Treatment and survival after lung resection for non-small cell lung cancer in patients with microscopic residual disease at the bronchial stump

Recurrence/prognosis estimation using a molecularly positive surgical margin-based model calls for alternative curative strategies in pIIIA/N2 NSCLC

Stage pIIIA/N2 non-small cell lung cancer (NSCLC) is primarily treated by complete surgical resection combined with neoadjuvant/adjuvant therapies. However, up to 40% of patients experience tumor recurrence. Here, we studied 119 stage pIIIA/N2 NSCLC patients who received complete surgery plus adjuvant chemotherapy (CT) or chemoradiotherapy (CRT). The paired tumor and resection margin samples were analyzed using next-generation sequencing (NGS). Although all patients were classified as negative resection margins by histologic methods, NGS revealed that 47.1% of them had molecularly positive surgical margins. Patients who tested positive for NGS-detected residual tumors had significantly shorter disease-free survival (DFS) (P = 0.002). Additionally, metastatic lymph node ratio, erb-b2 receptor tyrosine kinase 2 (ERBB2) mutations, and SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a, member 4 (SMARCA4) mutations were also independently associated with DFS. We used these four features to construct a COX model that could effectively estimate recurrence risk and prognosis. Notably, mutational profiling through broad-panel NGS could more sensitively detect residual tumors than the conventional histologic methods. Adjuvant CT and adjuvant CRT exhibited no significant difference in eliminating locoregional recurrence risk for stage pIIIA/N2 NSCLC patients with molecularly positive surgical margins.

Postoperative radiotherapy in resected non-small cell lung cancer: The never-ending story

This manuscript collects in a joint and orderly manner the existing evidence at the present time about postoperative treatment with radiotherapy in non-small cell lung cancer. It also systematically reviews the current evidence, the international recommendations in the most relevant guidelines, the most controversial aspects in clinical and pathological staging, the specific technical aspects of radiotherapy treatment, and also collects all the potential risk factors that have been postulated as significant in the prognosis of these patients, evaluating the possibility of segmenting a particularly sensitive subpopulation with a high risk of relapse on which an adjuvant treatment with radiotherapy could have an impact on their clinical evolution. Finally, currently active trials that aspire to provide more evidence on this topic are reviewed.

Role of Postoperative Radiotherapy in the Management for Resected NSCLC - Decision Criteria in Clinical Routine Pre- and Post-LungART

BACKGROUND

The role of postoperative radiation therapy (PORT) in stage III N2 NSCLC is controversial. We analyzed decision-making for PORT among European radiation oncology experts in lung cancer.

METHODS

Twenty-two experts were asked before and after presentation of the results of the LungART trial to describe their decision criteria for PORT in the management of pN+ NSCLC patients. Treatment strategies were subsequently converted into decision trees and analyzed.

RESULTS

Following decision criteria were identified: extracapsular nodal extension, incomplete lymph node resection, multistation lymph nodes, high nodal tumor load, poor response to induction chemotherapy, ineligibility to receive adjuvant chemotherapy, performance status, resection margin, lung function and cardiopulmonary comorbidities. The LungART results had impact on decision-making and reduced the number of recommendations for PORT. The only clear indication for PORT was a R1/2 resection. Six experts out of ten who initially recommended PORT for all R0 resected pN2 patients no longer used PORT routinely for these patients, while four still recommended PORT for all patients with pN2. Fourteen experts used PORT only for patients with risk factors, compared to eleven before the presentation of the LungART trial. Four experts stated that PORT was never recommended in R0 resected pN2 patients regardless of risk factors.

CONCLUSION

After presentation of the LungART trial results at ESMO 2020, 82% of our experts still used PORT for stage III pN2 NSCLC patients with risk factors. The recommendation for PORT decreased, especially for patients without risk factors. Cardiopulmonary comorbidities became more relevant in the decision-making for PORT.

The influence of adjuvant therapy on survival in patients with indeterminate margins following surgery for non-small cell lung cancer

BACKGROUND

The significance of indeterminate margins following surgery for non-small cell lung cancer (NSCLC) is unknown. We evaluated the influence of adjuvant therapy on survival in patients whose cancer showed indeterminate margins.

METHODS

Patients whose cancer showed indeterminate margins following surgery for NSCLC were identified in the National Cancer Database between 2004 and 2015, and stratified by receipt of adjuvant treatment. The primary outcome was overall survival, which was evaluated with multivariable Cox proportional hazards.

RESULTS

Indeterminate margins occurred in 0.31% of 232,986 patients undergoing surgery for NSCLC and was associated with worse survival compared with margin negative resection (adjusted hazard ratio, 1.53; 95% confidence interval, 1.40-1.67). Anatomic resection was protective against the finding of indeterminate margins in logistic regression. Amongst 553 patients with indeterminate margins, 343 (62%) received no adjuvant therapy, 96 (17%) received adjuvant chemotherapy, 33 (6%) received adjuvant radiation, and 81 (15%) received adjuvant chemoradiation. Any mode of adjuvant therapy was not associated with improved survival compared with no further treatment.

CONCLUSIONS

The finding of indeterminate margins is reported in 0.31% of patients undergoing curative-intent surgery for NSCLC. This was associated with worse overall survival compared with complete resection and not mitigated by adjuvant therapy. The risks and benefits of adjuvant therapy should be carefully considered for patients with indeterminate margins after surgery for NSCLC.

Photodynamic therapy for R1 lung cancer resections

Theobjectivewas to evaluate the effectiveness of endobronchial photodynamic therapy (PDT) for preventing a non-small cell lung cancer (NSCLC) relapse after R1 resection with positive bronchial resection margins.

Material and methods.This study included 17 patients. The planned morphological diagnostics revealed the presence of tumor cell complexes at the bronchial resection margins in 5 (29 %) patients (cancer in situ – 2, invasive cancer – 3), in peribronchial tissues – in 5 (29 %) patients, in lymphatic vessels at the resection margins – in 7 (41 %) patients.

Results.All patients underwent one session of endobronchial PDT as an adjuvant treatment. No complications of PDT were noted. The five-year observation revealed a relapse at the bronchial stump area in 1 patient only (6 %). 16 (94 %) patients lived for 1 year, 12 (71 %) patients – for 5 years. Long-term results were significantly worse in patients with tumor complexes in lymphatic vessels at the bronchial resection margins (5-year survival rate – 29 %, p=0.04), with pN2 (0 %, p=0.01), lung adenocarcinoma (20 %, p=0.03).

Conclusion.The use of endobronchial PDT as an adjuvant treatment for patients with NSCLC after R1 resection with positive bronchial resection margins is simple, safe and characterized by good immediate and long-term results.

