EGFR Mutation is a Prognostic Factor in Lung Cancer Patients with Pleural Dissemination Detected During or After Surgery.

BACKGROUND: Primary lung tumors are sometimes resected when either pleural dissemination (PD) or malignant pleural effusion (MPE) exists. This study clarified the prognostic factors for non-small cell lung cancer (NSCLC) with either PD and MPE, or both, detected during or after surgery. PATIENTS AND METHODS: We examined patients with NSCLC from a multicenter database who had either PD, MPE, or both, detected during or after surgery between 2005 and 2015. Hazard ratios and 95% confidence intervals were estimated using the Cox proportional hazards model adjusted for potential confounding factors. RESULTS: Among 9463 registered patients, PD, MPE, or both, were found in 114 patients with NSCLC during or after surgery. Primary tumor resection and exploratory thoracotomy were performed in 65 and 49 patients, respectively. In univariate analysis, adenocarcinoma, clinically undetected lymph node metastasis (c-N0 or unknown), EGFR mutation, and combination of chemotherapy or tyrosine kinase inhibitors after surgery were better prognostic factors for overall survival (OS), whereas in the multivariate analysis, adenocarcinoma, clinically undetected lymph node metastasis, and EGFR mutation were favorable independent prognostic factors in OS. Additionally, limited to patients with EGFR mutation, patients with primary lung tumor resection showed a significantly better 5-year OS than those with exploratory thoracotomy (86.4 vs. 44.8%; p < 0.001). CONCLUSION: Our findings show that surgical resection of primary tumors could improve the prognosis of patients with PD, MPE, or both, detected during or after surgery when the tumors harbor an EGFR mutation.

Surgery Outcomes for Pulmonary Metastases from Renal Cell Carcinoma.

Pulmonary metastatic resection is a standard therapy for renal cell carcinoma (RCC). Although patients with pulmonary metastases who do not undergo any treatment have poor prognoses, it has been reported that resection for pulmonary metastases yields good clinical outcomes. We investigated the prognoses of the 10 Japanese patients (eight males, two females) who underwent a surgical resection of pulmonary metastasectomy from RCC at our institution between April 1, 2012 and March 31, 2020 and analyzed the prognostic factors. We determined the prognoses and calculated the 5-year overall survival (OS) and disease-free survival (DFS) rates. To identify prognostic factors, we compared the median DFS duration for each factor. Elderly patients (median age, 75.5 years) were more predominant compared to previous studies, and all 10 patients underwent a complete resection. The 5-year DFS rate was 30.5% (95%CI: 0.045-0.63) and the 5-year OS rate was 80% (95%CI: 0.20-0.97). The following factors were associated with better prognosis: female, disease-free interval≥36 months, and metastases size<12 mm. These results indicate that complete resection for pulmonary metastases from RCC resulted in good clinical outcomes, particularly for patients with better prognostic factors.

A Rare Presentation of Invasive Aspergillosis: An Asymptomatic Man with an Abscess Localized to a Parietal Pleura.

Aspergillosis is an infection caused by Aspergillus species, and it manifests in various clinical presentations. We describe the case of a 73-year-old man with a small area of thickening on the thoracic wall detected by computed tomography. Surgical resection confirmed the diagnosis of an Aspergillus abscess. We report this case in view of the rarity of Aspergillus abscess localized to a parietal pleura without any signs of lung parenchymal involvement. After a thorough literature review, we consider this could be the first report of this manifestation. Accumulation of similar cases will be necessary to help spread recognition of this condition.

Randomized phase II study of daily and alternate-day administration of S-1 for adjuvant chemotherapy in completely-resected stage I non-small cell lung cancer: results of the Setouchi Lung Cancer Group Study 1301.

