Do-Youn Oh

Predictive and Prognostic Impact of Epidermal Growth Factor Receptor Mutation in Non–Small-Cell Lung Cancer Patients Treated With Gefitinib

PURPOSE This study was undertaken to investigate the effects of epidermal growth factor receptor (EGFR) mutation and its downstream signaling on response and survival in non-small-cell lung cancer (NSCLC) patients treated with gefitinib. PATIENTS AND METHODS For 90 consecutive NSCLC patients who had received gefitinib, EGFR mutation was analyzed by DNA sequencing of exons 18, 19, 21, and 23 in the EGFR tyrosine kinase domain. Expressions of phosphorylated (p) -Akt and p-Erk were determined via immunohistochemistry. Response rate, time to progression (TTP), and overall survival were compared between each group according to EGFR mutation, as well as p-Akt and p-Erk expression. RESULTS Seventeen patients (18.9%; 95% CI, 10.8 to 27.0) harbored EGFR mutations. These mutations include deletions in exon 19 in seven patients, L858R in six patients, G719A in three patients, and a novel A859T in one patient. Response rate in patients with EGFR mutation was 64.7% (11 of 17 patients; 95% CI, 42.0 to 87.4), in contrast to 13.7% (10 of 73 patients; 95% CI, 5.8 to 21.6) in patients without mutation (P < .001). Moreover, these 17 patients with EGFR mutation had significantly prolonged TTP (21.7 v 1.8 months; P < .001) and overall survival (30.5 v 6.6 months; P < .001) compared with the remaining 73 patients without mutation. Although no significant correlation was detected between EGFR mutation and expressions of p-Akt or p-Erk, p-Akt overexpression was associated with prolonged TTP in patients with EGFR mutation. CONCLUSION Our data further support the importance of EGFR mutation with regard to gefitinib sensitivity. In addition to its predictive role, EGFR mutation confers significant survival benefits on NSCLC patients treated with gefitinib.

Ki-67 can be used for further classification of triple negative breast cancer into two subtypes with different response and prognosis

IntroductionTriple negative breast cancer (TNBC) has a poorer survival, despite a higher response rate to neoadjuvant chemotherapy. The purpose of this study was to identify the predictive or prognostic value of Ki-67 among patients with TNBC treated with neoadjuvant chemotherapy, and the role of Ki-67 in further classification of TNBC.MethodsA total of 105 TNBC patients who received neoadjuvant docetaxel/doxorubicin chemotherapy were included in the present study. Pathologic complete response (pCR) rate, relapse-free survival (RFS), and overall survival (OS) were compared according to the level of Ki-67.ResultspCR was observed in 13.3% of patients. TNBC with high Ki-67 expression (≥10%) showed a higher pCR rate to neoadjuvant chemotherapy than TNBC with low Ki-67 expression. None of the low Ki-67 group achieved pCR (18.2% in the high Ki-67 group vs. 0.0% in the low Ki-67 group, P = 0.019). However, a high Ki-67 expression was significantly associated with poor RFS and OS in TNBC, despite a higher pCR rate (P = 0.005, P = 0.019, respectively). In multivariate analysis, high Ki-67 was an independent prognostic factor for RFS in TNBC (hazard ratio = 7.82, P = 0.002). The high Ki-67 group showed a similar pattern of recurrence with overall TNBC, whereas the low Ki-67 group demonstrated a relatively constant hazard rate for relapse.ConclusionsTNBC with high Ki-67 was associated with a more aggressive clinical feature despite a higher pCR rate. High proliferation index Ki-67 can be used for further classification of TNBC into two subtypes with different responses and prognosis.