Photodynamic Therapy for Bronchial Microscopic Residual Disease After Resection in Lung Cancer

BACKGROUND

The goal of lung cancer surgery is a complete tumor resection (R0 resection) with clear margins. 4% to 5% of resections have microscopic residual disease associated with worse prognosis. Definitive management is resection of residual tumor, which may not be tolerated by many patients, and definitive management is not well studied in these patients. We treated patients with stage I cancer and bronchial mucosal residual disease (MRD) with bronchoscopic photodynamic therapy (PDT).

METHODS

All patients who underwent definitive surgery for early-stage lung cancer were reviewed. Patients with R1 resection, stage I disease with MRD and or carcinoma in situ along the stump site were treated with bronchoscopic PDT. Patient characteristics, histology, type and site of surgery, pattern of recurrence, recurrence status, adverse events, and survival data were evaluated.

RESULTS

Eleven patients with bronchial mucosal R1 resection were treated with PDT along the stump site. The median age was 67. Three patients had carcinoma in situ and 8 had MRD. One patient (9%) had local recurrence 1 year after PDT treatment and was treated with radiation. Four patients (36%) had no evidence of recurrence to date after a median follow-up of 4 years and the other 6 patients had evidence of regional (16%) or distant (39%) recurrence. The local control rate was 91%. One patient developed pneumonia and other had photosensitivity reaction.

CONCLUSION

Bronchoscopic PDT is safe and effective in selected group of patients with non-small cell lung cancer who have MRD along the stump site.

[Progress of Lung Margin During Sublobar Resection for Early-staged Non-small Cell Lung Cancer]

近年来随着低剂量计算机断层扫描(low-dose computed tomography, LDCT)、高分辨率CT(high-resolution CT, HRCT)的普及, 早期非小细胞肺癌的发现比率不断上升, 越来越多的胸外科医生探索手术方式的改良, 推动手术切除范围向更加合理的方向进展。临床研究发现肺切缘阴性较阳性有更低的局部肿瘤复发率, 因此亚肺叶切除术治疗早期肺癌术中保证肺切缘阴性具有重要的临床意义, 本文将就这一领域研究现状和进展作一综述。

Survival after radiation for stage I and II non-small cell lung cancer with positive margins

BACKGROUND

There is limited data guiding treatment for positive margins following lobectomy for early-stage non-small cell lung cancer (NSCLC). Using data from the National Cancer Data Base, we sought to determine whether radiation therapy following lobectomy for stage I or II NSCLC was associated with improved overall survival in patients with positive margins.

METHODS

Patients who underwent lobectomy without induction therapy for stage I or II NSCLC (1998-2006) with positive resection margins were selected. Patients were stratified by administration of radiation therapy following surgery, and overall survival was estimated using the Kaplan-Meier method. The association between radiation therapy and survival was adjusted for nonrandom treatment selection using Cox proportional hazards regression modeling.

RESULTS

Positive margins were recorded in 1934 of 49,563 (3.9%) patients who underwent lobectomy for stage I or II NSCLC. Positive margin status was associated with significantly worse 5-year survival (34.5% versus 57.2%, P < 0.001). After selection of patients with positive margins and known radiation status and exclusion of patients who had upstaged disease or received radiation therapy for palliative indications, radiation therapy was used in 579 of 1579 patients (38.2%) but was not associated with a significant difference in the likelihood of death during subsequent follow-up (hazard ratio: 1.10, 95% confidence interval: 0.90, 1.35).

CONCLUSIONS

Positive margins following lobectomy for stage I or II NSCLC are associated with reduced 5-year survival. Postsurgical radiation is not strongly associated with an improvement in overall survival among these patients.

Radiation Therapy is Independently Associated with Worse Survival After R0-Resection for Stage I-II Non-small Cell Lung Cancer: An Analysis of the National Cancer Data Base

BACKGROUND

The 1998 post-operative radiotherapy meta-analysis for lung cancer showed a survival detriment associated with radiation for stage I-II resected non-small cell lung cancer (NSCLC), but has been criticized for including antiquated radiation techniques. We analyzed the National Cancer Database (NCDB) to determine the impact of radiation after margin-negative (R0) resection for stage I-II NSCLC on survival.

METHODS

Adult patients from 2004 to 2014 were analyzed from the NCDB with respect to receiving radiation as part of their first course of treatment for resected stage I-II NSCLC; the primary outcome measure was overall survival.

RESULTS

A total of 197,969 patients underwent R0 resection for stage I-II NSCLC, and 4613 received radiation. Median radiation dose was 55 Gy with a 50-60 Gy interquartile range. On adjusted analysis, treatment at a community cancer program, sublobectomy, tumor size (3-7 cm), and pN1/Nx were associated with receiving radiation (odds ratio > 1, p < 0.05). The irradiated group had shorter median survival (45.8 vs. 77.5 months, p < 0.001), and radiation was independently associated with worse overall survival (hazard ratio (HR) 1.339, 95% confidence interval (CI) 1.282-1.399). After propensity score matching, radiation remained associated with worse overall survival (HR 1.313, 95% CI 1.237-1.394, p < 0.001).

CONCLUSIONS

Radiotherapy was independently associated with worse survival after R0 resection of stage I-II NSCLC in the NCDB and was more likely to be delivered in community cancer programs.

A Novel Neoadjuvant Therapy for Operable Locally Invasive Non-Small-Cell Lung Cancer. Phase I Study of Neoadjuvant Stereotactic Body Radiotherapy. LINNEARRE I (NCT02433574)

BACKGROUND

Despite improved staging and surgical techniques, the rate of incomplete resection (R1) of non-small-cell lung cancer (NSCLC) has not significantly decreased. Patients with R1 resection have worse survival compared with those with complete resection (R0). Stereotactic body radiotherapy (SBRT) is a rapid and convenient radiotherapy treatment that delivers high-dose radiotherapy to tumors with high precision while sparing normal organs. Although its efficacy in treating small lung tumors is documented, its use as neoadjuvant therapy for locally advanced (LA) NSCLC has not been examined. We hypothesized that a short course of preoperative SBRT is feasible and can be delivered safely as a neoadjuvant therapy in patients at risk for incomplete resection.

METHODS

In this phase I study, 20 patients with cT3 to 4, N0 to 1, M0 NSCLC at risk for incomplete resection will be treated with neoadjuvant SBRT followed by surgery and adjuvant chemotherapy. Four groups of 5 patients will be treated with escalating doses (35, 40, 45, and 50 Gy) in 10 daily fractions. The primary outcome is feasibility (ie, the ability to complete SBRT and surgery as planned; within 7 weeks). Secondary outcomes include acute and late adverse events; R0, R1, and R2 rates; and secondary surrogates of feasibility and safety.

