• Journal of Korean Neurosurgical Society
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• v.64 no.6
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• pp.983-994
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• 2021

Objective : The effectiveness of gamma knife radiosurgery (GKR) in the treatment of brain metastases is well established. The aim of this study was to evaluate the efficacy and safety of maximizing the radiation dose in GKR and the factors influencing tumor control in cases of small and medium-sized brain metastases from non-small cell lung cancer (NSCLC). Methods : We analyzed 230 metastatic brain tumors less than 5 mL in volume in 146 patients with NSCLC who underwent GKR. The patients had no previous radiation therapy for brain metastases. The pathologies of the tumors were adenocarcinoma (n=207), squamous cell carcinoma (n=18), and others (n=5). The radiation doses were classified as 18, 20, 22, and 24 Gy, and based on the tumor volume, the tumors were categorized as follows : small-sized (less than 1 mL) and medium-sized (1-3 and 3-5 mL). The progression-free survival (PFS) of the individual 230 tumors and 146 brain metastases was evaluated after GKR depending on the pathology, Eastern Cooperative Oncology Group (ECOG) performance score (PS), tumor volume, radiation dose, and anti-cancer regimens. The radiotoxicity after GKR was also evaluated. Results : After GKR, the restricted mean PFS of individual 230 tumors at 24 months was 15.6 months (14.0-17.1). In small-sized tumors, as the dose of radiation increased, the tumor control rates tended to increase (p=0.072). In medium-sized tumors, there was no statistically difference in PFS with an increase of radiation dose (p=0.783). On univariate analyses, a statistically significant increase in PFS was associated with adenocarcinomas (p=0.001), tumors with ECOG PS 0 (p=0.005), small-sized tumors (p=0.003), radiation dose of 24 Gy (p=0.014), synchronous lesions (p=0.002), and targeted therapy (p=0.004). On multivariate analyses, an improved PFS was seen with targeted therapy (hazard ratio, 0.356; 95% confidence interval, 0.150-0.842; p=0.019). After GKR, the restricted mean PFS of brain at 24 months was 9.8 months (8.5-11.1) in 146 patients, and the pattern of recurrence was mostly distant within the brain (66.4%). The small and medium-sized tumors treated with GKR showed radiotoxicitiy in five out of 230 tumors (2.2%), which were controlled with medical treatment. Conclusion : The small-sized tumors were effectively controlled without symptomatic radiation necrosis as the radiation dose was increased up to 24 Gy. The medium-sized tumors showed potential for symptomatic radiation necrosis without signifcant tumor control rate, when greater than 18 Gy. GKR combined targeted therapy improved the tumor control of GKR-treated tumors.

• Journal of Chest Surgery
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• v.54 no.4
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• pp.239-245
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• 2021

Video-assisted thoracoscopic surgery (VATS) has been established as the surgical approach of choice for lobectomy in patients with early-stage non-small cell lung cancer (NSCLC). Patients with clinical stage I NSCLC with no lymph node metastasis are considered candidates for VATS lobectomy. To rule out the presence of metastasis to lymph nodes or distant organs, patients should undergo meticulous clinical staging. Assessing patients' functional status is required to ensure that there are no medical contraindications, such as impaired pulmonary function or cardiac comorbidities. Although various combinations of the number, size, and location of ports are available, finding the best method of port placement for each surgeon is fundamental to maximize the efficiency of the surgical procedure. When conducting VATS lobectomy, it is always necessary to comply with the following oncological principles: (1) the vessels and bronchus of the target lobe should be individually divided, (2) systematic lymph node dissection is mandatory, and (3) touching the lymph node itself and rupturing the capsule of the lymph node should be minimized. Most surgeons conduct the procedure in the following sequence: (1) dissection along the hilar structure, (2) fissure division, (3) perivascular and peribronchial dissection, (4) individual division of the vessels and bronchus, (5) specimen retrieval, and (6) mediastinal lymph node dissection. Surgeons should obtain experience in enhancing the exposure of the dissection target and facilitating dissection. This review article provides the basic principles of the surgical techniques and practical maneuvers for performing VATS lobectomy easily, safely, and efficiently.

