High prevalence of occult endobronchial malignancy in high risk patients with moderate sputum atypia

2020 Innovation-Based Optimism for Lung Cancer Outcomes

Lung cancer is the leading cause of cancer death in both males and females in the U.S. and worldwide. Owing to advances in prevention, screening/early detection, and therapy, lung cancer mortality rates are decreasing and survival rates are increasing. These innovations are based on scientific discoveries in imaging, diagnostics, genomics, molecular therapy, and immunotherapy. Outcomes have improved in all histologies and stages. This review provides information on the clinical implications of these innovations that are practical for the practicing physicians, especially oncologists of all specialities who diagnose and treat patients with lung cancer. IMPLICATIONS FOR PRACTICE: Lung cancer survival rates have improved because of new prevention, screening, and therapy methods. This work provides a review of current standards for each of these areas, including targeted and immunotherapies. Treatment recommendations are provided for all stages of lung cancer.

Diagnosis and treatment of bronchial intraepithelial neoplasia and early lung cancer of the central airways: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Bronchial intraepithelial lesions may be precursors of central airway lung carcinomas. Identification and early treatment of these preinvasive lesions might prevent progression to invasive carcinoma.

METHODS

We systematically reviewed the literature to develop evidence-based recommendations regarding the diagnosis and treatment of intraepithelial lesions.

RESULTS

The risk and timeline for progression of bronchial intraepithelial lesions to carcinoma in situ (CIS) or invasive carcinoma are not well understood. Multiple studies show that autofluorescence bronchoscopy (AFB) is more sensitive that white light bronchoscopy (WLB) to identify these lesions. In patients with severe dysplasia or CIS in sputum cytology who have chest imaging studies showing no localizing abnormality, we suggest use of WLB; AFB may be used as an adjunct when available. Patients with known severe dysplasia or CIS of central airways should be followed with WLB or AFB, when available. WLB or AFB is also suggested for patients with early lung cancer who will undergo resection for delineation of tumor margins and assessment of synchronous lesions. However, AFB is not recommended prior to endobronchial therapy for CIS or early central lung cancer. Several endobronchial techniques are recommended for the treatment of patients with superficial limited mucosal lung cancer who are not candidates for resection.

CONCLUSION

Additional information is needed about the natural history and rate of progression of preinvasive central airway lesions. Patients with severe dysplasia or CIS may be treated endobronchially; however, it remains unclear if these therapies are associated with improved patient outcomes.

Detection and minimally invasive treatment of early squamous lung cancer

Non-small cell lung cancer (NSCLC) is the most common cause of cancer deaths worldwide. The majority of patents presenting with NSCLC have advanced disease, which precludes curative treatment. Early detection and treatment might result in the identification of more patients with early central lung cancer and improve survival. In addition, the study of early lung cancer improves understanding of lung carcinogenesis and might also reveal new treatment targets for advanced lung cancer. Bronchoscopic investigation of the central airways can reveal both early central lung cancer in situ (stage 0) and other preinvasive lesions such as dysplasia. In the current review we discuss the detection of early squamous lung cancer, the natural history of preinvasive lesions and whether biomarkers can be used to predict progression to cancer. Finally we will review the staging and management of preinvasive lung cancer lesions and the different therapeutic modalities that are available.

Chemoprevention of lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Lung cancer is the most common cause of cancer death in men and women in the United States. Cigarette smoking is the main risk factor. Former smokers are at a substantially increased risk of developing lung cancer compared with lifetime never smokers. Chemoprevention refers to the use of specific agents to reverse, suppress, or prevent the process of carcinogenesis. This article reviews the major agents that have been studied for chemoprevention.

METHODS

Articles of primary, secondary, and tertiary prevention trials were reviewed and summarized to obtain recommendations.

RESULTS

None of the phase 3 trials with the agents β-carotene, retinol, 13-cis-retinoic acid, α-tocopherol, N-acetylcysteine, acetylsalicylic acid, or selenium has demonstrated beneficial and reproducible results. To facilitate the evaluation of promising agents and to lessen the need for a large sample size, extensive time commitment, and expense, surrogate end point biomarker trials are being conducted to assist in identifying the most promising agents for later-stage chemoprevention trials. With the understanding of important cellular signaling pathways and the expansion of potentially important targets, agents (many of which target inflammation and the arachidonic acid pathway) are being developed and tested which may prevent or reverse lung carcinogenesis.

CONCLUSIONS

By integrating biologic knowledge, additional early-phase trials can be performed in a reasonable time frame. The future of lung cancer chemoprevention should entail the evaluation of single agents or combinations that target various pathways while working toward identification and validation of intermediate end points.

A new lung cancer biomarker--a preliminary report

OBJECTIVE

To investigate a unique biomarker from the blood plasma and sputum of lung cancer patients based on native fluorescence analysis of body fluids.

