Molecular assessment of lymph nodes in patients with resected stage I non-small cell lung cancer: preliminary results of a prospective study

Systematic review and meta-analysis of the prognostic impact of lymph node micrometastasis and isolated tumour cells in patients with stage I-IIIA non-small cell lung cancer

Lymph node micrometastases could be one of the reasons for the high recurrence rate after complete surgical resection in stage I-IIIA non-small cell lung cancer (NSCLC). The standard evaluation of a single haematoxylin and eosin (H&E) slide of a paraffin-embedded section of a lymph node is insufficient for the detection of micrometastases, and there is a need for additional histopathological evaluation. The association of lymph node micrometastases with survival remains as yet unresolved. The aim of this systematic review and meta-analysis is to investigate if lymph node micrometastases and isolated tumour cells in patients with stage I-IIIA NSCLC, detected with multiple sectioning and/or immunohistochemistry (IHC) and/or reverse transcriptase polymerase chain reaction (RT-PCR), are associated with overall survival (OS) and disease-free survival (DFS) after surgical resection. We performed a meta-analysis of time-to-event outcomes based on 15 articles using ancillary techniques to detect micrometastases. We extracted the OS and DFS every 3-6 months after surgery, for patients with and without occult lymph node micrometastasis, from the survival curves published in each article. These data were used to reconstruct OS and DFS for 'micrometastasis' and 'no micrometastasis' groups. Based on all included studies that used IHC, serial sectioning, or RT-PCR, we found a 5-year OS of 55% (micrometastasis) vs. 75% (no micrometastasis), and a 5-year DFS of 53% (micrometastasis) vs. 75% (no micrometastasis). Patients with stage I-IIIA NSCLC with lymph node micrometastases detected by ancillary histopathological and molecular techniques have a significantly poorer OS and DFS compared to patients without lymph node micrometastases.

Molecular Nodal Restaging Based on CEACAM5, FGFR2b and PTPN11 Expression Adds No Relevant Clinical Information in Resected Non-Small Cell Lung Cancer

BACKGROUND

The relapse rate in non-small cell lung cancer (NSCLC) is high, even in localized disease, suggesting that the current approach to pathological staging is insufficiently sensitive to detect occult micrometastases present in resected lymph nodes. Therefore, we aimed to determine the prognostic value of the expression of embryonic molecular markers in histologically-negative lymph nodes of completely-resected NSCLC.

METHODS

76 completely-resected NSCLC patients were included: 60 pN0 and 16 pN1. Primary tumors and 347 lymph node were studied. CEACAM5, FGFR2b, and PTPN11 expression levels were evaluated through mRNA analysis using real-time RT-qPCR assay. Statistical analyses included the Kruskal-Wallis test, Kaplan Meier curves, and log-rank tests.

RESULTS

CEACAM5 expression levels were scored as high in of 90 lymph nodes (26%). The molecular-positive lymph nodes lead to the restaging of 37 (62%) pN0 patients as molecular N1 or N2 and 5 (31%) pN1 cases were reclassified as molecular-positive N2. Surprisingly, molecular-positive patients associated with a better OS (overall survival, p = 0,04). FGFR2b overexpression was observed in 41 (12%) lymph nodes leading to the restaging of 17 patients (22%). Again a trend was observed toward a better DFS (disease-free survival) in the restaged patients (p = 0,09). Accordingly, high expression levels of CEACAM5 or FGFR2b in the primary were related to better DFS (p = 0,06; p < 0,02, respectively).

CONCLUSION

Molecular nodal restaging based on expression levels of CEACAM5 and/or FGFR2b, does not add relevant clinical information to pathological staging of NSCLC likely related to the better prognosis of their overexpression in primary tumors.

Potential Molecular Signatures Predictive of Lung Cancer Brain Metastasis

Brain metastases are the most common tumors of the central nervous system (CNS). Incidence rates vary according to primary tumor origin, whereas the majority of the cerebral metastases arise from primary tumors in the lung (40-50%). Brain metastases from lung cancer can occur concurrently or within months after lung cancer diagnosis. Survival rates after lung cancer brain metastasis diagnosis remain poor, to an utmost of 10 months. Therefore, prevention of brain metastasis is a critical concern in order to improve survival among cancer patients. Although several studies have been made in order to disclose the genetic and molecular mechanisms associated with CNS metastasis, the precise mechanisms that govern the CNS metastasis from lung cancer are yet to be clarified. The ability to forecast, which patients have a higher risk of brain metastasis occurrence, would aid cancer management approaches to diminish or prevent the development of brain metastasis and improve the clinical outcome for such patients. In this work, we revise genetic and molecular targets suitable for prediction of lung cancer CNS disease.

Usefulness of conventional transbronchial needle aspiration in the diagnosis, staging and molecular characterization of pulmonary neoplasias by thin-prep based cytology: experience of a single oncological institute

BACKGROUND

Conventional transbronchial needle aspiration (c-TBNA) contributed to improve the bronchoscopic examination, allowing to sample lesions located even outside the tracheo-bronchial tree and in the hilo-mediastinal district, both for diagnostic and staging purposes.

METHODS

We have evaluated the sensitivity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of the c-TBNA performed during the 2005-2015 period for suspicious lung neoplasia and/or hilar and mediastinal lymphadenopathy at the Thoracic endoscopy of the Thoracic Surgery Department of the Regina Elena National Cancer Institute, Rome. Data from 273 consecutive patients (205 males and 68 females) were analyzed.

