Yutaka Tokuda

Loss of Human Epidermal Growth Factor Receptor 2 (HER2) Expression in Metastatic Sites of HER2-Overexpressing Primary Breast Tumors

PURPOSE We evaluated whether patients with human epidermal growth factor receptor 2 (HER2) -positive primary breast tumors had metastatic tumors that were HER2 positive (concordant) or HER2 negative (discordant). We then evaluated whether treatment with trastuzumab or chemotherapy before biopsy of the metastasis had any effect on the rate of HER2 discordance. We also compared the overall survival durations of patients with HER2-concordant and -discordant tumors. PATIENTS AND METHODS We retrospectively identified all patients who initially had been diagnosed with HER2-positive (immunohistochemistry 3+ and/or fluorescent in situ hybridization positive) primary breast cancer between 1997 and 2008 at MD Anderson Cancer Center who also had metastatic tumor biopsy results available for review. RESULTS We included 182 patients who met our criteria. Forty-three (24%) of the 182 patients with HER2-positive primary tumors had HER2-negative metastatic tumors. The HER2 discordance rates differed significantly on the basis of whether patients received chemotherapy (P = .022) but not on the basis of whether patients received trastuzumab (P = .296). Patients with discordant HER2 status had shorter overall survival than did patients with concordant HER2 status (hazard ratio [HR], 0.43; P = .003). A survival difference remained among the 67 patients who received trastuzumab (HR, 0.56; P = .083) and 101 patients who did not (HR, 0.53; P = .033) before their metastasis biopsies. CONCLUSION We confirmed that loss of HER2-positive status in metastatic tumors can occur in patients with primary HER2-positive breast cancer. Our data strongly support the need for biopsies of metastatic lesions to accurately determine patient prognosis and appropriate use of targeted therapy.

Dose escalation and pharmacokinetic study of a humanized anti-HER2 monoclonal antibody in patients with HER2/neu-overexpressing metastatic breast cancer.

SummaryWe conducted a phase I pharmacokinetic dose escalation study of a recombinant humanized anti-p185HER2 monoclonal antibody (MKC-454) in 18 patients with metastatic breast cancer refractory to chemotherapy. Three or six patients at each dose level received 1, 2, 4 and 8 mg kg–1 of MKC-454 as 90-min intravenous infusions. The first dose was followed in 3 weeks by nine weekly doses. Target trough serum concentration has been set at 10 μg ml–1 based on in vitro observations. The mean value of minimum trough serum concentrations at each dose level were 3.58 ± 0.63, 6.53 ± 5.26, 40.2 ± 7.12 and 87.9 ± 23.5 μg ml–1 respectively. At 2 mg kg–1, although minimum trough serum concentrations were lower than the target trough concentration with a wide range of variation, trough concentrations increased and exceeded the target concentration, as administrations were repeated weekly. Finally 2 mg kg–1 was considered to be sufficient to achieve the target trough concentration by the weekly dosing regimen. One patient receiving 1 mg kg–1 had grade 3 fever, one at the 1 mg kg–1 level had severe fatigue defined as grade 3, and one at 8 mg kg–1 had severe bone pain of grade 3. No antibodies against MKC-454 were detected in any patients. Objective tumour responses were observed in two patients; one receiving 4 mg kg–1 had a partial response in lung metastases and the other receiving 8 mg kg–1 had a complete response in soft tissue metastases. These results indicate that MKC-454 is well tolerated and effective in patients with refractory metastatic breast cancers overexpressing the HER2 proto-oncogene. Further evaluation of this agent with 2–4 mg kg–1 weekly intravenous infusion is warranted.

Functional CD5+ B cells develop predominantly in the spleen of NOD/SCID/γcnull (NOG) mice transplanted either with human umbilical cord blood, bone marrow, or mobilized peripheral blood CD34+ cells

OBJECTIVE Human CD5+ B cells are the major B cell subset in fetal spleen and umbilical cord blood (CB), and their number gradually diminishes in both spleen and peripheral blood from infancy through childhood while conventional B cells increase. In this study, we investigated whether CD5+ cells differentiate from adult hematopoietic stem cells (HSCs) as well as fetal ones in immunodeficient mice. METHODS In our system, NOD/SCID/gammac(null) (NOG) mice were transplanted with CD34+ cells from CB (hCB model), adult bone marrow (hBM model), and mobilized peripheral blood (hMPB model). RESULTS In these model mice, a high proportion of CD19+IgM+CD5+ mature B cells appeared in the spleen, regardless of the CD34+ cell origin, 4 to 8 weeks after transplantation, while the majority were CD19+IgM-CD5- immature B cells in BM. The CD19+CD5- BM cells showed to express CD5 after the coculture with NOG spleen cells. In the sera of immunized hCB model mice with DNP-KLH, antigen-specific IgM but not IgG was enhanced. CONCLUSION Our results show that adult CD34+ cells develop into functional CD5+ B cells in NOG spleen as much as fetal CD34+ cells do.

