A Systematic Review of Restaging After Induction Therapy for Stage IIIa Lung Cancer: Prediction of Pathologic Stage

Restaging after induction therapy for non-small-cell lung cancer

SUMMARY Select patients with stage IIIa-N2 non-small-cell lung cancer will benefit from treatment with induction chemoradiotherapy followed by surgical resection. The identification of patients with residual N2 disease may allow for selection of those patients most likely to benefit from resection. The optimal strategy for restaging of mediastinal lymph nodes following induction therapy is controversial. Noninvasive, imaging-based strategies are largely ineffective. Minimally invasive approaches such as endobronchial ultrasound-transbronchial needle aspiration and endoscopic ultrasound-guided fine needle aspiration may identify residual nodal disease, but require surgical confirmation of negative results. Repeat mediastinoscopy may be effective at centers that specialize in this technique, but in the authors opinion its use cannot be broadly recommended. A thoughtful and minimally invasive approach to initial staging of N2 nodes is recommended, reserving mediastinoscopy for restaging whenever possible.

The use and misuse of positron emission tomography in lung cancer evaluation

This article discusses the potential benefits and limitations of positron emission tomography (PET) for characterizing lung nodules, staging the mediastinum, identifying occult distant metastasis, determining prognosis and treatment response, guiding plans for radiation therapy, restaging during and after treatment, and selecting targets for tissue sampling. The key findings from the medical literature are presented regarding the capabilities and fallibilities of PET in lung cancer evaluation, including characterization of pulmonary nodules and staging in patients with known or suspected non-small-cell lung cancer. The discussion is limited to PET imaging with fluorodeoxyglucose.

Mediastinal re-staging of non small-cell lung cancer

Selected patients with non small-cell lung cancer (NSCLC) with mediastinal lymph node involvement may have a survival benefit from surgical resection, particularly if mediastinal nodal down-staging occurs after induction therapy and complete resection is achieved with lobectomy. Accurate re-staging of the mediastinum after induction therapy is therefore crucial in determining prognosis and subsequent treatment. Non-invasive imaging techniques usually require a confirmatory tissue sampling method to improve the accuracy of mediastinal re-staging. As in the initial staging of the mediastinum, minimally invasive endosonography-guided needle sampling techniques such as endobronchial ultrasound-guided fine-needle aspiration (EBUS-TBNA) and endoscopic ultrasound-guided fine-needle aspiration show promise in re-staging the mediastinum, though invasive surgical re-staging remains the gold standard. Despite a lower sensitivity in the mediastinal re-staging of NSCLC, EBUS-TBNA with or without EUS-FNA may still be the preferred initial mediastinal re-staging technique.

Multidisciplinary approach in stage III non-small-cell lung cancer: standard of care and open questions

Lung cancer is the most frequent cause of cancer death worldwide and its global incidence has been steadily increasing during recent decades. A third of patients with newly diagnosed non-small-cell lung cancer (NSCLC) present with locally advanced disease. There is not a single widely accepted standard of care for these patients because of the wide spectrum of presentation of the disease. Although feasible and safe in experienced hands, evidence that surgical resection after induction treatment improves overall survival (OS) is lacking. For resectable or potentially resectable stage III, the findings of two phase III trials suggest that surgical resection should not be considered a standard of care but rather reserved for selected patients after critical multidisciplinary assessment, in whom surgery improves survival after downstaging if pneumonectomy can be avoided or in some T4N0-1 resectable tumours. For unresectable stage III NSCLC the standard of care is a combination of chemotherapy and radiotherapy. In those patients with good performance status and minimal weight loss, the concurrent approach has resulted in a statistically significant improvement in OS rates compared with a sequential approach in randomised clinical trials, although several questions remain unresolved.

Transesophageal ultrasound-guided fine-needle aspiration for the mediastinal restaging of non-small cell lung cancer

INTRODUCTION

Selected patients with stage III (N2/N3) non-small cell lung cancer (NSCLC) who are downstaged to N0 by chemoradiation therapy might benefit from subsequent surgical resection of the tumor. How mediastinal lymph nodes can be best reevaluated is subject of debate. Transesophageal ultrasound-guided fine-needle aspiration (EUS-FNA) is a minimally invasive technique to sample mediastinal nodes. We assessed sensitivity and false-negative rate of EUS-FNA for the mediastinal restaging of patients with stage III NSCLC.

METHODS

Fifty-eight consecutive patients with stage III NSCLC and tissue-proven lymph node metastases N2/N3) who underwent EUS-FNA for restaging purposes after chemoradiation therapy were retrospectively analyzed. Surgical-pathological staging was used as the reference standard for nodal metastases.

RESULTS

EUS-FNA found persistent nodal metastases (N2/N3) in 15 patients (26%). Of the 43 patients without persistent mediastinal metastases at EUS, 33 patients subsequently underwent surgical verification of the mediastinal nodes in whom persistent metastases (yN2/N3) were found in 19 patients (58%), and loco-regional downstaging (yN0) was achieved in the other 14 (42%). The prevalence of persistent nodal metastases in the 48 patients who could be analyzed was 71%. Sensitivity and the false-negative rate of EUS-FNA for mediastinal restaging were 44 and 58%, respectively.

