EGFR inhibitors with concurrent thoracic radiation therapy for locally advanced non-small cell lung cancer

Prognostic implications of combining EGFR-TKIs and radiotherapy in Stage IV lung adenocarcinoma with 19-Del or 21-L858R mutations: A real-world study

OBJECTIVE

To elucidate the potential benefits of combining radiotherapy and epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) for individuals with Stage IV lung adenocarcinoma (LUAD) harboring either exon 19 deletion (19-Del) or exon 21 L858R mutation (21-L858R).

METHODS

In this real-world retrospective study, 177 individuals with Stage IV LUAD who underwent EGFR-TKIs and radiotherapy at Shandong Cancer Hospital from June 2012 to August 2017 were included. The main focus of this real-world study was overall survival (OS).

RESULTS

The clinical characteristics of patients with Stage IV LUAD harboring 19-Del were similar to those harboring 21-L858R (p > 0.05). Overall, the patients had a median OS (mOS) of 32.0 months (95% confidence interval [CI]: 28.6-35.5). Subsequently, multivariate analysis indicated that both EGFR mutations and thoracic radiotherapy were independent predictors of OS (p = 0.001 and 0.013). Furthermore, subgroup analysis highlighted a longer OS for the 19-Del group compared to the 21-L858R group, especially when EGFR-TKIs were combined with bone metastasis or thoracic radiotherapy (mOS: 34.7 vs. 25.1 months and 51.0 vs. 29.6 months; p = 0.0056 and 0.0013, respectively). However, no significant differences were found in OS when considering patients who underwent brain metastasis radiotherapy (mOS: 34.7 vs. 25.1 months; p = 0.088).

CONCLUSIONS

Patients with Stage IV LUAD harboring 19-Del experience a notably prolonged OS following combined therapy with EGFR-TKIs and radiotherapy, while this OS benefit is observed despite the absence of substantial differences in the clinical characteristics between the 19-Del and 21-L858R groups.

Systemic Therapy for Mutation-Driven NSCLC

Lung cancer is the leading cause of cancer deaths worldwide, and patients with nonsmall cell lung cancer have traditionally had a poor prognosis. An improved understanding of targetable oncogenic molecular alterations has led to a growing number of effective and first-line therapies in targeted patient populations. This review provides an overview of systemic therapy options available for patients with mutation-driven nonsmall cell lung cancer, as well as a discussion of data regarding safety when combined with radiation therapy.

Stereotactic radiotherapy in targeted therapy treated oligo-metastatic oncogene-addicted (non-small-cell) lung cancer

While the prognosis of metastatic non-small-cell lung cancer has shown significant progress these last years, notably with the discovery of oncogen-driven subtypes and the development of targeted therapies, significant improvements are still needed. More recently, numerous authors studied the oligo-metastasis concept, where the metastasis are limited in number and sites involved, and that could benefit from an aggressive approach of these lesions, for instance with the help of stereotactic radiotherapy. Nevertheless, there is no clear consensus existing for the time being for the treatment of these tumors. Three main clinical situations can be distinguished: oligo-metastasis state de novo at diagnosis (synchronous) or as first metastatic event of an initially locally limited affection (metachronous); oligo-progression during systemic treatment of a pluri-metastatic disease; and finally oligo-persistence of some remaining metastatic lesions at the nadir of the systemic therapy effect. In this review, we will discuss the place of stereotactic radiotherapy in the treatment of non-small-cell oligo-metastatic oncogene-addicted cancers treated with targeted therapies, differentiating these three main clinical situations. In all these indications, this technique could provide a benefit in terms of local control, possibly even in specific survival, when associated with targeted therapy continuation, related to local control of the oligo-metastatic cerebral or extracerebral lesions.

