Fig. 2
From: Assessing lung cancer progression and survival with infrared spectroscopy of blood serum
Survival analysis based on single covariate using Kaplan-Meier estimation. a Survival functions for all study patients, and survival functions separately by gender status (female - blue line; male - red line; combined - black line). b Survival functions for patients with operable (blue line) and non-operable (red line) lung cancer tumors. c Stratified survival functions by TNM staging (stage I - blue; stage II - violet; stage II - black; stage IV - red line). d Stratified survival functions concerning lung cancer tumor histology (squamous cell carcinoma - blue line; adenocarcinoma - red line)