Response to gefitinib in bronchioloalveolar carcinoma in the absence of EGFR mutation

Mutations in the tyrosine kinase (TK) domain of the epidermal growth factor receptor (EGFR) gene in non-small cell lung cancers are associated with increased sensitivity of these cancers to drugs that inhibit EGFR kinase activity such as gefitinib and erlotinib. Responses to TK inhibitors in the absence of EGFR gene mutation for BAC patients have not been reported. A case of a patient with BAC refractory to chemotherapy who responded to gefitinib in the absence of EGFR gene mutations is reported. Tyrosine kinase inhibitors may have a role in BAC in the absence of EGFR gene mutations. Additional studies on other molecular alterations of the EGFR family members are needed to better predict response to these agents.     

Frondoside A enhances the antiproliferative effects of gemcitabine in pancreatic cancer

Pancreatic cancer has a very poor prognosis. While gemcitabine is the mainstay of therapy and improves quality of life, it has little impact on survival. More effective treatments are desperately needed for this disease. Frondoside A is a triterpenoid glycoside isolated from the Atlantic sea cucumber, Cucumaria frondosa. Frondoside A potently inhibits pancreatic cancer cell growth and induces apoptosis in vitro and in vivo. The aim of the present study was to investigate whether frondoside A could enhance the anti-cancer effects of gemcitabine.Effects of frondoside A and gemcitabine alone and in combination on proliferation were investigated in two human pancreatic cancer cell lines, AsPC-1 and S2013. To investigate possible synergistic effects, combinations of low concentrations of the two drugs were used for a 72 h treatment period in vitro. Growth inhibition was significantly greater with the drug combinations than their additive effects.Combinations of frondoside A and gemcitabine were tested in vivo using the athymic mouse model. Xenografts of AsPC-1 and S2013 cells were allowed to form tumours prior to treatment with the drugs alone or in combination for 30 days. Tumours grew rapidly in placebo-treated animals. Tumour growth was significantly reduced in all treatment groups. At the lowest dose tested, gemcitabine (4 mg/kg/dose), combined with frondoside A (100 μg/kg/day) was significantly more effective than with either drug alone.To conclude: The present data suggest that combinations of frondoside A and gemcitabine may provide clinical benefit for patients with pancreatic cancer.     

A phase II trial of gefitinib monotherapy in pretreated patients with advanced non-small cell lung cancer not harboring activating EGFR mutations: implications of sensitive EGFR mutation test

Purpose

Efficacy of gefitinib therapy strongly depends on epidermal growth factor receptor (EGFR) mutation status in patients with non-small cell lung cancer (NSCLC). However, cumulative data from many clinical studies demonstrated that some patients with wild-type (WT) EGFR also responded to gefitinib with durable disease control rate (DCR). The aim of this trial was to evaluate the efficacy and toxicity of gefitinib in NSCLC patients with WT EGFR who failed previous chemotherapy.

Patients and methods

Patients with advanced or recurrent NSCLC whose tumors have WT EGFR were eligible. Gefitinib (250 mg/day) was administered until disease progression or unacceptable toxicity occurred. The primary end point was DCR at 8 weeks.

Results

A total of 85 patients (53 men and 32 women; median age, 60 years; range 30–86) were enrolled between October 2010 and May 2013. Seventy-four patients (87.1 %) had adenocarcinoma. Forty-two patients (49.4 %) were treated with gefitinib as second-line chemotherapy. Eleven patients showed partial response, and 21 had stable disease. Thus, objective response rate was 12.9 %, and DCR at 8 weeks was 37.6 %. The median progression-free survival (PFS) and overall survival were 1.9 and 10.9 months, respectively. Skin rash was the most common side effect. It is of note that patients with skin rash of any grade had improved PFS with gefitinib as compared with patients experiencing no skin rash (median PFS: 3.0 vs. 1.7 months, P = 0.004). One patient developed interstitial lung disease (grade 2). Of 11 gefitinib responders, 6 patients were identified as having tumor with activating EGFR mutation by peptide nucleic acid (PNA)-mediated PCR clamping method. Regarding the outcomes of the 79 patients, excluding 6 positive mutations, the response rate was 6.3 %, and DCR at 8 weeks was 31.8 %.

