The usefulness of progression-free survival in surgical treatment of lung metastases

Introduction
The history of the treatment of neoplastic metastases and its evolution over more than one hundred years has raised many doubts as to the purposefulness of such management. The main problem that made it difficult to draw certain statistically confirmed conclusions was the inability to conduct prospective studies. Over the years, based on the experience gained and the multicenter analyses carried out, it was determined which elements of the surgical treatment affect the prognosis. Some doubts are raised by the issue of the progression of secondary proliferative disease, which results in a greater number of metastasectomies.

Aim
To investigate the factors influencing progression-free survival (PFS) after surgical treatment of secondary proliferative disease with lung involvement. This parameter is directly related to the overall survival time.

Material and methods
Five hundred and seventy-seven patients treated surgically due to secondary neoplastic disease with lung involvement were included. One-, three- and five-year PFS was examined. PFS was defined as the time from the first to the next metastasectomy or death from any other cause. One-factor and multi-factor statistical analysis was used.

Results
Longer PFS was found in patients over 60 years of age, after unilateral and radical metastasectomies, with a longer time from primary tumor resection to secondary lesions (disease-free interval, DFI). The longest PFS was found for colorectal cancer, the shortest for sarcoma. The presence of nodal metastases and gender did not differentiate PFS.

Conclusions
The greatest probability of longer relapse-free survival, and thus longer overall survival, occurs in patients after radical unilateral metastasectomy. Another parameter that positively influences PFS is longer DFI. Histological type differentiates PFS.