BACKGROUND: The aim of this multicenter, randomized phase II study was to analyze the feasibility and safety of alternate-day S-1, an oral fluoropyrimidine, for adjuvant chemotherapy in patients with completely resected pathological stage I (tumor diameter > 2 cm) non-small cell lung cancer (NSCLC). METHODS: Patients were randomly assigned to receive adjuvant chemotherapy for 1 year comprising either alternate-day oral administration of S-1 (80 mg/m2/day) for 4 days a week (Group A) or a 2-week oral administration of S-1 (80 mg/m2/day) followed by 1 week of rest (Group B). The primary endpoint was feasibility, which was defined as the proportion of patients who completed the allocated intervention for 6 months with a relative dose intensity (RDI) of 70% or more. RESULTS: Ninety-three patients were enrolled of whom 90 patients received S-1 treatment. Median follow-up was 66.9 months. The treatment completion rate based on an RDI of 70% or more for 6 months was 84.4% (95%CI; 70.5-93.5%) in group A and 64.4% (95%CI; 48.8-78.1%) in group B. There were no grade 4 adverse events in either group. Moderate or severe adverse events (grade 2 or grade 3) were significantly more frequent in group B (67%) compared with group A (29%, P = 0.001). The 5-year relapse-free survival rate was 87.0 and 80.9% for group A and B, respectively (P = 0.451). The 5-year overall survival rate for all patients (n = 93) was 100 and 89.4% for group A and B, respectively (P = 0.136). CONCLUSION: Alternate-day oral administration of S-1 for 1 year as adjuvant chemotherapy was demonstrated to be feasible with low toxicity in completely resected stage I (tumor diameter > 2 cm) NSCLC. TRIAL REGISTRATION: Trial registration number: UMIN000011994 . Date of registration: 10/8/2013.

Thoracoscopic Localization of Small Peripheral Pulmonary Lesions Using Percutaneous Computed Tomography-guided Pleural Dye Marking: A Retrospective Analysis.

Small pulmonary lesions are often difficult to localize during thoracoscopic surgery. We describe a new com-puted tomography (CT)-guided pleural dye-marking method for small peripheral pulmonary lesions that does not involve a visceral pleural puncture. We used this technique for 23 lesions (22 patients) who underwent tho-racoscopic partial lung resection (Nov. 2016-Jan. 2018). With the patient in the lateral decubitus position, pre-operative CT-guided marking on the skin over the lesion was performed. During the surgery, we marked the visceral pleura with a skin marker directly or with an infant-size nutrition catheter with crystal violet at the tip through a venous indwelling needle inserted perpendicular to the skin marking. We localized and resected the lesions in all cases, without complications. The median nodule size measured histopathologically was 8 (4-20) mm overall, and 7 (0-20) mm of the solid part; the median distance from the visceral pleura to the nodule was 9 (1-33) mm. The median operation time was 67 (37-180) min. The median postoperative hospital stay was 3 (3-11) days. Our CT-guided pleural dye-marking method is useful and safe for the localization of small periph-eral pulmonary lesions in thoracoscopic partial lung resections.

Feasibility of adjuvant chemotherapy with S-1 plus carboplatin followed by single-agent maintenance therapy with S-1 for completely resected non-small-cell lung cancer: results of the Setouchi Lung Cancer Group Study 1001.

BACKGROUND: This multicenter study evaluated the feasibility of novel adjuvant chemotherapy with S-1 plus carboplatin followed by single-agent, long-term maintenance with S-1 in patients with completely resected stage II-IIIA non-small-cell lung cancer (NSCLC). METHODS: Patients received four cycles of S-1 (80 mg/m2/day for 2 weeks, followed by 2 weeks rest) plus carboplatin (area under the curve 5, day 1) followed by S-1 (80 mg/m2/day for 2 weeks, followed by a 1-week rest). Patients unable to continue S-1 plus carboplatin because of severe toxicity converted to single-agent S-1 maintenance. The duration of adjuvant chemotherapy was 10 months in both situations. The primary endpoint was feasibility, defined as the proportion of patients who completed four cycles of S-1 plus carboplatin and single-agent S-1 maintenance for 10 months. The treatment completion rate was determined; treatment was considered feasible if the lower 90% confidence interval (CI) was ≥50%. RESULTS: Eighty-nine patients were enrolled, of whom 87 were eligible and assessable. Seventy-eight patients (89.7%) completed four cycles of S-1 plus carboplatin and 55 (63.2%) completed the following S-1 maintenance therapy for a total of 10 months. The treatment completion rate was 63.2% (90% CI, 54.4-71.2%), indicating feasibility. There were no treatment-related deaths. Grade 3/4 toxicities included neutropenia (13.8%), thrombocytopenia (11.5%), and anorexia (4.6%). The 2-year relapse-free survival rate was 59.8%. CONCLUSIONS: We concluded that adjuvant chemotherapy with S-1 plus carboplatin followed by single-agent maintenance therapy with S-1 is feasible and tolerable in patients with completely resected NSCLC. CLINICAL REGISTRATION NUMBER: UMIN000005041.

