Individual patient data network meta-analysis using either restricted mean survival time difference or hazard ratios: is there a difference? A case study on locoregionally advanced nasopharyngeal carcinomas.

BACKGROUND: This study aimed at applying the restricted mean survival time difference (rmstD) as an absolute outcome measure in a network meta-analysis and comparing the results with those obtained using hazard ratios (HR) from the individual patient data (IPD) network meta-analysis (NMA) on the role of chemotherapy for nasopharyngeal carcinoma (NPC) recently published by the MAC-NPC collaborative group (Meta-Analysis of Chemotherapy [CT] in NPC). PATIENTS AND METHODS: Twenty trials (5144 patients) comparing radiotherapy (RT) with or without CT in non-metastatic NPC were included. Treatments were grouped in seven categories: RT alone (RT), induction CT followed by RT (IC-RT), RT followed by adjuvant CT (RT-AC), IC followed by RT followed by AC (IC-RT-AC), concomitant chemoradiotherapy (CRT), IC followed by CRT (IC-CRT), and CRT followed by AC (CRT-AC). The primary endpoint was overall survival (OS); secondary endpoints were progression-free survival and locoregional control. The rmstD was estimated at t* = 10 years in each trial. Random-effect frequentist NMA models were applied. P score was used to rank treatments. Heterogeneity and inconsistency were evaluated. RESULTS: The three treatments that had the highest effect on OS with rmstD were CRT-AC, IC-CRT, and CRT (respective P scores of 92%, 72%, and 64%) compared to CRT-AC, CRT, and IC-CRT when using HR (respective P scores of 96%, 71%, and 63%). Of the 32 HR and rmstD analyzed, 5 had a different interpretation, 3 with a direction change (different direction of treatment effect) and 2 with a change in significance (same direction but a change in statistical significance). Results for secondary endpoints were overall in agreement. CONCLUSION: The use of either HR or rmstD impacts the results of NMA. Given the sensitivity of HR to non-proportional hazards, this finding could have implications in terms of meta-analysis methodology.

Circulating innate immune markers and outcomes in treatment-naïve advanced non-small cell lung cancer patients.

INTRODUCTION: Innate immunity represents the first step of activation of the immune system and dictates the quality of adaptive immune responses. Studies have reported links between systemic inflammatory or innate immune markers and prognosis in patients with lung cancer. To our knowledge, the prospective and concomitant study of these systemic markers has never been performed. METHODS: Advanced treatment-naive non-small cell lung cancer (NSCLC) patients eligible for first-line platinum-based chemotherapy were prospectively included from December 2012 to July 2015 (N = 148). Blood samples of patients were collected before the first cycle for fresh NK cell phenotyping. Peripheral blood mononuclear cells were cryopreserved for natural cytotoxicity receptor (NCR) genotyping as well as sera for NCR's ligand quantification. Data on leukocytes, neutrophils and monocyte counts and lactate dehydrogenase (LDH) levels were extracted from electronic medical records. RESULTS: Among all studied markers, monocytosis, neutrophilia, leucocytosis, high LDH and sBAG6 levels and reduced levels of NCR3 transcripts were associated with poor overall survival (OS) in univariate analysis. The levels of NCR3 transcripts was linked to age, number of metastatic sites, monocyte counts, LDH and sBAG6 levels. Neutrophilia was associated to high sBAG6 levels. NCR3 was the unique innate immune parameter that remained as an independent factor associated with both OS (P = 0.003) and progression-free survival (P = 0.009) in the multivariate analysis. CONCLUSION: This study brought evidence that these biomarkers are entangled; parameters associated with an inflammatory process were related to reduced levels of NCR3 transcripts. Finally, the level of NCR3 transcripts was independently associated with outcomes in treatment-naive patients with advanced NSCLC.

Prognostic and predictive value of primary tumour side in patients with RAS wild-type metastatic colorectal cancer treated with chemotherapy and EGFR directed antibodies in six randomized trials.