Efficacy of gefitinib and radiotherapy combination in Indonesian patients with lung adenocarcinoma

INTRODUCTION

Combinations of gefitinib and radiotherapy have been observed to have synergistic and anti-proliferative effects on lung cancer in vitro. In the clinical setting, patients who presented with respiratory difficulties such as superior vena cava syndrome (SVCS), radiotherapy should be given immediately to address the emergency while waiting for the results of epidermal growth factor receptor (EGFR) mutation test. However, there has been no study that described the role of radio-therapy in Indonesian patients with EGFR-mutant lung adenocarcinoma.

METHODS

This preliminary study aimed to evaluate the efficacy and toxicities of gefitinib and radiotherapy combination in lung adenocarcinoma patients in Persahabatan National Respiratory Referral Hospital, Jakarta, Indonesia. Subjects were consecutively recruited between January 2013 and December 2016.

RESULTS

Thirty-one lung adenocarcinoma with EGFR mutations were enrolled. Most of them were male (51.61%) with a median age of 54.5 years old (range 38-70 years old). EGFR mutation characteristics were on exon 21 L858R point mutation (61.30%), exon 21 L861Q point mutation (16.12%) and exon 19 deletion (22.58%). Radiotherapy was given at doses between 30-60 Gy. Among these subjects, median progression-free survival (PFS) was 185 days (95%CI; 123.69 - 246.30), 1-year survival rate (1-yr) was 45.2%, and median overall survival (OS) was 300 days (95%CI; 130.94 - 469.06). There were no grade 3/4 hematological and nonhematological toxicities recorded. The most frequent grade 1 and 2 non-hematological toxicities were skin rash, diarrhea, and paronychia that might be related to tyrosine kinase inhibitor (TKI).

CONCLUSION

The combination of TKI with radiation may be considered in EGFR-mutant lung adenocarcinoma subjects.

Combination of S-1 and gefitinib increases the sensitivity to radiotherapy in lung cancer cells

OBJECTIVE

To investigate the potential radiosensitization of S-1 and gefitinib in human non-small cell lung cancer (NSCLC) in vitro and in vivo.

METHODS

The impact of radiation, 5-fluorouracil (5-Fu), and gefitinib on the proliferation and apoptosis of human NSCLC A549, H1299, H1975, and HCC827 cells was examined by MTT and flow cytometry. The effect of radiation, 5-Fu, and gefitinib on the clonogenicity of H1975 and HCC827 cells was determined by colony formation assay. The effect of radiation, 5-fluorouracil (5-Fu), and gefitinib on the EGFR, AKT, and ERK1/2 activation in H1975 cells was determined by Western blot. The therapeutic efficacy of radiation, S-1, and gefitinib in the growth of implanted H1975 tumors and the AKT activation in the tumors were examined in vivo and immunohistochemistry, respectively.

RESULTS

Combination of radiation, 5-Fu, and gefitinib significantly inhibited the proliferation of H1975 cells and triggered their apoptosis, but not other NSCLC cells tested. The combination therapy significantly mitigated the clonogenicity and attenuated the activation of EGFR and AKT signaling in H1975 cells. Furthermore, combination of S-1, gefitinib, and radiation significantly inhibited the growth of implanted H1975 tumors in mice and remarkably reduced the AKT phosphorylation in the tumors.

CONCLUSIONS

Our data indicated that combination of S-1 and gefitinib significantly increased radiosensitivity of H1975 cells. The triple combination therapies may benefit patients with the EGFR T790M mutant NSCLC.

Impact of EGFR mutations and KRAS amino acid substitution on the response to radiotherapy for brain metastasis of non-small-cell lung cancer

BACKGROUND

Our study aimed to evaluate response rate (RR) to brain metastasis radiotherapy (RT), depending on the genomic status of non-small-cell lung cancer.

MATERIAL & METHODS

We retrospectively reviewed 1971 non-small-cell lung cancer files of patients with EGFR and KRAS testing and focused on 157 patients who had undergone RT for brain metastasis.

