INTRODUCTION:Irreversible destruction of alveolar septa with resultant progressive decline in lung function characterizes pulmonary emphysema. No effective medical treatment exists once substantial air-space destruction occurs. Lung volume reduction surgery (LVRS) entails pulmonary resection of the worst emphysematous areas, allowing for improved ventilation and perfusion of previously compressed lung with relatively preserved functionality. Removal of non-functional hyperexpanded emphysematous lung areas also provides for improved mechanical function of the diaphragm and accessory muscles of respiration. The National Emphysema Treatment Trial showed a high mortality rate following LVRS in so-called high-risk patients defined having an FEV1<20% predicted and either a DLCO<20% predicted or homogeneous changes on CT scan of the chest. Lung transplantation provides the only surgical palliation of dyspnea for such high-risk patients.
CASE PRESENTATION:A 35 year-old woman was diagnosed with severe emphysema. She had a 50 pack-year history of smoking, and required supplemental oxygen to accomplish activities of daily living. Pulmonary function testing revealed an FEV1 of 0.84 L/min (28% of predicted) and a DLCO 23% of predicted. Her six-minute walk test was 1,465 feet with an oxygen desaturation to 80%.She was evaluated at another institution for LVRS and deemed to be too high-risk because of her poor pulmonary function tests. She was referred to our institution for evaluation for lung transplantation. As part of her evaluation, a computed tomography (CT) scan of the chest demonstrated severe bilateral upper lobe emphysema and an 8 mm ill defined right upper lobe nodule. Repeat CT scan three months later revealed a spiculated right upper lobe pulmonary nodule that had grown to 10 mm in diameter. A fusion CT/positron emission tomography scan showed the lung nodule to have a maximum standardized uptake value was 4.9 without any suspicious extralesional uptake. Despite seemingly prohibitive lung function tests, she was taken to the operating room for staging and resection of her pulmonary malignancy on the basis of the heterogenous distribution of her emphysema. With the lesion being in the most diseased portion of her lung, it was felt that she would tolerate a resection of that lobe. She underwent a negative mediastinoscopy for staging prior to a video-assisted thoracic surgery (VATS) right upper lobectomy and mediastinal lymphadenectomy. Pathology discovered a T1/N0/M0 (Stage IA) adenocarcinoma. She was discharged from hospital one week later in good condition with no further supplemental oxygen requirements.
DISCUSSIONS:Despite the diagnosis of primary bronchogenic adenocarcinoma, this patient’s long-term survival is likely predicated on the treatment of her severe emphysema. The 5-year survival of patients with an FEV1 of 0.75 is approximately 25%; which can be improved to 67% after LVRS1. By comparison, the 5-year post-resection survival of pathologic stage IA non-small cell lung cancer ranges from 65%-85%. Among patients with predominantly upper-lobe emphysema and low exercise capacity, the risk ratio for death following LVRS as compared with medical-therapy is 0.47 (P=0.005), indicating a significant benefit of surgery. Resection of the upper lobe provided an oncologic resection with the benefit of allowing expansion and improved performance of the remaining relatively preserved middle and lower lobes. Future treatment options for this patient include continued surveillance for cancer in addition to progression to LVRS on the contralateral side.
CONCLUSION:Patients with severe emphysema may still be candidates for pulmonary resection for cancer if they have heterogenous distribution of their emphysema with the tumor located in the more diseased, so-called “target” area. Potential benefit in lung function from volume reduction in these cases is possible.
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