Abstract P2-09-35: Differential Pathologic Response from Primary Systemic Chemotherapy across Breast Cancer Intrinsic Subtypes

Purpose: This study's purpose was to evaluate the clinical utility of breast cancer intrinsic subtypes in the prediction of pathological complete response (pCR) in a cohort of breast cancer patients receiving primary systemic chemotherapy.

Patients and Methods: Patients with stage II/III breast cancer received 4 cycles of XT (capecitabine 1650 mg/m2 on days 1-14 and docetaxel 60 mg/m2 on day 8 every 3 weeks), followed by 4 cycles of FEC (fluorouracil 500 mg/m2, epirubicin 90 mg/m2, cyclophosphamide 500 mg/m2 on day 1 every 3 weeks). Immunohistochemical analysis of estrogen receptor (ER), progesterone receptor (PgR), HER2, epidermal growth factor receptor (EGFR), cytokeratin (ck) 5/6, and Ki67 was performed in core needle biopsy samples at baseline. Tumors were classified as luminal A (ER+ and/or PgR+, and Ki67<20%), luminal B(ER+ and PgR+, and Ki67≥20%), luminal-HER2 (ER+ and/or PgR+, and HER2+), HER2-enriched (ER-PgR-, and HER2+), or triple-negative (ER-, PgR-, and HER2-). Triple-negative tumors with and without EGFR+ and/or ck 5/6+ were further classified as basal-like and non-basal-like TN (NBTN), respectively. pCR was defined as no microscopic evidence of residual viable tumor cells, invasive or noninvasive, in all resected specimens of the breast. Results: Twenty-six (31.3%) patients were classified as luminal A, 12 (14.5%) were luminal B, 15 (18.1%) were luminal-HER2, 9 (10.8%) were HER2, 10 (12.0%) were basal-like, and 11 (13.3%) were NBTN. The overall response rate was 90.4%, including a complete response in 30 patients and a partial response in 45 patients. The overall pCR rate was 15.5% (12/83). The highest pCR rate (40.0%) was observed in patients with basal-like tumors. In triple-negative patients, basal-like patients showed significantly higher pCR rate than NBTN patients (40.0% vs. 9.1%, p=0.01). There were no cases with pCR in a cohort of luminal-HER2 subtype patients. A higher proportion of luminal B patients had pCR than luminal A patients (25.0% vs. 3.8%, p=0.01). With 33 months median follow-up, estimated 2-year disease-free survival for luminal A, luminal B, luminal-HER2, HER2, basal-like, and NBTN was 80.8%, 83.3%, 66.7%, 88.9%, 80.0%, and 81.8%, respectively.

Conclusions: Our data indicate that breast cancer subtypes are useful predictive biomarkers of pCR in breast cancer patients treated with primary systemic chemotherapy.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-09-35.

Abstract P4-07-07: HOXB9 Expression as a New Independent Prognostic Factor in Human Breast Cancer

Background: There are several reports showing a HOX gene family, which plays the critical roles for the differentiation during the embryonic stage, is associated with the tumorigenicity. It was demonstrated that HOXB9 is overexpressed in 42% of breast cancers, specifically those with high histological grade, and we defined the functional consequences of elevated HOXB9 expression in breast cancer. Moreover, HOXB9 expression promotes increased neovascularization and tumor metastasis to the lung in mouse xenograft models (Hayashida et al., PNAS, 2010). The puropose of this report is to evaluate the correlation between HOXB9 and clinicopathological variables in breast cancer patients. Patients and methods: A consecutive series of 141 patients with invasive ductal carcinoma who underwent surgical treatment at Keio University Hospital from January 2004 to January 2005 was involved. HOXB9 expression was analyzed immunohistochemically on formalin-fixed, paraffin-embedded tumor sections using rabbit anti-human HOXB9polyclonal antibody. Moreover, immunohistochemical stainings for Ki-67, CD31, and CD34 were also performed to evaluate the association with HOXB9 expression.