• Journal of Korean Neurosurgical Society
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• v.60 no.1
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• pp.21-29
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• 2017

Objective : The purpose of this study was to analyze outcomes and identify prognostic factors in patients with cerebral metastases from non-small cell lung cancer (NSCLC) treated with gamma knife radiosurgery (GKS) particularly, focusing on associations of biomarkers and systemic treatments. Methods : We retrospectively reviewed the medical records of 134 patients who underwent GKS for brain metastases due to NSCLC between January 2002 and December 2012. Representative biomarkers including epidermal growth factor receptor (EGFR) mutation, K-ras mutation, and anaplastic lymphoma kinase (ALK) mutation status were investigated. Results : The median overall survival after GKS was 22.0 months (95% confidence interval [CI], 8.8-35.1 months). During follow-up, 63 patients underwent salvage treatment after GKS. The median salvage treatment-free survival was 7.9 months (95% CI, 5.2-10.6 months). Multivariate analysis revealed that lower recursive partition analysis (RPA) class, small number of brain lesions, EGFR mutation (+), and ALK mutation (+) were independent positive prognostic factors associated with longer overall survival. Patients who received target agents 30 days after GKS experienced significant improvements in overall survival and salvage treatment-free survival than patients who never received target agents and patients who received target agents before GKS or within 30 days (median overall survival: 5.0 months vs. 18.2 months, and 48.0 months with p-value=0.026; median salvage treatment-free survival: 4.3 months vs. 6.1 months and 16.6 months with p-value=0.006, respectively). To assess the influence of target agents on the pattern of progression, cases that showed local recurrence and new lesion formation were analyzed according to target agents, but no significant effects were identified. Conclusion : The prognosis of patients with brain metastases of NSCLC after GKS significantly differed according to specific biomarkers (EGFR and ALK mutations). Our results show that target agents combined with GKS was related to significantly longer overall survival, and salvage treatment-free survival. However, target agents were not specifically associated with improved local control of the lesion treated by GKS either development of new lesions. Therefore, it seems that currently popular target agents do not affect brain lesions themselves, and can prolong survival by controlling systemic disease status.

• Journal of Chest Surgery
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• v.23 no.5
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• pp.881-886
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• 1990

Thirty-three patients less than 40 years of age were diagnosed at CS Dept. of Catholic University Medical College between 1979 and 1988 as having primary lung cancer. There were 22 men and 11 women; the average age was 36.3 years. The youngest patients was 23 years old. Eighteen male patients were only habitual smokers more than 1 pack per day. In the 33 cases, the distribution by tumor type was as follows: squamous cell carcinoma 36.4%[13 cases]; adenocarcinoma 33.3%[11 cases]; small cell carcinoma 24.2%[8 cases]; and large cell carcinoma 3.0%[1 case]. At the time of diagnosis, 2 patients[6.1%] had stage I disease, 2[6.1%] had stage II disease, 5[15.6%] had stage IIIA disease, 10[30.3%] had stage lllB disease, and 14[42.4%] had stage IV disease. Thirteen patients[36.4%] underwent an exploratory thoracotomy. Of these patients, 9[27.3%] had surgical resection[six lobectomies, two pneumonectomies, and one wedge resection]. Thirty-one patients were treated with palliative radiation therapy, chemotherapy, or combinations of each. The survival rate at 1 year, 3 year, and 5 year were 48.2%, 14.5%, and 8.3% respectively. But in the resectable 9 patients, they were 78.1%, 43.6%, and 33.3% respectively.

• Journal of Life Science
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• v.34 no.7
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• pp.520-530
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• 2024

