The effect of postoperative change in bronchial angle on postoperative pulmonary function after upper lobectomy in lung cancer patients

OBJECTIVES

Upper lobectomy inevitably leads to an upward displacement of the remaining lower lobe. Such displacement may result in bronchial angulation, thereby narrowing the airway. We hypothesized that the degree of displacement of the bronchus is associated with the degree of exacerbation of postoperative pulmonary dysfunction. This study investigated whether bronchial angulation affects postoperative pulmonary function.

METHODS

Patients undergoing upper lobectomy for lung cancer were retrospectively evaluated. A check for the presence of dyspnoea, pulmonary function test, chest X-ray and chest computed tomography (CT) were performed at 3 and 12 months postoperatively in these patients. The angle formed by the main bronchus and the bronchus intermedius on the right side and that by the main bronchus and the lower lobar bronchus were measured using the coronal view of the chest CT. We analysed the relationship between the change in bronchial angle and pulmonary function.

RESULTS

Ninety-nine patients were enrolled in this study. Among these patients, 50 underwent left upper lobectomy (LUL) and 49 underwent right upper lobectomy (RUL). Nine patients who underwent LUL showed worsening symptoms, and among them, 8 presented an increase in the angle. However, among the 9 patients with worsening symptoms after RUL, only 4 presented an increase in the angle. Decreased forced expiratory volume in 1 s (FEV1) from 3 to 12 months after surgery was observed in 16 patients in the LUL group and 14 in the RUL group. Exacerbation of pulmonary dysfunction was associated with an increase in the bronchial angle (P = 0.04 for LUL and P = 0.02 for RUL). The degree of angle change was also associated with the extent of FEV1 reduction (P = 0.02 for LUL and P = 0.02 for RUL).

CONCLUSIONS

Although the change in the bronchial angle is a physiological condition, it can reduce postoperative pulmonary function. The measurement of the change in the angle using the coronal view of a chest CT is a useful screening tool for predicting the postoperative reduction in FEV1.

PD-L1 polymorphism can predict clinical outcomes of non-small cell lung cancer patients treated with first-line paclitaxel-cisplatin chemotherapy

This study was conducted to investigate whether polymorphisms of genes involved in immune checkpoints can predict the clinical outcomes of patients with advanced stage non-small cell lung cancer (NSCLC) after 1st line paclitaxel-cisplatin chemotherapy. A total of 379 NSCLC patients were enrolled. Twelve single nucleotide polymorphisms (SNPs) of PD-1, PD-L1, and CTLA-4 genes were selected and genotyped. The associations of SNPs with chemotherapy response and overall survival (OS) were analyzed. Among the 12 SNPs investigated, PD-L1 rs2297136T > C and rs4143815C > G were significantly associated with clinical outcomes after chemotherapy. The rs2297136T > C was significantly associated with both better chemotherapy response and better OS, and the rs4143815C > G had a significantly better response to chemotherapy. Consistent with the individual genotype analyses, rs2297136C-rs4143815G haplotype (ht4) carrying variant alleles at both loci was significantly associated with better chemotherapy response and OS compared with combined other haplotypes. Patients with at least one ht4 had significantly better chemotherapy response and OS compared to those without ht4. PD-L1 rs2297136T > C and rs4143815C > G polymorphisms may be useful for the prediction of clinical outcome of 1(st) line paclitaxel-cisplatin chemotherapy in NSCLC. Further studies are needed to confirm our findings and to understand the role of PD-L1 in the chemotherapy outcome of NSCLC patients.

Clinical implication of minimal presence of solid or micropapillary subtype in early-stage lung adenocarcinoma

BACKGROUND

We investigated the clinical features and surgical outcomes of lung adenocarcinoma with minimal solid or micropapillary (S/MP) components, with a focus on stage IA.

METHODS

We enrolled 506 patients with lung adenocarcinoma who underwent curative resection in this study. Clinical features and surgical outcomes were compared between the groups with and without the S/MP subtype (S/MP+ and S/MP-, respectively), and between the group with an S/MP proportion of ≤5% (S/MP5) and the S/MP-.

