Clinical development of a blood biomarker using apolipoprotein-A2 isoforms for early detection of pancreatic cancer.

BACKGROUND: We have previously reported apolipoprotein A2-isoforms (apoA2-is) as candidate plasma biomarkers for early-stage pancreatic cancer. The aim of this study was the clinical development of apoA2-is. METHODS: We established a new enzyme-linked immunosorbent sandwich assay for apoA2-is under the Japanese medical device Quality Management System requirements and performed in vitro diagnostic tests with prespecified end points using 2732 plasma samples. The clinical equivalence and significance of apoA2-is were compared with CA19-9. RESULTS: The point estimate of the area under the curve to distinguish between pancreatic cancer (n = 106) and healthy controls (n = 106) was higher for apoA2-ATQ/AT [0.879, 95% confidence interval (CI): 0.832-0.925] than for CA19-9 (0.849, 95% CI 0.793-0.905) and achieved the primary end point. The cutoff apoA2-ATQ/AT of 59.5 µg/mL was defined based on a specificity of 95% in 2000 healthy samples, and the reliability of specificities was confirmed in two independent healthy cohorts as 95.3% (n = 106, 95% CI 89.4-98.0%) and 95.8% (n = 400, 95% CI 93.3-97.3%). The sensitivities of apoA2-ATQ/AT for detecting both stage I (47.4%) and I/II (50%) pancreatic cancers were higher than those of CA19-9 (36.8% and 46.7%, respectively). The combination of apoA2-ATQ/AT (cutoff, 59.5 µg/mL) and CA19-9 (37 U/mL) increased the sensitivity for pancreatic cancer to 87.7% compared with 69.8% for CA19-9 alone. The clinical performance of apoA2-is was blindly confirmed by the National Cancer Institute Early Detection Research Network. CONCLUSIONS: The clinical performance of ApoA2-ATQ/AT as a blood biomarker is equivalent to or better than that of CA19-9.

A Phase I Study of TRK-250, a Novel siRNA-Based Oligonucleotide, in Patients with Idiopathic Pulmonary Fibrosis.

Purpose: TRK-250 is a novel single-stranded oligonucleotide carrying a human Transforming growth factor-beta 1-targeting siRNA motif tethered by two proline linkers. Nonclinical studies have shown that TRK-250 may have potency to prevent the progression of pulmonary fibrosis. Herein, a phase I study was conducted to investigate the safety and pharmacokinetics (PKs) of TRK-250 in patients with idiopathic pulmonary fibrosis (IPF). Method: In the phase I study, 34 IPF patients were partially randomized to receive a placebo or TRK-250 in 4 single doses of 2, 10, 30, and 60 mg or multiple rising doses of 10, 30, and 60 mg once per week for 4 weeks by oral inhalation. For both the single- and multiple-dose studies, the primary endpoint was safety, and the secondary endpoint was PKs. Result: In all IPF patients who orally inhaled TRK-250, no significant drug-related adverse events (AEs) were observed. The AEs were mild or moderate, except for one severe case with acute exacerbation. One of the more common AEs was coughing. One patient discontinued treatment before the last dose because of coughing. There were no medically important findings related to safety endpoints based on clinical laboratory data (clinical chemistry, hematology, or urinalysis), vital signs data, electrocardiogram data, physical examination findings, pulse oximetry data, spirometry data, or diffusing capacity of the lung for carbon monoxide data. All the bioanalytical results of PKs in the blood were below the lower limit of quantification. Conclusions: Both the single and multiple doses of TRK-250 were safe and well tolerated in this first study done in IPF patients. Furthermore, TRK-250 was not detected in the systemic circulation following inhalation, indicating low or virtually nonexistent systemic exposure. This study is registered at ClinicalTrials.gov with identifier number NCT03727802.

Surgical Management of Mycobacterial Infections and Related Complex Pleural Space Problems: From History to Modern Day.

Owing to the advent of effective drugs for tuberculosis in the mid-twentieth century, few cases require surgery for active tuberculosis in the present day in areas where effective drugs are available. However, surgical techniques developed to combat tuberculosis in the predrug era are still useful to manage the challenging chest pathology of our time surgically, such as destroyed lung or postresectional empyema. Thoracoplasty and open window thoracostomy are representative procedures and discussed in detail in this review.