RESULTS

Among 158 (58%) adequate specimens, 112 (41%) were neoplastic or contained atypical cells, 46 (17%) were negative or not diagnostic. We considered in the analysis first the overall period; then we compared the findings of the first [2005-2011] and second period [2012-2015] and, finally, only those of adequate specimens. During the overall period, sensibility and accuracy values were respectively of 53% and 63%, in the first period they reached 41% and 53% respectively; in the second period sensibility and accuracy reached 60% and 68%. Considering only the adequate specimens, sensibility and accuracy during the overall period were respectively of 80% and 82%; the values obtained for the first period were 68% and 72%. Finally, in the second period, sensibility reached 86% and accuracy 89%. Carcinoma-subtyping was possible in 112 cases, adenocarcinomas being diagnosed in 50 cases; further, in 30 cases molecular predictive data could be obtained.

CONCLUSIONS

The c-TBNA proved to be an efficient method for the diagnosis/staging of lung neoplasms and for the diagnosis of mediastinal lymphadenopathy. Endoscopist's skill and technical development, associated to thin-prep cytology and to a rapid on site examination (ROSE), were able to provide by c-TBNA a high diagnostic yield and molecular predictive data in advanced lung carcinomas.

Detection of occult tumor cells in regional lymph nodes is associated with poor survival in pN0 non-small cell lung cancer: a meta-analysis

BACKGROUND

patients of pN0 non-small cell lung cancer (NSCLC) with occult tumor cells (OTCs) in regional lymph nodes (LNs) are reported to have controversial prognostic outcomes.

METHOD

We pooled pN0 NSCLC patients with OTCs in LNs and compared with those without OTCs. Patient characteristics, hazard ratios (HRs) and 95% confidence intervals (CIs) for overall survival (OS) and/or disease-free survival (DFS) were analyzed. HR greater than 1 conferred an increased hazard for patients with OTCs.

RESULTS

Eighteen articles were finally enrolled in the meta-analysis and 15 studies provided sufficient data for extracting HRs for OS, resulting to 5 articles available for DFS analysis. The combined HRs of OS was 2.22 (95% CI, 1.87 to 2.64) and 2.4 (95% CI, 1.71 to 3.36) for analysis of DFS. The similar trend was obtained in the subgroup analyses regarding detection methods and study type. Interestingly, even in the analysis of mean numbers of LNs dissection (MLND) intraoperatively, both subgroups (LNs/Pts. <12 and ≥12) illustrated significant HRs of OS (HR: 3.13, 95% CI, 2.17 to 4.52 in LNs/Pts. <12 subgroup and HR: 2.09, 95% CI, 1.63 to 2.68 in LNs/Pts. ≥12). The combined HR of OS in this section was 2.37 (95% CI, 1.63 to 2.68). No publication bias was detected in all the meta-analysis sections. The prognosis of patients with OTCs is inferior to those without OTCs in the terms of OS and DFS regardless of detection methods, study types and MLND.

CONCLUSIONS

The prognosis of patients with OTCs is inferior to those without OTCs in the terms of OS and DFS regardless of detection methods, study types and MLND.

Staging lymph node metastases from lung cancer in the mediastinum

BACKGROUND

The presence of tumor metastases in the mediastinum is one of the most important elements in determining the optimal treatment strategy in patients with non-small cell lung cancer. This review is aimed at examining the current strategies for investigating lymph node metastases corresponding to an "N2" classification delineated by The International Staging Committee of the International Association for the Study of Lung Cancer (IASLC).

METHODS

Extensive review of the existing scientific literature related to the investigation of mediastinal lymph node metastases was undertaken in order to summarize and report current best practices.

CONCLUSIONS

N2 disease is very heterogeneous requiring multiple modalities for thorough investigation. New research is now focusing on better identifying, defining, and classifying lymph node metastases in the mediastinum. Molecular staging and sub-classifying mediastinal lymph node metastases are being actively researched in order to provide better prognostic value and to optimize treatment strategies. Non-invasive imaging, such as PET/CT and minimally invasive techniques such as endobronchial and endoscopic ultrasound guided biopsy, are now the lead investigative methods in evaluating the mediastinum for metastatic presence.

Fast cytological evaluation of lymphatic nodes obtained during transcervical extended mediastinal lymphadenectomy

OBJECTIVES

Evaluation of the diagnostic efficiency of the intraoperative cytological examination of lymphatic nodes obtained during transcervical extended mediastinal lymphadenectomy (TEMLA).

METHODS

All mediastinal nodes obtained during consecutive TEMLA operations in patients with confirmed lung cancer were examined. Cytological imprints from cross sections of nodes were performed, fixed in 96 proof alcohol and stained with Haematoxylin-Eosin. The cytological slides were evaluated by light microscopy intraoperatively, and a standard paraffin histological examination of the same nodes was done afterwards for confirmation of the final diagnosis.

RESULTS

Intraoperative cytological studies were performed in 63 patients (17 women and 46 men; overall in 453 mediastinal nodal stations) from 1 April 2009 to 28 February 2011. The mean number of nodes/procedure was 27.8. The mean time of performance of the examination was 37 min, including 7 min for smears, 13 min for staining and 17 min for microscopic examination (overall 37 min). The cytological study discovered neoplasmatic cells in 12 of 63 patients, nodal stations in 22 of 453 and nodes in 44 of 1724. According to the analysis of the 63 patients, the imprint cytology technique had a sensitivity of 92.3%, specificity of 100%, accuracy of 98.4%, positive predictive value of 100% and negative predictive value of 98.0%, as was confirmed by the final histopathological examination.

CONCLUSIONS

(i) Cytological imprints examination was characterized by a very high specificity and sensitivity, is technically simpler and faster and allows for the examination of several dozens of lymphatic nodes during a single TEMLA procedure within an acceptable time, and after the exclusion of N2 nodes enables the simultaneous performance of a radical lung resection. (ii) The presented technique was the alternative for the traditional histopathological examination of the material frozen in cryostat.