RESULTS

A total of 16 patients (10.2%) harbored EGFR mutations (mEGFR) and 45 patients (28.7%) KRAS (mKRAS). In univariate analysis, RR was significantly higher for mEGFR compared with wild-type EGFR/KRAS (odds ratio [OR]: 4.96; p = 0.05) or mKRAS (OR: 1.81; p = 0.03). In multivariate analysis, KRAS G12V or G12C status was associated with both poor RR (OR: 0.1; p < 0.0001) and overall survival (OR: 3.41; p < 0.0001).

CONCLUSION

mEGFR are associated with higher RR to brain RT than wild-type EGFR/RAS or mKRAS.

Treatment with a Small Synthetic Compound, KMU-193, induces Apoptosis in A549 Human Lung Carcinoma Cells through p53 Up-Regulation

Despite recent advances in therapeutic strategies for lung cancer, mortality still is increasing. In the present study, we investigated the anti-cancer effects of KMU-193, 2-(4-Ethoxy-phenyl)-N-{5-[2-fluoro-4-(4-methyl- piperazine-1-carbonyl)-phenylamino]-1H-indazol-3-yl}-acetamide in a human non-small cell lung cancer cell line A549. KMU-193 strongly inhibited the proliferation of A549 cells, but it did not have anti-proliferative effect in other types of cancer cell lines. KMU-193 further induced apoptosis in association with activation of caspase-3 and cleavage of PLC-γ1. However, KMU-193 had no apoptotic effect in untransformed cells such as TMCK-1 and BEAS-2B. Interestingly, pretreatment with z-VAD-fmk, a pan-caspase inhibitor, strongly abrogated KMU- 193-induced apoptosis. KMU-193 treatment enhanced the expression levels of p53 and PUMA. Importantly, p53 siRNA transfection attenuated KMU-193-induced apoptosis. Collectively, these results for the first time demonstrate that KMU-193 has strong apoptotic effects on A549 cells and these are largely mediated through caspase-3- and p53-dependent pathways.

In vitro synergistic antitumor efficacy of sequentially combined chemotherapy/icotinib in non‑small cell lung cancer cell lines

The concurrent administration of chemotherapy and epidermal growth factor receptor‑tyrosine kinase inhibitors (EGFR‑TKIs) has previously produced a negative interaction and failed to confer a survival benefit to non‑small cell lung cancer (NSCLC) patients compared with first‑line cytotoxic chemotherapy. The present study aimed to investigate the optimal schedule of the combined treatment of cisplatin/paclitaxel and icotinib in NSCLC cell lines and clarify the underlying mechanisms. HCC827, H1975, H1299 and A549 human NSCLC cell lines with wild‑type and mutant EGFR genes were used as in vitro models to define the differential effects of various schedules of cisplatin/paclitaxel with icotinib treatments on cell growth, proliferation, cell cycle distribution, apoptosis, and EGFR signaling pathway. Sequence‑dependent antiproliferative effects differed among the four NSCLC cell lines, and were not associated with EGFR mutation, constitutive expression levels of EGFR or downstream signaling molecules. The antiproliferative effect of cisplatin plus paclitaxel followed by icotinib was superior to that of cisplatin or paclitaxel followed by icotinib in the HCC827, H1975, H1299 and A549 cell lines, and induced more cell apoptosis and G0/G1 phase arrest. Cisplatin and paclitaxel significantly increased the expression of EGFR phosphorylation in the HCC827 cell line. However, only paclitaxel increased the expression of EGFR phosphorylation in the H1975 cell line. Cisplatin/paclitaxel followed by icotinib influenced the expression of p‑EGFR and p‑AKT, although the expression of p‑ERK1/2 remained unchanged. The results suggest that the optimal schedule of the combined treatment of cisplatin/paclitaxel and icotinib differed among the NSCLC cell lines. The results also provide molecular evidence to support clinical treatment strategies for NSCLC patients.