RESULTS

The S/MP subtype was present in 247 patients (48.8%); 129 (25.5%) were grouped as the S/MP5 group. The S/MP+ and S/MP5 groups had larger tumors, higher frequency of lymph node metastasis, and more advanced stages of disease than the S/MP- group (P < 0.001, all comparisons). Pleural, lymphatic, and vascular invasions occurred more frequently in the S/MP+ and S/MP5 groups (P < 0.001, all comparisons for S/MP+ vs. S/MP-; P ≤ 0.01, all comparisons for S/MP5 vs. S/MP-). The S/MP+ and S/MP5 groups showed a shorter time to recurrence and cancer-related death than the S/MP- group(P < 0.001, both comparisons). For stage I, the presence or absence of the S/MP subtype defined prognostic subgroups better than the stage IA/IB classification. Notably, in the multivariate analysis, the minimal S/MP component was a significant predictor of recurrence, even in stage IA.

CONCLUSIONS

The presence of the minimal S/MP component was a significant predictor of poor prognosis after surgery, even in stage IA patients. Clinical trials to evaluate the advantages of adjuvant chemotherapy for this subset of patients and further investigations to understand underlying biological mechanisms of poor prognosis are needed.

KEY POINTS

Significant findings of the study: We demonstrated that only minimal presence of solid or micropapillary component was profoundly associated with aggressive clinicopathological features and poor prognosis after complete resection even in stage IA lung adenocarcinoma.

WHAT THIS STUDY ADDS

Our results suggest that minimal presence of these subtypes is a strong prognostic factor which should be taken into account in the risk assessment for adjuvant chemotherapy in lung adenocarcinoma.

A Comparison of the Cerebral and Hemodynamic Effects of Mannitol and Hypertonic Saline in a Rabbit Model of Acute Cryogenic Brain Injury

There has recently been an increased interest in the use of hypertonic saline solutions in the fluid resuscitation of trauma victims and patients with uncontrollable intracranial hypertension. In this study, the cerebral and hemodynamic effects of 3.2% hypertonic saline solution were compared with those of an equiosmolar (20%) mannitol solution or 0.9% saline in a rabbit model of acute cryogenic brain injury. Forty-five minutes following the creation of a left hemispheric cryogenic brain lesion, equal volumes (10 ml/kg) of hypertonic saline, 0.9% saline, or mannitol were infused over a 5-min period. Monitored variables over the ensuing 120 min included mean arterial pressure, central venous pressure, intracranial pressure (ICP), hematocrit, and serum osmolality. At the conclusion of the 2-h study period, hemispheric water contents were determined by gravimetric analysis and the wet/dry weight method. There were no significant differences in mean arterial pressure between the three groups at any time during the experiment. Plasma osmolality was significantly increased by +/- 10 mOsm/kg following infusions in both the mannitol and hypertonic groups compared to the saline group. The infusion of either mannitol or hypertonic saline produced a transient and significant decrease in ICP during the first 60-90 min but not at 120 min after cryogenic brain lesion, whereas animals in the saline group demonstrated a continual increase in ICP. However, there appeared to be no significant differences in ICP between animals receiving mannitol or hypertonic saline at any time point following infusion of solutions. We conclude that following acute cryogenic brain injury, infusions of equal volumes of equiosmolar solutions of hypertonic saline or mannitol will transiently reduce ICP as compared to equal volumes of normal saline. However, hypertonic saline is not superior to mannitol in its ability to reduce ICP in this model of intracranial hypertension.

Genetic polymorphisms in glycolytic pathway are associated with the prognosis of patients with early stage non-small cell lung cancer

This study was conducted to investigate whether polymorphisms of genes involved in glycolysis are associated with the prognosis of patients with non-small cell lung cancer (NSCLC) after surgical resection. Forty-four single nucleotide polymorphisms (SNPs) of 17 genes in glycolytic pathway were investigated in a total of 782 patients with NSCLC who underwent curative surgical resection. The association of the SNPs with overall survival (OS) and disease free survival (DFS) were analyzed. Among the 44 SNPs investigated, four SNPs (ENO1 rs2274971A > G, PFKM rs11168417C > T, PFKP rs1132173C > T, PDK2 rs3785921G > A) were significantly associated with survival outcomes in multivariate analyses. When stratified by tumor histology, three SNPs (ENO1 rs2274971A > G, PFKM rs11168417C > T, and PDK2 rs3785921G > A) were significantly associated with OS and/or DFS only in squamous cell carcinoma, whereas PFKP rs1132173C > T exhibited a significant association with survival outcomes only in adenocarcinoma. When the four SNPs were combined, OS and DFS decreased as the number of bad genotypes increased (Ptrend = 8 × 10⁻⁴ and 3 × 10⁻⁵, respectively). Promoter assays showed that ENO1 rs2274971G allele had significantly higher promoter activity compared to the rs2274971A allele. The four SNPs, especially ENO1 rs2274971A > G, may be useful for the prediction of prognosis in patients with surgically resected NSCLC.

