[Classification and regression tree analysis of 154 patients with cancer of unknown primary].
OBJECTIVE
To explore the prognostic factors and their impact on survival of patients with cancer of unknown primary (CUP).


METHODS
The clinical and follow up data of 154 CUP patients referred to the Cancer Hospital & Institute, Chinese Academy of Medical Sciences from January 1, 2003 to December 31, 2007 were analyzed. Multivariate analysis of survival was performed using recursive partitioning referred to as classification and regression tree (CART) analysis.


RESULTS
The median survival for 154 eligible consecutive CUP patients was 18.2 months, and the 5-year survival rate was 1.3%. CART was performed with an initial split on age of 34, and 5 terminal subgroups were formed. The median survival of the 5 subsets ranged from 5.5 months (younger than 34 years old subgroup) to 61.8 months for patients at age of 34 to 60, with one or two organ sites involved, and non-adenocarcinoma histology subsets.


CONCLUSIONS
CART can be used to identify previously unappreciated patient subsets and is a useful method for dissecting complex clinical situations and identifying homogeneous patient populations in clinical practice and future clinical trials.
Clinical Oncology Department, Cancer Hospital & Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China. pingziwang@yahoo.com
Zi-ping
ZP
Wang
Yu-tao
YT
Liu
Juan
J
Yang
D000230:Adenocarcinoma / Q000473:pathology / Q000556:secondary*; D000328:Adult; D000368:Aged; D001859:Bone Neoplasms / Q000556:secondary*; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000556:secondary; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000556:secondary; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009382:Neoplasms, Unknown Primary / Q000145:classification* / Q000473:pathology; D012044:Regression Analysis; D015996:Survival Rate