Results: The age at the diagnosis ranged from 30 to 93 years (median age, 58 years), and median observation period was 62.2 months. Of 141 tumor specimens immunostained for HOXB9, 69 specimens (48.9%) were positive staining. Univariate logistic regression revealed ER negativity (P<0.001), PR negativity (P<0.001), HER2 positivity (p=0.031), high nuclear grade (P<0.001) and large pathological tumor size (p=0.002) as significant variables associated with HOXB9 expression. Notably, 12 (92. 3%) out of 13 triple negative breast cancer showed HOXB9 expression. The disease-free survival (DFS) at 5 year and the overall survival at 5 year were significantly different between the HOXB9 positive group and HOXB9 negative group; HR=8.5, 95%CI 3.3-21.9, p=0.001, HR 3.8, 95%CI 1.5-9.6, p=0.003, respectively. A Multivariate analysis indicated that HOXB9 expression was the independent prognostic factor for DFS (HR=14.1, 95% CI 1.851 to 107.4, p=0.011). Since HOXB9 expression accelerates the tumor angiogenesis in vitro and in vivo, we also evaluated the expression of vascular endothelial marker, CD31 and CD34 and cellular proliferation marker, Ki-67 in 45 patients with clinical T2 (tumor size, 2 to 5cm) tumor. In this subgroup analysis, HOXB9 positive patients (n=22) showed increased number of vasculature and Ki-67 ratio in comparison with HOXB9 negative patients (n=23) with statistical significance.

Correlations between HOXB 9 expression and Ki-67, CD31 and CD 34

Conclusion: The data identify HOXB9 expression as a new independent prognostic factor in breast cancer, which might help to improve the selection for appropriate therapy. Possibly, it might be useful to determine the application of anti-angiogenic therapy.

Abstract P1-11-04: A Phase II Preoperative Trial of Concurrent Trastuzumab and Paclitaxel without Anthracycline in HER2-Positive Operable Breast Cancer

Background

Concurrent trastuzumab with paclitaxel/fluorouracil, epirubicin, and cyclophosphamide (P/FEC) chemotherapy as neoadjuvant treatment revealed the high pathologic complete response (pCR) rate of 54.5% (Buzdar, 2007). Deregulation of the phosphatidylinositol 3-kinase (PI3K) pathway either through loss of PTEN or mutation of the catalytic subunit alpha of PI3K (PIK3CA) might confer resistance to trastuzumab. The objective of this study was to determine the efficacy of concurrent administration of trastuzumab and paclitaxel wtihout anthracycline as preoperative chemotherapy. The correlation between deregulation of PI3K and resistance to trastuzumab was also investigated. Patients & methods

Patients with HER2-positive, operable breast cancer received 12 cycles of weekly paclitaxel (80 mg/m2) and trastuzumab (4mg/kg loading dose then 2 mg/kg) for 12 weeks before surgery. PTEN status was evaluated by immunohistochemistry. PTEN staining intensity scores was recorded on an integer scale from 0 to 2+ (0; no staining, 1+; reduced staining, and 2+; equal staining as compared to the internal control). Sequencing of PIK3CA exons 9 and 20 was done by PCR amplification and direct sequencing. pCR was defined as no residual invasive carcinoma in the breast. Results

Twenty-eight patients were enrolled and assessable for clinical and pathologic responses. The overall response rate was 92.9%, including a complete response in 13 patients and a partial response in 13 patients. The pCR rate was 53.6% (15/28). Twenty-three patients (82.1%) underwent breast concerving surgery. Progesteron receptor (PgR) status was significantly correlated with pCR (p=0.025). Eight of 24 patients (33.3%) were scored PTEN negative. PIK3CA mutations were identified in 4 of 13 patients (30.8%). There was no significant difference in pCR rate and PTEN loss/PIK3CA mutation.

Correlation of PgR status and pCR

Conclusions

These data indicate that the combination of trastuzumab and paclitaxel without anthracycline is effective preoperative chemotherapy with high pCR rate. PTEN loss and/or PIK3CA mutation were not useful predictors of resistance to trastuzumab.

A Phase II Trial of Capecitabine and Docetaxel Followed by 5-FU/Epirubicin/Cyclophosphamide (FEC) as Preoperative Treatment in Women with Stage II/III Breast Cancer