Outcomes of Surgical Treatment for Mycobacterium abscessus Complex Pulmonary Disease.

BACKGROUND: Mycobacterium abscessus complex pulmonary disease is notoriously difficult to treat by medication alone. We report our experience with resectional surgery combined with preoperative and postoperative multidrug chemotherapy for the treatment of patients with M. abscessus complex pulmonary disease. METHODS: This is a retrospective review of 33 patients undergoing lung resection for M. abscessus complex pulmonary disease at a single center in Japan between January 2008 and December 2019. RESULTS: The median age of patients was 54.0 (interquartile range [IQR], 49.0-66.0) years; 27 (81.8%) were female. Nodular-bronchiectatic was the most common disease type (n = 24, 72.7%). Disease was limited in 18 (54.5%) patients and extensive in 15 (45.5%). The median duration of preoperative multidrug chemotherapy employing oral and parenteral antibiotics was 10.0 (IQR, 3.0-18.0) months. A total of 34 anatomical lung resections were performed as follows: 22 lobectomies, 5 segmentectomies, 4 combined resections, 2 bilobectomies, and 1 pneumonectomy. No operative mortalities and 4 (13.3%) morbidities occurred. The median duration of multidrug chemotherapy after the surgery was 18.0 (IQR, 12.0-31.0) months. Postoperative sputum-negative status was achieved in 31 (93.9%) patients; all 23 patients obtaining preoperative negative conversion remained negative, and 8 (80.0%) of 10 patients with preoperative positive sputum became negative postoperatively. Recurrence was observed in 2 (6.5%) patients. The recurrence-free probabilities were 96.3%, 96.3%, and 80.2% at 1 year, 3 years, and 5 years, respectively. CONCLUSIONS: Combined with preoperative and postoperative multidrug chemotherapy, resectional surgery can be performed safely and achieve favorable outcomes for patients with M. abscessus complex pulmonary disease.

A Novel Approach to Extensive Clarithromycin-Resistant Mycobacterium avium Complex Pulmonary Disease.

A 48-year-old woman with extensive clarithromycin-resistant Mycobacterium avium complex pulmonary disease (MAC-PD) was successfully treated by left lower lobectomy and lingulectomy following combination treatment of intravenous/inhaled amikacin plus bronchial occlusion by Endobronchial Watanabe Spigots (EWSs). A left pneumonectomy was initially indicated for removing all the lesions, but the procedure would have been barely tolerated by the patient. However, her preoperative combination treatment sufficiently reduced the lesions requiring resection to allow surgical preservation of the left upper division. This novel approach might be promising for patients with Mycobacterium avium complex lung disease whose pulmonary reserve will not allow an extensive parenchymal resection.

[Re-operation for Inflammatory Lung Diseases].

Two types of re-operations for inflammatory lung diseases are presented:thoracoplasty and cavernostomy. Thoracoplasty is used to obliterate a residual pleural space after upper lung resection with prolonged air leak. Usually, the 2nd to the 6th ribs are resected, according to the extent of the space. Posteriorly the ribs should be removed to the costotransverse joint to achieve sufficient space obliteration. The tip of the scapula is resected in case of the resection of the 6th rib, otherwise the scapula would impinge on the 7th rib. The resection of the 1st rib should be avoided because of a subsequent severe scoliosis. Cavernostomy is a procedure to open the infected cavity of the residual lung. Aspergillus and non-tuberculous mycobacteria are the most frequent pathogens. The site of skin incision depends on the location of the cavity:midaxially incision for an anterior cavity and paravertebral incision for a posterior cavity. Cutting "septum" in the cavity makes it a single space, contributing to sufficient drainage by gauze. The closure of the cavity will be considered after several months or years when the cavity is sterilized and the patient's nutritional status becomes well. These 2 procedures are effective in treating refractory lung inflammation after lung resection, although they are quite traditional.

Residual Destructive Lesions and Surgical Outcome in Mycobacterium avium Complex Pulmonary Disease.

