By David Douglas
NEW YORK (Reuters Health) - 14/5/2019
Ligating effluent veins rather than arteries first during thoracoscopic lobectomy for non-small-cell lung cancer may reduce tumor-cell dissemination and hence increase survival, according to Chinese researchers.
Numerous studies "have demonstrated that surgical manipulation could promote the dissemination of tumor cells into the circulation," note Dr. Lunxu Liu of Sichuan University, in Chengdu, and colleagues in JAMA Surgery, online May 1.
The vein-first approach eliminates "repeated squeezes and turning over of the tumor bearing lobe during surgery," they note, but studies have yielded conflicting results about the influence of the vessel-ligation sequence.
To investigate further, the team randomized 86 patients to receive vein-first or artery-first ligation during surgery. Following the procedure, incremental changes in folate-receptor-positive circulating tumor cells were seen in 65.0% of the artery-first group and 31.6% of those in the vein-first group (P=0.003).
Survival outcomes were not available because of the limited follow-up period. However, in a retrospective analysis, the investigators compared outcome data on 210 propensity-matched pairs of patients who underwent the vein-first or artery-first approach and found a poorer survival with the artery-first procedure.
At five years, the hazard ratio for poorer overall survival was 1.65 (P=0.03), for disease-free survival it was 1.43 (P=0.05), and for lung-cancer-specific survival, it was 1.65 (P=0.03).
The investigators call for further prospective studies with larger sample sizes and adequate postoperative surveillance, but conclude that, "Ligating effluent veins first during surgery may reduce tumor cell dissemination and improve survival outcomes in patients with non-small cell lung cancer."
Dr. Mark K. Ferguson of the University of Chicago, author of an accompanying editorial, told Reuters Health by email that "ligating the vein from the lung as the first step reduced the number of circulating tumor cells in the blood stream. This is an oncologically sound concept that has the potential to improve survival in patients who have surgery for early-stage lung cancer."
Dr. Ferguson notes in his editorial, "The study also suggests that additional surgical techniques aimed at avoiding release of tumor cells into the circulation should be explored."
Dr. Liu did not respond to requests for comments.
JAMA Surg 2019.