Tumor suppressor genes (TSGs) play a crucial role in maintaining cellular homeostasis. When the function of these genes is lost, it can lead to cellular plasticity that drives the development of various cancers, including small-cell lung cancer (SCLC), which is known for its aggressive nature. SCLC is primarily driven by numerous loss-of-function mutations in TSGs, often involving genes that encode epigenetic regulators. These mutations pose a significant therapeutic challenge as they are not directly targetable. However, understanding the molecular changes resulting from these mutations might provide insights for developing tumor intervention strategies. We propose that despite the heterogeneous genomic landscape of SCLC, the effects of mutations in patient tumors converge on a few critical pathways that drive malignancy. Specifically, alterations in epigenetic regulators lead to transcriptional dysregulation, pushing mutant cells toward a highly plastic state that makes them immune evasive and highly metastatic. This review will highlight studies showing how an imbalance of epigenetic regulators with opposing functions leads to the loss of immune recognition markers, effectively hiding tumor cells from the immune system. Additionally, we will discuss the role of epigenetic regulators in maintaining neuroendocrine features and how aberrant transcriptional control promotes epithelial-to-mesenchymal transition during tumor development. Although these pathways seem distinct, we emphasize that they often share common molecular drivers and mediators. Understanding the connection among frequently altered epigenetic regulators will provide valuable insights into the molecular mechanisms underlying SCLC development, potentially revealing preventive and therapeutic vulnerabilities for SCLC and other cancers with similar mutations.

• Radiation Oncology Journal
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• v.9 no.1
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• pp.81-85
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• 1991

The differentiation between post-radiotherapy lung fibrosis and tumor recurrence is often a dilemma to physicians. Twenty two patients with lung cancer who had received 45~60 Gy to the chest were chosen to study the possible role of gallium-67 scan. Seventeen squamous cell carcinomas were treated with only radiotherapy, 3 small cell carcinomas with combination chemotherapy, 2 adenocarcinomas with lobectomy. A total of 8 patients with pneumonitis with or without fibrosis and recurrence showed uptake of gallium at the site of inflammation. Of the 12 recurrences and residual diseases after radiotherapy, positive gallium uptake was present in 11 cases (92%). Of the 10 recurrence-free cases, all the 5 patients with pneumonitis revealed gallium accumulation. However, 4 of the 5 patients (80%) with recurrence-free fibrosis have not accumulated gallium in the fibrotic areas. Fibroses in S patients were developed after 8 months of completion of radiotherapy. These facts suggest that gallium-67 scan after 1 year post-treatment may aid for the discrimination of fibrosis from tumor recurrence unless pneumonitis is present.

• Tuberculosis and Respiratory Diseases
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• v.58 no.4
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• pp.359-366
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• 2005

Background : IGFBP-3 inhibits the mitogenic and anti-apoptotic activity of IGF by blocking the binding of IGF to its receptor. However, under certain circumstances, IGFBP-3 can enhance the activity of IGF by protecting IGF from its degradation. More than half of the interindividual variations in IGFBP-3 levels are known to be genetically determined by the polymorphism at -202 locus of IGFBP-3 gene. Method : We attempted to ascertain whether A-202C polymorphic variation of IGFBP-3 gene constitutes a risk factor for non-small cell lung cancer (NSCLC), using PCR-restriction fragment length polymorphism (RFLP). Our study included 104 NSCLC patients and 104 age-, gender-, and smoking status-matched control subjects. Result : In the 104 NSCLC subjects, the genotypic frequencies at the -202 site were as follows: AA = 67 (64.4%), AC = 35 (33.7%), and CC = 2 (1.9%). We did detect significant differences in the genotypic distribution between the NSCLC and the control subjects (p<0.05), and the NSCLC risk correlated significantly with AA genotype at the -202 locus (AA>AC>CC). Using CC genotype as a reference, the odds ratio (OR) for the subjects with AC genotype was 2.60 (95% CI: 0.89 - 8.60), and the OR associated with AA genotype was 5.89 (95% CI: 1.92 - 21.16). Conclusion : These results indicate that the dysregulation of IGF axis should now be considered as another important risk factor for NSCLC, and a potential target for novel antineoplastic therapies and/or preventative strategies in high-risk groups.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7719-7724
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• 2013