BACKGROUND: Successful surgical treatment of patients with Mycobacterium avium complex pulmonary disease is thought to require complete removal of parenchymal destructive lesions. This study aimed to evaluate the short-term and long-term outcomes and the predictors of microbiological recurrence after surgery for M avium complex pulmonary disease. METHODS: We conducted a retrospective review of 184 patients undergoing unilateral lung resection for M avium complex pulmonary disease at a single center in Japan between January 2008 and December 2017. RESULTS: Median age of the 184 patients was 55.5 years; 133 were female (72.3%). All but 2 patients had anatomical lung resection. A total of 116 patients had limited disease and underwent complete resection (63.0%); the remaining 68 patients had extensive disease and underwent debulking surgery (37.0%). No operative mortalities occurred. In 18 of 184 patients, 21 morbidities occurred (9.8%), including 3 bronchopleural fistulas (1.6%). Postoperative sputum-negative status was achieved in 183 patients (99.5%). Microbiological recurrences occurred in 15 patients (8.2%). By multivariate analysis, extensive disease was an independent risk factor for recurrence (hazard ratio, 5.432; 95% confidence interval, 1.372-21.50; P = .016). Recurrence-free rates were significantly higher in patients with limited disease compared with those with extensive disease (99.0%, 97.4%, and 95.0% versus 93.0%, 89.2%, and 75.1% at 1, 3, and 5 years, respectively; P < .001). CONCLUSIONS: Complete resection of parenchymal destructive lesions can achieve excellent microbiological control for patients with limited M avium complex pulmonary disease. The efficacy of debulking surgery in patients with extensive disease needs further investigation.

[Nontuberculous Mycobacteriosis Resistant for Chemotherapy which was Suspected to Coexist with Lung Cancer].

Nontuberculous mycobacteriosis (NTM) has been increasing recently. The treatment of choice of NTM is chemotherapy. Surgical treatment is sometimes indicated for patients with refractory NTM. When NTM lesion is enlarging despite of chemotherapy, there are 2 possibilities:intractable NTM and co-existing lung cancer. A 67-year-old male had been treated for fibro-cavitary NTM in the right upper lobe with chemotherapy. The cavitary lesion, however, was growing in spite of 6 months treatment. We suspected of a co-existing lung cancer because SCC level and standardized uptake value (SUV) in positron emission tomography (PET)-computed tomography (CT) were high. Bronchoscopy was performed but revealed no malignancy. He underwent a right upper lobectomy and the intraoperative pathology indicated NTM with no malignancy. After the operation, SCC levels decreased. This is a rare case with preoperative high SCC level which seemed to be related to NTM lesion.

Prognostic significance of PD-L1 expression and tumor infiltrating lymphocytes in large cell neuroendocrine carcinoma of lung.

OBJECTIVES: Since large cell neuroendocrine carcinoma (LCNEC) is a relatively rare histologic type of primary lung cancer, little is known about the immunological status of patients with LCNEC. We aimed to clarify the expression and prognostic impact of programmed cell death ligand 1 (PD-L1), CD8, CD4, and Forkhead box protein P3 (Foxp3) in LCNEC. METHODS: We retrospectively analyzed PD-L1, CD8, CD4, and Foxp3 expressions in 95 surgically resected LCNEC. PD-L1 positive staining was determined in tumors with more than 1% of tumor cells stained to any intensity, and CD8, CD4, and Foxp3 positivity was determined in tumors with more than 5% of lymphocytes stained. RESULTS: Positive expression of PD-L1, CD8, CD4, and Foxp3 was observed in 70 (74%), 52 (55%), 76 (80%), and 43 (45%) tumors, respectively. The expression of PD-L1 was significantly correlated with positive lymphatic permeation. Positive correlations were mutually observed among tumor infiltrating immune cells. Univariate and multivariate analyses showed that positive pleural invasion and Foxp3 negative expression were independent unfavorable prognostic factors for overall survival (OS). Advanced pathological stage, positive pleural invasion, CD4 negative expression in cancer stroma, and Foxp3 negative expression were identified as independent unfavorable prognostic factors for recurrence free survival (RFS). CONCLUSIONS: Foxp3 positive tumor infiltrating lymphocytes (TILs) were an independent favorable prognostic factor for both OS and RFS, whereas CD4 positive TILs were an independent significant unfavorable prognostic factor for RFS. The high frequency of PD-L1 expression could support the use of anti-programmed cell death 1 antibody in the treatment of LCNEC.