BACKGROUND

Conventionally, biomarkers indicative of malignancy are identified by biochemical or biophysical processes. Most of the cancer biomarkers, often useful in monitoring disease progression, have sensitivity and specificity in the range of 60%.

METHODS

We employed synchronous fluorescence excitation spectroscopy (SFXS) and fluorescence emission spectroscopy for the native fluorescence analysis of blood plasma of 32 normal controls, 32 patients with lung cancer, and 32 patients with other types of cancer.

RESULTS

Based on the native fluorescence analysis of blood plasma and sputum, we found that the structural protein elastin, with an excitation peak at 327 nm and an emission peak at 405 nm, is an exclusive biomarker for lung carcinoma with 77% sensitivity and 83% specificity from plasma alone, 92.3% sensitivity and 100% specificity from plasma acetone extract alone, and 66% sensitivity and 100% specificity from sputum alone.

CONCLUSION

In this preliminary report with a limited number of lung cancer patients, we have used SFXS of plasma and sputa as the basis for a new technique identifying elastin as an exclusive lung cancer biomarker. This technique has the potential to become a new protocol for rapid and cost-effective screening and diagnosis of lung cancer.

Value of autofluorescence bronchoscopy in patients with laryngeal cancer

BACKGROUND

Patients with squamous cell carcinoma of the head and neck constitute a high risk group for synchronous and metachronous tumours.

OBJECTIVE

This study aimed to investigate the usefulness of white light and autofluorescence bronchoscopy in the evaluation of pre-malignant and early neoplastic lesions in patients with laryngeal cancer, who are at high risk of concomitant lung cancer.

METHODS

This prospective, cross-sectional study included 30 patients who had undergone total laryngectomy for squamous cell carcinoma of the larynx. The tracheobronchial system was investigated for the presence of pre-malignant and malignant lesions, using a combination of white light and autofluorescence bronchoscopy. Biopsies were obtained from areas with a pathological appearance, and histopathological studies were performed.

RESULTS

All patients had a permanent tracheostomy. Light and autofluorescence bronchoscopy indicated that the tracheobronchial system was normal in 11 patients. A total of 27 biopsies was taken from the remaining 19 patients, and revealed invasive squamous cell carcinoma in one patient and pre-malignant changes in six.

CONCLUSION

Bronchoscopy is a valuable and practical tool for screening patients at high risk of lung cancer, and requires minimal intervention especially in patients with a permanent tracheostomy. Of the various bronchoscopic techniques becoming available, autofluorescence bronchoscopy shows promise for the detection of pre-invasive malignant changes of the tracheobronchial system in patients previously operated upon for laryngeal cancer.

The detection of chromosomal aneusomy by fluorescence in situ hybridization in sputum predicts lung cancer incidence

Lung cancer usually is disseminated (advanced) and has a poor prognosis at diagnosis. Current and former smokers are at a high risk for lung cancer and are candidates for prevention and early detection strategies. Sputum is a potential source of biomarkers that might determine either lung cancer risk or the presence of early lung cancer, but no current sputum test is sufficiently sensitive and specific for effective screening. We used fluorescence in situ hybridization (FISH) to measure chromosomal aneusomy (CA) in sputum samples collected prospectively from 100 incident lung cancer cases and 96 controls (matched on age, gender, and date of collection) nested within an ongoing high-risk cohort. The CA-FISH assay was aimed at four DNA targets: epidermal growth factor receptor, MYC, 5p15, and CEP 6. The sensitivity of a positive CA-FISH assay (abnormal for two or more of the four markers) for lung cancer was substantially higher for samples collected within 18 months (76% sensitivity) than for samples collected more than 18 months (31%) before lung cancer diagnosis. Sensitivity was higher for squamous cell cancers (94%) than for other histologic types (69%). CA-FISH specificity based on samples collected within 18 months before diagnosis was 88%. The adjusted odds ratio (OR) of lung cancer for specimens collected within 18 months before a cancer diagnosis was higher for the CA-FISH assay [OR, 29.9; 95% confidence interval (95% CI), 9.5-94.1] than for previously studied ORs of cytologic atypia (OR, 1.8; 95% CI, 1.3-2.6) and gene promoter methylation (OR, 6.5; 95% CI, 1.2-35.5). Whether CA-FISH is an indicator of extreme risk for incident lung cancer or detects exfoliated cancer cells is unknown. The apparent promise of CA-FISH in sputum for assessing lung cancer risk and/or for lung cancer early detection now needs to be validated in a clinical screening trial.

Premalignant and malignant cells in sputum from lung cancer patients

BACKGROUND

The objective of this study was to assess the frequency of premalignant and malignant cells in sputum from patients with lung cancer and to measure the dependence of these cells on cancer stage, histologic type, tumor size, and tumor location.

