Surgery for pulmonary oligometastasis: the good, the bad and the ugly

Abstract

Metastasis usually represents a late-stage of malignant disease and is the most common reason for cancer-related deaths. In 1995, Hellman and Weichselbaum [1] first postulated that single or limited number of metastasis, called oligometastasis, might represent an intermediate state between localized and systemically disseminated diseases. Different from polymetastatic disease, patients with oligometastasis are considered to have relatively less tumour burden and thus could benefit from local consolidative therapies including surgery [2]. In a previous multicentre phase II randomized study, both progression-free survival and overall survival were found to be improved in patients with oligometastatic non-small-cell lung cancer who received local consolidative therapy compared to those under maintenance therapy or clinical observation only [3]. In the meantime, pulmonary metastasis accounts for almost 30% of disseminations from extrapulmonary primary malignancies [4]. Pulmonary metastasectomy (PM) has been associated with prolonged survival in selected patients with colorectal cancer, osteosarcoma, breast cancer, renal cancer, melanoma, germ cell tumours, etc. [5, 6]. In this issue of the European Journal of Cardio-thoracic Surgery, Schlachtenberger et al. [7] studied the treatment results in patients with isolated pulmonary metastasis from head and neck cancers (HNC). All patients in this cohort had no greater than 5 metastatic lesions according to the current definition of oligometastasis [8]. It is not surprising that patients who received PM turned out to have significantly better survival than those patients having non-surgical therapies.