Im Il Na

Epithelial to mesenchymal transition derived from repeated exposure to gefitinib determines the sensitivity to EGFR inhibitors in A549, a non-small cell lung cancer cell line

Epithelial to mesenchymal transition (EMT) has been reported to be related with reduced sensitivity to EGFR tyrosine kinase (EGFR-TK) inhibitors. We performed this study to investigate whether this phenomenon would play a role in acquired resistance to gefitinib. In this study, we established a gefitinib-resistant subline (A549/GR), which was derived from the parental A549 cell line by chronic, repeated exposure to gefitinib. Compared with the A549 cells, the A549/GR cells were approximately 7.7-fold more resistant to gefitinib and they showed the cross-resistance against other EGFR-TK inhibitors, including CL-387,758, erlotinib and ZD6478. Phenotypic changes such as a spindle-cell shape and increased pseudopodia formation suggesting EMT was present in the A549/GR cells. These changes were accompanied by a decrease of E-cadherin and an increase of vimentin, which is a mesenchymal marker. In addition, the ability of invasion and migration was increased in the A549/GR cells. TGF-beta1 treatment for 72 h also induced EMT in the A549 cells and this transition led to resistance to gefitinib. Conversely, this was reversed through the removal of TGF-beta1. In conclusion, induction of EMT may contribute to the decreased efficacy of therapy in primary and acquired resistance to gefitinib.

EGFR Mutation and Brain Metastasis in Pulmonary Adenocarcinomas

Background: This study aimed to explore the potential association of mutation in the epidermal growth factor receptor (EGFR) with brain metastases in patients with pulmonary adenocarcinoma. Methods: We analyzed clinical data on 314 patients who were tested for EGFR mutation and underwent brain magnetic resonance imaging at diagnosis. The relationship between EGFR mutation status and brain metastases at the initial presentation was analyzed. In addition, prognostic significance of EGFR mutational status on the risk of brain metastasis was evaluated in subgroups of surgically treated patients. Results: Of the 314 patients, 138 patients (43.9%) had EGFR mutations. The frequency of EGFR mutation was statistically higher for patients with brain metastases (64.7%, brain metastases; 39.8%, no metastases; 40.2%, extracranial metastases; p = 0.005). A strong association between EGFR mutation status and brain metastasis was observed (adjusted odds ratio = 3.83, p = 0.001), whereas no association was observed between EGFR mutation status and extracranial metastases (adjusted odds ratio = 1.73, p = 0.079). In addition, the number of brain metastases was significantly correlated with the EGFR mutation status (p = 0.029). Further analysis of 133 patients treated with surgical resection showed that EGFR mutation status was a poor prognostic factor for the risk of brain metastasis (hazard ratio = 4.49, p = 0.026) after adjustment for pathologic N stage. Conclusions: We found a significant association between EGFR mutation and risk of brain metastases at the time of diagnosis and follow-up after curative resection for pulmonary adenocarcinoma. This result indicates the distinct clinical features of EGFR-mutated tumors in terms of brain metastases.

The Role of MET Activation in Determining the Sensitivity to Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors

The development of resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKI) seems almost inevitable, even in patients with lung cancer that initially respond well to EGFR-TKIs. MET amplification was recently found to be a mechanism of escape from the anticancer effect of EGFR inhibitors. In the present study, we investigated the means whereby MET affects sensitivity to EGFR-TKIs in PC-9 cells. Gefitinib- or erlotinib-resistant sublines were established by exposing the parental PC-9 cell line to chronic, repeated treatments with these drugs. These resistant sublines showed more than 100-fold more resistance to gefitinib and erlotinib and acquired cross-resistance to other EGFR-TKIs. The T790M EGFR mutation was found by pyrosequencing, and this seemed to be the cause of drug resistance. Resistant cells also showed MET activation, although gene amplification was not detected. Furthermore, the induction of MET activity was not found to be associated with sensitivity to EGFR-TKIs. Interestingly, increased passage number without exposure to gefitinib or erlotinib caused MET activation, but this did not affect sensitivity to EGFR-TKIs. In addition, hepatocyte growth factor was found to block the ability of EGFR-TKIs to inhibit MET activation. However, sustained MET activation by hepatocyte growth factor did not modulate the cellular effects of gefitinib or erlotinib. Rather, activated MET enhanced migration and invasion abilities. Summarizing, MET activation may be acquired during cancer cell proliferation and enhances migratory and invasive abilities without affecting cellular sensitivity to EGFR-TKIs. Accordingly, the present study suggests that MET activation caused by factors other than MET gene amplification is not a suitable surrogate marker of resistance to EGFR-TKIs. (Mol Cancer Res 2009;7(10):1736–43)

18F-FDG uptake and EGFR mutations in patients with non-small cell lung cancer: A single-institution retrospective analysis