BACKGROUND: There is increasing evidence that metastatic colorectal cancer (mCRC) is a genetically heterogeneous disease and that tumours arising from different sides of the colon (left versus right) have different clinical outcomes. Furthermore, previous analyses comparing the activity of different classes of targeted agents in patients with KRAS wild-type (wt) or RAS wt mCRC suggest that primary tumour location (side), might be both prognostic and predictive for clinical outcome. METHODS: This retrospective analysis investigated the prognostic and predictive influence of the localization of the primary tumour in patients with unresectable RAS wt mCRC included in six randomized trials (CRYSTAL, FIRE-3, CALGB 80405, PRIME, PEAK and 20050181), comparing chemotherapy plus EGFR antibody therapy (experimental arm) with chemotherapy or chemotherapy and bevacizumab (control arms). Hazard ratios (HRs) and 95% confidence intervals (CIs) for overall survival (OS) and progression-free survival (PFS) for patients with left-sided versus right-sided tumours, and odds ratios (ORs) for objective response rate (ORR) were estimated by pooling individual study HRs/ORs. The predictive value was evaluated by pooling study interaction between treatment effect and tumour side. RESULTS: Primary tumour location and RAS mutation status were available for 2159 of the 5760 patients (37.5%) randomized across the 6 trials, 515 right-sided and 1644 left-sided. A significantly worse prognosis was observed for patients with right-sided tumours compared with those with left-sided tumours in both the pooled control and experimental arms for OS [HRs = 2.03 (95% CI: 1.69-2.42) and 1.38 (1.17-1.63), respectively], PFS [HRs = 1.59 (1.34-1.88) and 1.25 (1.06-1.47)], and ORR [ORs = 0.38 (0.28-0.50) and 0.56 (0.43-0.73)]. In terms of a predictive effect, a significant benefit for chemotherapy plus EGFR antibody therapy was observed in patients with left-sided tumours [HRs = 0.75 (0.67-0.84) and 0.78 (0.70-0.87) for OS and PFS, respectively] compared with no significant benefit for those with right-sided tumours [HRs = 1.12 (0.87-1.45) and 1.12 (0.87-1.44) for OS and PFS, respectively; P value for interaction <0.001 and 0.002, respectively]. For ORR, there was a trend (P value for interaction = 0.07) towards a greater benefit for chemotherapy plus EGFR antibody therapy in the patients with left-sided tumours [OR = 2.12 (1.77-2.55)] compared with those with right-sided tumours [OR = 1.47 (0.94-2.29)]. Exclusion of the unique phase II trial or the unique second-line trial had no impact on the results. The predictive effect on PFS may depend of the type of EGFR antibody therapy and on the presence or absence of bevacizumab in the control arm. CONCLUSION: This pooled analysis showed a worse prognosis for OS, PFS and ORR for patients with right-sided tumours compared with those with left-sided tumours in patients with RAS wt mCRC and a predictive effect of tumour side, with a greater effect of chemotherapy plus EGFR antibody therapy compared with chemotherapy or chemotherapy and bevacizumab, the effect being greatest in patients with left-sided tumours. These predictive results should be interpreted with caution due to the retrospective nature of the analysis, which was carried out on subpopulations of patients included in these trials, and because none of these studies contemplated a full treatment sequence strategy.

Impact of thoracic radiotherapy timing in limited-stage small-cell lung cancer: usefulness of the individual patient data meta-analysis.

BACKGROUND: Chemotherapy (CT) combined with radiotherapy is the standard treatment of 'limited-stage' small-cell lung cancer. However, controversy persists over the optimal timing of thoracic radiotherapy and CT. MATERIALS AND METHODS: We carried out a meta-analysis of individual patient data in randomized trials comparing earlier versus later radiotherapy, or shorter versus longer radiotherapy duration, as defined in each trial. We combined the results from trials using the stratified log-rank test to calculate pooled hazard ratios (HRs). The primary outcome was overall survival. RESULTS: Twelve trials with 2668 patients were eligible. Data from nine trials comprising 2305 patients were available for analysis. The median follow-up was 10 years. When all trials were analysed together, 'earlier or shorter' versus 'later or longer' thoracic radiotherapy did not affect overall survival. However, the HR for overall survival was significantly in favour of 'earlier or shorter' radiotherapy among trials with a similar proportion of patients who were compliant with CT (defined as having received 100% or more of the planned CT cycles) in both arms (HR 0.79, 95% CI 0.69-0.91), and in favour of 'later or longer' radiotherapy among trials with different rates of CT compliance (HR 1.19, 1.05-1.34, interaction test, P < 0.0001). The absolute gain between 'earlier or shorter' versus 'later or longer' thoracic radiotherapy in 5-year overall survival for similar and for different CT compliance trials was 7.7% (95% CI 2.6-12.8%) and -2.2% (-5.8% to 1.4%), respectively. However, 'earlier or shorter' thoracic radiotherapy was associated with a higher incidence of severe acute oesophagitis than 'later or longer' radiotherapy. CONCLUSION: 'Earlier or shorter' delivery of thoracic radiotherapy with planned CT significantly improves 5-year overall survival at the expense of more acute toxicity, especially oesophagitis.