DISCUSSION

For mediastinal restaging of stage III NSCLC, EUS-FNA is a minimally invasive and safe method to confirm persistent nodal metastases, but this technique has a low negative predictive value and is therefore not useful for the exclusion of mediastinal metastases. Surgical restaging is indicated in the absence of mediastinal metastases at EUS-FNA.

[Indications for surgery in non-small cell lung cancer with lymph node invasion]

Surgery is indicated for N1 non-small cell lung cancer and performed, with good results in some patients, when N2 disease is not diagnosed preoperatively "minimal N2". Following the publication of the "EORTC 08941" and "Intergroup 0139" trials, it remains debatable for patients with proven N2 disease. Good prognostic factors before treatment or post-induction favour surgery, which seems superior to radiochemotherapy if the operative risk is low (lobectomies, and some pneumonectomies). N3 status is a contraindication to surgery, except in some rare cases with a strong response to induction treatment.

Surgical staging for non-small cell lung cancer

The treatment of non-small cell lung cancer is stage specific. Aggressive staging is associated with improved stage-specific prognosis. Available methods of surgical staging include scalene node biopsy, mediastinoscopy, anterior mediastinotomy, and thoracoscopy. In this article the various surgical staging methods are described and their respective roles are discussed.

Tumor volume as a potential imaging-based risk-stratification factor in trimodality therapy for locally advanced non-small cell lung cancer

INTRODUCTION

The role of trimodality therapy for locally advanced non-small cell lung cancer (NSCLC) continues to be defined. We hypothesized that imaging parameters on pre- and postradiation positron emission tomography (PET)-computed tomography (CT) imaging are prognostic for outcome after preoperative chemoradiotherapy (CRT)/resection/consolidation chemotherapy and could help risk-stratify patients in clinical trials.

METHODS

We enrolled 13 patients on a prospective clinical trial of trimodality therapy for resectable locally advanced NSCLC. PET-CT was acquired for radiation planning and after 45 Gy. Gross tumor volume (GTV) and standardized uptake value were measured at pre- and post-CRT time points and correlated with nodal pathologic complete response, loco-regional and/or distant progression, and overall survival. In addition, we evaluated the performance of automatic deformable image registration (ADIR) software for volumetric response assessment.

RESULTS

All patients responded with average total GTV reductions after 45 Gy of 43% (range: 27-64%). Pre- and post-CRT GTVs were highly correlated (R² = 0.9), and their respective median values divided the patients into the same two groups. ADIR measurements agreed closely with manually segmented post-CRT GTVs. Patients with GTV ≥ median (137 ml pre-CRT and 67 ml post-CRT) had 3-year progression-free survival (PFS) of 14% versus 75% for GTV less than median, a significant difference (p = 0.049). Pre- and post-CRT PET-standardized uptake value did not correlate significantly with pathologic complete response, PFS, or overall survival.

CONCLUSIONS

Preoperative CRT with carboplatin/docetaxel/45 Gy resulted in excellent response rates. In this exploratory analysis, pre- and post-CRT GTV predicted PFS in trimodality therapy, consistent with our earlier studies in a broader cohort of NSCLC. ADIR seems robust enough for volumetric response assessment in clinical trials.

Role of surgery for stage IIIA-N2 non-small cell lung cancer

Perhaps no topic other than stage IIIA-N2 non-small-cell lung cancer management is as controversial among surgeons, radiologists and medical oncologists. Much of the debate relates to the choice between surgical resection and radiation as the local control modality. Although limited, available evidence from randomized controlled trails raised concerns about the role of surgical resection. However, there is no perfect study, and the results should not be over-interpreted. This mini review will scrutinize these trials, focusing on the study design, results and, most importantly, limitations, and will explore the possible role of surgery for stage IIIA-N2 non-small-cell lung cancer.

PET/CT imaging in different types of lung cancer: an overview

Lung cancer (LC) still represents one of the most common tumours in both women and men. PET/CT is a whole-body non-invasive imaging procedure that has been increasingly used for the assessment of LC patients. In particular, PET/CT added value to CT is mainly related to a more accurate staging of nodal and metastatic sites and to the evaluation of the response to therapy. Although the most common PET tracer for LC evaluation is 18F-FDG, new tracers have been proposed for the evaluation of lung neuroendocrine tumours (68Ga-DOTA-peptides, 18F-DOPA) and for the assessment of central nervous system metastasis (11C-methionine). This review focuses on the main clinical applications and accuracy of PET/CT for the detection of non-small cells lung cancer (NSCLC), broncho-alveolar carcinoma (BAC), small cells lung cancer (SCLC), lung neuroendocrine tumours (NET) and solitary pulmonary nodules (SPN).