Randomized feasibility study of S-1 for adjuvant chemotherapy in completely resected Stage IA non-small-cell lung cancer: results of the Setouchi Lung Cancer Group Study 0701.

OBJECTIVE: The aim of this multicenter study was to determine the appropriate administration schedule for S-1, an oral fluoropyrimidine, for adjuvant chemotherapy in patients with completely resected pathological-Stage IA (tumor diameter, 2-3 cm) non-small-cell lung cancer. METHODS: Patients were randomly assigned to receive adjuvant chemotherapy consisting of either the 4-week oral administration of S-1 (80-120 mg/body/day) followed by a 2-week rest (Group A), or the 2-week oral administration of S-1 (80-120 mg/body/day) followed by a 1-week rest (Group B). The duration of adjuvant chemotherapy was 1 year in both arms. The primary endpoint was compliance, namely drug discontinuation-free survival, which was calculated using the Kaplan-Meier method with log-rank test. RESULTS: Eighty patients were enrolled in this study, and 76 patients actually received S-1 treatment. The drug discontinuation-free survival rates at 1 year were 49.1% in Group A and 52.7% in Group B (P = 0.373). The means of the relative dose intensities were 55.3% in Group A and 64.6% in Group B (P = 0.237). There were no treatment-related deaths. Patients with grade 3/4 toxicities were significantly more frequent in Group A (40.5%) than in Group B (15.4%, P = 0.021). The 2-year relapse-free survival rates were 97.5% in Group A and 92.5% in Group B, and the 2-year overall survival rates were 100% in both groups. CONCLUSIONS: The feasibility showed no significant difference between the two groups among patients with completely resected Stage IA (tumor diameter, 2-3 cm) non-small-cell lung cancer.

Two Cases of Thymic Cancer in Patients with Lynch Syndrome.

We herein report two cases of thymic cancer with Lynch syndrome showing a high frequency of microsatellite instability and loss of mismatch repair protein expression without MLH1 promoter hyper-methylation. In Case 1, a 71-year-old man had a pathogenic germline variant in MLH1 and underwent tumor resection. No relapse has been reported thus far. In Case 2, a 43-year-old man underwent genetic testing that also showed a pathogenic germline variant in MLH1. Since these two cases had MLH variants, we suspect a possible association between thymic cancer with Lynch syndrome and germline pathogenic variants in MLH1.

Randomized phase II study of daily versus alternate-day administrations of S-1 for the elderly patients with completely resected pathological stage IA (tumor diameter > 2 cm)-IIIA of non-small cell lung cancer: Setouchi Lung Cancer Group Study 1201.