Putative functional variants of XRCC1 identified by RegulomeDB were not associated with lung cancer risk in a Korean population

The Encyclopedia of DNA elements (ENCODE) project revealed that nearby or distantly located non-coding DNA regulates the expression of coding genes. RegulomeDB (http://regulome.stanford.edu) is a new database that can be used to predict whether a variant affects transcription factor binding and gene expression. We investigated the association between lung cancer risk and potentially functional polymorphisms of XRCC1 that were selected using RegulomeDB in a Korean population. A total of 185 polymorphisms of XRCC1 were evaluated using RegulomeDB. Strong evidence suggested that 10 polymorphisms, from among the 185, affected XRCC1 expression with scores of 1a-1f that were based on the RegulomeDB scoring system. The rs2854510 polymorphism was rare in Asians (minor allele frequency < 0.05). Eight polymorphisms were in strong linkage disequilibrium (LD). The rs2854509 polymorphism, which was one of the 8 polymorphisms in LD, and rs7248167, which was not in the LD block, were genotyped in 610 lung cancer patients and 607 age- and sex-matched controls. Additionally, four polymorphisms of XRCC1 (rs25487, rs25489, rs1799782, and rs3213245), which were investigated with regard to their association with lung cancer risk in previous studies, were also genotyped. Two polymorphisms (rs2854509 and rs7248167) that were predicted to affect XRCC1 expression based on their RegulomeDB scores were not associated with lung cancer risk (P = 0.31 and 0.93, respectively). When stratified according to age, gender, smoking status, and tumor histology, the two polymorphisms of XRCC1 were not associated with lung cancer risk. Among the four polymorphisms that were previously studied, only rs25489 of XRCC1 was significantly associated with lung cancer risk (dominant model, adjusted odds ratio = 0.61, 95% confidence interval = 0.46-0.83, P = 0.002). Although RegulomeDB is an attractive tool for predicting the regulatory potential of variants, the two polymorphisms that were selected using RegulomeDB were not associated with lung cancer risk.

The pri-let-7a-2 rs1143770C>T is associated with prognosis of surgically resected non-small cell lung cancer

BACKGROUND

Evidence indicates that let-7 of microRNA may be a prognostic factor in lung cancer. Genetic variation in microRNA precursors could influence the processing and expression of microRNAs, which could affect the prognosis of lung cancer. We aimed to investigate the impact of single nucleotide polymorphisms (SNPs) of pri-let-7 on the prognosis of non-small cell lung cancer (NSCLC).

METHOD

A total of 761 patients with surgically resected NSCLC were included. Four SNPs (pri-let-7a-2 rs1143770 and rs629367, pri-let-7a-1 rs10739971, and pri-let-7f-2 rs17276588) were genotyped using sequenom mass spectrometry-based genotyping assay. Overall survival (OS) and disease-free survival (DFS) were evaluated using Kaplan-Meier method and Cox proportional hazards model.

RESULTS

Of the 4 SNPs evaluated, the rs1143770C>T was found to be significantly associated with OS and DFS. The rs1143770 CT or TT genotype exhibited a significantly better OS and DFS compared with the rs1143770 CC genotype (adjusted hazard ratio for OS=0.67, confidence interval, 0.49-0.91, P=0.01 and adjusted hazard ratio for DFS=0.74, confidence interval, 0.58-0.95, P=0.02).

CONCLUSION

This observation indicates that pri-let-7a-2 rs1143770C>T may have a prognostic impact on surgically resected NSCLC.

Salvage radiotherapy for regional lymph node oligo-recurrence after radical surgery of non-small cell lung cancer

BACKGROUND

Currently, evidence-based guidelines for salvage therapy to treat mediastinal lymph node (LN) oligo-recurrence in post-resection non-small cell lung cancer (NSCLC) are limited. In patients previously treated by surgery without irradiation, radiotherapy (RT) might be safely utilized. We evaluate the clinical outcomes of salvage RT for patients with LN oligo-recurrence that developed after radical surgery for NSCLC.