METHODS

This analysis included 444 patients with lung cancer. First, all patients were asked to produce sputum spontaneously; then, they underwent sputum induction. Slide preparations of the sputa were screened for the presence of abnormal cells.

RESULTS

Of all patients with lung cancer who had produced adequate specimens, 74.6% had sputum that was positive for premalignant or worse cells, whereas 48.7% had sputum that was positive for malignant cells alone. Surprisingly, the presence of premalignant or worse cells in sputum depended only moderately on disease stage (82.9% of stage IV cancers vs 65.9% of stage I cancers), tumor size (78.6% of tumors >2 cm vs 64.7% of tumors <or=2 cm), and location (83.3% of central lesions vs 68% of peripheral lesions) and was found to be independent of histologic tumor type (78.4% of squamous cell carcinomas vs 71.5% of adenocarcinomas, 74.5% of small cell carcinomas, and 75% of large cell carcinomas).

CONCLUSIONS

The findings of the current study suggested the important potential of sputum cytology for lung cancer detection and risk assessment across all stages, histologic types, tumor sizes, and locations. However, the high sensitivities in this study were achieved with a level of scrutiny not feasible in the laboratory routine. The diagnostic potential of sputum cytology may be exploited better through the standardization and automation of sputum preparation and analysis.

Proliferative changes in the bronchial epithelium of former smokers treated with retinoids

BACKGROUND

Retinoids have shown antiproliferative and chemopreventive activity. We analyzed data from a randomized, placebo-controlled chemoprevention trial to determine whether a 3-month treatment with either 9-cis-retinoic acid (RA) or 13-cis-RA and alpha-tocopherol reduced Ki-67, a proliferation biomarker, in the bronchial epithelium.

METHODS

Former smokers (n = 225) were randomly assigned to receive 3 months of daily oral 9-cis-RA (100 mg), 13-cis-RA (1 mg/kg) and alpha-tocopherol (1200 IU), or placebo. Bronchoscopic biopsy specimens obtained before and after treatment were immunohistochemically assessed for changes in the Ki-67 proliferative index (i.e., percentage of cells with Ki-67-positive nuclear staining) in the basal and parabasal layers of the bronchial epithelium. Per-subject and per-biopsy site analyses were conducted. Multicovariable analyses, including a mixed-effects model and a generalized estimating equations model, were used to investigate the treatment effect (Ki-67 labeling index and percentage of bronchial epithelial biopsy sites with a Ki-67 index > or = 5%) with adjustment for multiple covariates, such as smoking history and metaplasia. Coefficient estimates and 95% confidence intervals (CIs) were obtained from the models. All statistical tests were two-sided.

RESULTS

In per-subject analyses, Ki-67 labeling in the basal layer was not changed by any treatment; the percentage of subjects with a high Ki-67 labeling in the parabasal layer dropped statistically significantly after treatment with 13-cis-RA and alpha-tocopherol treatment (P = .04) compared with placebo, but the drop was not statistically significant after 9-cis-RA treatment (P = .17). A similar effect was observed in the parabasal layer in a per-site analysis; the percentage of sites with high Ki-67 labeling dropped statistically significantly after 9-cis-RA treatment (coefficient estimate = -0.72, 95% CI = -1.24 to -0.20; P = .007) compared with placebo, and after 13-cis-RA and alpha-tocopherol treatment (coefficient estimate = -0.66, 95% CI = -1.15 to -0.17; P = .008).

CONCLUSIONS

In per-subject analyses, treatment with 13-cis-RA and alpha-tocopherol, compared with placebo, was statistically significantly associated with reduced bronchial epithelial cell proliferation; treatment with 9-cis-RA was not. In per-site analyses, statistically significant associations were obtained with both treatments.

Lung Cancer Chemoprevention

BACKGROUND

Lung cancer is the most common cause of cancer death in the United States. Cigarette smoking is the main risk factor. Former smokers are at a substantially increased risk for lung cancer compared with lifetime never-smokers. Chemoprevention is the use of specific agents to reverse, suppress, or prevent the process of carcinogenesis. This article reviews the major agents that have been studied for chemoprevention.

METHODS

Articles of primary, secondary, and tertiary prevention trials were reviewed and summarized to obtain recommendations.

RESULTS

None of the phase III trials with the agents beta carotene, retinol, 13-cis-retinoic acid, alpha-tocopherol, N-acetylcysteine, or acetylsalicylic acid has demonstrated beneficial, reproducible results. For facilitating the evaluation of promising agents and for lessening the need for a large sample size, extensive time commitment, and expense, focus is now turning toward the assessment of surrogate end point biomarkers for lung carcinogenesis. With the understanding of important cellular signaling pathways, various inhibitors that may prevent or reverse lung carcinogenesis are being developed.

