Value of autofluorescence bronchoscopy in patients with laryngeal cancer

Second primary lung cancer following laryngeal cancer: retrospective study of incidence and multivariate analysis of risk factors in 209 patients

OBJECTIVE

To analyse the incidence of second primary lung cancer following treatment for laryngeal cancer and to identify risk factors for its development.

METHOD

Retrospective case series.

RESULTS

The five-year actuarial incidence of second primary lung cancer was 8 per cent (1.6 per cent per year). This was associated with a very poor median survival of seven months following diagnosis. Supraglottic tumours were associated with an increased risk of second primary lung cancer compared to glottic tumours in both univariate (hazard ratio = 4.32, p = 0.005) and multivariate analyses (hazard ratio = 4.14, p = 0.03).

CONCLUSION

Second primary lung cancer occurs at a rate of 1.6 per cent per year following a diagnosis of laryngeal cancer, and this is associated in a statistically significant manner with supraglottic primary tumour. The recent National Lung Cancer Screening Trial suggests a survival advantage of 20 per cent at five years with annual screening using low-dose computed tomography scanning of the chest in a comparable cohort to ours. These findings have the potential to inform post-treatment surveillance protocols in the future.

Photodynamic diagnosis of visceral pleural invasion of lung cancer with a combination of 5-aminolevulinic acid and autofluorescence observation systems

BACKGROUND

Visceral pleural invasion (PL) is a prognostic factor in lung cancer. In the lung, lymph flows along the pleura, in addition to the flow toward the pulmonary hilum just as the pulmonary arteries and veins run toward it. Even with the same tumor diameter, a PL1 or higher level of pleural invasion is indicative of a more advanced disease stage. Final diagnosis based on the PL level is made by pathological examination of excised specimens. However, if an intraoperative diagnosis can be established, proper selection of the surgical procedure can be made, and unnecessary surgeries for disseminated lesions can be avoided. We investigated optical diagnostic techniques for identifying the presence or absence of visceral pleural invasion in lung cancer by capitalizing on the phenomenon of 5-amino-levulinic acid (5-ALA) being metabolized to a photosensitizing substance or protoporphyrin IX within malignant tumors, generating red luminescence in response to excitation light.

METHOD

This study included 38 patients with primary lung cancer who underwent surgery. They received 5-ALA (20mg/kg) orally 4h before surgery and then we assessed the presence or absence of pleural invasion using an autofluorescence observation system. At visceral pleural invasion sites, we were able to confirm tumor sites visualized in red with a clear border in contrast to the green autofluorescence generated in normal tissues.

RESULT

Red luminescence could be confirmed in 100% of PL1-PL3 patients (14/14) and 41.6% of PL0 patients (10/24) with primary lung cancer. PL0 patients in whom visualization was possible were preoperatively diagnosed as having PL1 and many of them showed vascular channel invasion. The sensitivity, specificity, positive predictive value, and negative predictive value of this diagnostic technique were 100%, 58.0%, 63.1%, and 100%, respectively. Red fluorescence emission was observed significantly more often in pleural invasion cases.

CONCLUSION

Accurate intraoperative diagnosis for visceral pleural invasion in lung cancer may contribute to determining the indications for limited operations such as segmental resection. In addition, accurate local diagnosis has the possibility of being applicable to photodynamic therapy.

White light, autofluorescence and narrow-band imaging bronchoscopy for diagnosing airway pre-cancerous and early cancer lesions: a systematic review and meta-analysis

BACKGROUND

We aimed to summarize the diagnostic accuracy of white light bronchoscopy (WLB) and advanced techniques for airway pre-cancerous lesions and early cancer, such as autofluorescence bronchoscopy (AFB), AFB combined with WLB (AFB + WLB) and narrow-band imaging (NBI) bronchoscopy.

METHODS

We searched for eligible studies in seven electronic databases from their date of inception to Mar 20, 2015. In eligible studies, detected lesions should be confirmed by histopathology. We extracted and calculated the 2×2 data based on the pathological criteria of lung tumor, including high-grade lesions from moderate dysplasia (MOD) to invasive carcinoma (INV). Random-effect model was used to pool sensitivity, specificity, diagnostic odds ratio (DOR) and the area under the receiver-operating characteristic curve (AUC).