METHODS

Thirty-one patients with stage I-IIIA NSCLC who developed regional LN oligo-recurrence between 2008 and 2013 were reviewed. The median time from surgery to recurrence was 12 months. Fifteen patients (48.4%) had single LN recurrence. All patients were irradiated by 3-dimensional conformal RT at the recurrent LN area with daily fractions of 2-3 Gy, with a median dose of 66 Gy (range 51-66). Sixteen patients also received chemotherapy.

RESULTS

After salvage RT, 16 patients achieved a complete response, nine a partial response, and six had stable disease. The median follow-up was 14 months (range 3-76). One and two-year in-field control rates were 88.4% and 75.8%, respectively. One and two-year progression-free survival rates were 73.1% and 50.9%, respectively. Progression sites were predominantly distant. Ten of the 31 patients (32.3%) met the revised Response Evaluation Criteria for Solid Tumors for a complete response by the final follow-up. Recurrent LN size (<3 vs. ≥3 cm) was a significant prognostic factor for progression-free survival (P = 0.013).

CONCLUSION

Salvage RT for patients with regional LN oligo-recurrence after radical surgery was an effective treatment option with an acceptable level of toxicity.

Serial changes in pulmonary function after video-assisted thoracic surgery lobectomy in lung cancer patients

BACKGROUND

The aim of this study is to evaluate the serial changes in pulmonary function and the recovery time for the observed postoperative values to reach the predicted postoperative values after video-assisted thoracic surgery (VATS) lobectomy for lung cancer.

PATIENTS AND METHODS

Patients undergoing VATS lobectomy for lung cancer were prospectively evaluated using complete preoperative and repeated postoperative pulmonary function tests (PFTs). The parameters of PFT at each time were compared according to the resected lobe as well as the presence of chronic obstructive pulmonary disease (COPD). The differences between the observed and predicted postoperative values of PFT and the recovery time for the observed values to reach the predicted values were calculated.

RESULTS

Seventy-two patients (33 men, 39 women; mean age: 63.9 years) received complete pre- and postoperative regular PFT after undergoing VATS lobectomy. Of these patients, 24 (33.3%) patients satisfied the criteria for COPD. During the immediate postoperative period, forced vital capacity (FVC) percentage of the patients who received right lower lobectomy patients was decreased most significantly compared with the preoperative values. Compared with the upper lobectomy (UL) group, the lower lobectomy (LL) group showed a significant decrease of FVC% up to 6 months. However, there was no significant difference at 12 months after surgery. Patients with COPD showed little reduction of FEV1% that persisted significantly until 1 month after the surgery in both UL and LL groups. The recovery time was shortest in the left lower lobectomy patients, and it was shorter in the LL group than in the UL group.

CONCLUSIONS

Postoperative pulmonary function and recovery time were different depending on the lobe resected and presence of COPD in VATS lobectomy patients. The information obtained from postoperative serial PFT would help accurately predict postoperative pulmonary function changes and recovery time after VATS lobectomy for lung cancer.

Functional intronic ERCC1 polymorphism from regulomeDB can predict survival in lung cancer after surgery

We searched for potential regulatory single nucleotide polymorphisms (SNPs) in excision repair cross-complementing group 1 (ERCC1) using RegulomeDB, a database integrating information from the Encyclopedia of DNA Elements (ENCODE) project, and investigated their association with survival after surgery in non-small cell lung cancer (NSCLC). Among 364 SNPs found within ERCC1 region using RegulomeDB, four top priority SNPs (rs2298881C>A, rs1049739A>G, rs10415949A>G and rs6509214G>T) were selected for this study. The four SNPs were investigated in 316 patients. A replication study was performed (n = 579). Of the four SNPs analyzed in the discovery set, rs2298881C>A and rs6509214G>T were significantly associated with survival outcomes. The association was consistently observed only for rs2298881C>A in the validation cohort. In combined analysis, rs2298881C>A was significantly associated with worse overall survival and disease-free survival (P = 0.0002 and 0.02, respectively). A decreased reporter gene expression for rs2298881 A allele was observed compared with C allele by luciferase assay (P = 0.02). ERCC1 rs2298881C>A, an intronic SNP, is the first genetic polymorphism with functional evidence of regulating its expression, and the SNP is associated with prognosis of NSCLC. Our result supports the role of RegulomeDB as a comprehensive source of prioritized candidate SNPs for genetic association studies.