RELEVANCE

This study is an important first step in introducing a new therapeutic modality to patients with LA NSCLC that could improve surgical outcomes in the future. If neoadjuvant SBRT is found to be feasible and safe for LA NSCLC, its effect in achieving R0 resection could be investigated in randomized trials.

Prevalence, Prognostic Implications, and Survival Modulators of Incompletely Resected Non-Small Cell Lung Cancer in the U.S. National Cancer Data Base

INTRODUCTION

The impact of incomplete lung cancer resection on survival has never been systematically quantified, nor has the value of postoperative adjuvant therapy in this setting been determined.

METHODS

We evaluated lung cancer resections in the National Cancer Data Base from 2004 to 2011 to identify factors associated with margin involvement. We compared the survival of patients with and without positive margins and evaluated the impact of postoperative adjuvant therapy.

RESULTS

Of 112,998 resections performed during the 8 years, 5,335 (4.7%) had positive margins. Patient demographic and clinical factors associated with an increased adjusted OR of incomplete resection included black race (p = 0.006), age-based Medicare insurance (p = 0.006), urban residence (p = 0.01), histologic diagnosis of squamous cell carcinoma, high tumor grade, tumor overlapping more than one lobe, and advanced pathologic stage (p < 0.001 for all clinical factors). Community cancer programs (p = 0.002), institutions with high proportions of underinsured patients (p = 0.01), and institutions with a lower volume of cancer resections (p = 0.006) also had an increased adjusted OR. The crude 5-year survival rates of patients with complete versus incomplete resections were 58.5% versus 33.8% (log-rank p < 0.001). After an incomplete resection, adjuvant chemotherapy was associated with improved 5-year survival across all stages (p < 0.01); radiotherapy was associated with worse survival in patients with stage I disease (p < 0.001).

CONCLUSIONS

Margin involvement significantly impaired survival after lung cancer resection irrespective of stage. Causative institutional and provider practices should be identified to minimize this adverse outcome. Postoperative adjuvant chemotherapy mitigated mortality risk independently of stage, whereas postoperative radiotherapy exacerbated the risk in patients with stage I disease. These findings need validation in prospective trials.

Postoperative radiotherapy for lung cancer: Is it worth the controversy?

INTRODUCTION

The role of postoperative radiation therapy (PORT) in patients with completely resected non-small cell lung cancer (NSCLC) with pathologically involved mediastinal lymph nodes (N2) remains unclear. Despite a reduction of local recurrence (LR), its effect on overall survival (OS) remains unproven. Therefore we conducted a review of the current literature.

METHODS

To investigate the benefit and safety of modern PORT, we identified published phase III trials for PORT. We investigated modern PORT in low-risk (ypN0/1 and R0) and high-risk (ypN2 and/or R1/2) patients with stage III-N2 NSCLC treated with induction chemotherapy and resection.

RESULTS

Seventeen phase III trials using PORT were selected. Of all PORT N2 studies, 4 were eligible for evaluation of LR, all in high-risk patients only. In these high-risk patients receiving PORT, the mean LR rate at 5years was 20.9% (95% CI 16-24). Two trials were suitable to assess LR rates after chemotherapy and surgery without PORT. In these low-risk patients, the mean 5-year LR was 33.1% (95% CI 27-39). No significant difference in non-cancer deaths between PORT vs. non-PORT patients was observed in N2 NSCLC.

CONCLUSION

PORT is worth the controversy because data illustrate that PORT may increase the OS. However, prospective randomized trials are needed to verify this.

Detection of Pre-Invasive Lung Cancer: Technical Aspects of the LIFE Project

Lung cancer is the leading cause of cancer deaths in both men and women in the United States. The LIFE (Light Induced Fluorescence Endoscopy) Project was initiated at the University of North Carolina Medical Center in November, 1999, for the dual purposes of (1) detecting pre-invasive lung cancer in high-risk patients and (2) studying the molecular biology of pre-invasive lesions of the bronchus for possible development of molecular biomarkers. Of the 47 patients enrolled, all were current or former tobacco smokers, except for 1. Fluorescence endoscopy was utilized, in addition to white light bronchoscopy, to increase the detection of intraepithelial lesions. Adjacent biopsies were submitted for permanent and frozen sections, respectively, from four predetermined sites as well as from any abnormal areas. The snap-frozen specimens were cryostat sectioned, and the mucosal epithelial cells laser capture microdissected for DNA analysis. The great majority of specimens yielded sufficiently abundant and intact DNA to accomplish the molecular objectives. Histologic concordance of adjacent permanent and frozen sections was equivalent to the concordance of adjacent permanent sections, suggesting that frozen section diagnosis was adequate for the research purpose of correlating histology with molecular analysis.

Clinical implications of positive margins following non-small cell lung cancer surgery

Positive margins following pulmonary resection of non-small cell lung cancer (NSCLC) occur in approximately 5-15% of patients undergoing a curative procedure. The presence of positive margins negatively impacts long-term outcomes by setting the stage for local and potentially distant disease recurrence. Despite major clinical ramifications, there are very few dedicated reports that examine the implications of positive margins following surgery for NSCLC. Furthermore, published series are typically retrospective studies from single institutions. In this review we analyze published data with special consideration of four pertinent questions: (i) what are the long term outcomes of a positive margin following pulmonary resection?, (ii) is intraoperative margin assessment by frozen section reliable?, (iii) what is the optimal distance of the tumor margin to the surgical margin?, and (iv) should adjuvant chemotherapy and/or radiation therapy be used in the setting of a positive surgical margin?

Outcome and prognostic factors of postoperative radiation therapy (PORT) after incomplete resection of non-small cell lung cancer (NSCLC)

PURPOSE

Current guidelines recommend postoperative radiation therapy (PORT) for incompletely resected non-small cell lung cancer (NSCLC). However, there is still a paucity of evidence for this approach. Hence, we analyzed survival in 78 patients following radiotherapy for incompletely resected NSCLC (R1) and investigated prognostic factors.

PATIENTS AND METHODS

All 78 patients with incompletely resected NSCLC (R1) received PORT between December 2001 and September 2014. The median total dose for PORT was 60 Gy (range 44-68 Gy). The majority of patients had locally advanced tumor stages (stage IIA (2.6%), stage IIB (19.2%), stage IIIA (57.7%) and stage IIIB (20.5%)). 21 patients (25%) received postoperative chemotherapy.

