphamide (TC)-containing chemotherapy regimens in a multicenter randomized phase II study. The main aim was to investigate whether anthracyclines are needed or can be omitted, and whether the order of chemotherapy is important, for treating luminal-type breast cancer.

Methods: We recruited patients (pts) with ER-positive, HER2-negative breast cancer aged 20–70 years, and histo-pathologically invasive breast cancer (T1c-3, N0-1, M0), T≤7cm. Pts were randomized to 3 groups for the following treatments: 6 cycles of TC; 3 cycles of 5-FU/epirubicin/cyclophosphamide (FEC) followed by 3 cycles of TC (FEC-TC); and 3 cycles of TC followed by 3 cycles of FEC (TC-FEC). TC treatment consisted of administration of docetaxel at 75 mg/m2 and cyclophosphamide at 600 mg/m2 once every 3 weeks. FEC treatment consisted of administration of 5-FU at 500 mg/m2, epirubicin at 100 mg/m2, and cyclophosphamide at 500 mg/m2 once every 3 weeks. We aimed to enroll 65 pts per group based on an expected pCR rate among regimens of adding 10% at a threshold of 9%. The primary endpoint was pathological complete response (pCR) rate. Secondary endpoints were overall response rate (ORR), breast conservation rate and safety.

Results: A total of 195 pts (median age, 49.5 years (range, 26–69); median tumor size, 32.8 mm (range, 9–82); 91 pts with N(+) (51%)) were enrolled and randomized as follows: FEC-TC (n = 65), TC-FEC (n = 63), and TC group (n = 67). There were no differences in backgrounds among groups. Both the intention-to-treat population and the safety analysis set included 65, 63 and 65 pts in these groups, respectively. The 6-cycle treatment completion rates were 96.9%, 96.8% and 84.6%, respectively. pCR, defined as yT0/isyN0, was achieved by 9.2% of pts in the FEC-TC group, 8.1% in the TC-FEC group, and 15.9% in the TC group (p = 0.321). A quasi pCR in breast (yT0/is and near pCR) was achieved by 13.9%, 14.5%, and 17.5%, respectively. These responses did not differ among the 3 groups. ORRs, assessed by MRI or CT, were 75.8% (CR: 12.9%), 75% (CR: 5%), and 82.2% (CR: 17.9%) in the FEC-TC, TC-FEC and TC groups, respectively. Breast conservation rates were 50.8%, 45.2%, and 73.0%, respectively.Adverse events of Grade≥3 were observed in 20.0%, 27.0%, and 20.3% of pts in the FEC-TC, TC-FEC, and TC groups, respectively, with no significant differences. Febrile neutropenia was observed in 17.2%, 21.0%, and 11.3%, respectively, but in most cases it was managed sufficiently on an outpatient basis. Of 28, 27 and 23 pts in these groups in whom mastectomy was planned, 9 (32%), 5 (19%), and 10 (44%) were successfully converted to undergo breast-conserving surgery. Of 37, 35 and 40 pts in the FEC-TC, TC-FEC and TC groups in whom breast-conserving surgery was planned, 13 (35%), 12 (34%), and 4 (10%) underwent mastectomy.

Conclusion: Six cycles of TC had therapeutic effects and safety equivalent to FEC-TC and TC-FEC. The 3 treatment groups showed similar pCR rates, although the breast conservation rate was significantly higher in the TC group than in the other 2 groups. It may be possible to conduct preoperative chemotherapy for pts with ER-positive breast cancer without using an anthracycline.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-14-05.

Imaging of thrombosis and microcirculation in mouse lungs of initial melanoma metastasis with in vivo cryotechnique

Microscopic bioimaging of blood flow and distribution of cancer cells in lungs is essential to analyze mechanism of lung metastasis. Such cancer metastasis has been well known to induce hypercoagulable states and thrombosis. In histopathological tissue sections, however, it has been difficult to capture rapid phenomenon of thrombus formation due to technical problems associated with much less retention of soluble serum components as well as dynamic histological features reflecting their living states. In this study, to achieve bioimaging of both hypercoagulable states and thrombosis induced by early metastasis of mouse B16-BL6 melanoma, "in vivo cryotechnique" (IVCT) was used, which retained soluble components at their original sites. Glutathione-coated quantum dots (QDs) were subsequently injected after melanoma cells via right ventricles to examine plasma flow with fluorescence emission. At 5s after the melanoma injection, melanoma cells were mostly stacked and intruded in alveolar capillaries with changing their shapes. Assembly of platelets initially appeared at 1min, and they aggregated around the stacked melanoma cells at 5min. Such aggregated platelets were immunopositive for both phospho-tyrosine 418 and 527 of Src, indicating their partial signal activation. Fibrin monomers were also immunolocalized around both melanoma cells and platelet aggregates, and massive immunoreaction deposits of fibrinogen were also detected near the same areas, but more strongly detected around the melanoma cells, indicating initial thrombus formation. In those areas, QDs were rarely detected, probably because of the lack of blood supply. Thus, IVCT revealed histopathological features of initial thrombosis under their circulatory conditions.