Extent of visceral pleural invasion and the prognosis of surgically resected node-negative non-small cell lung cancer

Background

Visceral pleural invasion (VPI) is generally considered a poor prognostic factor in non‐small cell lung cancer (NSCLC). VPI is defined as penetration beyond the elastic layer of visceral pleura (PL1), including the visceral pleural surface without the involvement of adjacent structures (PL2) by cancer cells. The aim of this study was to evaluate the influence of the extent of VPI on NSCLC prognosis.

Methods

This was a retrospective study of 90 patients with resected node‐negative NSCLC with VPI. The overall survival (OS) and disease‐free survival (DFS) rates were estimated using the Kaplan–Meier method. Multivariate analysis for prognostic factors was performed using a Cox proportional hazards regression model. The pattern of recurrence was also compared between PL1 and PL2 groups.

Results

Seventy‐three patients had PL1. The three‐year OS rates for the PL1 and PL2 groups were 97.4% and 82.4%, respectively (P = 0.004). The two‐year DFS rates for PL1 and PL2 groups were 81.0% and 76.5%, respectively (P = 0.419). According to the multivariate analysis, PL2 was not a significant prognostic factor for survival outcome in node‐negative NSCLC with VPI compared to PL1 (hazard ratio for DFS 1.753, 95% confidence interval 0.582–5.284; P = 0.319). In this study, six patients in the PL1 and one in PL2 group developed ipsilateral pleural recurrence (P = 1.000).

Conclusion

VPI extent may not influence survival outcomes in patients with surgically resected node‐negative NSCLC with VPI.

Intronic variant of EGFR is associated with GBAS expression and survival outcome of early-stage non-small cell lung cancer

BACKGROUND

Genome-wide association studies have indicated that most of the currently identified disease and trait-associated single nucleotide polymorphisms (SNPs) are intronic or intergenic. RegulomeDB is a recently developed database that provides functional annotations for regulatory features of SNPs located in non-coding regions. We evaluated the potential regulatory SNPs in the EGFR gene region using RegulomeDB and their associations with prognosis after surgery in non-small cell lung cancer (NSCLC) patients.

METHODS

A total of 698 patients with surgically resected NSCLC were enrolled and seven SNPs were selected based on the RegulomeDB database. All SNPs were genotyped using SEQUENOM MassARRAY iPLEX assay.

RESULTS

Among the seven SNPs evaluated, rs9642391 (EGFR ivs19+2851C>G) was significantly associated with survival outcome (adjusted hazard ratio [HR] for overall survival = 0.70, 95% confidence interval [CI] 0.56-0.87, P = 0.001; adjusted HR for disease-free survival = 0.82, 95% CI 0.70-0.97, P = 0.02; under a codominant model). According to RegulomeDB, rs9642391C>G, which is located in intron 19 of EGFR, was predicted to influence the expression of GBAS but not EGFR. As predicted, rs9642391C>G was associated with GBAS (P = 0.024) but not EGFR messenger RNA expression in tumor tissues.

CONCLUSION

In conclusion, our study provides evidence that rs9642391C>G in the intron of EGFR is associated with GBAS expression and survival outcomes of patients with surgically resected early-stage NSCLC.

Partly solid pulmonary nodules: waiting for change or surgery outright?

OBJECTIVES

It has been assumed that if the prognosis and rate of lymph node metastases differ between two groups of patients being followed up for partly solid tumours, those with an increased solid component and those without change, these differences can help to decide on the time of surgery for patients with partly solid tumours. Therefore, this study compared the differences in pathological results and prognosis after surgical resection between patients with no change and and those with change in partly solid tumours during the preoperative period.

METHODS

Surgery was performed in patients who had an increased size of the solid component during the follow-up observation of partly solid tumours, as well as patients who had no change in the size of the solid component during a certain period of time. The 'No change group' in this study comprised those who had no change in at least two chest computed tomography scans during a minimum period of 6 months, but who underwent surgery.

