Surgical resection of lung metastases is routine procedure for selected patients with pulmonary nodules and solid tumors. In some cases, patients present with unilateral pulmonary metastases amenable to surgical resection. Surgeons are still divided between unilateral approach directed to the radiologically detected nodules, or bilateral exploratory thoracotomy. This study evaluates the need for bilateral thoracotomy in patients diagnosed with unilateral lung metastases. A retrospective evaluation was made of a prospective database from a single institution (1990-1997) of all consecutive patients (n = 267) diagnosed on admission with unilateral (n = 179) or bilateral (n= 88) lung nodules. Ipsilateral thoracotomy was performed on all patients with unilateral disease. Bilateral thoracotomy was performed on all patients with bilateral lung metastases.
Histology: adenocarcinoma (25%), osteosarcoma (23%), squamous cell carcinoma (18%), soft-tissue sarcoma (18%), and other (16%). Median follow-up was 17 months. Contralateral disease-free survival and overall survival were determined. Univariate and multivariate analyses were performed to determine prognostic factors for overall and contralateral disease-free survival. The two groups of patients with confirmed bilateral metastases (synchronous or metachronous) were compared. Actuarial overall 5-year survival was 34.9%. Contralateral recurrence-free 6-month, 12-month, and 5-year survival were 95%, 89%, and 78%, respectively. Patients who experienced recurrence in the contralateral lung within 3, 6, or 12 months had an overall 5-year survival rate of 24%, 30%, and 37%, respectively. When patients with recurrence in the contralateral lung were compared to patients with bilateral metastases on admission, there was no significant difference in overall survival. Only histology and the number of pathologically proven metastases significantly (p < 0.05) predicted recurrence in the contralateral lung. Bilateral exploration of unilateral lung metastases is not warranted in all cases. Most patients will have only unilateral disease, and delaying contralateral thoracotomy until disease is detected radiologically does not appear to affect outcome.