TY - JOUR
T1 - Prognostic factors as a function of disease-free interval after definitive (Chemo)radiation for non-small cell lung cancer using conditional survival analysis
AU - Hong, Jidong
AU - Liao, Zhongxing
AU - Zhuang, Yan
AU - Levy, Lawrence B.
AU - Sheu, Tommy
AU - Heymach, John V.
AU - Nguyen, Quynh Nhu
AU - Xu, Ting
AU - Komaki, Ritsuko
AU - Gomez, Daniel R.
N1 - Publisher Copyright:
© 2015 Wolters Kluwer Health, Inc. All rights reserved.
PY - 2015/11/3
Y1 - 2015/11/3
N2 - Purpose: We analyzed overall and disease-free survival (OS and DFS) after definitive (chemo)radiation for stage III non-small cell lung cancer with 2 statistical methods: Kaplan-Meier (KM) analysis, with diagnosis as index date, and conditional survival (CS) analysis, with a variety of disease-free index dates, and determined whether prognostic factors varied based on the reference date. Materials and Methods: All 651 patients analyzed received definitive (chemo)radiotherapy for stage III non-small cell lung cancer in November 1998 to December 2010 at a single institution; all had Karnofsky performance status scores Z60 and received Z60Gy. OS and DFS were first calculated with the KM method, and then CS was used to calculate 2 outcomes: OS conditioned on DFS time (OS|DFS) and DFS conditioned on DFS time (DFS|DFS). Factors predicting OS and DFS conditioned on 1-, 2-, and 3-year DFS were sought in univariate and multivariate analyses. Results: KM analysis produced 1-, 2-, and 3-year DFS rates of 48%, 30%, and 26%; OS rates were 64%, 41%, and 29%. By CS analysis, both OS|DFS and DFS|DFS showed an increase in 5-year OS after 6 months, and CS after 30 months approached 100%. On multivariate analyses, age and concurrent chemoradiation predicted OS|DFS; age, smoking history, tumor histology, disease stage, and radiation dose predicted DFS|DFS. Conclusions: CS analysis showed that the probability of long-Term survival increases sharply after 6 months with no evidence of disease; factors predicting survival differed based on the method and endpoint used.
AB - Purpose: We analyzed overall and disease-free survival (OS and DFS) after definitive (chemo)radiation for stage III non-small cell lung cancer with 2 statistical methods: Kaplan-Meier (KM) analysis, with diagnosis as index date, and conditional survival (CS) analysis, with a variety of disease-free index dates, and determined whether prognostic factors varied based on the reference date. Materials and Methods: All 651 patients analyzed received definitive (chemo)radiotherapy for stage III non-small cell lung cancer in November 1998 to December 2010 at a single institution; all had Karnofsky performance status scores Z60 and received Z60Gy. OS and DFS were first calculated with the KM method, and then CS was used to calculate 2 outcomes: OS conditioned on DFS time (OS|DFS) and DFS conditioned on DFS time (DFS|DFS). Factors predicting OS and DFS conditioned on 1-, 2-, and 3-year DFS were sought in univariate and multivariate analyses. Results: KM analysis produced 1-, 2-, and 3-year DFS rates of 48%, 30%, and 26%; OS rates were 64%, 41%, and 29%. By CS analysis, both OS|DFS and DFS|DFS showed an increase in 5-year OS after 6 months, and CS after 30 months approached 100%. On multivariate analyses, age and concurrent chemoradiation predicted OS|DFS; age, smoking history, tumor histology, disease stage, and radiation dose predicted DFS|DFS. Conclusions: CS analysis showed that the probability of long-Term survival increases sharply after 6 months with no evidence of disease; factors predicting survival differed based on the method and endpoint used.
KW - Conditional Survival
KW - Kaplan-Meier Analysis
KW - Non-Small Cell Lung Cancer
KW - Survival
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U2 - 10.1097/COC.0000000000000235
DO - 10.1097/COC.0000000000000235
M3 - Article
C2 - 26535988
AN - SCOPUS:84946429516
SN - 0277-3732
VL - 41
SP - 46
EP - 52
JO - American Journal of Clinical Oncology: Cancer Clinical Trials
JF - American Journal of Clinical Oncology: Cancer Clinical Trials
IS - 1
ER -