RESULTS

Twenty-four patients were enrolled in this study. Among these patients, 14 were included in the No change group, and ten were included in the 'Change group'. There was no difference in the ratio of other postoperative pathological results, adenocarcinoma in situ, minimally invasive adenocarcinoma or invasive adenocarcinoma between the two groups. There was no difference in the pathological size of the tumour, including the in situ component between the two groups, but the size of the invasive component in the Change group was 2.5-fold that of the No change group, a statistically significant difference. During the median follow-up period of 59 months, neither recurrence nor cancer-related deaths occurred.

CONCLUSIONS

The pathological results and prognosis of lung cancer patients with persistent partly solid tumours who develop changes in their lesions after a certain period of follow-up time were not different from those of patients who did not develop any changes in the lesions. Therefore, surgery can be deferred until those lesions demonstrate changes in size or growth in their solid component when the overall size of ground-glass opacity (GGO) is less than 3 cm and the proportion of GGO is greater than 50%.

Glucose Transporter 1 Gene Variants Predict the Prognosis of Patients with Early-Stage Non-small Cell Lung Cancer

BACKGROUND

This study was conducted to investigate whether polymorphisms of glucose transporter 1 (GLUT1) gene are associated with the prognosis of patients with non-small cell lung cancer (NSCLC) after surgical resection.

METHODS

Five single nucleotide polymorphisms (SNPs) in GLUT1 were investigated in a total of 354 patients with NSCLC who underwent curative surgery. The association of the SNPs with patients' survival was analyzed.

RESULTS

Among the five SNPs investigated, two SNPs (GLUT1 rs3820589T > A and rs4658G > C) were significantly associated with OS in multivariate analyses. GLUT1 rs3820589T > A was associated with significantly better OS (adjusted hazard ratio [aHR] = 0.57, 95% confidence interval [CI] = 0.34-0.94, P = 0.03, under dominant model), and rs4658G > C was associated with significantly worse OS (aHR = 1.91, 95% CI = 1.09-3.33, P = 0.02, under recessive model). In the stratified analysis by tumor histology, the effect of these SNPs on OS was only significant in squamous cell carcinoma but not in adenocarcinoma. When the two SNPs were combined, OS decreased as the number of bad genotypes increased (Ptrend = 4 × 10^-3).

CONCLUSIONS

This study suggests that genetic variation in GLUT1 may be useful in predicting survival of patients with early stage NSCLC.

TGFBI Promoter Methylation is Associated with Poor Prognosis in Lung Adenocarcinoma Patients

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related deaths worldwide and has high rates of metastasis. Transforming growth factor beta-inducible protein (TGFBI) is an extracellular matrix component involved in tumour growth and metastasis. However, the exact role of TGFBI in NSCLC remains controversial. Gene silencing via DNA methylation of the promoter region is common in lung tumorigenesis and could thus be used for the development of molecular biomarkers. We analysed the methylation status of the TGFBI promoter in 138 NSCLC specimens via methylation-specific PCR and evaluated the correlation between TGFBI methylation and patient survival. TGFBI promoter methylation was detected in 25 (18.1%) of the tumours and was demonstrated to be associated with gene silencing. We observed no statistical correlation between TGFBI methylation and clinicopathological characteristics. Univariate and multivariate analyses showed that TGFBI methylation is significantly associated with poor survival outcomes in adenocarcinoma cases (adjusted hazard ratio = 2.88, 95% confidence interval = 1.19-6.99, P = 0.019), but not in squamous cell cases. Our findings suggest that methylation in the TGFBI promoter may be associated with pathogenesis of NSCLC and can be used as a predictive marker for lung adenocarcinoma prognosis. Further large-scale studies are needed to confirm these findings.

Inadvertently transected left superior pulmonary vein during thoracoscopic left lower lobectomy

Background

There are several anatomical variations of the pulmonary vein which can cause serious complications in pulmonary lobectomy.

Case presentation

We inadvertently divided the left superior pulmonary vein during thoracoscopic left lower lobectomy in a lung cancer patient. Retrospective review of the preoperative computed tomography showed extra-pericardial common trunk of the left pulmonary venous system. Left superior pulmonary vein was reimplanted into stump of divided common trunk via thoracotomy.

Conclusions

Awareness of vascular anomalies will help thoracic surgeons to prevent potential morbidity and mortality from complications.