BACKGROUND: It is shown that the postoperative adjuvant chemotherapy for non-small cell lung cancer (NSCLC) was associated with survival benefit in an elderly population. We aimed to analyze the feasibility and efficacy of alternate-day S-1, an oral fluoropyrimidine, for adjuvant chemotherapy in elderly patients with completely resected pathological stage IA (tumor diameter > 2 cm) to IIIA (UICC TNM Classification of Malignant Tumours, 7th edition) NSCLC. METHODS: Elderly patients were randomly assigned to receive adjuvant chemotherapy for one year consisting of either alternate-day oral administration of S-1 (80 mg/m2/day) for 4 days a week (Arm A) or a daily oral administration of S-1 (80 mg/m2/day) for 14 consecutive days followed by 7-day rest (Arm B). The primary endpoint was feasibility (treatment completion rate), which was defined as the proportion of patients who completed the allocated intervention for 6 months with a relative dose intensity (RDI) of 70% or more. RESULTS: We enrolled 101 patients in which 97 patients received S-1 treatment. The treatment completion rate at 6 months was 69.4% in Arm A and 64.6% in Arm B (p = 0.67). Treatment completion rate in Arm B tended to be lower compared to Arm A, as the treatment period becomes longer (at 9 and 12 months). RDI of S-1 at 12 months and completion of S-1 administration without dose reduction or postponement at 12 months was significantly better in Arm A than in Arm B (p = 0.026 and p < 0.001, respectively). Among adverse events, anorexia, skin symptoms and lacrimation of any grade were significantly more frequent in Arm B compared with Arm A (p = 0.0036, 0.023 and 0.031, respectively). The 5-year recurrence-free survival rates were 56.9% and 65.7% for Arm A and B, respectively (p = 0.22). The 5-year overall survival rates were 68.6% and 82.0% for Arm A and B, respectively (p = 0.11). CONCLUSION: Although several adverse effects were less frequent in Arm A, both alternate-day and daily oral administrations of S-1 were demonstrated to be feasible in elderly patients with completely resected NSCLC. TRIAL REGISTRATION: Unique ID issued by UMIN: UMIN000007819 (Date of registration: Apr 25, 2012) https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000009128. Trial ID issued by jRCT: jRCTs061180089 (Date of registration: Mar 22, 2019, for a shift toward a "specified clinical trial" based on Clinical Trials Act in Japan) https://jrct.niph.go.jp/en-latest-detail/jRCTs061180089.

Clinical Features of Patients With Second Primary Lung Cancer After Head and Neck Cancer.

BACKGROUND: In survivors of head and neck cancer (HNC), second primary lung cancer (SPLC) often develop as a result of a common risk factor, that is, smoking. A multicenter experience was reviewed to evaluate how the history of a diagnosis of HNC affects the outcomes of patients undergoing pulmonary resection for SPLC. METHODS: A multicenter retrospective analysis of patients hospitalized between January 2012 and December 2018 was performed. From a cohort of 4521 patients undergoing therapeutic pulmonary resection for primary non-small cell lung cancer, 100 patients with a previous history of HNC (HNC group) were identified. These patients were compared with a control group consisting of 200 patients without an HNC history from the same cohort pair-matched with operating facility, age, sex, and pathologic stage of lung cancer. RESULTS: At the time of surgery for SPLC, the HNC group showed malnutrition with a lower prognostic nutritional index compared with the control group (P < .001). The HNC group was determined to have postoperative complications more frequently (P = .02). The 5-year overall survival rates in the HNC and control groups were 59.0% and 83.2%, respectively (P < .001). Statistically, HNC history, lower prognostic nutritional index, squamous cell lung cancer, and TNM stage were identified to be independently associated with poor survival. CONCLUSIONS: Patients with SPLC after primary HNC often present with malnutrition and are predisposed to postoperative complications and poor survival after pulmonary resection.

[Left lung cancer accompanied with a persistent left superior vena cava; report of a case].

A 77-year-old woman who had been treated for tongue cancer, esophageal cancer and laryngeal cancer, 25 years, 8 years and 8 months before respectively, was referred to our department because of the pulmonary tumor. Enhanced computed tomography showed a nodule of 32 mm in diameter in the left upper lobe and persistent left superior vena cava (PL-SVC). She underwent left upper lobectomy with mediastinal lymph node dissection, preserving PL-SVC. PL-SVC is a rare anomaly and may disturb the mediastinal lymph node dissection. Care should always be taken for the possibility of anomalous venous connection in performing thoracic surgery.