RESULTS

Median follow-up after radiotherapy was 17.7 months. Three-year overall (OS), progression-free (PFS), local (LPFS) and distant progression-free survival (DPFS) rates were 34.1, 29.1, 44.9 and 51.9%, respectively. OS was significantly prolonged at lower nodal status (pN0/1) and following dose-escalated PORT with total radiation doses >54 Gy (p=0.012, p=0.013). Furthermore, radiation doses >54 Gy significantly improved PFS, LPFS and DPFS (p=0.005; p=0.050, p=0.022). Interestingly, survival was neither significantly influenced by R1 localization nor by extent (localized vs. diffuse). Multivariate analyses revealed lower nodal status and radiation doses >54.0 Gy as the only independent prognostic factors for OS (p=0.021, p=0.036).

CONCLUSION

For incompletely resected NSCLC, PORT is used for improving local tumor control. Local progression is still the major pattern of failure. Radiation doses >54 Gy seem to support improved local control and were associated with better OS in this retrospective study.

Postoperative Radiation Therapy Is Associated With Improved Overall Survival in Incompletely Resected Stage II and III Non-Small-Cell Lung Cancer

PURPOSE

To review trends in the use of postoperative radiotherapy (PORT) for stage II and III incompletely resected non-small-cell lung cancer (NSCLC) and evaluate the association between PORT and survival in such patients.

PATIENTS AND METHODS

We identified patients with pathologic stage N0-2, overall American Joint Committee on Cancer stage II or III NSCLC within the National Cancer Data Base who had undergone a lobectomy or pneumonectomy with positive surgical margins. Only patients coded as receiving external-beam PORT at 50 to 74 Gy or observation were included. To account for perioperative mortality, we excluded patients who survived less than 4 months after diagnosis. Multivariable logistic regression was used to determine factors associated with PORT receipt. Cox proportional hazards regression was performed for multivariable analyses of overall survival.

RESULTS

Among 3,395 included patients, 1,207 (35.6%) received PORT. Predictors for the use of PORT among this patient population included age less than 60 years, treatment in a nonacademic facility, earlier year of diagnosis, decreased travel distance, lower nodal stage, and chemotherapy receipt. On multivariable analysis adjusting for demographic and clinicopathologic covariates, PORT (hazard ratio, 0.80; 95% CI, 0.70 to 092) was associated with improved survival. Subset analysis by nodal stage showed that PORT improved survival across all nodal stages.

CONCLUSION

PORT is associated with improved overall survival in patients with incompletely resected stage II or III N0-2 NSCLC. The use of PORT for this population in more recent years has been declining. In the absence of randomized trials evaluating PORT utilization for this patient population, our findings strongly support the delivery of PORT in patients with incompletely resected NSCLC.

Concurrent paclitaxel-based chemo-radiotherapy for post-surgical microscopic residual tumor at the bronchial margin (R1 resection) in non-small-cell lung cancer

BACKGROUND

The microscopic residual tumor at the bronchial margin after radical surgery (R1 resection) affects prognosis negatively in non-small-cell lung cancer (NSCLC) patients. For patients with good performance status, a potential cure still exists. Here, we report the outcomes of concurrent paclitaxel-based chemo-radiotherapy (CRT) for NSCLC patients with microscopically positive bronchial margins or peribronchial infiltration.

METHODS

A retrospective search in the clinical database was conducted in three hospitals. Patients were identified and evaluated if treated with radiotherapy combined with paclitaxel-based chemotherapy. The objects analyzed were local control time, progression-free survival (PFS), overall survival (OS), and treatment-related toxicity.

RESULTS

Sixty-one patients with microscopic residual tumor at the bronchial stump following pulmonary lobectomy were identified. Forty-six patients who had received concurrent paclitaxel-based CRT were analyzed. The median follow-up was 40 months (range: 15.0-77.5 months). The 1-, 2- and 3-year survival rates were 97.8%, 60.9% and 36.9%, respectively. The local recurrences were recorded in 19.6% (9/46) patients. Median PFS and OS for the evaluated cohort were 23.0 [95% confidence interval (CI): 21.3-24.7] and 32.0 (95% CI: 23.7-40.3) months, respectively. The most common side effects were hematological toxicity (neutropenia, 93.5%; anemia, 89.1%; and thrombocytopenia, 89.1%) and no treatment-related deaths. Grade ≥2 acute radiation-induced pneumonitis and esophagitis were recorded in 43.5% (20/46) and 26.1% (12/46) patients, respectively. By univariate analysis, non-squamous cell lung cancer was associated with a significantly longer survival time (45.1 vs 26.4 months, p = 0.013).

CONCLUSIONS

For NSCLC patients with post-surgical microscopic residual tumor at the bronchial stump, concurrent paclitaxel-based chemo-radiotherapy achieved promising outcomes with accepted treatment-related toxicity.

Postoperative radiation therapy following the incomplete resection of a non-small cell lung cancer

Purpose

To review the results of postoperative radiation therapy (PORT) for residual non-small cell lung cancer (NSCLC) following surgical resection and evaluate multiple clinicopathologic prognostic factors.

Materials and Methods

A total of 58 patients, who completed scheduled PORT for positive resection margin, among 658 patients treated with PORT from January 2001 to November 2011 were retrospectively analyzed. Radiation therapy was started at 4 to 6 weeks after surgery. Chemotherapy was also administered to 35 patients, either sequentially or concurrently with PORT.

Results

The median age of patients was 63 years (range, 40 to 82 years). The postoperative pathological stage I NSCLC was diagnosed in 10 (17.2%), stage II in 18 (31.0%), and stage III in 30 patients (51.7%). Squamous cell carcinoma was identified in 43, adenocarcinoma in 10, large cell in 1, others in 4 patients. Microscopic residual disease (R1) was diagnosed in 55 patients (94.8%), and the remaining three patients were diagnosed with gross residual disease (R2). The median dose of PORT was 59.4 Gy (range, 50.0 to 64.8 Gy). Chemotherapy was administered to 35 patients (60%), and the median follow-up time was 22.0 months (range, 6.0 to 84.0 months). The 3-year locoregional relapse-free survival and distant metastasis-free survival rates were 82.1% and 52.9%, respectively. The median overall survival was 23.8 months (range, 6.0 to 84.1 months), and the 3-year overall survival rate was 58.2%. Chemotherapy did not influence the failure pattern or survival outcome.

Conclusion

PORT is an effective modality for improving local tumor control in incompletely resected NSCLC patients. Major failure pattern was distant metastasis despite chemotherapy.

