Death-associated protein kinase promoter methylation correlates with clinicopathological and prognostic features in nonsmall cell lung cancer patients: A cohort study.

OBJECTIVE: The objective was to study the correlation between death-associated protein kinase (DAPK) promoter methylation and the clinicopathological and prognostic features in nonsmall cell lung cancer (NSCLC) patients. MATERIALS AND METHODS: A total of 117 NSCLC patients were recruited into our study between December 2012 and December 2014. Methylation-specific polymerase chain reaction was employed to detect the methylation status of DAPK in cancer tissues, peficancerous tissues, and serum samples of 117 NSCLC patients. In addition, serum samples of 115 healthy subjects were analyzed as controls. A literature search of English and Chinese databases, based on predefined criteria, identified published studies closely related to this study. Data were extracted, and meta-analysis was performed using STATA 12.0 software (STATA Corporation, College Station, TX, USA). RESULTS: Our study results showed that DAPK promoter methylation frequency was significantly higher in NSCLC tissues compared to peficancerous normal tissues (58.1% vs. 12.8%, χ2 = 52.45, P < 0.001). When serum samples were compared, DAPK methylation frequency in NSCLC patients was higher than the control group (27.4% vs. 0, χ2 = 37.07, P < 0.001). Our meta-analysis results demonstrated that DAPK methylation frequency was lower in tumor node metastasis (TNM) stage I-II compared to TNM stage III-IV (relative risk [RR] =0.87, 95% confidence interval [CI] =0.76-0.99, P = 0.041). DAPK promoter methylation frequency in NSCLC patients with lymph node metastasis was significantly higher compared to the patients with no metastases (RR = 1.26, 95% CI = 1.04-1.52, P = 0.020). Finally, the 5-year survival rate was lower in NSCLC patient group with high frequency of DAPK methylation, compared to the patient group with unmethylated DAPK (RR = 0.71, 95% CI = 0.56-0.89, P = 0.004). CONCLUSION: Our results showed that DAPK promoter methylation is tightly correlated with clinicopathological features of NSCLC and is associated with poor prognosis in patients.

DAPK promoter methylation status correlates with tumor metastasis and poor prognosis in patients with non-small cell lung cancer.

OBJECTIVE: This meta-analysis investigated the correlation between the promoter methylation of death-associated protein kinase (DAPK) and the clinicopathological features in patients with non-small cell lung cancer (NSCLC). METHOD: Scientific literature databases were exhaustively searched to retrieve published studies relevant to DAPK methylation and NSCLC. Retrieved studies published in English and Chinese languages were screened according to the stringent predefined inclusion and exclusion criteria, and high quality studies were selected for meta-analysis. All statistical analyses were performed utilizing STATA software (Version 12.0, Stata Corporation, College Station, TX, USA). RESULTS: A total of 14 published studies (5 in English and 9 in Chinese) were enrolled in the present meta-analysis, and contained 1238 patients with NSCLC. The results indicated that NSCLC patients with metastatic phenotype were strongly associated with significantly higher methylation rate of DAPK compared to NSCLC patients without metastasis. Additionally, in NSCLC patients carrying tumors with DAPK methylation, the 5-year survival rate was remarkedly lower than NSCLC patients without DAPK methylation. However, we did not find significant correlation between DAPK methylation and histological stage or tumor node metastasis (TNM) stage in NSCLC patients. CONCLUSION: Our meta-analysis results reveal that DAPK promoter methylation might be associated with tumor metastasis and poor prognosis in NSCLC patients, although no correlation with histological types and TNM stage in NSCLC patients were found.

Intensity-modulated radiotherapy and volumetric-modulated arc therapy have distinct clinical advantages in non-small cell lung cancer treatment.

This study was conducted to compare the efficacy of intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) in delivering the planned dosage in the treatment of non-small cell lung cancer (NSCLC). Between September 2013 and March 2014, 125 NSCLC patients were randomly chosen and allocated to the IMRT group (n = 65) and VMAT group (n = 60). We compared multiple parameters such as target dose, organ dosimetry, monitor unit (MU) and time of therapy between IMRT and VMAT groups. The prescribed dose coverage of both planning techniques was 95 % of the planning target volumes (PTVs). PTV 95 % and homogeneous index in IMRT plan were greater than those in VMAT plan (both P < 0.05), while no significant difference in conformity index was observed (P > 0.05). The mean total lung V5 and V10 in VMAT group were markedly higher than those in IMRT group, but the V20, V30, and V40 in VMAT group were significantly lower (all P < 0.05), but no statistically significant difference was observed in V15 and V20 (P > 0.05). Furthermore, the planning spine and esophagus at risk volume showed no statistical significances in both groups (P > 0.05). MU of IMRT plan was about 4.2 % less than that of VMAT plan, which was statistically significant (P < 0.001). Both IMRT and VMAT had significant advantages in the treatment of NSCLC. The IMRT may be better for NSCLC patients with poor pulmonary function, and VMAT may be recommended for NSCLC patients with normal pulmonary function.