[Lung cancer associated with pulmonary aspergillosis in the nodule of old mycobacterial infection].

A 66-year-old man was admitted to our hospital to examine abnormal shadow in the right lung in May 2009. Chest computed tomography (CT) showed a nodule in the apex of right lung adjacent to the old shadow which was thought to be inflammatory and had been followed up since November 2002. Fluorodeoxyglucose-positron emission tomography (FDG-PET) showed significant accumulation of the isotope in the new nodule. Lung cancer was strongly suspected and the nodule with the joining lesion was surgically removed. Pathological examination revealed poorly to well differentiated papillary adenocarcinoma in the cancer lesion and aspergillosis in the necrotic and old fibrocaseous lesion. In the present case, lung cancer is thought to develop adjacent to the pulmonary aspergillosis.

[Leiomyoma of the trachea; report of a case].

Leiomyoma of the trachea is a rare benign tumor. The patient was a 44-year-old male with a chief complaint of cough. Chest X-ray and computed tomography (CT) scan demonstrated a tracheal tumor. Bronchofiberscopy revealed a polypoid round tumor in the trachea. The tumor originated from the membranous portion of the trachea without narrow stalk. Tracheal circumferential resection with primary end-to-end anastomosis was performed via right postero-lateral thoracotomy, and postoperative course was uneventful. Definitive diagnosis of tracheal leiomyoma was made by histological examination. Although the reports of transbronchial endoscopic treatment for tracheal leiomyoma were increasing, tracheal resection was selected for this case considering the risk of perforation of the membranous portion of the trachea.

Resected case of stage IV pleomorphic carcinoma of the lung with long-term survival.

BACKGROUND: No established treatments for pulmonary pleomorphic carcinoma exist because of its rarity, and the prognosis is poorer than that of other non-small cell lung cancers. CASE REPORT: We present a case of stage IV pleomorphic carcinoma; the patient was a 66-year-old male. He was referred to our hospital because of a right adrenal hemorrhage and a lung tumor. A systemic examination revealed that the lung tumor was a primary lung cancer and that the adrenal hemorrhage was due to a metastatic cancer. We performed an adrenalectomy and resection of the lung tumor and obtained a diagnosis of pleomorphic carcinoma with adrenal metastasis. The patient has remained recurrence-free for 6 years since the surgery. CONCLUSIONS: We report a patient with stage IV pleomorphic carcinoma of the lung and an oligometastasis in whom a complete resection enabled a good outcome. Additional reports are needed to clarify definite prognostic factors and the optimal treatment for pleomorphic carcinoma.

Impact of somatic mutations on prognosis in resected non-small-cell lung cancer: The Japan Molecular Epidemiology for lung cancer study.

BACKGROUND: To report the follow up data and clinical outcomes of the JME study (UMIN 000008177), a prospective, multicenter, molecular epidemiology examination of 876 surgically resected non-small-cell lung cancer (NSCLC) cases, and the impact of somatic mutations (72 cancer-associated genes) on recurrence-free survival (RFS) and overall survival (OS). METHODS: Patients were enrolled between July 2012 and December 2013, with follow up to 30th November 2017. A Cox proportional hazards model was used to assess the impact of gene mutations on RFS and OS, considering sex, smoking history, age, stage, histology, EGFR, KRAS, TP53, and number of coexisting mutations. RESULTS: Of 876 patients, 172 had ≥2 somatic mutations. Median follow-up was 48.4 months. On multivariate analysis, number of coexisting mutations (≥2 vs 0 or 1, HR = 2.012, 95% CI: 1.488-2.695), age (≥70 vs <70 years, HR = 1.583, 95% CI: 1.229-2.049), gender (male vs female, HR = 1.503, 95% CI: 1.045-2.170) and pathological stage (II vs I, HR = 3.386, 95% CI: 2.447-4.646; ≥III vs I, HR = 6.307, 95% CI: 4.680-8.476) were significantly associated with RFS, while EGFR mutation (yes vs no, HR = 0.482, 95% CI: 0.309-0.736), number of coexisting mutations (≥2 vs 0 or 1, HR = 1.695, 95% CI: 1.143-2.467), age (≥70 vs <70 years, HR = 1.932, 95% CI: 1.385-2.726), and pathological stage (II vs I, HR = 2.209, 95% CI: 1.431-3.347; ≥III vs I, HR = 5.286, 95% CI: 3.682-7.566) were also significant for OS. CONCLUSION: A smaller number of coexisting mutations, earlier stage, and younger age were associated with longer RFS and OS, while EGFR mutations were significantly associated with improved OS.

