The Diagnosis and Treatment of Bronchopulmonary Carcinoid

Abstract

Background: The spectrum of primary neuroendocrine tumors of the lungs ranges from typical carcinoid tumors, which are relatively benign, to highly aggressive small-cell carcinoma. In this review, we summarize the treatment of bronchopulmonary carcinoid, a disease with an incidence of 0.5 per 100,000 persons per year in Western countries.

Method: We selectively searched the PubMed database for scientific evidence on the treatment of bronchopulmonary carcinoid, considering only articles published up to February 2015. We also performed a survival analysis of 84 patients with this disease who underwent interdisciplinary treatment at the University of Freiburg Medical Center.

Results: Carcinoid tumors account for less than 1% of all lung tumors. They manifest themselves clinically with cough (35%), hemoptysis (25%), and/or bronchial obstruction (40%), depending on their location, size, and pattern of growth. 30% of patients are asymptomatic, and less than 1% have hormone-associated symptoms. Typical and atypical carcinoid tumors are distinguished on a histological basis; the histologic differential diagnosis also includes large-cell neuroendocrine tumors and small-cell carcinoma of the lung. 80% of patients who undergo resection of typical carcinoid tumors survive at least 10 years. Atypical carcinoid tumors recur more commonly than typical ones. If the mediastinal lymph nodes are involved, adjuvant treatment should be considered.

Conclusion: Because of their rarity, the treatment of bronchopulmonary carcinoid tumors presents an interdisciplinary challenge. Surgical resection, the treatment of choice for local carcinoid tumors, generally leads to long-term survival. The existing registers should be made more comprehensive so that the treatment of this disease can be better in the future.

Figure 1

Atypical carcinoid tumor (AC) in a 70-year-old patient with chronic cough. The computed tomogram shows a stenosing tumor (a; arrows) in the right lower lobe bronchus. Bronchoscopy showed a strongly vascularized tumor (b). After complete surgical resection, histological analysis confirmed AC without lymph node involvement (Union internationale contre le cancer [UICC] stage IB). Further therapy was not indicated.

Figure 2

Algorithm of the University Medical Center Freiburg for the purpose of interdisciplinary treatment of bronchopulmonary carcinoids PET, positron emission tomography; SRS, somatostatin receptor scintigraphy; SSR, somatostatin receptor; TACE, transarterial chemoembolization; 5-FU, 5-fluorouracil

Figure 3

Somatostatin receptor (SSTR)-PET/CT using ⁶⁸gadolinium-DOTATATE in a 72-year-old woman, who had been recurrence-free 4 years after resection of an AC (stage IA) of the left upper pulmonary lobe in a non-local hospital. Owing to a follow-up CT, a metastasis in the 12^th thoracic vertebra was suspected. Further investigations using SSTR/PET/CT showed multiple metastases in mediastinal lymph nodes, the thoracic wall, the liver, and the skeletal system. Palliative peptide receptor radionuclide therapy (PRRT) using ¹⁷⁷Lutetium-DOTATATE was initiated. The patient was in partial remission after three therapeutic cycles.

Figure 4

Total survival at 5 years after surgical resection. Survival rates of patients whose carcinoid tumors were curatively resected at the University Medical Center Freiburg. From 2003 to 2013, 84 patients were operated on, using the described resection methods. 5-year survival in patients with TC was 91% and in patients with AC, 90%. The median observation period was 43 months; survival data were available for all patients.