Prognostic impact of clinicopathologic parameters in stage II/III breast cancer treated with neoadjuvant docetaxel and doxorubicin chemotherapy: paradoxical features of the triple negative breast cancer

BackgroundPrognostic factors in locally advanced breast cancer treated with neoadjuvant chemotherapy differ from those of early breast cancer. The purpose of this study was to identify the clinical significance of potential predictive and prognostic factors in breast cancer patients treated by neoadjuvant chemotherapy.MethodsA total of 145 stage II and III breast cancer patients received neoadjuvant docetaxel/doxorubicin chemotherapy were enrolled in this study. We examined the clinical and biological factors (ER, PR, p53, c-erbB2, bcl-2, and Ki-67) by immunohistochemistry. We analyzed clinical outcome and their correlation with clinicopathologic parameters.ResultsAmong the clinicopathologic parameters investigated, none of the marker was correlated with response rate (RR) except triple negative phenotype. Patients with triple negative phenotype showed higher RR (83.0% in triple negative vs. 62.2% in non-triple negative, p = 0.012) and pathologic complete RR (17.0% in triple negative vs. 3.1% in non-triple negative, p = 0.005). However, relapse free survival (RFS) and overall survival (OS) were significantly shorter in triple negative breast cancer patients (p < 0.001, p = 0.021, respectively). Low histologic grade, positive hormone receptors, positive bcl-2 and low level of Ki-67 were associated with prolonged RFS. In addition, positive ER and positive bcl-2 were associated with prolonged OS. In our homogeneous patient population, initial clinical stage reflects RFS and OS more precisely than pathologic stage. In multivariate analysis, initial clinical stage was the only significant independent prognostic factor to impact on OS (hazard ratio 3.597, p = 0.044).ConclusionSeveral molecular markers provided useful predictive and prognostic information in stage II and III breast cancer patients treated with neoadjuvant docetaxel/doxorubicin chemotherapy. Triple negative phenotype was associated with shorter survival, even though it was associated with a higher response rate to neoadjuvant chemotherapy.

The clinicopathologic characteristics and prognostic significance of triple-negativity in node-negative breast cancer.

BackgroundTriple-negative (TN) breast cancer, which is defined as being negative for the estrogen receptor (ER), the progesterone receptor (PR), and the human epidermal growth factor receptor 2 (HER-2), represents a subset of breast cancer with different biologic behaviour. We investigated the clinicopathologic characteristics and prognostic indicators of lymph node-negative TN breast cancer.MethodsMedical records were reviewed from patients with node-negative breast cancer who underwent curative surgery at Seoul National University Hospital between Jan. 2000 and Jun. 2003. Clinicopathologic variables and clinical outcomes were evaluated.ResultsAmong 683 patients included, 136 had TN breast cancer and 529 had non-TN breast cancer. TN breast cancer correlated with younger age (< 35 y, p = 0.003), and higher histologic and nuclear grade (p < 0.001). It also correlated with a molecular profile associated with biological aggressiveness: negative for bcl-2 expression (p < 0.001), positive for the epidermal growth factor receptor (p = 0.003), and a high level of p53 (p < 0.001) and Ki67 expression (p < 0.00). The relapse rates during the follow-up period (median, 56.8 months) were 14.7% for TN breast cancer and 6.6% for non-TN breast cancer (p = 0.004). Relapse free survival (RFS) was significantly shorter among patients with TN breast cancer compared with those with non-TN breast cancer (4-year RFS rate 85.5% vs. 94.2%, respectively; p = 0.001). On multivariate analysis, young age, close resection margin, and triple-negativity were independent predictors of shorter RFS.ConclusionTN breast cancer had higher relapse rate and more aggressive clinicopathologic characteristics than non-TN in node-negative breast cancer. Thus, TN breast cancer should be integrated into the risk factor analysis for node-negative breast cancer.