In vitro and in vivo anti-tumour effects of a humanised monoclonal antibody against c-erbB-2 product.

The c-erbB-2 product is thought to be a unique and useful target for antibody therapy of cancers overexpressing the c-erbB-2 gene. In vitro and in vivo anti-tumour effects of a humanised antibody against the extracellular domain of the c-erbB-2 gene product, rhu4D5, were examined. Rhu4D5 was less effective than its murine counterpart, mu4D5, for the direct antiproliferative activity against the c-erbB-2-overexpressing SK-BR-3 cell line. In vivo treatment of severe combined immunodeficient (SCID) mice carrying the c-erbB-2-overexpressing 4-1ST human gastric carcinoma xenograft with 4hu4D5 revealed that the recombinant protein had potent anti-tumour activity. Furthermore, cytotoxicity of human peripheral blood mononuclear cells against 4-1ST was significantly augmented with rhu4D5, but not with mu4D5. These results indicate that rhu4D5 might perform better in patients than predicted from preclinical studies.

Oral Uracil and Tegafur Compared With Classic Cyclophosphamide, Methotrexate, Fluorouracil As Postoperative Chemotherapy in Patients With Node-Negative, High-Risk Breast Cancer: National Surgical Adjuvant Study for Breast Cancer 01 Trial

PURPOSE The primary aim of this study was to compare the effectiveness of oral uracil-tegafur (UFT) with that of classical cyclophosphamide, methotrexate, and fluorouracil (CMF) given as postoperative adjuvant treatment to women with node-negative, high-risk breast cancer. PATIENTS AND METHODS Women with node-negative, high-risk breast cancer were randomly assigned to receive either 2 years of UFT or six cycles of CMF after surgery. The primary end point was relapse-free survival (RFS). Overall survival (OS), toxicity, and quality of life (QOL) were secondary end points. The hypothesis was that UFT was not inferior to CMF in terms of RFS. RESULTS Between October 1996 and April 2001, a total of 733 patients were randomly assigned to receive either treatment. The median follow-up time was 6.2 years. The RFS rates at 5 years were 88.0% in the CMF arm and 87.8% in the UFT arm. OS rates were 96.0% and 96.2%, respectively. The hazard ratios of the UFT arm relative to the CMF arm were 0.98 for RFS (95% CI, 0.66 to 1.45; P = .92) and 0.81 for OS (95% CI, 0.44 to 1.48; P = .49). The toxicity profiles differed between the two groups. The QOL scores were better for patients given UFT than those given CMF. CONCLUSION RFS and OS with oral UFT were similar to those with classical CMF. Given the higher QOL scores, oral UFT is a promising alternative to CMF for postoperative adjuvant chemotherapy in women with node-negative, high-risk breast cancer.

High-Dose Chemotherapy With Autologous Stem-Cell Support As Adjuvant Therapy in Breast Cancer: Overview of 15 Randomized Trials

PURPOSE Adjuvant high-dose chemotherapy (HDC) with autologous hematopoietic stem-cell transplantation (AHST) for high-risk primary breast cancer has not been shown to prolong survival. Individual trials have had limited power to show overall benefit or benefits within subsets. METHODS We assembled individual patient data from 15 randomized trials that compared HDC versus control therapy without stem-cell support. Prospectively defined primary end points were relapse-free survival (RFS) and overall survival (OS). We compared the effect of HDC versus control by using log-rank tests and proportional hazards regression, and we adjusted for clinically relevant covariates. Subset analyses were by age, number of positive lymph nodes, tumor size, histology, hormone receptor (HmR) status, and human epidermal growth factor receptor 2 (HER2) status. RESULTS Of 6,210 total patients (n = 3,118, HDC; n = 3,092 control), the median age was 46 years; 69% were premenopausal, 29% were postmenopausal, and 2% were unknown menopausal status; 49.5% were HmR positive; 33.5% were HmR negative, and 17% were unknown HmR status. The median follow-up was 6 years. After analysis was adjusted for covariates, HDC was found to prolong relapse-free survival (RFS; hazard ratio [HR], 0.87; 95% CI, 0.81 to 0.93; P < .001) but not overall survival (OS; HR, 0.94; 95% CI, 0.87 to 1.02; P = .13). For OS, no covariates had statistically significant interactions with treatment effect, and no subsets evinced a significant effect of HDC. Younger patients had a significantly better RFS on HDC than did older patients. CONCLUSION Adjuvant HDC with AHST prolonged RFS in high-risk primary breast cancer compared with control, but this did not translate into a significant OS benefit. Whether HDC benefits patients in the context of targeted therapies is unknown.