Conclusion

Small proportion of NSCLC patients with the WT EGFR benefits with gefitinib. Optimized diagnosis through more sensitive bioassay could have major consequences in terms of the selection of candidate for EGFR TKI in patients with WT EGFR by direct sequencing.

     

EGFR mutations in patients with brain metastases from lung cancer: association with the efficacy of gefitinib

Gefitinib--a specific inhibitor of epidermal growth factor receptor (EGFR)-associated tyrosine kinase--has demonstrated efficacy in a subgroup of patients with non-small-cell lung carcinoma (NSCLC) who fail conventional chemotherapy. It is also reported to have an antitumor effect in brain metastases from NSCLC. Additionally, EGFR mutations have shown a strong association with gefitinib sensitivity for NSCLC. Here, we assessed the efficacy of gefitinib in brain metastases from NSCLC and evaluated the association of this efficacy with EGFR mutations. We retrospectively reviewed eight cases in which patients were suffering from brain metastases before the initiation of gefitinib treatment. Brain tumor response could be evaluated by MRI in these patients; EGFR gene analyses were also available. We evaluated whether objective tumor response was observed after gefitinib treatment and assessed the efficacy of gefitinib as effective, noneffective, or not assessable in consideration of the influence of previous radiotherapy. Of the eight patients, the efficacy of gefitinib was assessed as effective in three and as noneffective in three. All three patients demonstrating effective efficacy had EGFR mutations in the tyrosine kinase domain (deletion mutation in two patients and point mutation in one patients), whereas none of the three patients demonstrating noneffective efficacy had EGFR mutations. Gefitinib appears to be effective in treating brain metastases in a subgroup of patients. Our data suggested a possible association between the efficacy of gefitinib in the treatment of brain metastases and EGFR mutations.     

Biglycan enhances gastric cancer invasion by activating FAK signaling pathway

Biglycan (BGN) is an important member of small leucine-rich proteoglycans family, and has been implicated in oncogenesis and development of various human cancer types. Here we report that BGN promotes tumor invasion and metastasis of gastric cancer both in vitro and in vivo. BGN expression is significantly higher in gastric cancer tissues and associated with lymph node metastasis, depth of tumor invasion and TNM stage. BGN enhances gastric cancer cell wound healing, migration and invasion ability as well as the tube formation ability of endothelial cells in vitro. Animal experiments results in vivo are consistent with outcomes in vitro. BGN induces increased phosphorylation of FAK (Tyr576/577, Tyr925 and Tyr397) and Paxillin. These results indicate that BGN is upregulated, and plays an oncogenic role, in gastric cancer metastasis by activating the FAK signaling pathway.     

Impact of physical size on gefitinib efficacy in patients with non-small cell lung cancer harboring EGFR mutations

Gefitinib is an essential drug for the treatment of non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) gene mutations. The approved dosage is 250 mg/body/day without adjustment for physical size such as body surface area (BSA), and the impact of physical size on the efficacy of gefitinib has not been evaluated. Here, we sought to clarify this issue using a retrospective cohort. We reviewed the medical records of patients with consecutive advanced NSCLC harboring EGFR mutations who underwent gefitinib monotherapy at Okayama University Hospital. In total, 101 patients were included in this study, and the median BSA in this cohort was 1.5 m². The median progression-free survival (PFS) of the patients with higher BSA (≥1.5 m²) was significantly worse than that of those with lower BSA (<1.5 m²) (10.4 vs. 18.0 months; p = 0.019, log-rank test). Multivariate analysis also showed a significant impact of BSA on PFS (hazards ratio, 2.34; 95% confidence interval, 1.78–2.89; p = 0.002). By contrast, no significant association between BSA and PFS was observed in those undergoing cytotoxic chemotherapy (4.0 vs. 5.1 months; p = 0.989, log-rank test), suggesting that BSA is a predictive, rather than a prognostic, marker for gefitinib therapy in EGFR-mutated NSCLC. In conclusion, BSA affected PFS in patients with EGFR-mutated NSCLC who underwent gefitinib monotherapy, suggesting the need for appraisal of BSA-based dose adjustment, even for this molecular target-based therapy.     