A randomised, double-blind, placebo-controlled trial of trametinib, an oral MEK inhibitor, in combination with gemcitabine for patients with untreated metastatic adenocarcinoma of the pancreas

BACKGROUND Trametinib, an oral mitogen/extracellular signal-related kinase (MEK)1/2 inhibitor, holds promise for malignancies with rat sarcoma (RAS) mutations, like pancreas cancer. This phase II study was designed to determine overall survival (OS) in patients with pancreas cancer treated with trametinib and gemcitabine. Secondary end-points included progression-free survival (PFS), overall response rate (ORR) and duration of response (DOR); safety end-points were also assessed. METHODS Adults with untreated metastatic adenocarcinoma of the pancreas were randomised (1:1) to receive intravenous gemcitabine 1000 mg/m(2) (weekly × 7 for 8 weeks, then days 1, 8 and 15 of 28-day cycles) plus trametinib or placebo 2mg daily. RAS mutations were determined in circulating free DNA (cfDNA) and archival tumour tissue. OS was evaluated in kirsten rat sarcoma viral oncogene homolog (KRAS) mutant and wild-type subgroups. RESULTS Baseline characteristics for 160 patients were similar in both treatment arms. There was no significant difference in OS (hazard ratio (HR) 0.98; 95% confidence interval (CI), 0.67-1.44; P=.453); median OS was 8.4 months with gemcitabine plus trametinib and 6.7 months with gemcitabine plus placebo. Median PFS (16 versus 15 weeks), ORR (22% versus 18%) and median DOR (23.9 versus 16.1 weeks) were also similar for trametinib and placebo arms, respectively. KRAS mutation-positive patients (n=103) showed no difference in OS between arms. Thrombocytopenia, diarrhoea, rash and stomatitis were more frequent with trametinib, as was grade 3 anaemia. CONCLUSIONS The addition of trametinib to gemcitabine did not improve OS, PFS, ORR or DOR in patients with previously untreated metastatic pancreas cancer. Outcomes were independent of KRAS mutations determined by cfDNA.

The growth inhibitory effect of lapatinib, a dual inhibitor of EGFR and HER2 tyrosine kinase, in gastric cancer cell lines ☆

HER2 overexpression is observed in 5-25% of gastric cancers. Lapatinib is a dual inhibitor of the epidermal growth factor receptor and HER2 tyrosine kinase. We examined the antitumor effect of lapatinib in gastric cancer cell lines. Lapatinib induced selective and potent growth inhibition in two HER2-amplified gastric cancer cell lines (SNU-216 and NCI-N87). Lapatinib inhibited the phosphorylation of HER2, EGFR and downstream signaling proteins, resulting in G1 arrest in both cell lines with down-regulation of cMyc and induction of p27kip1. Lapatinib also induced apoptosis in NCI-N87 which has high HER2 amplification ratio. Lapatinib combined with 5-fluorouracil, cisplatin, oxaliplatin or paclitaxel showed an additive or synergistic effect. These results provide a rationale for the future clinical trials of lapatinib combined with cytotoxic drugs in the treatment of HER2-positive gastric cancer.

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are effective for leptomeningeal metastasis from non-small cell lung cancer patients with sensitive EGFR mutation or other predictive factors of good response for EGFR TKI

The purpose of this study was to demonstrate the beneficial effect of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in the treatment of leptomeningeal metastasis (LM) for a select group of non-small cell lung cancer (NSCLC) patients who had a sensitive EGFR mutation or good predictive clinical factors for EGFR TKI treatment. Eleven patients with NSCLC and LM were treated with a standard dose of erlotinib (n=9), or higher than standard dose of gefitinib followed by erlotinib (n=2). They were treated with various therapies including whole brain radiotherapy or intrathecal chemotherapy for CNS lesion previously and concurrently with EGFR TKI. Nine of 11 patients showed overt improvement in ECOG performance status. Six patients were alive >6 months, and 2 additional patients were alive 2.5+ and 4.4+ months with clinical improvement. Two patients showed responses to higher than standard dose of gefitinib. The median overall survival was not reached. In conclusion, EGFR TKIs are effective in the treatment of LM from NSCLC when patients were selected properly.