Molecular diagnosis and prognostic significance of lymph node micrometastasis in patients with histologically node-negative non-small cell lung cancer

Lymph node metastasis is a major prognostic factor in resected non-small cell lung cancer (NSCLC). However, 30-40 % rate of recurrence after performing complete resection in node-negative patients suggests that their nodal staging is suboptimal. We aimed to evaluate the molecular diagnosis and prognostic significance of lymph node micrometastasis in patients with node-negative NSCLC. Primary tumor samples from 62 patients with resected stage I-IIB NSCLC were screened for fragile histidine triad (FHIT) and CDKN2A mRNA deletion using reverse transcriptase polymerase chain reaction (RT-PCR). The molecular alternations were found in tumors of 49 patients. A total of 269 lymph nodes from these 49 NSCLC patients with FHIT or/and CDKN2A deletion tumors were examined. Fifteen positive-control nodes and ten negative-control nodes were also analyzed for FHIT and CDKN2A mRNA deletion. Thirty-nine (22 %) and 22 (18 %) lymph nodes from the 49 patients with FHIT and CDKN2A mRNA deletion in primary tumor had FHIT and CDKN2A mRNA deletion, respectively. The types of FHIT and CDKN2A mRNA deletion in lymph nodes were identical with those in their primary tumors. By combination of two markers, 16 patients (32.7 %) were found to have nodal micrometastasis. Survival analysis showed that patients with nodal micrometastasis had reduced disease-free survival (P = 0.001) and overall survival (P = 0.002) rates. Multivariate analysis demonstrated that nodal micrometastasis was an independent predictor for worse prognosis. Thus, the detection of lymph node micrometastasis by FHIT and CDKN2A mRNA deletion RT-PCR will be helpful to predict the recurrence and prognosis of patients with completely resected stage I-IIB NSCLC.

Randomized Phase III Study of Surgery Alone or Surgery Plus Preoperative Cisplatin and Gemcitabine in Stages IB to IIIA Non–Small-Cell Lung Cancer

Purpose

This study aimed to determine whether three preoperative cycles of gemcitabine plus cisplatin followed by radical surgery provides a reduction in the risk of progression compared with surgery alone in patients with stages IB to IIIA non–small-cell lung cancer (NSCLC).

Patients and Methods

Patients with chemotherapy-naive NSCLC (stages IB, II, or IIIA) were randomly assigned to receive either three cycles of gemcitabine 1,250 mg/m2days 1 and 8 every 3 weeks plus cisplatin 75 mg/m2day 1 every 3 weeks followed by surgery, or surgery alone. Randomization was stratified by center and disease stage (IB/IIA v IIB/IIIA). The primary end point was progression-free survival (PFS).

Results

The study was prematurely closed after the random assignment of 270 patients: 129 to chemotherapy plus surgery and 141 to surgery alone. Median age was 61.8 years and 83.3% were male. Slightly more patients in the surgery alone arm had disease stage IB/IIA (55.3% v 48.8%). The chemotherapy response rate was 35.4%. The hazard ratios for PFS and overall survival were 0.70 (95% CI, 0.50 to 0.97; P = .003) and 0.63 (95% CI, 0.43 to 0.92; P = .02), respectively, both in favor of chemotherapy plus surgery. A statistically significant impact of preoperative chemotherapy on outcomes was observed in the stage IIB/IIIA subgroup (3-year PFS rate: 36.1% v 55.4%; P = .002). The most common grade 3 or 4 chemotherapy-related adverse events were neutropenia and thrombocytopenia. No treatment-by-histology interaction effect was apparent.

Conclusion

Although the study was terminated early, preoperative gemcitabine plus cisplatin followed by radical surgery improved survival in patients with clinical stage IIB/IIIA NSCLC.

Personalized Medicine in Non–Small-Cell Lung Cancer: Is KRAS a Useful Marker in Selecting Patients for Epidermal Growth Factor Receptor–Targeted Therapy?

In patients with metastatic colorectal cancer, the predictive value of KRAS mutational status in the selection of patients for treatment with anti–epidermal growth factor (EGFR) monoclonal antibodies is established. In patients with non–small-cell lung cancer (NSCLC), the utility of determining KRAS mutational status to predict clinical benefit to anti-EGFR therapies remains unclear. This review will provide a brief description of Ras biology, provide an overview of aberrant Ras signaling in NSCLC, and summarize the clinical data for using KRAS mutational status as a negative predictive biomarker to anti-EGFR therapies. Retrospective investigations of KRAS mutational status as a negative predictor of clinical benefit from anti-EGFR therapies in NSCLC have been performed; however, small samples sizes as a result of low prevalence of KRAS mutations and the low rate of tumor sample collection have limited the strength of these analyses. Although an association between the presence of KRAS mutation and lack of response to EGFR tyrosine kinase inhibitors (TKIs) has been observed, it remains unclear whether there is an association between KRAS mutation and EGFR TKI progression-free and overall survival. Unlike colorectal cancer, KRAS mutations do not seem to identify patients who do not benefit from anti-EGFR monoclonal antibodies in NSCLC. The future value of testing for KRAS mutational status may be to exclude the possibility of an EGFR mutation or anaplastic lymphoma kinase translocation or to identify a molecular subset of patients with NSCLC in whom to pursue a drug development strategy that targets the KRAS pathway.

Assessing quality of life following neoadjuvant therapy for early stage non-small cell lung cancer (NSCLC): results from a prospective analysis using the Lung Cancer Symptom Scale (LCSS)

BACKGROUND

The assessment of the impact of neoadjuvant therapy on quality of life (QL) has rarely been prospectively planned and evaluated, although validated QL instruments are available-such as the Lung Cancer Symptom Scale (LCSS) used in this study. The modest but significant survival gains reported with neoadjuvant and adjuvant approaches need to be viewed in terms of the added risks and toxicities associated with two or three modalities of treatment.

