Chieh Lan

Molecular subtypes of breast cancer emerging in young women in Taiwan: evidence for more than just westernization as a reason for the disease in Asia.

Background: In the past two decades, the incidence of breast cancer in young Taiwanese females has been rapidly increasing, approaching the risk level of western countries. As a first step to investigate the possible etiology, we examined the molecular subtypes of female breast cancer in Taiwan. Methods: This study included 1,028 consecutive patients with breast cancer diagnosed in National Taiwan University Hospital between 2004 and 2006. Estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2, cytokeratin 5/6, and epidermal growth factor receptor expression and/or gene amplification were analyzed. Results: Younger (≤50 years) breast cancer patients had a higher prevalence of luminal A (67% versus 57%; P < 0.001) and a lower prevalence of basal-like subtype (9% versus 17%; P < 0.001) compared with older (>50 years) patients. The higher prevalence of luminal A subtype was mainly attributed to a higher ER (75% versus 63%; P < 0.001) and PR (47% versus 33%; P < 0.001) expression rate in younger patients than older patients. Tumors with histologic grade 3 were less prevalent in younger patients than in older patients (23% versus 30%; P = 0.01). For very young (<35 years) patients, the molecular subtype distribution, ER and/or PR expression rate, and histologic grade were not significantly different from those of less young (35-50 years) patients. Conclusions: Young breast cancer patients in Taiwan are characterized by a high prevalence of luminal A subtype and low prevalence of histologic grade 3 tumor and/or basal-like subtype. These features are distinct from young breast cancer patients in western countries. (Cancer Epidemiol Biomarkers Prev 2009;18(6):1807–14)

Prognostic significance of β‐catenin and topoisomerase IIα in de novo acute myeloid leukemia

The Wnt/β‐catenin signaling is important for controlling self‐renewal of hematopoietic stem cells and its constitutive activation has recently been documented in a significant proportion of acute myeloid leukemia (AML) cases. Topoisomerase IIα (Topo IIα) is a marker of cell proliferation and a crucial target for anthracycline cytotoxicity, the mainstay of management employed in AML. We retrospectively investigated the prognostic roles of β‐catenin and topo IIα in a cohort of 59 patients with newly diagnosed AML by immunohistochemistry. Aberrant β‐catenin expression was demonstrated in 13 patients (22%), and it was more likely to occur in those with unfavorable karyotypes. Advanced age and poor performance status adversely influenced the achievement of complete remission, while neither aberrant β‐catenin expression nor enhanced topo IIα activity did. On multivariate survival analysis, four factors independently predicted a shortened overall survival: aberrant β‐catenin expression, high topo IIα activity, poor‐risk cytogenetics, and presence of at least one comorbidity factor. Our results suggest that both β‐catenin and topo IIα independently predicted an adverse prognosis and might serve as new markers for risk stratification in AML patients. Am. J. Hematol., 2009.

erb-b2 amplification by fluorescence in situ hybridization in breast cancer specimens read as 2+ in immunohistochemical analysis

We conducted this study to ascertain the prevalence of erb-b2 gene amplification in breast cancer specimens read as 2+ in immunohistochemical analysis. Slides from patients with metastatic or recurrent breast cancer were eligible for fluorescent in situ hybridization (FISH) study if they were read as 2+ immunohistochemically for erb-b2 by a certified pathologist. The PathVysion kit (Vysis, Downers Grove, IL) was used for FISH studies. Amplification of the erb-b2 gene was defined as an erb-b2/CEP17 (chromosome 17 centromere) ratio of 2 or more in 30 tumor cells counted. From May 2003 to June 2004, 221 slides were submitted from 24 hospitals around the island. Of 216 successful hybridizations, 96 (44.4%) were determined to be erb-b2 amplified. In addition, the topoisomerase IIa gene was coamplified in 11 (21%) of 53 and deleted in 8 (15%) of 53 erb-b2 amplified cases. The erb-b2 gene amplification rate was very high in cases determined to be 2+ by immunohistochemical analysis; therefore, determination of erb-b2 status by FISH in cases scored 2+ immunohistochemically is strongly recommended.

Clinical significance of ESR1 gene copy number changes in breast cancer as measured by fluorescence in situ hybridisation

