Journal of Thoracic Oncology:
Letters to the Editor
Rintoul, Robert C. PhD, FRCP; Tournoy, Kurt G. MD, PhD; Annema, Jouke T. MD, PhD
Department of Thoracic Oncology, Papworth Hospital, Cambridge, United Kingdom, email@example.com
Disclosure: The authors declare no conflicts of interest.
We thank Navani and colleagues for their letter in response to our recent article published in the Journal of Thoracic Oncology.1 As they indicate, our article addressed the issue about the necessity of sampling positron emission tomography (PET) positive mediastinal lymph nodes before a treatment decision to confirm or refute that they contain malignancy. We described the test characteristics of curved-linear endobronchial ultrasound with transbronchial needle aspiration in this particular setting. However, the letter from Navani and colleagues addresses a very different issue. They are asking whether PET negative lymph nodes greater than 1 cm in short axis dimension should also be sampled given recent data indicating that PET has a significant false-negative rate for detection of metastatic disease in mediastinal nodes.2 This is an interesting and topical question which we did not address in our article.
Currently, the latest American College of Chest Physicians guidelines (2007) suggest that all enlarged (≥10 mm short axis) mediastinal lymph nodes should be biopsied regardless of Fluorodeoxyglucose (FDG) avidity. The European Society of Thoracic Surgeons guidelines use a cutoff of 16 mm.3 This is based on a meta-analysis of 14 studies, which examined the posttest probability of N2 disease in patients with enlarged but PET negative nodes.4 In nodes measuring 10 to 15 mm, N2 disease was present in 5% of patients whereas in nodes measuring ≥16 mm the prevalence was 21%. In addition, both guidelines recommend sampling of FDG negative mediastinal lymph nodes if there is either a central tumor or FDG positive N1 nodes are present. Although it is recognized that no amount of mediastinal staging will exclude all micrometastatic disease in every patient a balance needs to be struck between maximizing the chance of detecting occult N2 disease preoperatively while not subjecting patients to too many tests. Further work in this area is needed.
The current authors are presently completing recruitment to the Assessment of Surgical sTaging versus Endoscopic ultrasound in lung cancer: a Randomised controlled trial, a large international randomized controlled trial of endobronchial and endoscopic ultrasound guided mediastinal staging versus surgical staging for patients who require mediastinal staging before surgical resection.5 The entry criteria include both those with computed tomography-PET positive lymph nodes and those with enlarged (>10 mm) but PET negative lymph nodes. All patients in whom mediastinal staging is negative go forward for surgical resection with systematic lymph node sampling or dissection. Data from this study may also help to address the issue about what should be done for those with enlarged but PET negative mediastinal nodes.
Dr. R.C. Rintoul was supported, in part, by the NIHR Cambridge Biomedical Research Centre.
Robert C. Rintoul, PhD, FRCP
Kurt G. Tournoy, MD, PhD
Jouke T. Annema, MD, PhD
Department of Thoracic Oncology
Cambridge, United Kingdom
1. Rintoul RC, Tournoy KG, El Daly H, et al. EBUS-TBNA for the clarification of PET positive intra-thoracic lymph nodes—an international multi-centre experience. J Thorac Oncol
2. Silvestri GA, Gould MK, Margolis ML, et al. Noninvasive staging of non-small cell lung cancer: ACCP evidenced-based clinical practice guidelines (2nd edition). Chest
3. De Leyn P, Lardinois D, Van Schil PE, et al. ESTS guidelines for pre-operative lymph node staging for non small cell lung cancer. Eur J Cardiothorac Surg
4. de Langen AJ, Raijmakers P, Riphagen I, Paul MA, Hoekstra OS. The size of mediastinal lymph nodes and its relation with metastatic involvement: a meta-analysis. J Cardiothorac Surg