CONCLUSIONS

By integrating biological knowledge, more trials can be performed in a reasonable time frame. The future of lung cancer chemoprevention should entail the evaluation of single agents or combinations that target various pathways while working toward identification and validation of intermediate end points.

Bronchial Intraepithelial Neoplasia/Early Central Airways Lung Cancer

BACKGROUND

An evidence-based approach is necessary for the localization and management of intraepithelial and microinvasive non-small cell lung cancer in the central airways.

METHODS

Material appropriate to this topic was obtained by literature search of a computerized database. Recommendations were developed by the writing committee and then reviewed by the entire guidelines panel. The final recommendations were made by the Chair and were voted on by the entire committee.

RESULTS

White light bronchoscopy has diagnostic limitations in the detection of microinvasive lesions. Autofluorescence bronchoscopy (AFB) is a technique that has been shown to be a sensitive method for detecting these lesions. In patients with moderate dysplasia or worse on sputum cytology and normal chest radiographic findings, bronchoscopy should be performed. If moderate/severe dysplasia or carcinoma in situ (CIS) is detected in the central airways, then bronchoscopic surveillance is recommended. The use of AFB is preferred if available. In a patient being considered for curative endobronchial therapy to treat microinvasive lesions, AFB is useful. A number of endobronchial techniques as therapeutic options are available for the management of CIS and can be recommended to patients with inoperable disease. In patients with operable disease, surgery remains the mainstay of treatment, although patients may be counseled about these techniques.

CONCLUSIONS

AFB is a useful tool for the localization of microinvasive neoplasia. A number of endobronchial techniques available for the curative treatment can be considered first-line therapy in inoperable cases. For operable cases, the techniques may be considered and discussed with the patients.

Autofluorescence bronchoscopy for lung cancer surveillance based on risk assessment

BACKGROUND

This is a preliminary report of an ongoing prospective bimodality lung cancer surveillance trial for high-risk patients. Bimodality surveillance incorporates autofluorescence bronchoscopy (AFB) and spiral CT (SCT) scanning in high-risk patients as a primary lung cancer surveillance strategy, based entirely on risk factors. AFB was used for surveillance and findings were compared with conventional sputum cytology for the detection of malignancy and pre-malignant central airway lesions.

METHODS

402 patients registering at Roswell Park Cancer Institute were evaluated with spirometric testing, chest radiography, history and physical examination, of which 207 were deemed eligible for the study. For eligibility, patients were required to have at least two of the following risk factors: (1) > or =20 pack year history of tobacco use, (2) asbestos-related lung disease on the chest radiograph, (3) chronic obstructive pulmonary disease with a forced expiratory volume in 1 s (FEV(1)) <70% of predicted, and (4) prior aerodigestive cancer treated with curative intent, with no evidence of disease for >2 years. All eligible patients underwent AFB, a low-dose SCT scan of the chest without contrast, and a sputum sample was collected for cytological examination. Bronchoscopic biopsy findings were correlated with sputum cytology results, SCT-detected pulmonary nodules and surveillance-detected cancers. To date, 186 have been enrolled with 169 completing the surveillance procedures.

RESULTS

Thirteen lung cancers (7%) were detected in the 169 subjects who have completed all three surveillance studies to date. Pre-malignant changes were common and 66% of patients had squamous metaplasia or worse. Conventional sputum cytology missed 100% of the dysplasias and 68% of the metaplasias detected by AFB, and failed to detect any cases of carcinoma or carcinoma-in-situ in this patient cohort. Sputum cytology exhibited 33% sensitivity and 64% specificity for the presence of metaplasia. Seven of 13 lung cancers (58%) were stage Ia or less, including three patients with squamous cell carcinoma. Patients with peripheral pulmonary nodules identified by SCT scanning of the chest were 3.16 times more likely to exhibit pre-malignant changes on AFB (p<0.001).

CONCLUSION

Bimodality surveillance will detect central lung cancer and pre-malignancy in patients with multiple lung cancer risk factors, even when conventional sputum cytology is negative. AFB should be considered in high-risk patients, regardless of sputum cytology findings.

The future of bronchoscopy in diagnosing, staging and treatment of lung cancer

Bronchoscopy is a central technique in diagnosing lung cancer, but also in different therapeutic approaches. A lot of techniques are available. The most common indication for bronchoscopy is for tissue sampling and determining the extent of lung cancer. Established diagnostic techniques are forceps biopsy, aspiration or brush cytology sampling, or needle aspiration. Laser therapy, electrocautery, cryotherapy and stenting are well-described techniques for the palliation of symptoms due to airway involvement in patients with advanced stages. Newer technologies, with an established role in clinical practice, are endobronchial ultrasound, autofluorescence bronchoscopy, and electromagnetic navigation. Other technologies, such as magnification, narrow-band imaging and confocal fluorescence microendoscopy, are in development for the use within the airways.