Use of adjuvant chemotherapy (CT) and radiotherapy (RT) in incompletely resected (R1) early stage Non-Small Cell Lung Cancer (NSCLC): a European survey conducted by the European Society for Medical Oncology (ESMO) young oncologists committee

BACKGROUND

Early stage Non-Small Cell Lung Cancer (NSCLC) is potentially curable with surgery. ESMO guidelines recommend cisplatin-based adjuvant chemotherapy (CT) for completely resected stage II-III NSCLC. There is limited evidence for the use of adjuvant CT and/or radiotherapy (RT) in incompletely resected (R1) early stage NSCLC.

MATERIALS AND METHODS

A European survey of thoracic oncologists was conducted to evaluate use of adjuvant CT and RT for R1-resected NSCLC and to identify factors influencing treatment decisions. Demographics and information on clinical stage, regimens, cycles planned, radiotherapy sites, multidisciplinary management and discussion about inconclusive evidence with the patient were collected. Univariate and multivariate analyses were performed.

RESULTS

768 surveys were collected from 41 European countries. 82.9% of participants were medical oncologists; 49.3% ESMO members; 37.1% based in University Hospitals; 32.6% practicing oncology for over 15 years and 81.4% active in research. 91.4% of participants prescribed adjuvant CT and mostly cisplatin/vinorelbine (81.2%) or cisplatin/gemcitabine (42.9%). 85% discussed limited clinical evidence with the patient. In the univariate analysis, a statistically significant association with CT prescription was found for medical oncology specialty (p<0.001), ESMO membership (p<0.001), activity in clinical research (p=0.002) and increased frequency of ESMO guidelines consultation (p for trend <0.001). 48.3% of participants prescribed adjuvant RT and its prescription were associated with radiation oncology specialty (p<0.001), not being an ESMO member (p<0.001), years practicing specialty (p for trend=0.001), workload of lung cancer patients (p for trend=0.027) and decreased frequency in consulting ESMO guidelines (p<0.001). In the multivariate analysis, medical oncology and radiation oncology were the best discriminator for prescription of adjuvant CT and RT, respectively.

CONCLUSION

This survey demonstrates that adjuvant CT and RT are commonly used in clinical practice for R1-resected NSCLC despite limited evidence. Prospective trials are necessary to clarify optimal management in this setting.

Patterns of failure after postoperative radiotherapy for incompletely resected (R1) non-small cell lung cancer: implications for radiation target volume design

OBJECTIVE

Overall survival (OS) and pattern of failure in R1-resected non-small cell lung cancer (NSCLC) patients treated with 3D-planned postoperative radiotherapy (PORT) was retrospectively evaluated. The outcomes and patterns of failure in patients with (+) and without (-) extracapsular nodal extension (ECE) were compared and analyzed with respect to the radiation target volume design.

MATERIALS AND METHODS

Eighty R1-resected (37 ECE+ and 43 ECE-) patients received PORT (60Gy, 2Gy daily) between 2002 and 2011. Patients with N2 disease received limited elective nodal irradiation (ENI); for pN0-1 disease the use of ENI was optional. Among ECE- (extranodal-R1) patients there were 35 pN0-1 and eight pN2 cases; in pN0-1 patients, patterns of failure and outcomes were analyzed with respect to the use of ENI. Loco-regional failure (LRF) was defined as in-field relapse; isolated nodal failure (INF) was defined as out-of-field regional nodal recurrence occurring without LRF, irrespective of distant metastases.

RESULTS

The actuarial 3-year OS rate was 36.3% (median: 30 months). Three-year OS rates in the ECE- and ECE+ group were 40.4% and 31.4%, with median OS of 31 and 24 months, respectively (p=0.43). In multivariate analysis, the presence of ECE was correlated with OS (HR=3.02; 95% CI: 1.00-9.16; p=0.05). Three-year cumulative incidence of LRF (CILRF) was 14.5% and 15.5% in the ECE- and ECE+ groups, respectively (p=0.98). Three-year cumulative incidence of INF (CIINF) was 14.1% in the ECE- group and 11.1% in the ECE+ group (p=0.76). For pN0-1 patients treated with and without ENI (13 and 22 patients) 3-year CILRF rates were 7.7% and 20.8%, respectively (p=0.20); 3-year CIINF rates were 9.1% and 16.3%, respectively (p=0.65).

CONCLUSION

PORT resulted in a relatively good survival of R1-resected NSCLC patients. Relatively high incidence of INF was found in both ECE+ and ECE- patients. For ECE+ patients, treated with limited ENI, distant failure remains a major concern, so the design of ENI fields seems of lesser importance. Omission of ENI in pN0-1 (extranodal-R1) patients resulted in an unacceptably high incidence of INF. We postulate the use of some form of ENI in this setting.

Postoperative radiotherapy for incompletely resected non-small cell lung cancer: clinical outcomes and prognostic value of the histological subtype

The purpose of this study was to evaluate the efficacy and toxicity of the postoperative radiotherapy in patients with incompletely resected NSCLC, and to investigate whether the histological subtype is a prognostic factor. Forty-one incompletely resected NSCLC patients who underwent postoperative radiotherapy were retrospectively analyzed. The microscopic residual tumor (R1 group) was recognized in 23 patients, and the macroscopic residual tumor (R2 group) in 18. The postoperative pathological stages were I (n = 3), II (n = 8), IIIA (n = 17), and IIIB (n = 13). The histology included squamous cell carcinoma (n = 23), adenocarcinoma (n = 14) or other types (n = 4). The first site of disease progression was distant metastases alone for 3 (13%) of 23 with squamous cell carcinoma, and for 9 (64%) of 14 with adenocarcinoma (p < 0.01). The 5-year overall, local control, disease-free, and distant metastasis-free survival rates were 56%, 63%, 37% and 49%. Univariate analyses showed that squamous cell carcinoma histology, N0-1 stage and the R1 group were significant predictors for better disease-free and distant metastasis-free survival. Multivariate showed that squamous cell carcinoma and N0-1 stage were significant predictors for better distant metastasis-free survival. Toxicity was generally mild; Grade 3 toxicities occurred in 3 patients (neutropenia, radiation pneumonia and esophageal stenosis), and no acute and late toxicities of Grade 4 to 5 were observed. In conclusion, postoperative radiotherapy for incompletely resected NSCLC could achieve a relatively high local control rate without severe toxicity. However, different treatment strategies for non-squamous cell carcinoma should be considered, because of the higher risk for the distant metastases.