This retrospective study was performed to evaluate a possible association between the presence of epidermal growth factor receptor (EGFR) mutations and the standardized uptake value (SUV) of (18)F-fluoro-2-deoxy-glucose ((18)F-FDG) uptake in patients with non-small cell lung cancer (NSCLC). We included 100 patients who were tested for EGFR mutations by direct sequencing of resected tissues and who underwent preoperative positron emission tomography/computed tomography at the time of diagnosis. The maximum SUV by the primary tumor was chosen for further analysis. EGFR mutations in exons 19 and 21 were detected in 21 NSCLC patients (21%). EGFR mutations were more frequent in never-smokers than ever-smokers (35% versus 11%; P=0.003), in adenocarcinomas than non-adenocarcinomas (34% versus 6%; P=0.001), and in females than males (41% versus 12%; P=0.001). The SUV ranged from 1.3 to 33.0 (median 10.6). Area under receiver operating characteristic curve for SUVs in respect to the presence of EGFR mutations was 0.74 (95% CI: 0.62-0.85). When a cut off value was used, patients with low SUVs were more likely to have EGFR mutations than those with high SUVs (40% versus 11%; P=0.001). On multivariate analysis, a low SUV remained a significant predictors for EGFR mutations (P=0.025). (18)F-FDG uptake was associated with the presence of EGFR mutation. These results extrapolate that (18)F-FDG uptake might be helpful to discriminate patients who harbor EGFR mutations, especially when a genetic test is not feasible.

18F-Fluoro-2-Deoxy-Glucose Uptake Predicts Clinical Outcome in Patients with Gefitinib-Treated Non–Small Cell Lung Cancer

Purpose: To evaluate response and survival according to 18F-fluoro-2-deoxy-glucose uptake at presentation in patients with gefitinib-treated non–small cell lung cancer. Experimental Design: We retrospectively analyzed 84 positron emission tomography/computed tomography findings. Patient characteristics, response rates, and survivals were evaluated according to the maximum standardized uptake value (SUV) of primary tumor. The cutoff value of SUVs was obtained from receiver operating characteristic analysis. Results: The response rate (RR) was higher for never-smokers (41%) than ever-smokers (9%; P = 0.001). Patients with adenocarcinoma showed higher RR than those with other tumor histopathology (35% versus 9%; P = 0.009). The SUV was significantly lower in patients who were never-smokers (P = 0.005), patients with adenocarcinoma (P < 0.001), and female patients (P = 0.017). Patients with a low SUV showed higher RR compared with those with a high SUV (53% versus 18%; P = 0.003). Prolonged progression-free survival was observed in patients with low SUVs compared with those with high SUVs (median, 33.1 weeks versus 8.6 weeks; P = 0.003). While controlling for performance status, smoking history, and pathology, the high SUV conferred unfavorable outcome (hazard ratio, 2.3; P = 0.012). In terms of overall survival, a low SUV was associated with favorable outcome in univariate analysis (P = 0.011). Patients with a low SUV showed prolonged survival in multivariate analysis (P = 0.043). Conclusions: These results suggest that low SUVs at presentation can predict favorable response and survival in gefitinib-treated non–small cell lung cancer patients.

Association Between Age at Diagnosis and the Presence of EGFR Mutations in Female Patients with Resected Non-small Cell Lung Cancer

Background: Our previous report showed an association between age and outcome in gefitinib-treated female patients with non-small cell lung cancer (NSCLC). Only limited numbers of molecular studies have been performed with respect to the presence of epidermal growth factor receptor (EGFR) mutations according to age. This retrospective study was performed to evaluate a possible association between age at the time diagnosis and the presence of EGFR mutations in female patients with NSCLC. Methods: Tumor specimens were collected retrospectively from paraffin blocks of 98 female patients with primary NSCLC who underwent surgical resection between January 1992 and December 2002 at the Korea Cancer Center Hospital. To detect EGFR mutations, a Scorpion Amplified Refractory Mutation System was used. Results: Most of the study population comprised never smokers (84%) and patients with adenocarcinoma (82%). The age at the time of diagnosis ranged from 34 to 74 years (median, 57 years). When the median age was used as a cutoff value, older patients were more likely to have EGFR mutations than younger patients (70 versus 39%; p = 0.004). After controlling for the effects of histology, smoking history, and stage, age remained a significant predictor for EGFR mutations (odds ratio, 4.03; 95% confidence interval, 1.61–10.09; p = 0.003). Conclusions: Our data suggest that age at the time of diagnosis in female patients with NSCLC may be associated with the frequency of EGFR mutations, a strong indicator for favorable outcomes.