The Different Effect of VEGF Polymorphisms on the Prognosis of Non-Small Cell Lung Cancer according to Tumor Histology

Vascular endothelial growth factor (VEGF) contributes to tumor angiogenesis. The role of VEGF single nucleotide polymorphisms (SNPs) in lung cancer susceptibility and its prognosis remains inconclusive and controversial. This study was performed to investigate whether VEGF polymorphisms affect survival outcomes of patients with early stage non-small cell lung cancer (NSCLC) after surgery. Three potentially functional VEGF SNPs (rs833061T>C, rs2010963G>C, and rs3025039C>T) were genotyped. A total of 782 NSCLC patients who were treated with surgical resection were enrolled. The association of the SNPs with overall survival (OS) and disease free survival (DFS) was analyzed. In overall population, none of the three polymorphisms were significantly associated with OS or DFS. However, when the patients were stratified by tumor histology, squamous cell carcinoma (SCC) and adenocarcinoma (AC) had significantly different OS (Adjusted hazard ratio [aHR] = 0.76, 95% CI = 0.56-1.03 in SCC; aHR = 1.33, 95% CI = 0.98-1.82 in AC; P for heterogeneity = 0.01) and DFS (aHR = 0.75, 95% CI = 0.58-0.97 in SCC; aHR = 1.26, 95% CI = 1.00-1.60 in AC; P for heterogeneity = 0.004) according to the rs833061T>C genotypes. Our results suggest that the prognostic role of VEGF rs833061T>C may differ depending on tumor histology.

Visceral Pleural Invasion Is a Significant Prognostic Factor in Patients with Partly Solid Lung Adenocarcinoma Sized 30 mm or Smaller

Background This study analyzed the impact of visceral pleural invasion (VPI) on the disease-free survival (DFS) of patients with partly solid pulmonary adenocarcinoma sized 30 mm or smaller.

Method This is a retrospective study of 147 patients with surgically resected pathologic N0 pulmonary adenocarcinoma that had a partly solid appearance on preoperative computed tomography. All patients presented with tumors of size 30 mm or smaller. The DFS rate was estimated using Kaplan–Meier method. A multivariate analysis for prognostic factors was performed using the Cox proportional hazards regression model.

Results VPI was found in 36 patients. The 5-year DFS in 111 patients without VPI (97.6%) was significantly higher than that in 36 patients with VPI (63%) (p < 0.0001). Univariate analysis revealed three significant poor prognostic predictors: the presence of VPI, the presence of lymphovascular invasion, and the size of the solid component on computed tomography (>20, ≤30 mm). According to the multivariate analysis, VPI was found to be a significant poor prognostic predictor (hazard ratio for DFS = 7.31, 95% confidence interval = 1.444–37.014, p = 0.016).

Conclusion VPI is a significant predictor of poor prognosis for small-sized (≤30 mm) partly solid lung adenocarcinoma. Therefore, upstaging of the T factor from T1 to T2 on the basis of VPI as described by the TNM staging system is mandatory regardless of ground-glass opacity in small lung adenocarcinoma.

Effects of polymorphisms identified in genome-wide association studies of never-smoking females on the prognosis of non-small cell lung cancer

A number of genome-wide association studies have reported several variants that influence the risk of lung cancer in never-smoking females. We evaluated the impact of these variants on survival outcome in never-smoking females with non-small cell lung cancer (NSCLC). In total, 510 never-smoking females with NSCLC who underwent curative surgery were enrolled. Eleven variants associated with lung cancer susceptibility in never-smoking females were genotyped and their associations with survival outcome were analyzed. Among these 11 variants, TP63 rs7631358 and CSF1R rs10079250 affected survival outcomes. TP63 rs7631358 G > A was associated with a relatively worse overall survival (under a dominant model; hazard ratio = 2.31, 95% confidence interval = 1.18-4.52, P = 0.01). CSF1R rs10079250 A > G was associated with a relatively better disease-free survival (under a codominant model; hazard ratio = 0.70, 95% confidence interval = 0.53-0.93, P = 0.01). These results suggest that TP63 rs7631358 G > A and CSF1R rs10079250 A > G may affect the prognosis of NSCLC in never-smoking females, as well as the risk of lung cancer.

Polymorphisms in Epithelial-Mesenchymal Transition-Related Genes and the Prognosis of Surgically Treated Non-small Cell Lung Cancer

BACKGROUND

This study was conducted to determine whether single-nucleotide polymorphisms (SNPs) in EMT-related genes may influence the prognosis of NSCLC after surgery.