Bronchial resection margin length and clinical outcome in non-small cell lung cancer

OBJECTIVE

Complete surgical resection with pathologic negative margin is associated with the best prognosis in early-stage non-small-cell lung cancer (NSCLC). However, the impact of the length of the bronchial margin remains unknown. This study aimed to determine whether an increased bronchial resection margin length is correlated with an improved disease-free and overall survival rate.

METHODS

A total of 3936 consecutive pulmonary resections were performed between 25 June 1992 and 31 December 2007 at Mayo Clinic Rochester. A subset consisting of 496 patients with completely resected lesions (R0-resection), and a documented bronchial margin length was analyzed retrospectively.

RESULTS

There were 340 men (68.5%) and 156 women (31.5%), with a mean age of 65.9±10.6 years. All patients underwent anatomic lobectomy or larger resection. Final pathology confirmed complete resection without microscopic residual tumor (R0-resection) in all patients. Mean length of the bronchial resection margin was 23.3±15.9mm. Overall, 190 patients (38.3%) suffered from disease recurrence with local recurrence in 35 patients, distant recurrence in 101, and both local and distant recurrence in 54 patients. Overall 5-year and 10-year local recurrence-free survival was 72.5% (95% confidence interval (CI): 67.3-78.1) and 68.0% (95% CI: 62.1-74.4), distant recurrence free survival 61.0% (95% CI: 55.8-66.6) and 52.9% (95% CI: 46.7-60.1) and overall survival 50.0% (95% CI: 45.1-55.3) and 28.8% (95% CI: 23.8-34.7). Tumor size and N-stage were associated with a worse prognosis in terms of local and distant recurrence, as well as survival (p<0.05). Histology was not significantly associated with local recurrence (p=0.28), though adenocarcinoma relative to squamous cell carcinoma was associated with an increased risk of distant recurrence (p<0.01). There was no significant association between type of surgical resection and local (p=0.37) or distant recurrence (p=0.37). Neither local (p=0.56) or distant recurrence (p=0.46), nor survival (p=0.54) was associated with the bronchial margin length. In multivariate models including age, N-stage, and gender there were no significant overall associations of margin length (≤5, 6-10, 11-15, 16-20, >20mm) and local recurrence (p=0.51), distant recurrence (p=0.33), or survival (p=0.75).

CONCLUSIONS

When complete surgical resection is achieved, the extent of the bronchial margin has no clinically relevant impact on disease-free and overall survival in NSCLC.

Significance of microscopic invasion into hilar peribronchovascular soft tissue in resection specimens of primary non-small cell lung cancer

INTRODUCTION

The significance and handling of microscopic invasion of non-small cell lung cancer (NSCLC) into hilar peribronchovascular soft tissue (SHEATH+) have not been defined in the TNM classification by AJCC/UICC; nevertheless, SHEATH+ may be equivalent to spread into the mediastinum. Also, assessment of the margin of peribronchial resection is challenging because of the technical difficulty of inking, and intraoperative and postoperative artifacts.

METHODS

Records of 592 consecutive Asian patients with primary NSCLC (excluding adenocarcinoma in situ) who had, without any preoperative therapy, undergone lobectomy, sleeve lobectomy and pneumonectomy were examined. SHEATH+, simply defined as invasion of hilar peribronchovascular soft tissue, without categorizing any invasive patterns, and its significance were statistically analyzed.

RESULTS

Forty-four SHEATH+ cases demonstrated significantly advanced TNM stages, and were statistically associated with central occurrence, pN1-3, and vascular invasion, as assessed by logistic regression analysis. No statistically significant differences were observed between TNM stage-adjusted frequency of recurrence and recurrence-free intervals. Kaplan-Meier's estimates of the rate of overall and recurrence-free survival after surgery showed no statistically significant differences between SHEATH+ and SHEATH-. Cox's multivariate analysis suggested SHEATH was not a statistically independent prognostic factor under the TNM classification by AJCC/UICC (7th edition).

CONCLUSIONS

SHEATH+ in NSCLC was simply associated with central occurrence and advanced TNM stages. To the best of our knowledge, this is the first report on the significance of SHEATH+ in NSCLC.

Trends in the use of postoperative radiotherapy for resected non–small-cell lung cancer

PURPOSE

A 1998 meta-analysis of postoperative radiotherapy (PORT) for non-small-cell lung cancer (NSCLC) found that PORT did not improve outcomes. Yet practice guidelines differ in their recommendations with regard to PORT use. We examine temporal trends in PORT use before and after the 1998 meta-analysis.

METHODS AND MATERIALS

Using data from the Surveillance, Epidemiology, and End Results (SEER) Program, we identified 22,953 patients with Stage I, II, or IIIA NSCLC who had resection between 1992 and 2002 in the United States and characterized each patient according to nodal status (N0, N1, or N2 disease). We measured use of PORT by calendar year. We examined the association between clinical and demographic characteristics and receipt of PORT using logistic regression.

RESULTS

For N0, N1, and N2 NSCLC, PORT use has declined. The proportion of patients with N0 disease receiving PORT declined from 8% in 1992 to 4% in 2002. For patients with N1 disease, PORT use declined from 51% in 1992 to 19% in 2002; and for patients with N2 disease, PORT use declined from 65% in 1992 to 37% in 2002.

CONCLUSION

In the context of uncertainty about what constitutes optimal adjuvant treatment for resected NSCLC, PORT use has substantially declined.

Patterns of Surgical Care of Lung Cancer Patients

BACKGROUND

This survey was performed to determine the patterns of surgical care provided patients with non-small cell lung carcinoma (NSCLC).

METHODS

In 2001, the American College of Surgeons carried out a patient care survey of 729 hospitals to retrieve information of NSCLC patients' history, evaluation, pathology, and surgical treatment.

RESULTS

Inclusion criteria were met by 40,090 patients: of whom 11,668 (29.1%) were treated surgically; 74.2% alone and 25.8% as part of multimodality therapy. Of these patients, 59.5% were in stage I, 17.5% in stage II, 17.0% in stage III, and 6.0% in stage IV. Surgery patient demographics were the following: 55% male and 45% female; 46.8% 70 years or older; and 76.3% had significant comorbidities. Tumor characteristics: squamous 28%, adenocarcinoma 37.6%, other 34.4%. Staging: in addition to radiologic examinations, preoperative mediastinoscopy was performed in 27.1% of operated patients with node biopsy in only 46.6% of these procedures.

OPERATIONS

wedge resection 15.6%, lobectomy 70.8%, pneumonectomy 13.6%. Surgical margins were positive in 7.8%, but only 65.2% had frozen section analysis. Perioperative mortality was 5.2%, but was 4.0% in nontransfused patients and 12.7% in transfused patients and was 3.2% in high-volume (more than 90 operations per year) versus 4.8% in low-volume hospitals (p < 0.001).