MATERIALS AND METHODS

The objective was to compare patient-determined QL ratings from baseline (prior to neoadjuvant chemotherapy) with those in subsequent months of follow-up. All patients had clinical stage I or II non-small cell lung cancer (NSCLC) and participated in one of two similar randomized protocols. Patients received preoperative chemotherapy (three cycles) of gemcitabine plus carboplatin or paclitaxel in one trial or gemcitabine plus carboplatin or cisplatin in the second. Patients completed the LCSS at baseline, every 3 weeks preoperatively, and every 3 months postoperatively up to 12 months.

RESULTS

Full QL data are available for 43 patients with at least one postsurgical evaluation and for 23 patients with evaluation at 1-year postsurgery. In patients with at least one postsurgical evaluation, 84% had an ECOG performance status of 0, 93% had a complete resection, and 67% (95% CI = 52, 81) of patients experienced improved or stable symptoms. A subgroup of patients (14 of 43) reported worsening of QL (33%). These patients experienced a mean worsening of 66% in individual symptom parameters, with an average of seven of nine LCSS symptom parameters declining.

CONCLUSIONS

Most patients reported improved or stable QL. Prospectively planned QL assessment is feasible with neoadjuvant trials and adds useful information not otherwise attainable.

Diagnostic surgical pathology in lung cancer: ACCP evidence-based clinical practice guidelines (2nd edition)

OBJECTIVE

The objective of this study was to provide evidence-based background and recommendations for the development of American College of Chest Physicians guidelines for the diagnosis and management of lung cancer.

METHODS

A systematic search of the medical and scientific literature using MEDLINE, MDCONSULT, UpToDate, Cochrane Library, NCCN guidelines, and NCI/NIH search engines was performed for the years 1990 to 2006 to identify evidence-based and consensus guidelines. The search was limited to literature on humans and articles in the English language.

RESULTS

The pathologic assessment of lung cancers is based on a set of well-accepted findings, including histologic type, tumor size and location, involvement of visceral pleura, and extension to regional and distant lymph nodes and organs. Bronchial-based incipient neoplasia needs to be recognized both grossly and microscopically because these lesions may be multifocal and represent multistep carcinogenesis and may be amenable to therapy. Cytologic assessment of the individual with no symptoms is, as yet, of insufficient clinical benefit for screening of lung cancer. In challenging situations of pathologic differential diagnosis, additional studies may provide information that enables the separation of distinct tumor types. Pathobiological and molecular biological studies may yield prognostic and predictive information for clinical management and should be considered as part of protocol studies. Enhanced pathologic and molecular techniques may identify the presence of micrometastatic disease within lymph nodes; however, the clinical utility of these approaches is still unresolved. Intraoperative consultations have high diagnostic accuracy and may aid ongoing treatment and management decisions.

CONCLUSIONS

Pathologic assessment is a crucial component for the diagnosis, management, and prognosis of lung cancer. Selective diagnostic techniques and decision analysis will increase diagnostic accuracy. Cytologic screening, molecular characterization of tumors, and micrometastatic analysis are potential but not yet proved modalities for the evaluation of lung cancers.

Genetic alterations in lung cancer: assessing limitations in routine clinical use

Lung cancer is the most frequent cause of cancer mortality worldwide, responsible for approximately 1.1 million deaths per year. Median survival is short, both as most tumours are diagnosed at an advanced stage and because of the limited efficacy of available treatments. The development of tumour molecular gene- tics carries the promise of altering this state of affairs, as it should lead to a more precise classification of tumours, identify specific molecular targets for therapy and, above all, allow the development of new methods for early diagnosis. Despite numerous studies demonstrating the usefulness of molecular genetic techniques in the study of lung cancer, its routine clinical use in Portugal has, however, been limited. In this study, we used a p53 mutation screen in multi- ple clinical samples from a series of lung cancer patients to attempt to identify the main practical limitations to the integration of molecular genetics in routine clinical practice. Our results suggest that the main limiting factor is the availability of samples with good quality DNA; a problem that could be overcome by alterations in common sample collection and storage procedures.

The use of real-time polymerase chain reaction in thoracic malignancies

Recent progress in the molecular analysis of NSCLC tumors and lymph node status will likely translate into a clearer understanding of the variables and predictors of tumor recurrence. This understanding may lead to more appropriate therapeutic decisions both in the operating room and in the clinic. With these analyses at the molecular level, a more precise molecular classification is on the horizon which includes a molecular substaging. All of these aspects of NSCLC biology await testing or final analysis of prospective multi-institutional trials such as that set forth in CALGB 9761.

Molecular mechanisms of metastasis

A major topic covered at the First International Symposium on Cancer Metastasis and the Lymphovascular System was the molecular mechanisms of metastasis. This has become of major interest in recent years as we have discovered new metastasis-related genes and gained understanding of the molecular events of lymphatic metastasis. The symposium covered new aspects and important questions related to the events of metastasis in both humans and animals. The basic and clinical related research covered in this topic represented many disciplines. The presentations showed novel findings and at the same time, raised many new unanswered questions, indicating the limited knowledge we still have regarding the molecular events of metastasis. The hope is that further unraveling of the direct and indirect molecular events of lymphatic metastasis will lead to new approaches in developing effective therapeutics.

Phase II Study of Neoadjuvant Chemotherapy With Gemcitabine and Vinorelbine in Resectable Non-small Cell Lung Cancer

OBJECTIVE

We assessed the efficacy of a non-platinum-containing doublet chemotherapy of gemcitabine and vinorelbine as induction therapy prior to surgical resection in patients with stage IB-IIIA and selected stage IIIB non-small cell lung cancer (NSCLC). The primary clinical end point was radiographic disease response rate, and the secondary end points were pathologic response rate, treatment-related toxicity, surgical resectability and outcome, and overall and disease-free survival.

