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.

[Lung cancer staging by endobronchial ultrasound with transbronchial needle aspiration]. / Endobronchiale ultrasonografie met transbronchiale naaldaspiratie bij stadiëring van longcarcinomen.

OBJECTIVE: To determine the diagnostic yield of endobronchial ultrasound with transbronchial needle aspiration (EBUS-TBNA) and to investigate the number of cervical mediastinoscopies that could be avoided when this technique was used as the initial modality in the invasive mediastinal staging of lung cancer. DESIGN: Retrospective cohort study. METHOD: At the St. Antonius Hospital, Nieuwegein, the Netherlands, results from all patients who had undergone EBUS-TBNA for mediastinal staging in lung cancer from September 2008 to January 2011 were collected. If metastases in the mediastinal lymph nodes had been demonstrated by EBUS-TBNA, no indication for additional mediastinoscopy ensued. The diagnostic yield of EBUS-TBNA as well as the number of mediastinoscopies that had been avoided, were calculated. RESULTS: EBUS-TBNA had been used for mediastinal staging in lung cancer in 77 patients. In 39 of these 77 patients (51%), mediastinal lymph node metastases was found using EBUS-TBNA and mediastinoscopy could thus be avoided. In 9 out of 38 (24%) patients whose EBUS-TBNA cytology results were found to be either benign or not representative, mediastinoscopy or endoscopic ultrasound eventually did reveal mediastinal lymph node metastases. In 13 of these 38 patients (34%), no additional cytologic or histologic testing was performed. Diagnostic yield was calculated for the two scenarios. The sensitivity and negative-predictive values for EBUS-TBNA were 64-81% and 42-76%, respectively. CONCLUSION: In more than 50% of lung cancer patients with suspected mediastinal lymph node metastases, cervical mediastinoscopy can be avoided when EBUS-TBNA is used. This examination is the technique of first choice for the invasive staging of the mediastinum in lung cancer, but it can not replace mediastinoscopy completely.

Weekly chemoradiation (docetaxel/cisplatin) followed by surgery in stage III NSCLC; a multicentre phase II study.

BACKGROUND: This prospective study analyzed the feasibility and efficacy of weekly concurrent chemoradiation (docetaxel/cisplatin) followed by surgery. The primary endpoint was radiological response. PATIENTS AND METHODS: Six chemotherapy (docetaxel/cisplatin) cycles were administered on days 1, 8, 15, 22, 29 and 36 with concurrent thoracic radiotherapy in fractions of 1.8 Gy, to a total dose of 45 Gy. Patients underwent surgery depending on results of invasive mediastinal re-staging. RESULTS: Forty-two out of 45 NSCLC stage III patients were evaluable. Nineteen patients showed partial/complete response (46%), 14 stable disease (34%) and eight (20%) progressive disease. Toxicity was mild. The 30-day postoperative mortality was 4.2%. Twenty-four patients (59%) proceeded to surgery and 20 (49%) underwent a complete resection (R0). CONCLUSION: Weekly concurrent chemoradiation (docetaxel/cisplatin) in stage III NSCLC results in a radiological response rate of 46% and mediastinal downstaging in 56%. Complete resection in downstaged patients was achieved in 49% of all patients.

Sequencing chemotherapy, radiotherapy and surgery in combined modality treatment of stage III nonsmall cell lung cancer.

PURPOSE OF REVIEW: Combined modality treatment is nowadays the standard of care in stage III nonsmall cell lung cancer, but the overall survival is still poor. Therefore, the challenge for clinicians is to optimize the combination of the treatment modalities. The review will focus on bimodality and trimodality approaches in stage III nonsmall cell lung cancer. Although the role of surgical resection in combined modality treatment is unclear, surgery will be discussed as a potential part of the treatment approach. RECENT FINDINGS: Concurrent chemoradiotherapy has proven to be more effective than chemotherapy followed by radiotherapy. Full-dose consolidation chemotherapy after concurrent chemoradiation showed an improvement of survival in some studies. Consolidation chemotherapy is, however, difficult to administer owing to its toxicity in these complex regimens. Both the Eastern Cooperative Oncology Group and the Radiation Therapy Oncology Group showed similar survival after surgery compared to sequential or concurrent chemoradiotherapy; however, pneumonectomies and residual malignant mediastinal disease after induction treatment had a negative impact on survival. SUMMARY: Concurrent chemoradiotherapy in combination with full-dose chemotherapy should be the standard of care for nonsmall cell lung cancer stage IIIA/B. Surgery is still experimental, but seems to be promising for certain subgroups of patients. More research has to be done in optimizing radiotherapy schedules and chemotherapy schemes in order to minimize toxicity. Novel therapeutics have to be introduced in the combined modality approach of stage III nonsmall cell lung cancer.

Surgery as part of combined modality treatment in stage IIIB non-small cell lung cancer.

BACKGROUND: The role of surgery after neoadjuvant chemotherapy in patients with stage IIIB non-small cell lung cancer (NSCLC) remains unclear. METHODS: A prospective multicenter trial of neoadjuvant chemotherapy followed by surgery or radiotherapy or both was conducted with 41 patients with stage IIIB NSCLC. End points were toxicity, response, downstaging, complete resectability, and survival. The diagnostic value of repeat mediastinoscopy after neoadjuvant chemotherapy (three courses of gemcitabine/cisplatin) was also studied. RESULTS: Response rate after neoadjuvant chemotherapy was 66% (27 of 41). Fifteen patients underwent repeat mediastinoscopy, which proved to be inadequate in 6 patients. Two repeat mediastinoscopies were false negative. Resection was performed in 18 patients, of which 10 proved to be radical. Hospital mortality was 2.4% (n = 1). Major complications occurred in 6 patients (fistula, empyema, hemorrhage). Histopathologically proven downstaging was seen in 16 patients (39%). Twenty-five patients underwent radiotherapy of whom 14 were diagnosed with stable/progressive disease and 9 with partial/complete response. Median survival for all patients was 15.1 months, for nonresponders 8.4 months and for responders 16.8 months (p = 0.11). Patients with partial/complete response had a mean survival of 21.5 months after resection and 13.0 months after radiotherapy (p = 0.0003). CONCLUSIONS: Radical surgery can be performed in 37% (10 of 27) of the responders resulting in a prolonged survival. Surgery as part of combined modality treatment is feasible in stage IIIB NSCLC. Results of a repeat mediastinoscopy are disappointing and proved to be a not-so-effective restaging tool because of the high number of incomplete procedures and because it yields false negative results.