Backgound: capecitabine (X) and docetaxel (T) have demonstrated synergistic effect in preclinical models and survival benefit in metastatic breast cancer. The sequential combination of anthracycline and taxane is a standard of care as preoperative setting, as well as adjuvant setting. This study's purpose was to determine the efficacy of X and T followed by 5-FU/epirubicin/cyclophosphamide (FEC) in the preoperative setting.Patients and Methods: Patients with stage II/III breast cancer received 4 cycles of XT (capecitabine 1650 mg/m2 on days 1-14 and docetaxel 60 mg/m2 on day 8 every 3 weeks), followed by 4 cycles of FEC (fluorouracil 500 mg/m2, epirubicin 90 mg/m2, cyclophosphamide 500 mg/m2 on day 1 every 3 weeks). Primary endpoints were the pathological complete response (pCR) rate and adverse drug reactions. pCR was defined as no microscopic evidence of residual viable tumor cells, invasive or noninvasive, in all resected specimens of the breast. Secondary endpoints were the clinical response rate, the breast conservation rate, and predictors for pCR.Results: From February 2005 to October 2008, 72 patients were enrolled and 71 patients were assessable for clinical and pathologic responses. The median age was 51 years (range, 27-69 years). The median tumor size was 3.5 cm (range, 2-8.3 cm). Forty-six (64.8%) patients were clinically node-positive. Overall, 50 (50.1%) patients had hormonal receptor (HR)-positive tumors, and 21 (29.6%) had HR-negative tumors. The overall response rate was 91.5%, including a complete response in 29 patients and a partial response in 36 patients. No patients showed clinical progression of disease. The pCR rate was 14.1% (10/71). Fifty-six patients (78.9%) underwent breast-conserving surgery. The breast-conserving rate in patients whose tumor size was 3 cm or smaller was 92.6%, and 69.0% of patients whose tumor size was larger than 3 cm underwent breast-conserving surgery. Grade 3/4 neutropenia was observed in 32.4% of patients, and febrile neutropenia was observed in 5.6% of patients. The most common grade 3/4 non-hematologic adverse event was hand-foot syndrome, observed in 11.3% of patients. The median relative dose intensities of FEC, T, and X were 0.982, 0.968, and 0.933, respectively. HR status and Ki67 expression were significantly correlated with pCR.Conclusions: These data indicate that the sequential combination of XT followed by FEC is a well-tolerated, effective preoperative treatment for stage II/III breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1101.

Influence of humic substances on the63Ni migration through crushed rock media

Column experiments were performed to study effects of humic acid on the mobility of63Ni(II) through crushed granite media. The63Ni concentration passing the column increased with increasing the concentration of humic acid. The migration behavior of63Ni, either retarded or non-retarded, could not be simulated by the widely-accepted, instantaneous equilibrium sorption model. The rate limited transformation model, taking into account non-equilibrium complexation of63Ni with humic acid facilitates the description of the observed migration behavior of63Ni.

Non-sentinel lymph node status and prognosis of the breast cancer patients with micrometastatic sentinel lymph nodes

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Background: Sentinel lymph node biopsy (SLNB) has become a standard therapy for clinically node-negative breast cancer patients and improvements of histopathological and molecular analysis of sentinel lymph node (SLN) have increased the rate of micrometastases identified. However it remains controversial whether to perform axillary lymph node dissection (ALND) for patients with micrometastases in SLNs and their prognostic significance is also a matter of debate. The purpose of this study is to determine the non- sentinel lymph node (NSLN) status and prognosis of the patients with micrometastatic SLNs. Methods: A prospective database of 666 breast cancer patients with the tumor size less than 3cm and clinical negative node, who underwent SLNB from January 2002 to July 2007 at Keio University Hospital was analyzed. SLNs were detected using a combined method of isosulfun blue dye and small-sized technetium-99m-labeled tin colloid. SLNs were diagnosed with standard hematoxylin and eosin (HE) staining and immunohistochemical (IHC) analysis. Results: Micrometastases in SLNs were found in 50 (7.5%) of 666 patients. Twenty nine (58.0%) of 50 patients with micrometastatic SLNs underwent ALND and revealed no NSLN metastasis. Among 21 (42.0%) patients with micrometastatic SLNs who skipped ALND, no axillary lymph node recurrence has been observed in the median follow-up time of 43 months, although 20 patients (95.2%) in 21 patients received adjuvant systemic therapy. There is no significant difference in recurrence free survival between the patients with micrometastatic and negative SLNs (98.0% vs. 95.7%, respectively). Conclusions: These date suggested that it may not be necessary to perform ALND for the patients with micrometastases in SLNs and the presence of micrometastases in SLNs may not be associated with prognosis.

No significant financial relationships to disclose.