Role of radiotherapy in metastatic non-small cell lung cancer

Radiotherapy has had important role in the palliation of NSCLC. Randomized trials tend to suggest that, in general, short regimens give similar palliation and toxicity compared to longer regimens. The benefit of combining chemotherapy to radiosensitize the palliative radiation treatment is an open question, but so far it has not been proved to be very useful in NSCLC. The addition of molecular targeted drugs to radiotherapy outside of approved regimens or clinical trials warrants careful consideration for every single case and probably should not be used as a routine management. Stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT) are modern techniques being used each time more frequently in the treatment of single or oligometastases. In general, they offer good tumor control with little toxicity (with a more expensive cost) compared to the traditionally fractionated radiotherapy regimens.

Isogenic radiation resistant cell lines: development and validation strategies

PURPOSE

The comparison of cell lines with differing radiosensitivities and their molecular response to radiation exposure has been used in a number of human cancer models to study the molecular response to radiation. This review proposes to analyze and compare the protocols used by investigators for the development and validation of these isogenic models of radioresistance.

CONCLUSION

There is large variability in the strategies used to generate and validate isogenic models of radioresistance. Further characterization of these models is required.

Clinical characteristics of brain metastases from lung cancer according to histological type: Pretreatment evaluation and survival following whole-brain radiotherapy

The histological type of lung cancer in patients with brain metastases may affect response to treatment and survival. We evaluated the clinical characteristics of brain metastases from lung cancer according to histological type in 70 consecutive patients with brain metastases from histologically confirmed lung cancer, who had been previously treated with whole-brain radiotherapy (WBRT). Histological type was divided into three categories: adenocarcinoma, small-cell lung carcinoma (SCLC) and other non-small cell lung cancer (NSCLC). The number, size and maximum diameter of brain metastases, the size and maximum diameter of peritumoral edema, the ratio of tumor and peritumoral edema, the asymptomatic ratio, the tumor size reduction rate, the complete response (CR) rate, the intracranial progression-free survival (PFS) and the overall survival (OS) were also evaluated. The median survival time for all patients was 26.2 weeks. Patients with SCLC exhibited a significantly smaller edema size and maximum diameter of edema compared to patients with other NSCLC (P=0.016 and 0.010, respectively). The ratio of tumor and peritumoral edema was also significantly lower in patients with SCLC compared to that in patients with adenocarcinoma and other NSCLC (P= 0.001). Significant differences in intracranial PFS and OS between adenocarcinoma and other NSCLC were also observed (P=0.018 and 0.004, respectively). Patients with adenocarcinoma who were treated with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) following WBRT, demonstrated a significant improvement in intracranial PFS and OS (P=0.008 and 0.004, respectively). The findings presented in this study may provide useful information for the management of brain metastases. Patients with SCLC exhibit a tendency to develop peritumoral edema to a lesser extent, compared to patients with other histological tumor types. Findings in the present study suggest that patients with adenocarcinoma, particularly those treated with EGFR-TKIs, exhibit improved survival rates.

Regulatory mechanisms and clinical perspectives of miRNA in tumor radiosensitivity

MicroRNA (miRNA) influences carcinogenesis at multiple stages and it can effectively control tumor radiosensitivity by affecting DNA damage repair, cell cycle checkpoint, apoptosis, radio-related signal transduction pathways and tumor microenvironment. MiRNA also efficiently modulates tumor radiosensitivity at multiple levels by blocking the two essential non-homologous end-joining repair and homologous recombination repair pathways in the DNA damage response. It interferes with four radio-related pathways in ionizing radiation, including the PI3-K/Akt, NF-κB, MAPK and TGFβ signaling pathways. Moreover, the regulatory effect of miRNA in radiosensitivity can be enhanced when interacting with various key molecules, including H2AX, BRCA1, ATM, DNA-PK, RAD51, Chk1, Cdc25A, p53, PLK1, HIF-1 and VEGF, which are involved in these processes. Therefore, thoroughly understanding the mechanism of miRNA in tumor radiosensitivity could assist in finding novel targets to improve the radiotherapeutic effects and provide new clinical perspectives and insights for developing effective cancer treatments.