METHODS

Patients underwent staging with CT of the chest and upper-abdomen, whole-body F-18 fluorodeoxyglucose positron emission tomography, bronchoscopy, and mediastinoscopy. The patients had to have medically and surgically resectable disease. Chemotherapy consisted of gemcitabine, 1,000 mg/m(2), and vinorelbine, 25 mg/m(2), administered on days 1, 8, 22, and 29. Imaging studies were repeated between days 43 and 50. Disease response was assessed by response evaluation criteria in solid tumors, and patients with resectable disease were offered surgery between days 50 and 70. Patients were followed up every 3 months for 2 years with chest CT.

RESULTS

Between January 2000 and March 2004, 27 patients with stage IB NSCLC, 15 patients with stage II NSCLC, and 20 patients with stage III NSCLC were entered. After induction chemotherapy 34% (95% confidence interval [CI], 23 to 48%) had an objective radiographic response, 2% had a complete pathologic response, 90% underwent thoracotomy, and 77% underwent a complete resection. There were four deaths in the 6-week period following surgery, and there were no deaths related to chemotherapy. There were no unexpected morbidities from surgery or chemotherapy. The 1-year and 2-year overall survival rates were 80% (95% CI, 68 to 88%) and 65% (95% CI, 50 to 76%), and the median overall survival was 38.2 months.

CONCLUSIONS

Induction chemotherapy with gemcitabine and vinorelbine results in 1-year and 2-year survival rates and a median survival time comparable to those obtained with platinum-containing doublets. However, it appears to be less efficacious in terms of radiographic and pathologic response rates compared with platinum-containing chemotherapy doublets.

Quantitative Real-time Polymerase Chain Reaction Detection of Lymph Node Lung Cancer Micrometastasis Using Carcinoembryonic Antigen Marker

STUDY OBJECTIVES

The survival of patients with surgically resected stage I non-small cell lung cancer (NSCLC) is not optimal, probably because of unsuspected systemic occult tumor dissemination. The current applied technologies and methods for scanning the body and examining lymph nodes for tumor cells have broadly recognized limitations. Several studies have reported that it is possible to detect occult lymph node metastases (micrometastases) using more sensitive methods such as immunohistochemistry or molecular technology. The aim of our study was to evaluate the utility of quantitative real-time reverse-transcriptase polymerase chain reaction (RT-PCR) for carcinoembryonic antigen (CEA) messenger RNA (mRNA) for detection of lymph node micrometastases and its impact on disease-free interval.

METHODS

Quantitative real-time RT-PCR for CEA mRNA was performed on primary lung tumors and regional lymph nodes from 44 surgically resected NSCLC patients classified as clinical stage I. Fourteen lymph nodes from five patients without malignancy were used as controls. The end point of clinical analysis was cancer recurrence. Average follow-up was 22.5 months.

RESULTS

CEA mRNA was detected in all but four lymph nodes used as controls. All primary tumors were positive for CEA mRNA. Of 261 lymph nodes analyzed, 35 lymph nodes (13.4%) showed CEA mRNA levels higher than those detected in control lymph nodes and were considered positive for micrometastasis. Survival analysis by micrometastases showed less cancer recurrences in patients with lymph nodes negative for CEA mRNA (log rank, 5.3; p = 0.021). Among tumor type, tumor grading, age, sex, and molecularly detected lymph node micrometastases, the most powerful predictor of cancer recurrences was the presence of micrometastases (Cox proportional hazard, 3.3; p = 0.027).

CONCLUSION

Quantitative real-time RT-PCR for CEA mRNA can be applied for detection of micrometastases in lymph nodes. This technique may be an appropriate tool in predicting cancer recurrences, and further studies are warranted to determine the most useful clinical applications.

The role of RAS oncogene in survival of patients with lung cancer: a systematic review of the literature with meta-analysis

The proto-oncogene RAS, coding for a 21 kDa protein (p21), is mutated in 20% of lung cancer. However, the literature remains controversial on its prognostic significance for survival in lung cancer. We performed a systematic review of the literature with meta-analysis to assess its possible prognostic value on survival. Published studies on lung cancer assessing prognostic value of RAS mutation or p21 overexpression on survival were identified by an electronic search. After a methodological assessment, we estimated individual hazard ratios (HR) estimating RAS protein alteration or RAS mutation effect on survival and combined them using meta-analytic methods. In total, 53 studies were found eligible, with 10 concerning the same cohorts of patients. Among the 43 remaining studies, the revelation method was immunohistochemistry (IHC) in nine and polymerase chain reaction (PCR) in 34. Results in terms of survival were significantly pejorative, significantly favourable, not significant and not conclusive in 9, 1, 31, 2, respectively. In total, 29 studies were evaluable for meta-analysis but we aggregated only the 28 dealing with non-small-cell lung cancer (NSCLC) and not the only one dealing with small-cell-lung cancer (SCLC). The quality scores were not statistically significantly different between studies with or without significant results in terms of survival, allowing us to perform a quantitative aggregation. The combined HR was 1.35 (95% CI: 1.16–1.56), showing a worse survival for NSCLC with KRAS2 mutations or p21 overexpression and, particularly, in adenocarcinomas (ADC) (HR 1.59; 95% CI 1.26–2.02) and in studies using PCR (HR 1.40; 95% CI 1.18–1.65) but not in studies using IHC (HR 1.08; 95% CI 0.86–1.34). RAS appears to be a pejorative prognostic factor in terms of survival in NSCLC globally, in ADC and when it is studied by PCR.