RESULTS

In 53 eligible studies (39 WLB, 39 AFB, 17 AFB + WLB, 6 NBI), diagnostic performance for high-grade lesions was analyzed based on twelve studies (10 WLB, 7 AFB, 7 AFB + WLB, 1 NBI), involving with totally 2,880 patients and 8,830 biopsy specimens. The sensitivity, specificity, DOR and AUC of WLB were 51% (95% CI, 34-68%), 86% (95% CI, 73-84%), 6 (95% CI, 3-13) and 77% (95% CI, 73-81%). Those of AFB and AFB + WLB were 93% (95% CI, 77-98%) and 86% (95% CI, 75-97%), 52% (95% CI, 37-67%) and 71% (95% CI, 56-87%), 15 (95% CI, 4-57) and 16 (95% CI, 6-41), and 76% (95% CI, 72-79%) and 82% (95% CI, 78-85%), respectively. NBI presented 100% sensitivity and 43% specificity.

CONCLUSIONS

With higher sensitivity, advanced bronchoscopy could be valuable to avoid missed diagnosis. Combining strategy of AFB and WLB may contribute preferable diagnosis rather than their alone use for high-grade lesions. Studies of NBI warrants further investigation for precancerous lesions.

Photodynamic diagnosis of pleural malignant lesions with a combination of 5-aminolevulinic acid and intrinsic fluorescence observation systems

BACKGROUND

We have developed a new diagnostic method using the photosensitizer 5-aminolevulinic acid (5ALA) for diagnosing intrathoracic malignant lesions. When ingested exogenously, 5ALA is metabolized to a heme precursor, protoporphyrin IX, which stays in malignant cells and emits red to pink luminescence of about 630 nm.

METHODS

We enrolled 40 patients who underwent respiratory surgery and consented to participate in this study. Twenty-eight patients had primary lung cancer, 8 metastatic lung tumors, 2 malignant pleural tumors, and 2 benign tumors. Localization of malignant lesions was attempted by observing such lesions with an autofluorescence imaging system and by comparing the color tone of the autofluorescence between malignant lesions and normal tissues after oral administration of 5ALA. Malignant lesions on the pleural surface emitted pink autofluorescence in contrast to the green autofluorescence of the surrounding normal tissues.

RESULTS

When 28 patients with primary lung cancer were examined according to the degree of pleural infiltration (pl), red fluorescence was confirmed in 10 of 10 patients (100%) with p11-p13 and 5 of 18 patients (27.7%) with p10. The latter 5 patients had been diagnosed with PL1 preoperatively or intraoperatively.

CONCLUSION

This system achieved accurate localization of malignant lesions, suggesting that it may also be applicable to photodynamic therapy.

Photodynamic diagnoses of malignant pleural diseases using the autofluorescence imaging system

BACKGROUND

We conducted a study on photodynamic diagnosis (PDD) using autofluorescence in video-assisted thoracic surgery for minute intrathoracic small dissemination or early malignant pleural mesothelioma.

METHODS

Autofluorescence is the spontaneous emission of light that occurs when mitochondria, lysosomes, and other intracellular organelles absorb light. In normal tissues, green autofluorescence of approximately 520 nm is observed in response to 400-450 nm blue excitation rays. However, in cancer lesions, green autofluorescence is reduced due to thickening of the mucosal epithelium, a decrease in autofluorescent substances, etc., and the color spectrum thus shifts to red-violet. This phenomenon is the basis of PDD.

RESULTS

The color spectrum shift was observed in all tumors located on the pleural surface but not in cases with pleural fibrous disease. Among patients with primary lung cancer, those with pleural infiltration (pl) scores of 1 or greater showed color spectrum shifts due to reduced autofluorescence.

CONCLUSION

Localization of pleural lesions by autofluorescence imaging was found to be useful. In primary lung cancer cases, differentiation between pl0 and pl1 lesions appears to be useful for determining therapeutic strategies including surgical procedures.