CONCLUSIONS

(1) Patients being operated for NSCLC are elderly with significant comorbid conditions. (2) More patients than previously are female and have adenocarcinoma. (3) Mediastinoscopy is infrequently performed and lymph nodes are biopsied in less than 50% of them. (4) Lobectomy is the most common operation, and positive surgical margins are too frequent. (5) Operative mortality is reasonable but transfusion is a marker for increased risk and outcomes are superior in high-volume hospitals. (6) Hospitals with higher volume had fewer perioperative deaths.

The natural history of carcinoma in situ involving bronchial resection margins

STUDY OBJECTIVES

Microscopic residual disease in the bronchial resection margins after surgical resection of lung cancer is rare, and its clinical significance remains unsettled. We studied the natural history of patients with carcinoma in situ (CIS) at their bronchial resection margins to focus on the issue of stump recurrence.

METHODS

Eleven individuals who had undergone radical surgery for N0M0 lung tumors were found to have CIS at the bronchial resection margins. All of the resection specimens were reviewed with respect to the pattern of CIS extension and reclassified as follows: superficial CIS, involving surface epithelium only (CIS-S), CIS extending into the submucosal gland ducts but not deeper (CIS-D), and CIS extending into submucosal gland acini (CIS-A). Patients were followed using autofluorescence bronchoscopy and high-resolution computer tomography. Clinical parameters and the local extent of CIS at histology review were correlated with outcome.

RESULTS

Median follow-up was 35 months (range, 15 to 89). Histology review showed two CIS-S cases, six CIS-D cases, and three CIS-A cases. All of the patients with CIS-A developed stump recurrences in contrast with those with only CIS-S. Three patients with CIS-D have developed metachronous primaries in the contralateral lung, whereas the stump region remained free of tumor.

CONCLUSIONS

The presence of CIS in the bronchial resection margin after resection of lung cancers is associated with stump recurrences. Although absolute numbers are too small for firm conclusions, our data suggest that those with deep glandular extension of CIS bear the highest risk of early recurrence. However, the development of new primaries away from the stump region and the possible development of distant disease are equally relevant considerations with respect to the choice of additional therapy.

Promoter hypermethylation of resected bronchial margins: a field defect of changes?

PURPOSE

Histologically positive bronchial margins after resection for non-small cell lung cancer are associated with shortened patient survival due to local recurrence. We hypothesized that DNA promoter hypermethylation changes at bronchial margins could be detected in patients with no histological evidence of malignancy and that they would reflect epigenetic events in the primary tumor.

EXPERIMENTAL DESIGN

Bronchial margins, primary tumor, bronchoalveolar fluid, and paired nonmalignant lung were obtained from 20 non-small cell lung cancer patients who underwent a lobectomy or greater resection. Disease-specific recurrence was the primary end point. The methylation status of p16, MGMT, DAPK, SOCS1, RASSF1A, COX2, and RARbeta was examined using methylation-specific polymerase chain reaction.

RESULTS

All malignancies had methylation in at least one locus. Concordance of one gene with an identical epigenetic change in the tumor or bronchial margin was observed in 85% of patients. Only one patient had methylation at the bronchial margin for a gene that was not methylated in the corresponding tumor. Median time to recurrence was 37 months (range, 5-71 months). There were two local recurrences and five metastases. There were no significant correlations between DNA methylation in tumor, margins, or bronchoalveolar fluid specimens and either regional recurrence or distant metastases.

CONCLUSIONS

Histologically negative bronchial margins of resected non-small cell lung cancer exhibit frequent hypermethylation changes in multiple genes. These hyper-methylation abnormalities are also present in the primary tumor and thus may represent a field defect of preneoplastic changes that occurs early in carcinogenesis.

Bronchial margins in lung cancer resection specimens: utility of frozen section and gross evaluation

Pathology reports for all lobectomy and pneumonectomy specimens at UNC Hospitals between 1991 and 2000 (n=405) were reviewed for correlation between frozen section and final bronchial margin, gross distance between tumor and margin and tumor type. Frozen section was performed in 268 cases (66%). A total of 243 were true negatives (90.6 %), 16 (6.0%) were true positives, four (1.5%) were false positives and five (1.9%) were false negatives. The site of tumor in true-positive cases was mucosal (11), submucosal (three), lymphatics (one), peribronchial (one). The site of tumor in false-negative cases was submucosal (two), lymphatics (one), peribronchial (two). In 137 cases, no bronchial frozen section was performed; there was one case (0.7%) with positive margin. There was no correlation between final margin positivity and distance between gross tumor and margin. Tumor distance to margin in positive margin cases varied from grossly involved to 3 cm away. There were 72 cases in which wedge resection was performed before lobectomy in which no gross tumor remained in the lobectomy, and in all cases final bronchial margins were negative. In all, 373 of cases (92%) were nonsmall carcinomas. Of these, 10 (2.7%) had positive margins. Tumors other than nonsmall cell carcinoma accounted for a disproportionate number of positive margins. In all, 3/6 of adenoid cystic/mucoepidermoid carcinoma, 1/7 small cell carcinoma and 1/1 lymphoma cases had positive margins. In conclusion, frozen section evaluation of bronchial margins is helpful in central lung tumors. Mucosal tumor is preferentially identified in frozen section. Gross evaluation of margins is problematic, as intramucosal carcinoma or tumor in lymphatics may not be detected, but 3 cm was a 'safe' distance for gross tumor from margin. In lobectomies following wedge resection in which no gross tumor remained, all had negative margins. Salivary gland-type tumors have a high incidence of positive margins, and frozen section is particularly indicated in these tumors.

Carbonic anhydrase IX expression, a novel surrogate marker of tumor hypoxia, is associated with a poor prognosis in non-small-cell lung cancer

PURPOSE

To evaluate carbonic anhydrase (CA) IX as a surrogate marker of hypoxia and investigate the prognostic significance of different patterns of expression in non-small-cell lung cancer (NSCLC).

METHODS

Standard immunohistochemical techniques were used to study CA IX expression in 175 resected NSCLC tumors. CA IX expression was determined by Western blotting in A549 cell lines grown under normoxic and hypoxic conditions. Measurements from microvessels to CA IX positivity were obtained.