Molecular margin analysis predicts local recurrence after sublobar resection of lung cancer

Sublobar resection for early-stage lung cancer has been used for patients who are not candidates for lobar resection. However, sublobar resection is associated with high local recurrence rates in the context of tumor-free parenchymal margins. The mechanism underlying this high recurrence rate is not well understood. We hypothesized that this elevated risk of local recurrence is due to undetected tumor cells present at parenchymal margins thought to be negative by conventional light microscopy. Thirteen of 44 patients who underwent sublobar resection for lung cancer were found to have a k-ras mutation at codon 12.1. A novel fluorescence-based assay for detection of rare copies of mutant DNA in a background of wild-type DNA, fluorescent gap ligase chain reaction, was used to quantitate the mutant/wild-type DNA in a range of 1 to 1/10,000 in histologically normal margins from these resections. Nine of 13 patients had at least one margin with the number of mutant cells over or equal to a threshold of 1/5,000, and of these, 6/9 (67%) recurred locally. None of the remaining 4 patients without mutant DNA in any surgical margin had evidence of recurrence. The higher rate of local recurrence associated with sublobar resection of lung cancer is likely due to the occult presence of tumor cells at resection margins. These occult tumor cells can be quantitated using a novel fluorescence-based assay and define a group of patients at high risk for local recurrence who are candidates for adjuvant therapy or more extensive resection. This methodology may be adaptable to a real-time format for intraoperative use.

Real-time gap ligase chain reaction: a rapid semiquantitative assay for detecting p53 mutation at low levels in surgical margins and lymph nodes from resected lung and head and neck tumors

PURPOSE

We have developed a real-time semiquantitative gap ligase chain reaction for detecting p53 point mutations at low level in a background of excess of wild-type DNA.

EXPERIMENTAL DESIGN

This method was validated by direct comparison to a previously validated but cumbersome phage plaque hybridization assay. Forty-one surgical margins and lymph nodes from 10 cases of head and neck squamous cell carcinoma and lung carcinoma were tested for p53 mutant clones.

RESULTS

Both methods detected p53 mutants in margins from 8 of the 10 cases, whereas standard pathology detected cancer cells in only 3 cases. Positive margins included tissue samples with a tumor/normal DNA ratio of up to 1:1000.

CONCLUSIONS

This novel molecular approach can be performed in <5 h facilitating intraoperative use for real-time surgical resection.

Detection of lymph node micrometastases by gene promoter hypermethylation in samples obtained by endosonography- guided fine-needle aspiration biopsy

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has become a fundamental procedure for gastrointestinal and lung cancer staging. However, there is growing evidence that micrometastases are present in lymph nodes, which cannot be detected with standard pathological methods. The aim of this study was to evaluate whether hypermethylation gene promoter analysis was feasible on samples obtained by EUS-FNA from lymph nodes, as well as to establish the usefulness of this strategy for the detection of micrometastases in patients with gastrointestinal and non-small cell lung cancer. Suspicious lymph nodes based on EUS findings from consecutive patients with esophageal, gastric, rectal, and non-small cell lung cancer were sampled by EUS-FNA. Hypermethylation analysis of the MGMT, p16(INK4a), and p14(ARF) gene promoter CpG islands were performed by methylation-specific PCR. Effectiveness of conventional cytology, methylation analysis, and their combination were established with respect to the definitive diagnosis. Twenty-seven patients were included, thus representing a total of 42 lymph nodes (esophageal cancer, n = 11; rectal cancer, n = 7; gastric cancer, n = 3; and lung cancer, n = 21). According to definitive diagnosis, 21 (50%) corresponded to metastatic lymph nodes. Sensitivity, specificity, and overall accuracy of conventional cytology were 76%, 100%, and 88%, respectively, whereas the corresponding values for the methylation analysis were 81%, 67%, and 74%, respectively. Combination of both techniques increased sensitivity (90%) but decreased specificity (67%) with respect to conventional cytology. In conclusion, it is feasible to detect occult neoplastic cells in EUS-FNA samples by hypermethylation gene promoter analysis. Moreover, addition of methylation analysis to conventional cytology may increase its sensitivity at the expenses of a decrease in its specificity.

P53and K-rasmutations are frequent events in microscopically negative surgical margins from patients with nonsmall cell lung carcinoma

BACKGROUND

The objective of the current study was to determine whether tumor cells harboring P53 and K-ras mutations could be detected in histopathologically tumor-free surgical margins in patients with nonsmall cell lung carcinoma who underwent complete pulmonary resection.

METHODS

In 118 consecutive patients, DNA obtained from primary tumors and from surgical margins was extracted for molecular analysis. A fragment of P53 gene encompassing exons 5-8 and codon 12 of the K-ras gene were amplified with the polymerase chain reaction technique and were assayed for the presence of mutations.

RESULTS

P53 and K-ras mutations were found in 30% and 39% of primary tumors, respectively, and in 11 (9%) and 22 (18%) apparently tumor-free surgical margins, respectively. At least 1 of those mutations was found in surgical margins in 29 patients (25%), and both mutations were found in 2 patients (1.7%). P53 mutations in surgical margins accompanied mutations in primary tumors in 9 of 35 patients (26%), and K-ras mutations accompanied mutations in primary tumors in 20 of 46 patients (44%). Among patients with either mutation in primary tumors, the incidence of at least 1 mutation in surgical margins was 43% (28 of 65 patients). In four patients, mutations (two K-ras mutations and two P53 mutations) were found in surgical margins despite the absence of the corresponding mutations in primary tumors. The presence of mutations in primary tumors and in surgical margins was not related significantly to clinical characteristics or to patient outcomes.

CONCLUSIONS

P53 and K-ras mutations are frequent events in surgical margins determined to be tumor free on light microscopy. The clinical relevance of these findings remains to be established.