Association of PD-L1 overexpression with activating EGFR mutations in surgically resected nonsmall-cell lung cancer

BackgroundRecent clinical trials have shown that immune-checkpoint blockade yields a clinical response in a subset of individuals with advanced nonsmall-cell lung cancer (NSCLC). We examined whether the expression of programmed death–ligand 1 (PD-L1) is related to clinicopathologic or prognostic factors in patients with surgically resected NSCLC.Patients and methodsThe expression of PD-L1 was evaluated by immunohistochemical analysis in 164 specimens of surgically resected NSCLC. Cell surface expression of PD-L1 in NSCLC cell lines was quantified by flow cytometry.ResultsExpression of PD-L1 in tumor specimens was significantly higher for women than for men, for never smokers than for smokers, and for patients with adenocarcinoma than for those with squamous cell carcinoma. Multivariate analysis revealed that the presence of epidermal growth factor receptor gene (EGFR) mutations and adenocarcinoma histology were significantly associated with increased PD-L1 expression in a manner independent of other factors. Cell surface expression of PD-L1 was also significantly higher in NSCLC cell lines positive for activating EGFR mutations than in those with wild-type EGFR. The EGFR inhibitor erlotinib downregulated PD-L1 expression in the former cell lines but not in the latter, suggesting that PD-L1 expression is increased by EGFR signaling conferred by activating EGFR mutations. A high level of PD-L1 expression in resected tumor tissue was associated with a significantly shorter overall survival for NSCLC patients.ConclusionsHigh expression of PD-L1 was associated with the presence of EGFR mutations in surgically resected NSCLC and was an independent negative prognostic factor for this disease.     

EZH2 inhibition enhances the efficacy of an EGFR inhibitor in suppressing colon cancer cells

Metastatic colon cancer has a 5-year survival of less than 10% despite the use of aggressive chemotherapeutic regimens. As signaling from epidermal growth factor receptor (EGFR) is often enhanced and epigenetic regulation is often altered in colon cancer, it is desirable to enhance the efficacy of EGFR-directed therapy by co-targeting an epigenetic pathway. We showed that the histone methyltransferase EZH2, which catalyzes methylation of histone H3 lysine 27 (H3K27), was upregulated in colon cancers in The Cancer Genome Atlas (TCGA) database. Since co-inhibition of both EGFR and EZH2 has not been studied in colon cancer, we examined the effects of co-inhibition of EGFR and EZH2 on 2 colon cancer cell lines, HT-29 and HCT-15. Co-inhibition of EZH2 and EGFR with the small molecules UNC1999 and gefitinib, led to a significant decrease in cell number and increased apoptosis compared to inhibition of either pathway alone, and similar results were noted after EZH2 shRNA knockdown. Moreover, co-inhibition of EZH2 and EGFR also significantly induced autophagy, indicating that autophagy may play a role in the observed synergy. Together, these findings suggest that inhibition of both EZH2 and EGFR serves as an effective method to increase the efficacy of EGFR inhibitors in suppressing colon cancer cells.     

Comparison of gefitinib and erlotinib in advanced NSCLC and the effect of EGFR mutations

Introduction

Erlotinib and gefitinib are tyrosine kinase (TK) inhibitors of epidermal growth factor receptor (EGFR) that are effective in treating non-small cell lung cancer (NSCLC). This study aimed to compare their clinical uses and the influence of EGFR mutation.