The impact of histology and ground-glass opacity component on volume doubling time in primary lung cancer.

BACKGROUND: Correlations between volume doubling time (VDT) of primary lung cancer (PLC), histology, and ground glass opacity (GGO) components remain unclear. The purpose of this study was to evaluate and compare VDT of PLC in terms of histology and presence or absence of GGO components. METHODS: A total of 371 surgically resected PLCs from 2003 to 2015 in our institute were retrospectively reviewed. The VDT was calculated both from the diameters of the entire tumor and of consolidation by using the approximation formula of Schwartz. RESULTS: The median VDTs of adenocarcinoma, squamous cell carcinoma, and others (large cell neuroendocrine carcinomas, small cell lung carcinomas, pulmonary pleomorphic carcinomas, and large cell carcinomas combined) were 261, 70, and 70 days, respectively; these differ significantly (P<0.001). All PLCs with GGO were adenocarcinomas. The VDT of adenocarcinomas with GGO was significantly longer than that of those without GGO (median VDT: 725 and 177 days, respectively), squamous cell carcinomas, and others. When the VDT calculated from the maximum diameter of consolidation component was compared, adenocarcinomas with GGO also showed significantly slower growth than those without GGO (median VDT: 248 versus 177 days, respectively, P=0.040). CONCLUSIONS: The VDT of PLCs is longest for adenocarcinomas. VDT was significantly longer in adenocarcinomas with GGO components than in those without such components, irrespective of VDT calculated on the basis of either the entire tumor diameter or consolidation diameter.

2-Deoxy-2-[fluorine-18] fluoro-d-glucose uptake on positron emission tomography is associated with programmed death ligand-1 expression in patients with pulmonary adenocarcinoma.

2-Deoxy-2-[fluorine-18] fluoro-d-glucose (18F-FDG) positron emission tomography (PET) is a useful modality for the assessment of tumour glucose metabolism by upregulation by hypoxia. Little is known whether the uptake of 18F-FDG within cancer cells is linked to the expression of programmed death ligand-1 (PD-L1), a predictor of anti-PD-1 antibody. We conducted a clinicopathological study to assess the expression of PD-L1 and tumour-infiltrating lymphocytes (TILs) in patients with surgically resected pulmonary adenocarcinoma (AC) who received preoperative 18F-FDG PET. A total of 315 patients with lung AC who received 18F-FDG PET were enrolled in the study. Tumour specimens were stained by immunohistochemistry for glucose transporter 1 (Glut1), hypoxia-inducible factor-1α (HIF-1α), PD-L1, CD4 and CD8. We assessed whether the uptake of 18F-FDG was correlated with clinicopathological variables. PD-L1 was highly expressed in 60% of all patients with AC, and the expression level was significantly correlated with 18F-FDG uptake, glucose metabolism and hypoxia. PD-L1 and the maximum standardised uptake value (SUVmax) were identified as independent prognostic predictors by multivariate analysis. In particular, PD-L1 could be a significant marker for predicting worse outcomes in AC patients with high 18F-FDG uptake but not in those with low 18F-FDG uptake. According to the epidermal growth factor receptor (EGFR) mutation status, the expression of PD-L1 was significantly correlated with SUVmax in patients with EGFR mutation, whereas, PD-L1 was a significant predictive negative factor in those with wild-type EGFR. 18F-FDG uptake was significantly correlated with PD-L1 expression, and the latter was closely linked to the presence of glucose metabolism and hypoxia in patients with pulmonary AC.

Highly sensitive detection of a HER2 12-base pair duplicated insertion mutation in lung cancer using the Eprobe-PCR method.