Aggressiveness of Cancer-Care near the End-of-Life in Korea

OBJECTIVE The aim of this study was to examine the appropriateness of chemotherapy and care in Korean cancer patients near the end-of-life. METHODS We designed a retrospective cohort composed of patients diagnosed as having metastatic cancer and who received palliative chemotherapy at Seoul National University Hospital in 2002. Two hundred and ninety-eight patients who died of cancer were evaluated in terms of the appropriateness of the cancer-care they received, including chemotherapy. RESULTS Median duration of chemotherapy was 6.02 months compared with 8.67 months for median overall survival. The median period between last chemotherapy and death was 2.02 months. Of the 298 patients, 50.3% received chemotherapy during the last 2 months of life. Furthermore, 17 patients (5.7%) died within 2 weeks after receiving chemotherapy. The proportion who visited an emergency room (ER) more than once during the last months of life was 33.6%, and the average number of ER visits after a diagnosis of cancer was 1.72. Only 9.1% of patients were referred to a hospice consultation service and only 11.7% of patients agreed with written DNR. CONCLUSIONS Among patients who died of cancer, significant proportions were found to have received chemotherapy up to the end-of-life and to have visited ERs. Hospice referrals and discussions about DNR were not conducted well during the end-of-life period in Korea.

Lapatinib, a Dual EGFR and HER2 Tyrosine Kinase Inhibitor, Downregulates Thymidylate Synthase by Inhibiting the Nuclear Translocation of EGFR and HER2

Background Epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) has been shown to exert a synergistic antitumor effect when combined with fluoropyrimidine. This synergy may be attributable to the downregulation of thymidylate synthase (TS), which is frequently overexpressed in fluoropyrimidine-resistant cancer cells. However, the molecular mechanism underlying the downregulation of TS has yet to be clearly elucidated. Methodology and Principal Findings In this study, we demonstrate that lapatinib, a dual TKI of EGFR and HER2 downregulates TS via inhibition of the nuclear translocation of EGFR and HER2. From our cDNA microarray experiments, we determined that a variety of nucleotide synthesis-related genes, including TS, were downregulated with lapatinib, and this was apparent in HER2-amplified cells. Targeted and pharmacologic inhibition assays confirmed that the dual inhibition of EGFR and HER2 is required for the more effective reduction of TS as compared to what was observed with gefitinib or trasutuzumab alone. Additionally, we determined that co-transfected EGFR and HER2 activate the TS gene promoter more profoundly than do either EGFR or HER2 alone. The translocation of EGFR and HER2 into the nucleus and the subsequent activation of the TS promoter were inhibited by lapatinib. Conclusions and Significance These results demonstrate that lapatinib inhibits the nuclear translocation of EGFR and HER2 and downregulates TS, thus sensitizing cancer cells to fluoropyrimidine.

Class II histone deacetylases play pivotal roles in heat shock protein 90-mediated proteasomal degradation of vascular endothelial growth factor receptors

Vascular endothelial growth factor receptors (VEGFRs) perform pivotal roles in both tumor growth and angiogenesis. In this study, we report that histone deacetylase inhibitors (HDIs) induce a reduction in VEGFR1 and VEGFR2 protein expression via the inhibition of class II histone deacetylases (HDACs) in human cancer cell lines. After HDI treatment, VEGFR1 and VEGFR2 were shown to be downregulated in a proteasome-dependent manner. HDI treatment induced a reduction in the binding of heat shock protein (Hsp) 90 to VEGFR1 or VEGFR2, followed by an increase of the binding of Hsp70 to VEGFR1 or VEGFR2. However, we noted no remarkable changes in the binding of Hsp90/Hsp70 to VEGFR3. HDI treatment effectively inhibited the activities of HDAC6 and HDAC10. Furthermore, the knock-down of HDAC6 or HDAC10, which was accomplished via the siRNA transfection, induced depletion of VEGFR1 or VEGFR2 proteins. Overall, these results indicate that HDAC6 and HDAC10 play important roles in Hsp-mediated VEGFR regulation.