Background: Overexpression of survivin, a known inhibitor of apoptosis, is associated with tumor progression and drug resistance in numerous malignancies, including leukemias. The aim of this study was to investigate the effect of a specific survivin small interference RNA (siRNA) on proliferation and the sensitivity of HL-60 acute myeloid leukemia (AML) cells to the chemotherapeutic drug etoposide. Materials and Methods: The cells were transfected with siRNAs using Lipofectamine $^{TM}2000$ transfection reagent. Relative survivin mRNA and protein levels were measured by quantitative real-time PCR and Western blotting, respectively. Trypan blue exclusion assays were performed to monitor tumor cell proliferation after siRNA transfection. The cytotoxic effects of etoposide and survivin siRNA, alone and in combination, on leukemic cells were determined using MTT assay. Apoptosis was assessed by ELISA cell death assay. Results: Survivin siRNA markedly reduced both mRNA and protein expression levels in a time-dependent manner, leading to distinct inhibition of cell proliferation and increased spontaneous apoptosis. Surprisingly, survivin siRNA synergistically increased the cell toxic effects of etoposide. Moreover, survivin down-regulation significantly enhanced its induction of apoptosis. Conclusions: Our study suggests that down-regulation of survivin by siRNA can trigger apoptosis and overcome drug resistance of leukemia cells. Therefore, survivin siRNA may be an effective adjuvant in AML chemotherapy.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.7
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• pp.4279-4282
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• 2013

Background: The activation and inactivation of receptor tyrosine kinases are tightly regulated to ensure faithful replication of cells. After having transduced extracellular growth activating signals, activated EGFR is subjected to downregulation either by clathrin mediated endocytosis or c-Cbl mediated proteasome degradation depending on the ligand concentration. c-Cbl is an ubiquitin ligase which requires a phosphorylated tyrosine residue at position 1045 in the cytoplasmic domain of EGFR to interact and add ubiquitin molecules. While activating mutations in exons 19 and 21 have been associated with the development of several cancers, the status of mutations at tyrosine 1045 coding exon 27 of EGFR remain to be investigated. Consistently, defective phosphorylation at 1045 has been associated with sustained phosphorylation of EGFR in non-small lung carcinomas. Hence in the present study we investigated the genetic status of the tyrosine 1045 coding site within exon 27 of EGFR gene to explore for possible occurrence of mutations in this region, especially since no studies have addressed this issue so far. Materials and Methods: Tumor chromosomal DNA isolated from thirty five surgically excised oral squamous cell carcinoma tissues was subjected to PCR amplification with intronic primers flanking the tyrosine 1045 coding exon 27 of EGFR gene. The PCR amplicons were subsequently subjected to direct sequencing to elucidate the mutation status. Results: Sequence analysis identified no mutations in the tyrosine 1045 codon of EGFR in any of the thirty five samples that were analyzed. Conclusions: The lack of identification of mutation in the tyrosine 1045 codon of EGFR suggests that mutations in this region may be relatively rare in oral squamous cell carcinomas. To the best of our knowledge, this study is the first to have explored the genetic status of exon 27 of EGFR in oral squamous cell carcinoma tissue samples.

• Tuberculosis and Respiratory Diseases
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• v.76 no.3
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• pp.114-119
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• 2014

Background: Epigallocatechin-3-gallate (EGCG), a major biologically active component of green tea, has anti-cancer activity in human and animal models. We investigated the schedule-dependent effect of EGCG and paclitaxel on growth of NCI-H460 non-small cell lung cancer cells. Methods: To investigate the combined effect of EGCG (E) and paclitaxel (P), combination indices (CIs) were calculated, and cell cycle analysis was performed. For the effect on cell apoptosis, western blot analysis was also performed. Results: CI analysis demonstrated that both concurrent and sequential E ${\rightarrow}$ P treatments had antagonistic effects (CIs >1.0), but sequential P ${\rightarrow}$ E had synergistic effects (CIs <1.0), on the growth inhibition of NCI-H460 cells. In the cell cycle analysis, although paclitaxel induced $G_2/M$ cell cycle arrest and increased the sub-G1 fraction, concurrent EGCG and paclitaxel treatments did not have any additive or synergistic effects compared with the paclitaxel treatment alone. However, western blot analysis demonstrated that sequential P ${\rightarrow}$ E treatment decreased the expression of Bcl-2 and procaspase-3 and increased poly(ADP-ribose) polymerase (PARP) cleavage; while minimal effects were seen with concurrent or sequential E ${\rightarrow}$ P treatments. Conclusion: Concurrent or sequential E ${\rightarrow}$ P treatment had opposite effects to P ${\rightarrow}$ E treatment, where P ${\rightarrow}$ E treatment showed a synergistic effect on growth inhibition of NCI-H460 cells by inducing apoptosis. Thus, the efficacy of EGCG and paclitaxel combination treatment seems to be schedule-dependent.