Pulmonary resection in octogenarians with stage I nonsmall cell lung cancer: a 22-year experience

BACKGROUND

Recent reports indicate that age is not a contraindication to pulmonary resection for octogenarians with nonsmall cell lung cancer (NSCLC), but other data are lacking. The purpose of this study was to determine outcomes in these patients, particularly short- and long-term survival with stage I disease.

METHODS

A retrospective cohort of 68 octogenarians with NSCLC who underwent curative resection from 1980 to 2002 was followed-up for outcomes.

RESULTS

Median age was 82 years old (range, 80-87 years old) consisting of 44 males (65%), with a mean follow-up of 32 months (range, 1-178 months). Operations included: 47 lobectomies (69%), 11 wedge resections (16%), 5 segmentectomies (8%), 4 bilobectomies (6%), and 1 pneumonectomy (1%). There were 31 adenocarcinomas (46%), 18 squamous carcinomas (26%), 12 bronchioalveolar carcinomas (18%), 4 large cell carcinomas (6%), and 3 miscellaneous malignant neoplasms (4%). Median hospital stay was 7 days (range, 3-53 days). Thirty-day mortality was 8.8% (n = 6) with 83% developing cardiopulmonary complications. Overall actuarial survival at 1, 3, and 5 years was 73%, 51%, and 34%, respectively. Of 41 patients (60%) with stage I disease, 23 were T1 lesions. Five-year survival was significantly different between stages Ia and Ib patients (61% and 10%, respectively, p = 0.001). Patients in more advanced stages had a 5-year survival of 3/27 (11%). Multivariate analysis identified advanced tumor stage, lower ASA physical status, and low FEV(1) as factors associated with poorer long-term survival.

CONCLUSIONS

The 5-year survival, particularly in patients with stage Ia tumors with favorable ASA and FEV(1), supports the notion that health status and tumor stage outweigh chronologic age in determining surgical candidates.

Prognostic significance of micrometastasis in non-small-cell lung cancer

Accurate staging of non-small-cell lung cancer (NSCLC) determines prognosis and facilitates decisions regarding treatment options. Unfortunately, even after an apparently complete resection in patients with stage I disease, the recurrence rates range from 25% to 50%, and overall survival is not encouraging. One possible reason for this may be that those patients with a poor outcome actually have more extensive disease, with occult locoregional and/or distant metastasis than originally identified by routine pathologic staging techniques. There is now a sizable body of literature on the detection and possible prognostic role of occult disease in lung cancer. The majority of these studies are based on immunohistochemical analysis of lymph nodes and/or bone marrow, but a handful of studies use molecular approaches. The purpose of this review is to summarize and critique the current literature on occult tumor cell spread to lymph nodes and bone marrow in patients with NSCLC. Based on this literature, we believe that the prognostic significance of bone marrow micrometastasis remains unclear. However, the majority of studies indicate that occult lymph node disease is associated with a poor outcome. Thus, our ability to detect individual tumor cells could result in more accurate staging of NSCLC in patients and would potentially lead to the development of novel therapies, as well as influence decisions regarding the use of appropriate multimodality treatment strategies, the choice of surgical technique, and extent of dissection. As data accumulate, the presence or absence of occult nodal involvement should probably be considered at the next revision of the staging system for NSCLC.

Lung cancer and cyclooxygenase-2

Lung cancer is by far the leading cause of cancer-related death. Overall survival is poor and has not improved substantially over the last half century. It is clear that new approaches are needed and these should include prevention, screening for early detection, and novel treatments based on our understanding of the molecular biology of this disease. Recently attention has been drawn to the role of the cyclooxygenase (COX) enzyme and its involvement in tumorigenesis. Investigations have documented two isoforms, COX-1 and COX-2, encoded by different genes. COX-1 is constitutively expressed in most tissues and appears to be responsible for the production of prostaglandins mediating normal physiologic functions, such as the maintenance of gastric mucosa and regulation of renal blood flow. In contrast, COX-2 is normally undetectable in most tissues, and is induced by cytokines, growth factors, oncogenes, and tumor promoters. A growing body of evidence indicates COX-2 plays a key role in lung cancer, and can serve as a potential marker of prognosis in this disease. Furthermore, the recent availability of COX-2 inhibitor medications offers a unique opportunity to interfere with the development of lung cancer and the progression of metastasis. Because COX-2 inhibitors have been demonstrated to interfere with tumorigenesis, the COX-2 enzyme may be an attractive target for therapeutic and chemoprotective strategies in lung cancer patients.

Cyclooxygenase-2 inhibition decreases primary and metastatic tumor burden in a murine model of orthotopic lung adenocarcinoma

OBJECTIVE

To assess cyclooxygenase-2 inhibition on primary tumor and mediastinal metastases in a murine model of orthotopic lung adenocarcinoma.

METHODS

Human lung adenocarcinoma cells (CRL5908, female nonsmoker with cyclooxygenase-2 expression by Western blot) were implanted under direct visualization through the parietal pleura in the upper lobe of the left lung (2 x 10(6) cells/animal) of SCID mice. Mice were randomly assigned to 2 groups, either untreated (n = 62) or celecoxib-treated (n = 60). Celecoxib, a selective cyclooxygenase-2 antagonist, was solubilized in the animals' drink (25 mg/kg per day). Mice were arbitrarily killed at 1, 2, 3, and 4 weeks. A blinded observer assessed primary tumor volume and metastatic disease grossly and histologically.