Methods

The usages of erlotinib and gefitinib in advanced NSCLC were analyzed. Clinical data and EGFR mutational status of tumors were collected.

Results

Seven hundred and sixteen (716) patients received gefitinib (n = 440) or erlotinib (n = 276) for stage IIIb or IV NSCLC. Erlotinib was prescribed more frequently than gefitinib in males (58.2% vs. 41.8%, p < 0.001), smokers (60.5% vs. 39.5%, p < 0.001), and non-adenocarcinoma (70.6% vs. 29.4%, p < 0.001). Of the 716 study patients, 327 underwent testing for EGFR mutations (170 with mutant EGFR and 157 with wild-type EGFR). Adenocarcinoma in patients with mutant EGFR and non-smoker status in patients with wild-type EGFR were associated with better overall survival after TK inhibitor treatment. In both patient groups with mutant EGFR or wild-type EGFR, the effectiveness of gefitinib and erlotinib, including drug response or overall survival, were not different.

Conclusions

Our study revealed the obvious disparity in drug selection between erlotinib and gefitinib in clinical practice. Type of TK inhibitors did not influence treatment outcomes in patients with EGFR mutation or wild-type EGFR.     

Epidermal growth factor receptor (EGFR) is overexpressed in anaplastic thyroid cancer, and the EGFR inhibitor gefitinib inhibits the growth of anaplastic thyroid cancer.

PURPOSE: No effective treatment options currently are available to patients with anaplastic thyroid cancer (ATC), resulting in high mortality rates. Epidermal growth factor (EGF) has been shown to play a role in the pathogenesis of many types of cancer, and its receptor (EGFR) provides an attractive target for molecular therapy. EXPERIMENTAL DESIGN: The expression of EGFR was determined in ATC in vitro and in vivo and in human tissue arrays of ATC. We assessed the potential of the EGFR inhibitor gefitinib ("Iressa," ZD1839) to inhibit EGFR activation in vitro and in vivo, inhibit ATC cellular proliferation, induce apoptosis, and reduce the growth of ATC cells in vivo when administered alone and in combination with paclitaxel. RESULTS: EGFR was overexpressed in ATC cell lines in vitro and in vivo and in human ATC specimens. Activation of EGFR by EGF was blocked by the addition of gefitinib. In vitro studies showed that gefitinib greatly inhibited cellular proliferation and induced apoptosis in ATC cell lines and slowed tumor growth in a nude mouse model of thyroid carcinoma cells injected subcutaneously. CONCLUSIONS: ATC cells consistently overexpress EGFR, rendering this receptor a potential target for molecular therapy. Gefitinib effectively blocks activation of EGFR by EGF, inhibits ATC cellular proliferation, and induces apoptosis in vitro. Our in vivo results show that gefitinib has significant antitumor activity against ATC in a subcutaneous nude mouse tumor model and therefore is a potential candidate for human clinical trials.     

Clinical outcomes and secondary epidermal growth factor receptor (EGFR) T790M mutation among first-line gefitinib,erlotinib and afatinib-treated non-small cell lung cancer patients with activating EGFR mutations