Somatic mutation in human epidermal growth factor receptor-related 2 gene (HER2) is one of the driver mutations in lung cancer. HER2 mutations are found in about 2% of lung adenocarcinomas (ADCs). Previous reports have been based mainly on diagnostic screening by Sanger sequencing or next-generation sequencing (NGS); however, these methods are time-consuming and complicated. We developed a rapid, simple, sensitive mutation detection assay for detecting HER2 12 base pair-duplicated insertion mutation based on the Eprobe-mediated PCR method (Eprobe-PCR) and validated the sensitivity of this assay system for clinical diagnostics. We examined 635 tumor samples and analyzed HER2 mutations using the Eprobe-PCR method, NGS, and Sanger sequencing. In a serial dilution study, the Eprobe-PCR was able to detect mutant plasmid DNA when its concentration was reduced to 0.1% by mixing with wild-type DNA. We also confirmed amplification of the mutated plasmid DNA with only 10 copies per reaction. In ADCs, Eprobe-PCR detected the HER2 mutation in 2.02% (9/446), while Sanger sequencing detected it in 1.57% (7/446). Eprobe-PCR was able to detect the mutation in two samples that were undetectable by Sanger sequencing. All non-ADC samples were wild-type. There were no discrepancies between frozen and formalin-fixed paraffin-embedded tissues in the nine samples. HER2 mutations detected by NGS data validated the high sensitivity of the method. Therefore, this new technique can lead to precise molecular-targeted therapies.

Prognostic potential of the MDM2 309T>G polymorphism in stage I lung adenocarcinoma.

The MDM2 protein plays an important role in the regulation of cell proliferation and apoptosis via ubiquitination and proteasome-mediated degradation of p53. The genetic polymorphism rs2279744 (c.309T>G) of the MDM2 gene is reportedly associated with susceptibility and/or prognosis in various cancers. In this study, we investigated the risk factors for worse survival in patients with lung adenocarcinoma (AC). We examined the association between c.309T>G and the prognosis of lung cancer by retrospectively reviewing 453 lung cancer patients. We studied both, clinicopathological and genetic characteristics, including the c.309T>G, p53 Arg72Pro, EGFR, KRAS, and p53 mutations. Associations between these factors and survival outcome were analyzed using Cox proportional hazards models. The frequencies of MDM2 polymorphisms were T/T, 20.8%; T/G, 48.6%, and G/G, 30.7%. The overall survival (OS) of AC patients with pathological stage I disease and the MDM2 T/T genotype was significantly shorter than that of those with the T/G or G/G genotypes (P = 0.02). Multivariate analysis revealed that the MDM2 T/T genotype was an independent, significant prognostic factor (hazard ratio [HR] = 2.23; 95% confidence interval [CI]: 1.07-4.65; P = 0.03). The MDM2 T/T genotype was predictive of poorer survival in a Japanese population. Genotyping for this polymorphism might predict the clinical outcomes of stage I AC patients.

Impact of the Bim Deletion Polymorphism on Survival Among Patients With Completely Resected Non-Small-Cell Lung Carcinoma.

PURPOSE: A deletion polymorphism of the Bim gene has been reported to be a prognostic factor for patients with non-small-cell lung cancer (NSCLC) treated with epidermal growth factor receptor-tyrosine kinase inhibitors in the Asian population. We investigated the impact of the Bim deletion polymorphism on survival among patients with completely resected NSCLC. PATIENTS AND METHODS: The Bim polymorphism was detected by polymerase chain reaction analysis. We measured overall survival (OS) and recurrence-free survival rates in 411 patients and postrecurrence survival (PRS) in 94 patients who experienced recurrence and received additional anticancer therapy. RESULTS: The Bim deletion polymorphism was detected in 61 patients (14.8%). OS rates were significantly lower for patients with the Bim deletion polymorphism than for those with the wild-type sequence. On multivariable analysis, the Bim deletion polymorphism was identified as an independent prognostic factor for OS (hazard ratio, 1.98; 95% CI, 1.17 to 3.36; P = .011). Among the 94 patients who experienced recurrence and were treated with anticancer therapy, patients with the Bim deletion polymorphism showed significantly poorer PRS than those with the wild-type sequence (median, 9.8 months v 26.9 months, respectively; P < .001). Multivariable analysis revealed that the Bim deletion polymorphism was an independent predictor of PRS (hazard ratio, 3.36; 95% CI, 1.75 to 6.47; P < .001). This trend remained apparent in subgroup analyses stratified by EGFR status, histology, and therapeutic modality. CONCLUSION: The Bim deletion polymorphism is a novel indicator of shortened PRS among patients with recurrent NSCLC treated with anticancer therapy in the Asian population.

