Thoracoscopic surgery versus open surgery for lung metastases of colorectal cancer: a multi-institutional retrospective analysis using propensity score adjustment†.
OBJECTIVE
Thoracoscopic surgery for lung metastasectomy remains controversial. The study aimed at determining the efficacy of thoracoscopic surgery for lung metastasectomy.


METHODS
This was a multi-institutional, retrospective study that included 1047 patients who underwent lung metastasectomy for colorectal cancer between 1999 and 2014. Prognostic factors of overall survival were compared between the thoracoscopic and open thoracotomy groups using the multivariate Cox proportional hazard model. The propensity score, calculated using the preoperative covariates, included the era of lung surgery as a covariate. A stepwise backward elimination method, with a probability level of 0.15, was used to select the most powerful sets of outcome predictors. The difference between the radiological tumour number and the resected tumour number (delta_num) was also evaluated.


RESULTS
The c -statistics and the P -value of the Hosmer-Lemeshow Chi-square of the propensity score model were 0.7149 and 0.1579, respectively. After adjusting for the propensity score, the thoracoscopy group had a better survival rate than the open group (stratified log-rank test: P  = 0.0353). After adjusting for the propensity score, the most powerful predictive model for overall survival was that which combined thoracoscopy [hazard ratio (HR): 0.468, 95% CI: 0.262-0.838, P  = 0.011] and anatomical resection (HR: 1.49, 95% CI: 1.134-1.953, P  = 0.004). Before adjusting for the propensity score, the delta_num was significantly greater in the open group than in the thoracoscopy group (thoracoscopy: 0.06, open: 0.33, P  = 0.001); however, after adjustment, there was no difference in the delta_num (thoracoscopy: 0.04, open: 0.19, P  = 0.114).


CONCLUSIONS
Thoracoscopic metastasectomy showed better overall survival than the open approach in this analysis. The thoracoscopic approach may be an acceptable option for resection of pulmonary metastases in terms of tumour identification and survival outcome in the current era.
Department of Thoracic Surgery, The University of Tokyo Graduate School of Medicine, Tokyo, Japan.
Tomohiro
T
Murakawa
Department of Health Policy and Technology Assessment, National Institute of Public Health, Saitama, Japan.
Hajime
H
Sato
Department of Thoracic Surgical Oncology, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
Sakae
S
Okumura
Department of Thoracic Surgery, The University of Tokyo Graduate School of Medicine, Tokyo, Japan.
Jun
J
Nakajima
Department of Thoracic Surgery, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan.
Hirotoshi
H
Horio
Department of Thoracic Surgery, National Defense Medical College, Saitama, Japan.
Yuichi
Y
Ozeki
Department of General Thoracic Surgery, Keio University School of Medicine, Tokyo, Japan.
Hisao
H
Asamura
First Department of Surgery, Tokyo Medical University, Tokyo, Japan.
Norihiko
N
Ikeda
Division of Chest Surgery, Department of Surgery, Toho University School of Medicine, Tokyo, Japan.
Hajime
H
Otsuka
Division of Thoracic Surgery, Tochigi Cancer Center, Tochigi, Japan.
Haruhisa
H
Matsuguma
Department of General Thoracic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan.
Ichiro
I
Yoshino
Department of General Thoracic Surgery, Dokkyo Medical University, Tochigi, Japan.
Masayuki
M
Chida
Department of General Thoracic Surgery, Saitama Medical Center, Saitama, Japan.
Mitsuo
M
Nakayama
Department of Thoracic Surgery, Chiba Caner Center, Chiba.
Toshihiko
T
Iizasa
Department of General Thoracic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
Meinoshin
M
Okumura
Department of Thoracic Surgery, Yamagata Prefectural Central Hospital, Yamagata, Japan.
Satoshi
S
Shiono
Department of General Thoracic Surgery, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.
Ryoichi
R
Kato
Department of Thoracic Surgery, Kimitsu Central Hospital, Chiba, Japan.
Tomohiko
T
Iida
Department of Surgery, Teikyo University School of Medicine, Tokyo, Japan.
Noriyuki
N
Matsutani
Department of Surgery, Teikyo University School of Medicine, Tokyo, Japan.
Masafumi
M
Kawamura
Department of Thoracic Surgery, Aichi Cancer Center Hospital, Aichi, Japan.
Yukinori
Y
Sakao
First Department of Surgery, Hamamatsu University School of Medicine, Shizuoka, Japan.
Kazuhito
K
Funai
Department of Thoracic Surgery, Nagaoka Chuo General Hospital, Niigata, Japan.
Go
G
Furuyashiki
Department of Thoracic Surgery, Saitama Cancer Center, Saitama, Japan.
Hirohiko
H
Akiyama
Respiratory Department, Tomei Atsugi Hospital, Kanagawa, Japan.
Shigeki
S
Sugiyama
Department of General Thoracic Surgery, Nihonkai General Hospital, Yamagata, Japan.
Naoki
N
Kanauchi
Section of Chest Surgery, Fukujuji Hospital, Tokyo, Japan.
Yuji
Y
Shiraishi
D000368:Aged; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000601:surgery; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000453:epidemiology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011013:Pneumonectomy / Q000009:adverse effects / Q000401:mortality / Q000706:statistics & numerical data; D057216:Propensity Score; D012189:Retrospective Studies; D013906:Thoracoscopy / Q000009:adverse effects / Q000401:mortality / Q000706:statistics & numerical data
Lung metastasectomy (colorectal cancer); Outcomes; Propensity matching; Statistics; Thoracoscopy/VATS; Thoracotomy