Bronchoscopic debulking for endobronchial malignancy: Predictors of recanalization and recurrence

Abstract

Background: Central airway obstruction related to endobronchial malignancy is one of the most difficult oncological complications and requires efficient palliative intervention.

Methods: Fifty-three consecutive patients with unresectable endobronchial malignancy receiving bronchoscopic cryotherapy as palliative treatment were retrospectively reviewed. Efficiency was evaluated by the improvement of performance status (PS), and the best achievement of tumor removal was assessed as complete or partial removal.

Result: Patients' PS after cryotherapeutic tumor removal improved from the baseline PS (P = 0.006). In multivariate logistic regression analysis, the compression part of the tumor (odds ratio [OR] 0.42; 95% confidence interval [CI] 0.23∼0.75, P = 0.004) and the thin tumor stalk (OR 87.86; 95% CI 2.31∼3337.37, P = 0.016) were independent predictors of complete tumor removal. Tumors larger than 9.3 cm, including compression and invasion parts, had the highest odds of being only partially removed (positive predictive value [PPV]: 88.2%, likelihood ratio [LR]+: 10.49); tumors smaller than 9.3 cm were likely to be completely removed (negative predictive value [NPV]: 80.6%, LR-: 0.34). After cryotherapy, re-obstruction was significantly associated with non-squamous cell carcinoma (65.7 vs. 16.7%, P = 0.001) and patients who had longer overall survival (11.7 vs. 1.5 months, P < 0.001). Odds of tumor re-obstruction increased 2.28-fold (PPV: 81.6%, LR+: 2.28) beyond two months; the odds decreased by 81% (NPV: 73.3%, LR-: 0.19) within two months.

Conclusion: Debulking of a tumor using cryotherapy is a useful palliative treatment for endobronchial obstruction secondary to a variety of malignancies.

Keywords: Bronchoscopic; cryotherapy; endobronchial; malignancy.

Figure 1

The measurement of the long-axis of the compressive part is indicated by the black double-head arrow, while the yellow arrow indicates a thin tumor stalk affixing to the trachea (a) Tracing up the segment of tracheal obstruction on transverse planes reveals the tip of the invasive part as a representative image (b, yellow arrow head), in this case three planes equivalent to 1.5 cm. (c) Direct measurement of the invasive part could be assisted by bronchoscopy from the root of the tumor stalk in this case, as shown by the blue arrow. (d) The invasive part of the tumor (blue arrowhead) was still free from recurrence on the bronchoscopy follow-up at four weeks after tumor removal.

Figure 2

Change in performance status (PS) is illustrated by the number of subjects with each PS at baseline and after cryotherapy. (a) In all patients, cryotherapy improved PS compared to baseline PS (P = 0.006). (b) Improvement in PS after cryotherapy was significant for individuals experiencing total tumor removal (P = 0.037). (c) Improvement in PS for individuals experiencing partial removal was not significant (P = 0.149). ECOG: Eastern Cooperative Oncology Group. P-value was calculated using the Wilcoxon matched-pairs signed-ranks test. (a) , N = 10; , N = 3; , N = 5; , N = 5, N = 30; (b) , N = 4; , N = 3; , N = 3; , N = 2; , N = 19; (c) , N = 6; , N = 2; , N = 3; , N = 11.

Figure 3

(a) The receiver operating characteristic curve is plotted using tumor size, in terms of the invasion part (blue), compression part (green), and summation of both (yellow) to discriminate the best achievement of tumor removal. Discriminatory power was best using a summation of both based on area under the curve (AUC) measurement. (b) The distribution of tumor size with respect to the best achievement of tumor removal as complete or partial removal. The cut-off (C) represents 9.3 cm, corresponding to the likelihood ratio [LR]+: 10.49, positive predictive value [PPV]: 88.2%. *: summation of the size of the compression and invasion parts of the endobronchial tumor. Tumor size: , invasion part; , compression part; , summation*; , reference line. CI, confidence interval.

Figure 4

The receiver operating characteristic curve is plotted using overall survival to discriminate whether tumor re-obstruction was observed. The discriminatory power was significant based on area under the curve measurement. AUC, area under the curve; CI, confidence interval.