Clinical significance of coexpression of L-type amino acid transporter 1 (LAT1) and ASC amino acid transporter 2 (ASCT2) in lung adenocarcinoma.

BACKGROUND: L-type amino acid transporter 1 (LAT1) and ASC amino acid transporter 2 (ASCT2) have been associated with tumor growth and progression. However, the clinical significance of LAT1 and ASCT2 coexpression in the prognosis of patients with lung adenocarcinoma remains unclear. METHODS: In total, 222 patients with surgically resected lung adenocarcinoma were investigated retrospectively. Tumor sections were stained immunohistochemically for LAT1, ASCT2, CD98, phosphorylated mammalian target-of-rapamycin (p-mTOR), and Ki-67, and microvessel density (MVD) was determined by staining for CD34. Epidermal growth factor receptor (EGFR) mutation status was also examined. RESULTS: LAT1 and ASCT2 were positively expressed in 22% and 40% of cases, respectively. Coexpression of LAT1 and ASCT2 was observed in 12% of cases and was associated significantly with disease stage, lymphatic permeation, vascular invasion, CD98, Ki-67, and p-mTOR. Only LAT1 and ASCT2 coexpression indicated a poor prognosis for lung adenocarcinoma. Furthermore, this characteristic was recognized in early-stage patients, especially those who had wild-type, rather than mutated, EGFR. Multivariate analysis confirmed that the coexpression of LAT1 and ASCT2 was an independent factor for predicting poor outcome. CONCLUSIONS: LAT1 and ASCT2 coexpression is an independent prognostic factor for patients with lung adenocarcinoma, especially during the early stages, expressing wild-type EGFR.

Eprobe-mediated screening system for somatic mutations in the KRAS locus.

Activating mutations in the Kirsten rat sarcoma viral oncogene homolog (KRAS) loci are largely predictive of resistance to epidermal growth factor receptor (EGFR) therapy in colorectal cancer (CRC). A highly sensitive detection system for the KRAS gene mutations is urgently needed; however, conventional methods have issues with feasibility and cost performance. Here, we describe a novel detection system using a fluorescence 'Eprobe' capable of detecting low level KRAS gene mutations, via real-time PCR, with high sensitivity and simple usability. We designed our Eprobes to be complementary to wild-type (WT) KRAS or to the commonly mutated codons 12 and 13. The WT Eprobe binds strongly to the WT DNA template and suppresses amplification by blocking annealing of the primer during PCR. Eprobe-PCR with WT Eprobe shows high sensitivity (0.05-0.1% of plasmid DNA, 1% of genomic DNA) for the KRAS mutation by enrichment of the mutant type (MT) amplicon. Assay performance was compared to Sanger sequencing using 92 CRC samples. Discrepancies were analyzed by mutation genotyping via Eprobe-PCR with full match Eprobes for 7 prevalent mutations and the next generation sequencing (NGS). Significantly, the Eprobe system had a higher sensitivity for detecting KRAS mutations in CRC patient samples; these mutations could not be identified by Sanger sequencing. Thus, the Eprobe approach provides for highly sensitive and convenient mutation detection and should be useful for diagnostic applications.

Single-nucleotide polymorphism (c.309T>G) in the MDM2 gene and lung cancer risk.

