Cure model survival analysis after hepatic resection for colorectal liver metastases.
BACKGROUND
Statistical cure is achieved when a patient population has the same mortality as cancer-free individuals; however, data regarding the probability of cure after hepatectomy of colorectal liver metastases (CLM) have never been provided. We aimed to assess the probability of being statistically cured from CLM by hepatic resection.


METHODS
Data from 1,012 consecutive patients undergoing curative resection for CLM (2001-2012) were used to fit a nonmixture cure model to compare mortality after surgery to that expected for the general population matched by sex and age.


RESULTS
The 5- and 10-year disease-free survival was 18.9 and 15.8 %; the corresponding overall survival was 44.3 and 32.7 %. In the entire study population, the probability of being cured from CLM was 20 % (95 % confidence interval 16.5-23.5). After the first year, the mortality excess of resected patients, in comparison to the general population, starts to decline until it approaches zero 6 years after surgery. After 6.48 years, patients alive without tumor recurrence can be considered cured with 99 % certainty. Multivariate analysis showed that cure probabilities range from 40.9 % in patients with node-negative primary tumors and metachronous presentation of a single lesion <3 cm, to 1.5 % in patients with node positivity, and synchronous presentation of multiple, large CLMs. A model for the calculation of a cure fraction for each possible clinical scenario is provided.


CONCLUSIONS
Using a cure model, the present results indicate that statistical cure of CLM is possible after hepatectomy; providing this information can help clinicians give more precise answer to patients' questions.
Department of Medical and Surgical Sciences, S. Orsola-Malpighi Hospital, Alma Mater Studiorum - University of Bologna, Bologna, Italy.
Alessando
A
Cucchetti
Alessandro
A
Ferrero
Matteo
M
Cescon
Matteo
M
Donadon
Nadia
N
Russolillo
Giorgio
G
Ercolani
Giacomo
G
Stacchini
Federico
F
Mazzotti
Guido
G
Torzilli
Antonio Daniele
AD
Pinna
D000368:Aged; D015179:Colorectal Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006498:Hepatectomy / Q000401:mortality*; D006801:Humans; D008113:Liver Neoplasms / Q000401:mortality* / Q000556:secondary / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D015996:Survival Rate