A proposal for a comprehensive risk scoring system for predicting postoperative complications in octogenarian patients with medically operable lung cancer: JACS1303.

OBJECTIVES: Although some retrospective studies have reported clinicopathological scoring systems for predicting postoperative complications and survival outcomes for elderly lung cancer patients, optimized scoring systems remain controversial. METHODS: The Japanese Association for Chest Surgery (JACS) conducted a nationwide multicentre prospective cohort and enrolled a total of 1019 octogenarians with medically operable lung cancer. Details of the clinical factors, comorbidities and comprehensive geriatric assessment were recorded for 895 patients to develop a comprehensive risk scoring (RS) system capable of predicting severe complications. RESULTS: Operative (30 days) and hospital mortality rates were 1.0% and 1.6%, respectively. Complications were observed in 308 (34%) patients, of whom 81 (8.4%) had Grade 3-4 severe complications. Pneumonia was the most common severe complication, observed in 27 (3.0%) patients. Five predictive factors, gender, comprehensive geriatric assessment75: memory and Simplified Comorbidity Score (SCS): diabetes mellitus, albumin and percentage vital capacity, were identified as independent predictive factors for severe postoperative complications (odds ratio = 2.73, 1.86, 1.54, 1.66 and 1.61, respectively) through univariate and multivariate analyses. A 5-fold cross-validation was performed as an internal validation to reconfirm these 5 predictive factors (average area under the curve 0.70). We developed a simplified RS system as follows: RS = 3 (gender: male) + 2 (comprehensive geriatric assessment 75: memory: yes) + 2 (albumin: <3.8 ng/ml) + 1 (percentage vital capacity: ≤90) + 1 (SCS: diabetes mellitus: yes). CONCLUSIONS: The current series shows that octogenarians can be successfully treated for lung cancer with surgical resection with an acceptable rate of severe complications and mortality. We propose a simplified RS system to predict severe complications in octogenarian patients with medically operative lung cancer. Trial Registration Number: JACS1303 (UMIN000016756).

Restrictive ventilatory impairment is associated with poor outcome in patients with cT1aN0M0 peripheral squamous cell carcinoma of the lung.

BACKGROUND: Patients with squamous cell carcinoma (SqCC) of the lung sometimes have a comorbid pulmonary disease such as pulmonary emphysema or an interstitial lung disease (ILD), both of which negatively affect patient outcome. The aim of this study was to determine the outcome of patients in a multicenter database who underwent surgery for cT1aN0M0 peripheral SqCC lung cancer. METHODS: The medical records of a total of 228 eligible patients from seven institutions were reviewed to evaluate the impact of concomitant impaired pulmonary function and other clinicopathological factors on overall survival (OS) and relapse-free survival (RFS). RESULTS: Six patients with positive or unclear tumor margins were excluded. Of the 222 remaining study patients, 42 (18.9%) and 97 (43.7%) patients were found to have coexisting restrictive or obstructive ventilatory impairment, respectively. Over a median follow-up period of 30.6 months, the 5-year OS and RFS were 69.0% and 62.6%, respectively. By multivariate analysis, ILDs identified on high-resolution computed tomography (HRCT), pulmonary function test results indicating a restrictive ventilatory impairment, and wedge resection were found to be independent risk factors for poor OS. An increased level of serum squamous cell carcinoma antigen (SCC-Ag) (>1.5 ng/mL) and the same risk factors for poor OS were independent risk factors for recurrence. Among patients who underwent anatomical lung resection (lobectomy and segmentectomy, n=173), a restrictive ventilatory impairment was an independent risk factor for poor OS, and increased serum SCC-Ag level, ILDs on HRCT, and restrictive ventilatory impairment were independent risk factors for poor RFS by multivariate analysis. Factors such as visceral pleural invasion, and lymphatic or vascular invasion were not significantly associated with outcome. CONCLUSIONS: A restrictive ventilatory impairment negatively affects the outcome of patients with cT1aN0M0 peripheral SqCC lung cancer.