Prognostic factors for classifying extranodal NK/T cell lymphoma, nasal type, as lymphoid neoplasia

This study evaluated the applicability of prognostic factors commonly used for diagnosis of classical lymphoma outcomes to extranodal NK/T cell lymphoma, nasal type (NTCL). Clinical features and their associations with lactate dehydrogenase (LDH) were evaluated in 70 patients. RLDH was defined as the ratio of LDH to the upper normal limit. RLDH was associated with stage (I–II vs. III–IV), lymph node involvement (LNI), and International Prognostic Index score (<2 vs. ≥2). Poor performance status and advanced stage were common in patients with local tumor invasiveness (LTI). LDH level, classified into three levels (low, high, and very high) was associated with survival (P < 0.001). In multivariate analysis, the predictive values of LDH level, B symptom, performance status, and stage remained significant whereas those of LTI and LNI did not. Scoring was performed by weighting each factor with 0.5 or 1.0 according to its hazard ratio. Scores were classified into four groups. Groups with high scores were associated with unfavorable outcomes (P < 0.001). Current study suggests that prognostic factors for NHL may be useful to predict the outcome of NTCL but the model should take LDH level and the prognostic weight of each factor into account.

Phase II Study of Low-dose Paclitaxel and Cisplatin as a Second-line Therapy after 5-Fluorouracil/Platinum Chemotherapy in Gastric Cancer

This study was performed to evaluate the efficacy and toxicity of low-dose paclitaxel/cisplatin chemotherapy in patients with metastatic or recurrent gastric cancer that had failed 5-fluorouracil/platinum-based chemotherapy. Thirty-two patients with documented progression on or within 6 months after discontinuing 5-fluorouracil/platinum-based chemotherapy were enrolled. As a second-line treatment, paclitaxel (145 mg/m2) and cisplatin (60 mg/m2) was administered on day 1 every 3 weeks. Among 32 patients enrolled, 8 (25%) responded partially to paclitaxel/cisplatin, 8 (25%) had stable disease, and 14 (44%) had progressive disease. Two patients (6%) were not evaluable. The median time to progression (TTP) and overall survival for all patients were 2.9 months and 9.1 months, respectively. The most common hematologic toxicity was anemia (47%). Grade 3 neutropenia developed in three patients (9%), but no other grade 3/4 hematologic toxicity occurred. The most common non-hematologic toxicities were emesis (31%) and peripheral neuropathy (38%). Three cases (9%) of grade 3/4 emesis and 2 cases (6%) of grade 3 peripheral neuropathy developed. In conclusion, low-dose paclitaxel and cisplatin chemotherapy showed moderate activity with favorable toxicity profiles. However, relatively short TTP of this regimen warrants the development of more effective paclitaxel-based regimens other than combination with cisplatin in these patients as second-line therapies.

Primary Gastric Choriocarcinoma: Two Case Reports and Review of the Literatures

Primary gastric choriocarcinoma (PGC) is a rare tumor, and its pathogenesis is still uncertain. Most PGCs have been reported to possess an adenocarcinoma component of variable extent, and pure PGC is especially rare. The diagnosis of PGC is confirmed by exhibition of choriocarcinomatous components on biopsy and exhibition of beta-hCG positive cell on immunohistochemical stain and elevation of the serum beta-hCG. Moreover it must be confirmed that no other site including gonads displays any tumor masses. The PGC tends to be more invasive and to have early metastasis. The median survival is known to be less than several months. We report two cases. The first case was a 62 year-old man who was diagnosed as advanced gastric cancer (AGC) by endoscopic biopsy with hepatic metastasis and received palliative chemotherapy with modified FOLFOX regimen and Genexol plus cisplatin regimen. He underwent subtotal gastrectomy due to perforation of the stomach during chemotherapy. On post-operative biopsy, He was re-diagnosed as PGC and received another palliative chemotherapy modified FOLFIRI, BEP, EMACO, VIP. However, multiple liver metastases were aggravated, and also serum AFP level increased. Ultimately, the patient died 10 months after initial diagnosis. Another case was a 45 year-old man. On endoscopic biopsy, he was diagnosed as AGC of adenocarcinoma. On Chest and Abdomen CT, multiple pulmonary and hepatic metastasis were also confirmed. On liver biopsy, He was diagnosed as PGC. The immunohistochemical stains were performed and the results were cytokeratin positive, EMA negative and beta-hCG weak positive. The serum beta-hCG level was highly elevated. BEP, VIP and EMA/CO combination therapy were administered, but he died at 12th months after the initial diagnosis.

High incidence of mucosa-associated lymphoid tissue in primary thyroid lymphoma: a clinicopathologic study of 18 cases in the Korean population.

The present study aimed to evaluate the clinicopathologic features and treatment outcomes of patients with primary thyroid lymphoma (PTL). The patients included 14 women and four men with a median age of 50 years (range 31 – 82 years). Thirteen cases involved the thyroid alone (stage IE) and five cases involved the regional lymph nodes (stage IIE). Histopathologic studies revealed marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) in 13 patients and diffuse large B-cell lymphoma (DLBCL) in three patients. The other two patients showed features of both MALT and DLBCL. Surgery and chemotherapy with or without radiotherapy were performed. All patients achieved complete remission. All 18 patients were alive with a median follow-up period of 55 months. The prognosis of patients with primary thyroid lymphoma appears to be favourable.