E-cadherin expression in the subepithelial nevus cells of the giant congenital nevocellular nevi (GCNN) correlates with their migration ability in vitro

BACKGROUND

Giant congenital nevocellular nevi (GCNN) are histologically characterized by the broad distribution of nevus cells in the epidermis and dermis.

OBJECTIVE

To characterize E-cadherin in GCNN and define its role in nevic cell migrations.

METHODS

Twenty-four cases were immunohistochemically examined and in five cases cells were isolated for primary culture for migration assays.

RESULTS

The nevus cells in the superficial region showed the immunoreactivity of E-cadherin in a membranous pattern, but those in the deep part of dermis had little immunoreactivity. Ultra-structural analysis of the superficial nevus cells revealed that E-cadherin immunodeposits in the fibrillar processes around the cell body in a spotted pattern. This distribution pattern is quite different from that in the adherens junction of skin squamous epithelial cells. Boyden chamber experiments were performed using primary cultures of intradermal nevus cells. EDTA pretreatment reduced cell migration to the E-cadherin positive side when the E-cadherin positive population was relatively large in the primary cultures.

CONCLUSIONS

These results indicate that E-cadherin in the nevus cells may affect nevus cell motility rather than intercellular attachment.

Association of erythrocyte indices with glycated haemoglobin in pre-menopausal women

AIMS

Although HbA(1c) is known to be affected by the lifespan of erythrocytes, any association of erythrocyte indices with HbA(1c) in subjects without anaemia is poorly understood. Pre-menopausal women may be relatively iron deficient because of menstruation. In this study, we examined the relationship between HbA(1c) and erythrocyte indices in pre- and post-menopausal women.

METHODS

We determined HbA(1c), red blood cell (RBC) count, haematocrit, haemoglobin, mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH) in 423 women with normal glucose tolerance who had undergone health checks. In addition, age at menopause was recorded in post-menopausal subjects.

RESULTS

RBC counts of the 180 pre-menopausal women were positively associated with HbA(1c), whereas haemoglobin, MCV and MCH showed a negative association. In contrast, no significant association of any indices with HbA(1c) was detected in the 243 post-menopausal women. Stepwise multivariate regression analysis in the pre-menopausal women identified fasting plasma glucose and age as positively associated and MCH as negatively associated with HbA(1c), regardless of whether or not these pre-menopausal women were anaemic.

CONCLUSIONS

Erythrocyte indices are associated with HbA(1c), independently of plasma glucose levels, in pre-menopausal women even when they are not anaemic. This should be appreciated when interpreting HbA(1c) in pre-menopausal patients with diabetes.

Validity of sentinel lymph node biopsy in breast cancer patients after neoadjuvant chemotherapy

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Background: Sentinel lymph node biopsy (SLNB) is a potential alternative procedure to conventional axillary lymph node dissection (ALND) in clinically node-negative breast cancer patients. Neoadjuvant chemotherapy (NAC) is a standard of care for patients with locally advanced breast cancer and indications of NAC have been widespread to operable breast cancer patients to facilitate breast conserving surgery. However, the validity of SLNB in breast cancer patients who received NAC is still controversial. Methods: Forty-six patients with stage II or III breast cancer who were treated with NAC from January 2002 to May 2006 were included in the study. Consecutive 122 patients who had SLNB without NAC during the same period were used as a control group. All patients underwent SLNB followed by completion ALND. Sentinel lymph node (SLN) was detected using a combined method of injecting isosulfan blue dye and small-sized technetium- 99m-labeled tin colloid (particle size: 200–400 nm in diameter) peritumorally and subcutaneously. SLNs were evaluated by means of H&E and immunohistochemical staining. Results: SLNs were successfully identified in 42/46 patients (91.3%) treated with NAC and 112/113 patients (99.1%) without NAC (p=0.01). Metastases in the SLNs were found in 16/42 patients (38.1%) with NAC and 32/112 patients (28.6%) without NAC (p=0.2). There were 5 false negative cases (false negative rate: 23.8%) in the NAC group and 2 false negative cases (false negative rate: 5.9%) in the control group (p=0.05). Accuracy of SLNB in the NAC group was also significantly inferior to the control group (88.1% vs. 98.2%, p<0.01). The presence of clinically positive axillary lymph nodes before NAC was not correlated with false negative rate. Conclusions: These data suggest that NAC might be considered a contraindication to SLNB even in patients with clinically negative axillary lymph nodes before NAC.

No significant financial relationships to disclose.