RESULTS

CA IX immunostaining was detected in 81.8% of patients. Membranous (m) (P =.005), cytoplasmic (c) (P =.018), and stromal (P <.001) CA IX expression correlated with the extent of tumor necrosis (TN). The mean distance from vascular endothelium to the start of tumor cell positivity was 90 micro m, which equates to an oxygen pressure of 5.77 mmHg. The distance to blood vessels from individual tumor cells or tumor cell clusters was greater if they expressed mCA IX than if they did not (P <.001). Hypoxic exposure of A549 cells for 16 hours enhanced CA IX expression in the nuclear and cytosolic extracts. Perinuclear (p) CA IX (P =.035) was associated with a poor prognosis. In multivariate analysis, pCA IX (P =.004), stage (P =.001), platelet count (P =.011), sex (P =.027), and TN (P =.035) were independent poor prognostic factors.

CONCLUSION

These results add weight to the contention that mCA IX is a marker of tumor cell hypoxia. The absence of CA IX staining close to microvessels suggests that these vessels are functionally active. pCA IX expression is representative of an aggressive phenotype.

Prognostic implications of microscopic proximal bronchial extension in non-small cell lung cancer

BACKGROUND

The loss of approximately one third of early stage lung cancer patients undergoing complete resection by the end of 5 years implies the existence of unknown or undetected factors at the time of operation. We investigated the possible correlation between microscopic proximal bronchial extension (MPBE) and survival with clinicopathologic features in patients with non-small cell lung cancer.

METHODS

The bronchial tree with the tumor was dissected and extracted from the lung parenchyma in a total of 62 surgical specimens with non-small cell lung cancer. The tumor-related bronchus was sectioned into serial blocks at a thickness of 5 mm in the transverse plane. Histologically, cut serial sections were examined for MPBE.

RESULTS

A total of 15 (24.2%) specimens showed MPBE, whereas 47 (75.8%) specimens showed no evidence of MPBE. The median survival time of MPBE-positive patients was 10.0 months, whereas that of MPBE-negative patients was 42.0 months. The 5-year survival rates of MPBE-positive and MPBE-negative groups were 13.3% and 35.8%, respectively, which was a significant difference (p = 0.0203). Multivariate analysis revealed lymph node status (p = 0.0161), histology (p = 0.0268), and MPBE-positivity (p = 0.0447) as independent prognostic factors.

CONCLUSIONS

Microscopic proximal bronchial extension has an adverse effect on survival in non-small cell lung cancer.

Therapy for stage I and stage II non-small cell lung cancer

Despite complete resection of what seems to be all evident tumor, one third to three quarters of patients with stages I and II NSCLC ultimately succumb to this neoplasm. Patients who are cured of an original NSCLC or small cell cancer remain at risk for a new primary lung cancer. Although the importance of lifelong surveillance is clear, the extent and timing of optimal follow-up remain undefined. Although clinicians refer to the development after treatment of clinically discernible sites of tumor as "recurrence," it is probably more accurate to consider these foci as "persistence"--that is, the locoregional site was not sterilized by surgery, and the distant implants were present from the outset but undetected. Although data are sparse, induction and improved adjuvant therapy for early NSCLC may be helpful. Much further experience is needed. Further study and application of biologic indicators in addition to TNM staging likely will help identify patients at high risk for surgical failure who may benefit by combination treatment.

Significance of lymphangiosis carcinomatosa at the bronchial resection margin in patients with non-small cell lung cancer

BACKGROUND

Treatment options for patients with microscopic residual disease at the bronchial margin (R1-resection) after resection for non-small cell lung cancer include observation, radiotherapy, reoperation, or even systemic therapy. The present study was performed to identify a parameter that would estimate the prognosis of these patients more precisely to permit a well-founded treatment recommendation for the individual patient.

METHODS

A total of 1,162 patients with resected non-small cell lung cancer were analyzed in this retrospective study. Fifty-four patients (4.6%) had R1-resections at the bronchial margin. Type of residual disease (mucosal, extramucosal, or involvement of the entire bronchial wall) and occurrence of tumor cells in the lymphatic vessels (lymphangiosis carcinomatosa) were recorded as distinct parameters and analyzed by univariate and multivariate analyses (Log rank test; Cox regression model).

RESULTS

Lymphangiosis carcinomatosa at the bronchial margin was detected in 22 patients (40.7%) and was associated with a significantly shortened survival (median survival with lymphangiosis carcinomatosa, 13.3 months; without lymphangiosis carcinomatosa, 20.1 months; p = 0.026). Early stage patients (stage I-II) without lymphangiosis carcinomatosa showed a median survival of 49 months. Multivariate analysis revealed that lymphangiosis carcinomatosa at the resection margin is an independent prognostic parameter (p = 0.038). Even after postoperative radiotherapy the prognosis was still poor if a lymphangiosis carcinomatosa was detected (median survival, 17.1 months). All other parameters (T-stage, N-stage, tumor histology, type of bronchial wall involvement) were not of prognostic significance in R1-resected patients.

CONCLUSIONS

Lymphangiosis carcinomatosa at the bronchial resection margin predicts a poor prognosis in patients with non-small cell lung cancer. It is more than questionable whether these patients would benefit from local treatment options like radiotherapy.

Proximal bronchial extension with special reference to tumor localization in non-small cell lung cancer

OBJECTIVE

Surgery is the optimal treatment in patients with non-small cell lung cancer (NSCLC) and tumor-negative bronchial resection margins should be maintained for a curative resection. The epidemiology of NSCLC, including the aspects of tumor localization, has been changing during the recent decades. The aim of this study was to evaluate microscopic proximal bronchial extension with special reference to the site of the tumor.

METHODS

Surgical specimens of 70 NSCLC cases were examined histologically for proximal bronchial extension of the tumor. The entire bronchial tree with the tumor was extracted from the specimen and serially cut at a thickness of 5 mm in the transverse plane of the bronchus. Microscopic proximal extension of the tumor was classified as either endobronchial or peribronchial.

RESULTS

Thirty-three (47.1%) tumors had central and 37 (52.9%) had peripheral localization. Among the central and peripheral tumors, 10 (30.3%) and seven (18.9%) had microscopic proximal extension, respectively. In total, the mean length of proximal extension was 10.94 +/- 7.07 mm. The mean length of extension for peripheral tumors was 15.71 +/- 8.38 mm, significantly greater than that of central tumors, which was 7.60 +/- 3.47 mm (P = 0.026). Peripheral tumors showed a significant peribronchial extension (P = 0.024).

CONCLUSIONS

A greater percentage of central tumors show microscopic proximal bronchial extension, whereas the length of microscopic proximal bronchial extension is significantly greater in peripheral tumors. Peripheral tumors preferentially have a peribronchial extension pattern.