RESULTS

Gross metastatic lymph nodes were present at 3 weeks in none of 15 (0%) treated and 12 of 15 (80.0%) untreated animals (P <.0001). Mean primary tumor volumes at 3 weeks for treated mice were 7.9 +/- 10.0 mm(3) and for untreated mice were 533.1 +/- 453.6 mm(3) (mean +/- SD, P <.0001). Gross metastatic lymph nodes were present at 4 weeks in 3 of 15 (20%) treated and 17 of 17 (100%) untreated animals (P <.0001). Mean primary tumor volumes at 4 weeks for treated mice were 37.1 +/- 46.2 mm(3) and for untreated mice were 809.6 +/- 1226.4 mm(3) (mean +/- SD, P <.0001). Mean blood levels of celecoxib in treated mice were 236.8 +/- 34.2 ng/mL (mean +/- SD).

CONCLUSIONS

Cyclooxygenase-2 inhibition results in decreased primary and metastatic tumor burden in a murine model using human lung adenocarcinoma. Cyclooxygenase-2 inhibition has the potential to decrease tumor progression and metastases in patients with lung adenocarcinoma.

The prognostic significance of intranodal isolated tumor cells and micrometastases in patients with non-small cell carcinoma of the lung

OBJECTIVE

To study whether isolated tumor cells and micrometastases, as defined by the current American Joint Committee on Cancer criteria for extrapulmonary neoplasms, have prognostic value for patients with resected non-small cell carcinoma of the lung.

METHODS

Intrathoracic lymph nodes (n = 1063) from 60 patients with non-small cell carcinoma of the lung were studied for the presence of metastases with serial histologic sections and keratin immunostains. Metastases were classified as isolated tumor cells, pN1mi, pN1, pN2mi, and pN2. Isolated tumor cells were smaller than 0.2 mm, while pN1mi and pN2mi measured 0.2 mm to 2 mm. Survival analysis was performed, stratifying by nodal status and stage.

RESULTS

Isolated tumor cells were detected in 11 lymph nodes from 5 of 33 pN0 patients and in 9 pN1 and pN2 patients. The lymph nodes from 3 patients were reclassified as pN1mi. No pN2mi were detected. A survival model based on a stratification of the cohort into stages I to III was significant (chi-square = 7.426, df = 2, P =.024) but demonstrated considerable overlap between the survival curves of stage I and II patients. A model stratifying isolated tumor cells and pN1mi into stage I disease was significant (chi-square = 7.985, df = 2, P =.018) and showed no overlap between the survival curves of stage I and II patients. There were no significant survival function differences between patients with pN0, isolated tumor cells, and pN1mi.

CONCLUSIONS

Patients with non-small cell carcinoma of the lung with isolated tumor cells and pN1mi have similar survivals to those with pN0, consistent with the findings reported for breast cancer patients. Future larger studies of patients with non-small cell carcinoma of the lung are needed to confirm whether current American Joint Committee on Cancer staging criteria should be modified to include the pN1mi category.

Radiation sensitization of human cancer cells in vivo by inhibiting the activity of PI3K using LY294002

Multiple genetic alterations such as in Ras or EGFR can result in sustained signaling through PI3K. Our previous experiments have shown that resistance to radiation results from PI3K activity in cells in culture. Here we examined whether inhibition of PI3K in vivo would sensitize tumors to radiation. The human bladder cancer cell line T24 has amplified and mutated H-Ras resulting in sustained PI3K activity and phosphorylation of the downstream target of PI3K, Akt. Nude mice bearing T24 tumor cell xenografts were randomly assigned to one of four groups: control, radiation alone, the PI3K inhibitor LY294002 alone, or combined LY294002 and radiation. The LY294002 was delivered intraperitoneally to the mice. Downregulation of Akt was documented by Western blot analysis of tumor lysates. In vivo sensitization was measured using clonogenic assays or regrowth assays.A dose of 100 mg/kg of LY294002, but not 50 mg/kg, consistently eliminated the phosphorylation of Akt. This inhibition was transient, and Akt activity returned after 30 min. This dose resulted in severe respiratory depression and lethargy resolving without lethality. It is not possible to tell whether these side effects of LY294002 were mechanism-based or idiosyncratic. The PI3K inhibitor LY294002 by itself had minimal antitumor effect. The combination of LY294002 and radiation resulted in significant and synergistic reduction in clonogenicity and growth delay. Inhibition of PI3K by LY294002 can synergistically enhance radiation efficacy. This acts as a proof of principle that inhibition of the Ras to PI3K pathway could be useful clinically.

Detection of telomerase expression in mediastinal lymph nodes of patients with lung cancer

Mediastinal lymph nodes are the most common site of tumor spread in non-small cell lung cancer (NSCLC). We hypothesized that micrometastatic disease could be detected by reverse transcription-polymerase chain reaction (RT-PCR) for expression of human telomerase reverse transcriptase (hTERT) in mediastinal lymph nodes and that a minimally invasive technique (endoscopic ultrasound-guided fine-needle aspiration [EUS-FNA]) is capable of sampling lymph nodes for PCR analysis without surgery. Mediastinal lymph nodes were sampled with EUS-FNA in patients with NSCLC and negative control subjects undergoing EUS for benign disease. Total RNA was harvested from samples, and RT-PCR was performed to detect telomerase gene expression. RNA was available from 87 of 100 lymph node aspirates from 39 patients with NSCLC and from 12 negative control patients. hTERT was expressed in 0 of 14 negative control lymph nodes in 18 of 57 pathologically negative lymph nodes from cancer patients and in 10 of 16 pathologically positive lymph nodes (p < 0.05). Five of 18 (28%) patients with no pathologically evident mediastinal disease expressed telomerase in at least one lymph node. Minimally invasive EUS-FNA with RT-PCR is capable of detecting expression of cancer specific mRNA in lymph nodes. Approximately one-third of pathologically negative mediastinal lymph nodes in NSCLC patients express hTERT mRNA. The clinical significance of this observation is yet to be determined.