Murine double minute 2 (MDM2) is a negative regulator of p53. A single-nucleotide polymorphism (SNP) (rs2279744: c.309T>G) in the promoter region of the MDM2 gene has been shown to result in higher levels of MDM2 RNA and protein. Regarding the contribution of c.309T>G in the MDM2 gene to the lung cancer risk, previous studies are conflicting. In order to evaluate the association between c.309T>G and the lung cancer risk, a case-control study was performed. The MDM2 genotypes were determined in 762 lung cancer patients and in 700 cancer-free control subjects using the Smart Amplification Process. Statistical adjustment was performed for gender, age and pack-years of smoking. The distributions of c.309T>G (T/T, T/G, G/G) were 20.1, 49.7, 30.2% in the case group and 21.7, 47.9, 30.4% in the healthy-control group. There were no overall associations between the MDM2 genotypes and the risk of lung cancer [T/G genotype: Adjusted odds ratio (AOR), 1.30; 95% confidence interval (CI), 0.88-1.93; and G/G genotype: AOR, 1.18; 95% CI, 0.78-1.80]. The subgroup analysis of gender, histology, smoking status and epidermal growth factor receptor mutation status also indicated that there was no association with lung cancer. Additionally, the genotypes did not have an effect on the age at the time of diagnosis of lung cancer (P=0.25). In conclusion, the G allele frequency in the lung cancer cases was 0.551, which was similar to other studies. The results of the present study suggest that the c.309T>G is not significantly associated with lung cancer.

Assessment of DDR2, BRAF, EGFR and KRAS mutations as therapeutic targets in non-adenocarcinoma lung cancer patients.

Molecular-targeted therapy has not been established in non-adenocarcinoma lung cancer (non-AdLC), as no targets that affect the clinical efficacy of molecular-targeted drugs have yet been identified. In this study, we investigated the frequency of genetic variations in discoidin domain receptor 2 (DDR2), v-raf murine sarcoma viral oncogene homolog B1 (BRAF), epidermal growth factor receptor (EGFR) and v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) in non-AdLC patients, in order to evaluate the possibility of genetic mutations in these genes being used as therapeutic targets for the treatment of patients with non-AdLC. For this purpose, we enrolled 150 non-AdLC patients who had undergone surgery at the Gunma University Hospital between December, 2003 and December, 2012. Genetic mutations in the EGFR, KRAS, DDR2 and BRAF genes were detected by a sequencing method or probe assay using DNA derived from cancer tissues. No somatic mutations in DDR2 or BRAF were detected in non-AdLC patients. Conversely, genetic mutations in EGFR exon 19 were found in 3 squamous cell carcinoma (SCC) and 3 adenosquamous carcinoma patients, whereas KRAS codon 12 mutations were also found in 3 SCC patients and 1 large-cell neuroendocrine carcinoma patient. EGFR and KRAS mutations were mutually exclusive. This study indicated that, although DDR2 and BRAF mutations may only rarely be used as therapeutic targets, EGFR and KRAS mutations may represent candidate therapeutic targets, at least in the non-AdLC patients investigated.

Postrecurrence survival of surgically resected pulmonary adenocarcinoma patients according to EGFR and KRAS mutation status.

The aim of this study was to investigate the prognosis of pulmonary adenocarcinoma patients following postoperative recurrence, according to epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma 2 viral oncogene homolog (KRAS) gene mutation status and recurrence site. In total 58 adenocarcinoma patients with recurrence following surgical resection were retrospectively evaluated between 2002 and 2011. The patients were divided into groups according to the presence or absence of EGFR and KRAS mutations and the clinicopathological characteristics, recurrence sites and postrecurrence survival were compared. EGFR and KRAS mutations were detected in 26 (45%) and 11 patients (19%), respectively. Initial recurrence was distant in 25 (43%), local in 17 (29%) and both distant and local in 16 cases (28%). In EGFR-mutant (EGFR+) cases, bilateral/contralateral lung recurrence was a frequent finding. EGFR+ cases exhibited significantly better outcomes compared to KRAS+ and EGFR-KRAS- (wild-type) cases. The 2-year post-recurrence survival rates were 81, 18 and 47% in EGFR+, KRAS+ and wild-type cases, respectively. The patients with distant organ recurrence exhibited significantly worse survival compared with those without distant recurrence in wild-type, but not in the EGFR+ cases or the entire cohort. Multivariate analysis revealed that EGFR mutations and a number of recurrent lesions were the only statistically significant independent predictors of postrecurrence prognosis. Our results indicated distinct survival differences in recurrent adenocarcinoma patients according to driver mutations. Patients with EGFR-mutated tumors exhibited increased survival, regardless of recurrence at distant sites, whereas patients with KRAS-mutated adenocarcinoma exhibited poor outcome following postoperative recurrence. Therefore, the assessment of driver mutations is essential for predicting postrecurrence survival following surgical resection.