Gefitinib, erlotinib and afatinib are approved for first-line treatment of advanced non-small cell lung cancer (NSCLC) bearing an activating epidermal growth factor receptor (EGFR) mutation. However, the clinical outcomes among the three EGFR tyrosine kinase inhibitors (TKIs) are still controversial. We aimed to evaluate clinical outcomes and secondary EGFR T790M mutation among the three EGFR TKIs. From May 2014 to January 2016, a total of 301 patients received treatment with gefitinib, erlotinib or afatinib, for first-line treatment of advanced NSCLC with an activating EGFR mutation, based on their clinicians’ choice. The median overall survival (OS) was 37.0 months. Although the baseline characteristics of patients were unequal, progression-free survival and OS did not differ among the 3 groups. Multivariate analysis found that gefitinib (adjusted odds ratio [aOR] 3.29, 95% confidence interval [CI], 1.15–9.46, p = 0.027), EGFR TKI treatment duration more than 13 months (aOR 3.16, 95% CI, 1.20–8.33, p = 0.020), male (aOR 3.25, 95% CI, 1.10–9.66, p = 0.034), initial liver metastasis (aOR 4.97, 95% CI 1.18–20.96, p = 0.029) and uncommon EGFR mutation (aOR 0.14, 95% CI, 0.02–0.97, compared to EGFR deletion 19, p = 0.047) were independent factors for secondary T790M mutation. In real-world practice, choosing first line EGFR TKI based on the patients’ clinical characteristics yielded good clinical outcomes. First-line gefitinib, longer EGFR TKI treatment duration, male, initial liver metastasis and uncommon EGFR mutations may be independent factors for secondary EGFR T790M mutation.     

PF00299804, an irreversible pan-ERBB inhibitor, is effective in lung cancer models with EGFR and ERBB2 mutations that are resistant to gefitinib

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors gefitinib and erlotinib are effective treatments for a subset of non-small cell lung cancers. In particular, cancers with specific EGFR-activating mutations seem to be the most sensitive to these agents. However, despite their initial response, such cancers almost invariably develop resistance. In 50% of such cancers, a secondary EGFR mutation, T790M, has been identified that renders gefitinib and erlotinib ineffective inhibitors of EGFR kinase activity. Thus, there is a clinical need to develop novel EGFR inhibitors that can effectively inactivate T790M-containing EGFR proteins. In this study, we evaluate the effectiveness of a novel compound, PF00299804, an irreversible pan-ERBB inhibitor. The results from these studies show that PF00299804 is a potent inhibitor of EGFR-activating mutations as well as the EGFR T790M resistance mutation both in vitro and in vivo. Additionally, PF00299804 is a highly effective inhibitor of both the wild-type ERBB2 and the gefitinib-resistant oncogenic ERBB2 mutation identified in lung cancers. These preclinical evaluations support further clinical development of PF00299804 for cancers with mutations and/or amplifications of ERBB family members.     

DNA methyltransferase inhibitor 5-aza-CdR enhances the radiosensitivity of gastric cancer cells

The National Comprehensive Cancer Network guidelines recommend radiotherapy as a standard treatment for patients with a high risk of recurrence in gastric cancer. Because radiation is harmful to the surrounding organs, a radiation sensitizer might therefore be useful to decrease the side effects of patients with advanced gastric carcinoma. The aim of the current study was to clarify the effect of a DNA methyltransferase inhibitor, 5-aza-2'-deoxycytidine (CdR), on radiation sensitivity in gastric cancer cells. Five gastric cancer cell lines, OCUM-2M, OCUM-12, KATO-III, MKN-45, and MKN-74, were used. The effects of 5-aza-CdR with irradiation on the growth activity, cell-cycle distribution, apoptosis, and apoptosis-associated gene expression were examined. 5-aza-CdR sensitized three of five gastric cancer cell lines to radiation. A combination of irradiation and 5-aza-CdR significantly ( P <  0.05) decreased the growth activity compared with irradiation alone in OCUM-2M, OCUM-12, and MKN-45 cells, but not in KATO-III and MKN-74 cells. The percentage of cells in G₂–M phase and the apoptotic rate with irradiation in combination with 5-aza-CdR were increased in OCUM-2M, OCUM-12, and MKN-45 cells compared with irradiation alone, but not in KATO-III and MKN-74 cells. 5-aza-CdR increased the expression of p53 , RASSF1 , and death-associated protein kinases (DAPK) genes compared with the control or irradiation alone. These findings suggest that 5-aza-CdR might therefore be useful as a radiation sensitizer to treat some types of gastric carcinoma. The arrest at G₂–M phase and increased apoptotic rate might be partly mediated by enhanced expression of the p53 , RASSF1 , or DAPK gene families by 5-aza-CdR. ( Cancer Sci 2009; 100: 181–188)     