METHODS

There were 88 SNPs in EMT-related genes evaluated in a discovery set of 376 patients who underwent curative surgery for NSCLC. Significantly, 14 SNPs were evaluated in a validation set of 428 patients. Luciferase assay and RT-PCR were conducted to examine functional relevance of polymorphisms.

RESULTS

Fourteen SNPs that were associated with survival outcomes in a discovery set were selected for validation. Among those, two SNPs (FOXF2 rs1711972A>C and HEYL rs784621G>A) were replicated in a validation study. In combined analysis, FOXF2 rs1711972 AC+CC genotype was associated with significantly better overall survival (OS) and disease-free survival (DFS) compared with AA genotype (adjusted hazard ratio [aHR] for OS = 0.67, 95% confidence interval [CI] 0.51-0.88, P = 0.004; and aHR for DFS = 0.77, 95% CI 0.62-0.95, P = 0.01). HEYL rs784621 AA genotype exhibited a significantly worse OS compared with GG+GA genotype (aHR for OS = 2.65, 95% CI 1.63-4.31, P = 8 × 10^-5). FOXF2 rs1711972C allele had a significantly increased promoter activity than rs1711972A allele (P = 0.01), and HEYL rs784621A allele had a significantly lower promoter activity than rs784621G allele (P = 0.004). FOXF2 rs1711972A>C was significantly associated with increased FOXF2 mRNA expression.

CONCLUSIONS

FOXF2 rs1711972A>C and HEYL rs784621G>A were associated with survival outcomes of surgically treated NSCLC. These SNPs may help to identify patients at high risk of poor disease outcomes.

Bronchial stump coverage with fibrin glue-coated collagen fleece in lung cancer patients who underwent pneumonectomy

PURPOSE

Bronchopleural fistula (BPF) is a serious complication following pneumonectomy in lung cancer patients. The aim of this retrospective study is to investigate the efficacy of bronchial stump reinforcement with a collagen fleece coated with fibrin glue(TachoComb®).

METHODS

The bronchial stumps of 43 lung cancer patients who underwent pneumonectomy between January 1998 and January 2003 were covered with pericardial fat pad.From February 2003 to the March 2011, we used TachoComb to cover the bronchial stumps of all lung cancer patients undergoing pneumonectomy (20 cases). Several preoperative, intraoperative, and postoperative variables were recorded retrospectively.

RESULTS

Univariate analysis of comorbidities and risk factors did not show any significant differences between the two groups except for neoadjuvant chemotherapy. Postpneumonectomy BPF occurred in three of the 43 (7%) patients who had pericardial fat pad coverage and in none of the patients treated by TachoComb.

CONCLUSION

Reinforcement of the bronchial stump with TachoComb is a simple procedure, comparable to coverage with viable tissue, and should be considered in the prevention of postpneumonectomy BPF.

Polymorphisms in cancer-related pathway genes and lung cancer

We evaluated the associations between potentially functional variants in a comprehensive list of cancer-related genes and lung cancer in a Korean population.

A total of 1969 potentially functional single nucleotide polymorphisms (SNPs) of 1151 genes involved in carcinogenesis were evaluated using an Affymetrix custom-made GeneChip in 610 nonsmall cell lung cancer patients and 610 healthy controls. A replication study was conducted in an independent set of 490 cases and 486 controls. 68 SNPs were significantly associated with lung cancer in the discovery set and tested for replication.

Among the 68 SNPs, three SNPs (corepressor interacting with RBPJ 1 (CIR1) rs13009079T>C, ribonucleotide reductase M1 (RRM1) rs1465952T>C and solute carrier family 38, member 4 (SLC38A4) rs2429467C>T) consistantly showed significant associations with lung cancer in the replication study. In combined analysis, adjusted odds ratio for CIR1 rs13009079T>C, RRM1 rs1465952T>C and SLC38A4 rs2429467C>T were 0.69, 0.71 and 0.73, respectively (p=4×10−5, 0.01 and 0.001, respectively) under the dominant model. The relative mRNA expression level of CIR1 was significantly associated with rs13009079T>C genotypes in normal lung tissues (ptrend=0.03).

These results suggest that the three SNPs, particularly CIR1 rs13009079T>C, may play a role in the pathogenesis of lung cancer.