Aims The ESR1 gene encodes for oestrogen receptor (ER) α, which plays a crucial role in mammary carcinogenesis and clinical outcome in patients with breast cancer. However, the clinical significance of the ESR1 gene copy number change for breast cancer has not been clarified. Methods ESR1 gene copy number was determined by fluorescence in situ hybridisation (FISH) on tissue sections. A minimum of 20 tumour cells were counted per section, and a FISH ratio of ESR1 gene to CEP6 ≥2.0 was considered ESR1 amplification. A ratio >1.2 but <2.0 was considered ESR1 gain. The ESR1 copy number was further measured by quantitative real-time PCR (Q-PCR) with ASXL2 as a reference. Results FISH revealed ESR1 amplification in six cases (4.0%) and ESR1 gain in 13 cases (8.7%) from a total of 150 cases. ESR1 gain and amplification were more common in older patients (p<0.001), and correlated well with ER protein expression (p=0.03) measured by immunohistochemistry, and ESR1 copy number (p<0.001) measured by Q-PCR. Furthermore, the multivariate analysis revealed that ESR1 amplification was associated with a shorter disease-free survival (HR=5.56, p=0.03) and a shorter overall survival (HR=5.11, p=0.04). Conclusions In general, the frequency of ESR1 amplification in breast cancer is low when measured by FISH in large sections. ESR1 gain and amplification in breast cancer may be associated with older age and poorer outcomes.

Abstract 3867: EGFR genotype impacts expression of chemotherapeutic target biomarkers in NSCLC

BACKGROUND: Non small cell lung cancer EGFR mutations are prevalent in the East Asian population, especially in female non-smokers, the L858R and del 747-753 in exons 18-21 of the EGFR tyrosine kinase domains are activating mutations with increased sensitivity to the EGFR tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib. EGFR gene amplification also increases susceptibility to EGFR TKIs as has been reported in the IDEAL / INTACT non small cell lung cancer (NSCLC) trials. Our study evaluated chemotherapeutic target biomarkers in Chinese NSCLC patients with varying EGFR genotypes. METHODS: Seventy NSCLC patients with known EGFR genotype received chemotherapy and EGFR TKI therapy with known response and survival, their pathology specimen were retrospectively retrieved for evaluation. EGFR and KRAS were sequenced for mutations and deletions. Fluorescent in situ hybridization (FISH) was performed for EGFR genes. Immunohistochemical analyses were performed for topoisomerase 1, c-myc, RRM-1, class III beta tubulin, topoisomerase IIα, p53, thymidylate synthase, and ERCC-1. The percentage of nuclear-stained malignant cells were recorded for T IIα, T1, p53, ERCC-1, c-myc, whereas for TS, tau, RRM-1, class III beta tubulin were cytoplasmic stains, only positive or negative was reported, eventually only 63 patients had complete data for evaluation. RESULTS: Significant increase in overall survival was found in females (p=0.002), non-smokers (p=0.005), younger age (p=0.001), less advanced staging (p=0.048), EGFR mutation (p=0.038); but not with KRAS genotype, or expression of any chemotherapeutic markers. Patients in this study were consecutive patients, 60-70% received treatment. When EGFR mutant tumors were compared to EGFR wildtype tumors, the mutant tumors had lower KRAS mutation (4% vs 19%, p=0.1238), more were ERCC1- (76% vs 63%, p=0.2925), more topoisomerase 1 + (28% vs 17%, p=0.3719), less RRM1+ (24% vs 35%, p=0.4142), more TS- (93% vs 86%, p=0.4478), lower class III beta tubulin (45% vs 57%, p=0.4515). CONCLUSIONS: A difference in expression of chemotherapeutic target markers has been detected in differing EGFR genotypes, although its significance has been dampened by our small patient population, and larger patients groups will be needed to evaluate the impact of different chemotherapies on survival of the different EGFR genotype tumors. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3867. doi:10.1158/1538-7445.AM2011-3867

Palliative MEFLEP therapy in advanced pancreatic cancer: excellent response in a patient with Her-2/neu amplification.

Introduction Patients with pancreatic cancer often present initially in advanced disease with many compromising factors, and yet they may still be responsive to chemotherapy. Aims The response of 23 patients with advanced pancreatic cancer to continuous infusion therapy was investigated. Methodology From September 1995 to February 1998, 23 patients with advanced pancreatic cancer, many with compromising factors, were treated with a MEFLEP regimen: biweekly 24-hour infusions of etoposide, 5-fluorouracil, leucovorin, epirubicin, and cisplatin, all given through an infusion pump, plus megestrol acetate, 160 mg/d, taken daily. A total of 145 courses were given. Overall response rate was 21% (4/19) for assessable chemo-naive patients; median survival for all 23 patients was 6 months; 22% of patients were alive at 1 year; and a clinical response benefit was attained in 35%. Results Toxicity was manageable; grade 3 or 4 leukopenia occurred in 1 patient each, 1 patient had fever and grade 3 infection, and grade 3 and 4 hyperammonemic encephalopathy developed in 3 and 1 patients, respectively. All four of the latter patients recovered uneventfully within 2 days of initiation of therapy. Nine patients were evaluated by fluorescence in situ hybridization for the Her-2/ neu oncogene, but for only one patient did amplification of the gene occur. She attained complete remission with treatment and lived for 26.7 months after diagnosis. Conclusion Biweekly MEFLEP is an active and manageable regimen for patients with advanced pancreatic cancer with compromised clinical status.