AZD3409 inhibits the growth of breast cancer cells with intrinsic resistance to the EGFR tyrosine kinase inhibitor gefitinib

AKT and MAPK signaling are involved in the resistance of breast cancer cells to the EGFR tyrosine kinase inhibitor gefitinib. RAS proteins are upstream mediators that transfer messages from surface receptors to intracellular signal transducers including MAPK and AKT pathways. AZD3409 is a novel prenyl inhibitor that has shown activity against both farnesyl transferase and geranylgeranyl transferase in isolated enzyme studies. We explored the activity of AZD3409 on breast cancer cell lines with high (SK-Br-3), intermediate (MDA-MB-361) or low (MDA-MB-468) sensitivity to gefitinib. We found that AZD3409 inhibits the growth of breast cancer cells in a dose-dependent manner, with the MDA-MB-468 and MDA-MB-361 cell lines showing higher sensitivity as compared with SK-Br-3 cells. Treatment with AZD3409 produced a significant reduction in the levels of activation of AKT in the three cell lines. AZD3409 also induced an increase in the expression of p27kip-1 and of hypophosphorylated forms of pRb2 in MDA-MB-468 cells that was associated with accumulation of cells in G0/G1 and the appearance of a sub-G1 peak suggestive of apoptosis. In contrast, AZD3409 produced a G2 arrest associated with reduced expression of pRb2 in MDA-MB-361 cells. A synergistic anti-tumor effect was observed when MDA-MB-468 or MDA-MB-361 cells were treated with both AZD3409 and gefitinib, whereas this combination was only additive in SK-Br-3 cells. However, treatment of breast cancer cells with AZD3409 and gefitinib did not produce a more significant blockade of AKT signaling as compared with gefitinib alone. These data suggest that AZD3409 might be active in gefitinib-resistant breast carcinoma.     

Combined epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor and chemotherapy in non-small-cell lung cancer: Chemo-refractoriness of cells harboring sensitizing-EGFR mutations in the presence of gefitinib

Background

Combined epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) with chemotherapy is believed to be more effective in treating non-small-cell lung cancer (NSCLC) with sensitizing-EGFR mutation (SEM). This hypothesis failed to be realized clinically and needs to be examined in vitro.

Materials and methods

Using the tetrazolium colorimetric assay and classical isobole method, we investigated the combination effects of 6 gefitinib-chemotherapeutic doublets (gefitinib/cisplatin, gemcitabine, pemetrexed, paclitaxel, docetaxel, or vinorelbine) in a panel of 15 NSCLC cell lines.

Results

Upon treatment with the 6 gefitinib-chemotherapeutic doublets, the 12 cell lines that did not harbor SEM displayed a broad spectrum of group results, from obvious synergism to robust antagonism. The values of group mean combination index (mCIs) ranged from 0.769 to 1.201. In contrast, the 3 cell lines with SEM showed a tendency toward consistent antagonism to the tested doublets, impressively, with a narrow range of higher group mCIs (0.993–1.141). In the presence of gefitinib, the SEM or gefitinib-sensitive group was more chemo-refractory than the non-SEM (index of chemo-refractoriness (RI): 69.33 versus 42.67; P = 0.036) or gefitinib-resistant group (68.25 versus 40.64, P = 0.0108), respectively. The results of using the gefitinib/drug combinations with the gefitinib-sensitive non-SEM cell line H322 and the gefitinib-resistant EGFR mutant H820 shared patterns similar to those with the SEM and non-SEM cell lines, respectively.

Conclusion

Gefitinib-treated EGFR-TKI-sensitive NSCLC cells showed a wide spectrum of chemo-refractoriness, suggesting that concomitantly combined EGFR-TKI-chemotherapy might not be a good treatment strategy for NSCLC harboring SEM.