FDG-PET/CT Compared with Conventional Imaging in the Detection of Distant Metastases of Primary Breast Cancer

PURPOSE Evidence from studies with small numbers of patients indicates that (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) accurately detects distant metastases in the staging of primary breast cancer. We compared the sensitivity and specificity of PET/CT and conventional imaging (CT, ultrasonography, radiography, and skeletal scintigraphy) for the detection of distant metastases in patients with primary breast cancer. PATIENTS AND METHODS We performed a retrospective review that identified 225 patients with primary breast cancer seen from January 2000 to September 2009 for whom PET/CT data were available for review. Imaging findings were compared with findings on biopsy, subsequent imaging, or clinical follow-up. Sensitivity and specificity in the detection of distant metastases were calculated for PET/CT and conventional imaging. Fishers exact tests were used to test the differences in sensitivity and specificity between PET/CT and conventional imaging. RESULTS The mean patient age at diagnosis was 53.4 years (range, 23-84 years). The sensitivity and specificity in the detection of distant metastases were 97.4% and 91.2%, respectively, for PET/CT and 85.9% and 67.3%, respectively, for conventional imaging. The sensitivity and specificity of PET/CT were significantly higher than those of conventional imaging (p = .009 and p < .001, respectively). Eleven cases of distant metastases detected by PET/CT were clinically occult and not evident on conventional imaging. CONCLUSION PET/CT has higher sensitivity and specificity than conventional imaging in the detection of distant metastases of breast cancer. A prospective study is needed to determine whether PET/CT could replace conventional imaging to detect distant metastases in patients with primary breast cancer.

Increased phosphorylation of Akt in triple-negative breast cancers

Cells from breast cancers lacking hormone receptors (estrogen receptor [ER], progesterone receptor [PgR]) and human epidermal growth factor receptor (HER) 2 strongly express the cell proliferation marker Ki‐67. However, the mechanisms of and stimulus signals involved in cell proliferation of this type of breast cancer are not well understood. The aim of the present study was to examine the characteristics of signal transduction in triple‐negative (ER‐, PgR‐, and HER2‐negative) breast cancers. For 44 tumor samples, western blotting analysis was conducted to examine the phosphorylation of HER2, external signal‐regulated kinase (ERK)1 and ‐2 and Akt, and the immunohistochemical phenotypes of the samples with respect to ER and HER2 were also assessed. Phosphorylation of HER2 was detected in 4 of 15 immunohistochemically HER2‐positive tumor samples (26.7%). ERK1/2 was more highly phosphorylated in triple‐negative breast cancers. Phosphorylation of Akt kinase was significantly higher in triple‐negative breast cancers. Triple‐negative breast cancers are characterized by increased phosphorylation of Akt kinase. In the present study, we found for the first time that there is a population with a significantly activated Akt pathway in this type of breast cancer. (Cancer Sci 2007; 98: 1889–1892)

Immunohistochemical studies on oncogene products (c-erbB-2, EGFR, c-myc) and estrogen receptor in benign and malignant breast lesions. With special reference to their prognostic significance in carcinoma.

It is a matter of debate whether the amplification of c-erbB-2 oncogene or production of the oncoprotein in breast cancers correlate with the presence of lymph node metastasis and with a poor prognosis. This study was aimed at elucidating the immunohistochemical localization of oncogene products which are related to cell growth, c-erbB-2 product, epidermal growth factor receptor (EGFR), c-myc protein and estrogen receptor (ER), in benign and malignant lesions of the breast. Fresh frozen sections of 25 breast cancers and 11 fibroadenomas from Japanese women were studied by indirect immunoperoxidase method with proper fixation. C-erbB-2 product and EGFR were localized on the cell membrane whereas c-myc protein and ER were observed in the nuclei. Immunohistochemical expression of oncogene products and ER were not only observed in the mammary carcinomas but also in the fibroadenomas. However immunoreactivities of EGFR and ER were more frequently seen in the fibroadenomas (p<0.05). In breast cancers, the incidence of immunoreactivity for c-erbB-2 was higher in the cases with lymph node metastasis than cases without nodal metastasis (p < 0.05) and there was reciprocal correlation between the expressions of EGFR and ER (p<0.05). Regarding the size of the primary tumour, there was no statistically significant correlation with the expressions of c-erbB-2, EGFR, c-myc or ER. Histological grade correlated only with the expression of ER (p<0.05).

Treatment Outcome and Prognostic Factors for Patients with Bone-Only Metastases of Breast Cancer: A Single-Institution Retrospective Analysis

The study defines prognostic factors for breast cancer patients with bone-only metastases and examines progression-free and overall survival times in patients with hormone receptor–positive disease and bone-only metastases treated with different therapies.