Kazuhiro Nagayama

BACKGROUND: The introduction of the lung allocation score has brought lung transplantation (LTX) of patients on extracorporeal membrane oxygenation (ECMO) bridge into the focus of interest. We reviewed our institutional experience with ECMO as a bridge to LTX. METHODS: Between 1998 and 2011, 38 patients (median age 30.1 years, range 13-66 years) underwent ECMO support with intention to bridge to primary LTX. The underlying diagnosis was cystic fibrosis (n=17), pulmonary hypertension (n=4), idiopathic pulmonary fibrosis (n=9), adult respiratory distress syndrome (n=4), hemosiderosis (n=1), bronchiolitis obliterans (n=1), sarcoidosis (n=1), and bronchiectasis (n=1). The type of extracorporeal bridge was venovenous (n=18), venoarterial (n=15), interventional lung assist (n=1), or a stepwise combination of them (n=4). The median bridging time was 5.5 days (range 1-63) days. The type of transplantation was double LTX (n=7), size-reduced double LTX (n=8), lobar LTX (n=16), split LTX (n=2), and lobar LTX after ex vivo lung perfusion (n=1). RESULTS: Four patients died before transplantation. Thirty-four patients underwent LTX, of them eight patients died in the hospital after a median stay of 24.5 days (range 1-180 days). Twenty-six patients left the hospital and returned to normal life (median hospital stay=47.5 days; range 21-90 days). The 1-, 3-, and 5-year survival for all transplanted patients was 60%, 60%, and 48%, respectively. The 1-, 3-, and 5-year survival conditional on 3-month survival for patients bridged with ECMO to LTX (78%, 78%, and 63%) was not worse than for other LTX patients within the same period of time (90%, 80%, and 72%, respectively, P=0.09, 0.505, and 0.344). CONCLUSION: Transplantation of patients bridged on ECMO to LTX is feasible and results in acceptable outcome.

Genome scanning at a 1-Mb resolution was undertaken in 29 lung cancer cell lines to clarify the distribution of homozygous (i.e., both allele) deletions along lung cancer genomes, using a high-resolution single nucleotide polymorphism array. Eighteen regions, including two known tumor suppressor loci, CDKN2A at 9p21 and FHIT at 3p14, were found homozygously deleted. Frequencies of deletions at the 18 regions were evaluated by genomic polymerase chain reaction in 78 lung cancer cell lines. Seven regions, 2q24, 3p14, 5q11, 9p21, 9p23, 11q14, and 21q21, were homozygously deleted in two or more cell lines. The CDKN2A locus at 9p21 was most frequently deleted (20/78, 26%), and the deletions were detected exclusively in non-small-cell lung carcinomas (NSCLCs). The PTPRD (protein tyrosine phosphatase receptor type D) locus at 9p23 was the second-most frequently deleted (8/78, 10%), and the deletions were detected in both small-cell lung carcinomas (SCLC) and NSCLC. In addition, the 9p24 region was deleted in a NSCLC. In total, 24 (31%) cell lines carried at least one deletion on chromosome arm 9p, while deletions on the remaining chromosome arms were observed at most in four (5%) cell lines. Deletions at 9p24, 9p23, and 9p21 were not contiguous with one another, and preferential co-occurrence or mutual exclusiveness for the deletions at these three loci was not observed. Thus, it was indicated that 9p is the most frequent target of homozygous deletions in lung cancer, suggesting that the arm contains multiple lung tumor suppressor genes and/or genomic features fragile during lung carcinogenesis.

The importance of neoantigens for cancer immunity is now well-acknowledged. However, there are diverse strategies for predicting and prioritizing candidate neoantigens, and thus reported neoantigen loads vary a great deal. To clarify this issue, we compared the numbers of neoantigen candidates predicted by four currently utilized strategies. Whole-exome sequencing and RNA sequencing (RNA-Seq) of four non-small-cell lung cancer patients was carried out. We identified 361 somatic missense mutations from which 224 candidate neoantigens were predicted using MHC class I binding affinity prediction software (strategy I). Of these, 207 exceeded the set threshold of gene expression (fragments per kilobase of transcript per million fragments mapped ≥1), resulting in 124 candidate neoantigens (strategy II). To verify mutant mRNA expression, sequencing of amplicons from tumor cDNA including each mutation was undertaken; 204 of the 207 mutations were successfully sequenced, yielding 121 mutant mRNA sequences, resulting in 75 candidate neoantigens (strategy III). Sequence information was extracted from RNA-Seq to confirm the presence of mutated mRNA. Variant allele frequencies ≥0.04 in RNA-Seq were found for 117 of the 207 mutations and regarded as expressed in the tumor, and finally, 72 candidate neoantigens were predicted (strategy IV). Without additional amplicon sequencing of cDNA, strategy IV was comparable to strategy III. We therefore propose strategy IV as a practical and appropriate strategy to predict candidate neoantigens fully utilizing currently available information. It is of note that different neoantigen loads were deduced from the same tumors depending on the strategies applied.

OBJECTIVES: Virtual-assisted lung mapping (VAL-MAP) is a preoperative bronchoscopic multispot dye-marking technique using virtual images. The purpose of this study was to evaluate the safety, efficacy and reproducibility of VAL-MAP among multiple centres. METHODS: Selection criteria included patients with pulmonary lesions anticipated to be difficult to identify at thoracoscopy and/or those undergoing sub-lobar lung resections requiring careful determination of resection margins. Data were collected prospectively and, if needed, compared between the centre that originally developed VAL-MAP and 16 other centres. RESULTS: Five hundred patients underwent VAL-MAP with 1781 markings (3.6 ± 1.2 marks/patient). Complications associated with VAL-MAP necessitating additional management occurred in four patients (0.8%) including pneumonia, fever and temporary exacerbation of pre-existing cerebral ischaemia. Minor complications included pneumothorax (3.6%), pneumomediastinum (1.2%) and alveolar haemorrhage (1.2%), with similar incidences between the original centre and other centres. Marks were identifiable during operation in approximately 90%, whereas the successful resection rate was approximately 99% in both groups, partly due to the mutually complementary marks. The contribution of VAL-MAP to surgical success was highly rated by surgeons resecting pure ground glass nodules ( P < 0.0001), tumours ≤ 5 mm ( P = 0.0016), and performing complex segmentectomy and wedge resection ( P = 0.0072). CONCLUSIONS: VAL-MAP was found to be safe and reproducible among multiple centres with variable settings. Patients with pure ground glass nodules, small tumours and resections beyond conventional anatomical boundaries are considered the best candidates for VAL-MAP. CLINICAL TRIAL REGISTRATION NUMBER: UMIN 000008031. University Hospital Medical Information Network Clinical Trial Registry ( http://www.umin.ac.jp/ctr/ ).