Association between Genetic Variants and Peripheral Neuropathy in Patients with NSCLC Treated with First-Line Platinum-Based Therapy.

Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a common, disabling side effect in non-small cell lung cancer (NSCLC) patients treated with platinum-based therapy. There is increasing evidence for associations between genetic variants and susceptibility to CIPN. The aim of this study was to further explore genetic risk factors for CIPN by investigating previously reported genetic associations. Methods: A multicenter prospective follow-up study (PGxLUNG, NTR NL5373610015) in NSCLC patients (stage II-IV) treated with first-line platinum-based (cisplatin or carboplatin) chemotherapy was conducted. Clinical evaluation of neuropathy (CTCAE v4.03) was performed at baseline and before each cycle (four cycles, every three weeks) of chemotherapy and at three and six months after treatment initiation. The relationship between 34 single nucleotide polymorphisms (SNPs) in 26 genes and any grade (grade ≥ 1) and severe (grade ≥ 2) CIPN was assessed by using univariate and multivariate logistic regression modelling. Results: In total, 320 patients were included of which 26.3% (n = 84) and 8.1% (n = 26) experienced any grade and severe CIPN, respectively. The GG-genotype (rs879207, A > G) of TRPV1, a gene expressed in peripheral sensory neurons, was observed in 11.3% (n = 36) of the patients and associated with an increased risk of severe neuropathy (OR 5.2, 95%CI 2.1−12.8, adjusted p-value 0.012). A quarter (25%, n = 9/36) of the patients with the GG-genotype developed severe neuropathy compared to 6% (n = 17/282) of the patients with the AG- or AA-genotype. Multivariate logistic regression analysis showed statistically significant associations between the GG-genotype (ORadj 4.7, 95%CI 1.8−12.3) and between concomitant use of paclitaxel (ORadj 7.2, 95%CI 2.5−21.1) and severe CIPN. Conclusions: Patients with the GG-genotype (rs879207) of TRPV1 have an almost 5-fold higher risk of developing severe neuropathy when treated with platinum-based therapy. Future studies should aim to validate these findings in an independent cohort and to further investigated the individualization of platinum-based chemotherapy in clinical practice.

The association between skeletal muscle measures and chemotherapy-induced toxicity in non-small cell lung cancer patients.

BACKGROUND: Chemotherapy-induced toxicities frequently occur in non-small cell lung cancer (NSCLC) patients treated with platinum-based chemotherapy. Low skeletal muscle mass (SMM) has been associated with a higher incidence of toxicities for several types of cancers and cytostatics. The aim of this study was to evaluate the association between skeletal muscle measures and chemotherapy-induced toxicity in a large cohort of NSCLC patients. METHODS: A multicentre prospective follow-up study (PGxLUNG, NTR number NL5373610015) in NSCLC patients was conducted. Included were patients diagnosed with NSCLC (stage II-IV) treated with first-line platinum-based (cisplatin or carboplatin) chemotherapy of whom pretreatment imaging was available. Skeletal muscle area (SMA) segmentation was performed on abdominal imaging at the level of the third lumbar vertebra (L3). SMA at the level of L3 was corrected for squared height (m2 ) to yield the lumbar skeletal muscle mass index (LSMI). Skeletal muscle density (SMD) was calculated as the mean Hounsfield Unit (HU) of the segmented SMA. SMM and SMD were categorized as low, intermediate, and high, based on LSMI and mean HU tertiles, respectively. Chemotherapy-induced toxicity was scored using CTCAE v4.03 and categorized into haematological (anaemia, leukocytopenia, neutropenia, and thrombocytopenia), non-haematological (nephrotoxicity, neurotoxicity, and esophagitis), and dose-limiting toxicity (DLT) (treatment switch, delay, de-escalation, discontinuation, or hospitalization). The relationship between SMM, SMD, and toxicities was assessed with logistic regression modelling taking into account potential confounders like gender and body mass index (BMI). RESULTS: In total, 297 patients (male n = 167, median age 64 years) were included. Haematological toxicity grade 3/4 was experienced in 36.6% (n = 108) of the patients, 24.6% (n = 73) experienced any non-haematological toxicity grade ≥2, and 55.6% (n = 165) any DLT. Multivariate logistic regression analysis showed that low SMM (ORadj 2.41, 95% CI 1.31-4.45, P = 0.005) and age at diagnosis >65 years (ORadj 1.76, 95% CI 1.07-2.90, P = 0.025) were statistically significantly associated with overall haematological toxicity grade 3/4. No statistically significant associations were found between low SMM or low SMD and non-haematological toxicities. Low SMM (ORadj 2.23, 95% CI 1.23-4.04, P = 0.008) and high SMD (ORadj 0.41, 95% CI 0.23-0.74, P = 0.003) were statistically significantly associated with a higher respectively lower risk of DLT. CONCLUSIONS: Non-small cell lung cancer patients with pretreatment low SMM are at significant higher risk for haematological toxicities grade 3/4 and DLT. NSCLC patients with high SMD are at significant lower risk for DLT. Further studies should be aimed to investigate whether platinum dosing based on skeletal muscle measurements and/or improvement of pretreatment SMM/SMD could reduce the risk of toxicity without compromising efficacy.

Association between Genetic Variants and Cisplatin-Induced Nephrotoxicity: A Genome-Wide Approach and Validation Study.

