Detailed assessment of microvasculature markers in non-small cell lung cancer reveals potentially clinically relevant characteristics.

Tumor angiogenesis is important for the progression of cancer and is orchestrated by various factors associated with tumor vessels, tumor cells, and stromal cells. Angiogenic signaling in non-small cell lung cancer (NSCLC) needs to be further clarified, especially regarding existing and upcoming therapeutic approaches. Expression of CD34, CD105, Mel-CAM, VE-cadherin, D2-40, VEGF, VEGFR1, and VEGFR2 was assessed immunohistochemically on a cohort of 371 well documented, surgically resected NSCLC using a standardized tissue microarray platform. Extensive clinical data and a postoperative follow-up period of up to 18 years allowed us to assess clinicopathological correlations in detail. Microvasculature in NSCLC was significantly denser at the tumor periphery as compared to the tumor center. Squamous cell carcinomas (SCC) were associated with a notably lower microvessel density (MVD) than adenocarcinomas (ACA). CD105 was present at significantly higher levels on stromal cells of ACA as compared to SCC. Expression of VE-cadherin by tumor cells (6% of cases, mainly ACA) as well as decreased MVD in the tumor centers was independently associated with poor prognosis in the entire cohort. Low MVD in SCC might be related to lower efficacy of and fatal bleeding during therapy with bevacizumab. In other NSCLC entities for which treatment with VEGF inhibitors is studied in clinical trials, the predictive value of MVD for therapy response merits to be prospectively examined. Our data suggest that patients with ACA may be candidates for therapies targeting CD105. VE-cadherin is another promising target for therapy, but its expression also provides independent prognostic information.

Molecular response assessment by quantitative real-time polymerase chain reaction after induction therapy in NPM1-mutated patients identifies those at high risk of relapse.

Monitoring minimal residual disease is an important way to identify patients with acute myeloid leukemia at high risk of relapse. In this study we investigated the prognostic potential of minimal residual disease monitoring by quantitative real-time polymerase chain reaction analysis of NPM1 mutations in patients treated in the AMLCG 1999, 2004 and 2008 trials. Minimal residual disease was monitored - in aplasia, after induction therapy, after consolidation therapy, and during follow-up - in 588 samples from 158 patients positive for NPM1 mutations A, B and D (with a sensitivity of 10(-6)). One hundred and twenty-seven patients (80.4%) achieved complete remission after induction therapy and, of these, 56 patients (44.1%) relapsed. At each checkpoint, minimal residual disease cut-offs were calculated. After induction therapy a cut-off NPM1 mutation ratio of 0.01 was associated with a high hazard ratio of 4.26 and the highest sensitivity of 76% for the prediction of relapse. This was reflected in a cumulative incidence of relapse after 2 years of 77.8% for patients with ratios above the cut-off versus 26.4% for those with ratios below the cut-off. In the favorable subgroup according to European LeukemiaNet, the cut-off after induction therapy also separated the cohort into two prognostic groups with a cumulative incidence of relapse of 76% versus 6% after 2 years. Our data demonstrate that in addition to pre-therapeutic factors, the course of minimal residual disease in an individual is an important prognostic factor and could be included in clinical trials for the guidance of post-remission therapy. The trials from which data were obtained were registered at www.clinicaltrials.gov (#NCT01382147, #NCT00266136) and at the European Leukemia Trial Registry (#LN_AMLINT2004_230).