Multiplex Ultrasensitive Genotyping of Patients with Non-Small Cell Lung Cancer for Epidermal Growth Factor Receptor (EGFR) Mutations by Means of Picodroplet Digital PCR.

Epidermal growth factor receptor (EGFR) mutations have been used as the strongest predictor of effectiveness of treatment with EGFR tyrosine kinase inhibitors (TKIs). Three most common EGFR mutations (L858R, exon 19 deletion, and T790M) are known to be major selection markers for EGFR-TKIs therapy. Here, we developed a multiplex picodroplet digital PCR (ddPCR) assay to detect 3 common EGFR mutations in 1 reaction. Serial-dilution experiments with genomic DNA harboring EGFR mutations revealed linear performance, with analytical sensitivity ~0.01% for each mutation. All 33 EGFR-activating mutations detected in formalin-fixed paraffin-embedded (FFPE) tissue samples by the conventional method were also detected by this multiplex assay. Owing to the higher sensitivity, an additional mutation (T790M; including an ultra-low-level mutation, <0.1%) was detected in the same reaction. Regression analysis of the duplex assay and multiplex assay showed a correlation coefficient (R2) of 0.9986 for L858R, 0.9844 for an exon 19 deletion, and 0.9959 for T790M. Using ddPCR, we designed a multiplex ultrasensitive genotyping platform for 3 common EGFR mutations. Results of this proof-of-principle study on clinical samples indicate clinical utility of multiplex ddPCR for screening for multiple EGFR mutations concurrently with an ultra-rare pretreatment mutation (T790M).

Prospective Analysis of Oncogenic Driver Mutations and Environmental Factors: Japan Molecular Epidemiology for Lung Cancer Study.

PURPOSE: Oncogenic driver mutations are critical for lung cancer development and serve as therapeutic targets. However, their associations with environmental factors are not fully understood. We aimed to elucidate the relationship between tumor developmental biology and exposure to environmental factors. PATIENTS AND METHODS: This was a prospective, multicenter, molecular epidemiology study. Eligible patients were those with newly diagnosed stages I to IIIB non-small-cell lung cancer (NSCLC) who underwent surgery. The tumors were examined for somatic mutations in 72 cancer-associated genes by targeted deep sequencing, estrogen receptor ß (ERß) expression using immunohistochemical staining, and infection with any of 37 types of human papillomavirus (HPV) using a polymerase chain reaction-based microarray system. Detailed information on patient demographics and environmental factors was obtained from a comprehensive questionnaire. RESULTS: From July 2012 to December 2013, 957 patients were enrolled, and molecular analyses were performed on 876 samples (from 441 ever- and 435 never-smokers). Oncogenic driver mutations in P53 and KRAS increased proportionally with smoking status, whereas mutations in EGFR and SMAD4 decreased. KRAS mutations in smokers and SMAD4 mutations were observed more frequently in proportion to body mass index. TP53 and NFE2L2 mutations were observed more frequently in advanced NSCLC stages. As for never-smokers, no environmental factors were significantly associated with mutational changes. EGFR mutations and TP53 mutations were observed more frequently in women and in men, respectively. Mutations in these two genes were also potentially associated with ERß expression. Only three patients (0.3%) were HPV positive. CONCLUSION: The mutational spectrum is associated with smoking, body mass index, and other environmental factors, as well as with ERß expression. Little association was observed between HPV and NSCLC.