This study aims to evaluate genetic risk factors for cisplatin-induced nephrotoxicity by investigating not previously studied genetic risk variants and further examining previously reported genetic associations. A genome-wide study (GWAS) was conducted in genetically estimated Europeans in a discovery cohort of cisplatin-treated adults from Toronto, Canada, followed by a candidate gene approach in a validation cohort from the Netherlands. In addition, previously reported genetic associations were further examined in both the discovery and validation cohorts. The outcome, nephrotoxicity, was assessed in two ways: (i) decreased estimated glomerular filtration rate (eGFR), calculated using the Chronic Kidney Disease Epidemiology Collaboration formula (CKD-EPI) and (ii) increased serum creatinine according to the Common Terminology Criteria for Adverse Events v4.03 for acute kidney injury (AKI-CTCAE). Four different Illumina arrays were used for genotyping. Standard quality control was applied for pre- and post-genotype imputation data. In the discovery cohort (n = 608), five single-nucleotide polymorphisms (SNPs) reached genome-wide significance. The A allele in rs4388268 (minor allele frequency = 0.23), an intronic variant of the BACH2 gene, was consistently associated with increased risk of cisplatin-induced nephrotoxicity in both definitions, meeting genome-wide significance (ß = -8.4, 95% CI -11.4--5.4, p = 3.9 × 10-8) for decreased eGFR and reaching suggestive association (OR = 3.9, 95% CI 2.3-6.7, p = 7.4 × 10-7) by AKI-CTCAE. In the validation cohort of 149 patients, this variant was identified with the same direction of effect (eGFR: ß = -1.5, 95% CI -5.3-2.4, AKI-CTCAE: OR = 1.7, 95% CI 0.8-3.5). Findings of our previously published candidate gene study could not be confirmed after correction for multiple testing. Genetic predisposition of BACH2 (rs4388268) might be important in the development of cisplatin-induced nephrotoxicity, indicating opportunities for mechanistic understanding, tailored therapy and preventive strategies.

Optimizing Mutation and Fusion Detection in NSCLC by Sequential DNA and RNA Sequencing.

INTRODUCTION: Frequently, patients with locally advanced or metastatic NSCLC are screened for mutations and fusions. In most laboratories, molecular workup includes a multitude of tests: immunohistochemistry (ALK, ROS1, and programmed death-ligand 1 testing), DNA sequencing, in situ hybridization for fusion, and amplification detection. With the fast-emerging new drugs targeting specific fusions and exon-skipping events, this procedure harbors a growing risk of tissue exhaustion. METHODS: In this study, we evaluated the benefit of anchored, multiplexed, polymerase chain reaction-based targeted RNA sequencing (RNA next-generation sequencing [NGS]) in the identification of gene fusions and exon-skipping events in patients, in which no pathogenic driver mutation was found by DNA-based targeted cancer hotspot NGS (DNA NGS). We analyzed a cohort of stage IV NSCLC cases from both in-house and referral hospitals, consisting 38.5% cytology samples and 61.5% microdissected histology samples, mostly core needle biopsies. We compared molecular findings in a parallel workup (DNA NGS and RNA NGS, cohort 1, n = 198) with a sequential workup (DNA NGS followed by RNA NGS in selected cases, cohort 2, n = 192). We hypothesized the sequential workup to be the more efficient procedure. RESULTS: In both cohorts, a maximum of one oncogenic driver mutation was found per case. This is in concordance with large, whole-genome databases and suggests that it is safe to omit RNA NGS when a clear oncogenic driver is identified in DNA NGS. In addition, this reduced the number of necessary RNA NGS to only 53% of all cases. The tumors of never smokers, however, were enriched for fusions and exon-skipping events (32% versus 4% in former and current smokers, p = 0.00), and therefore benefited more often from the shorter median turnaround time of the parallel approach (15 d versus only 9 d in the parallel workup). CONCLUSIONS: We conclude that sequentially combining DNA NGS and RNA NGS is the most efficient strategy for mutation and fusion detection in smoking-associated NSCLC, whereas for never smokers we recommend a parallel approach. This approach was shown to be feasible on small tissue samples including for cytology tests, can drastically reduce the complexity and cost of molecular workup, and also provides flexibility in the constantly evolving landscape of actionable targets in NSCLC.

Added Value of 50-Gene Panel Sequencing to Distinguish Multiple Primary Lung Cancers from Pulmonary Metastases: A Systematic Investigation.

Differentiation between multiple primary lung cancers and pulmonary metastases (PM) has important implications in staging, prognosis, and treatment strategies. Clinical and immunohistopathologic criteria have been standardized; however, a substantial number of cases remain difficult to classify. Using next-generation sequencing, it is now possible to improve the classification of multiple lung cancer lesions. This study systematically investigated the value of routine morphologic and IHC characteristics, p53 protein expression, TP53 mutation analysis, and 50-gene panel sequencing (GPS) in 111 lesions from 50 patients with multiple lung lesions. Based on immunohistopathologic criteria, 32 paired lesions were classified as multiple primary lung cancer (MPLC) and 21 as PM. TP53 mutation analysis indicated MPLC in 23 and PM in 6 pairs, but in the majority of cases (n = 28, 49%) no mutation was observed and no conclusion could be drawn. In contrast, only 2 pairs were not conclusive using GPS. In a significant number of matching tumor samples (n = 19, 39%), sequencing results were contradictory to the initial immunohistopathology diagnosis. No separation in overall survival for classifications based on immunohistopathology was observed, while a clear but nonsignificant trend was observed concerning survival in MPLC patients (hazard ratio = 3.98) using 50-gene GPS. In about one-third of the patients, GPS provided additional information to improve the differentiation between MPLC and PM.