Related Experiment Video
Updated: Feb 4, 2026

Measurement of Survival Time in Brachionus Rotifers: Synchronization of Maternal Conditions
Published on: July 22, 2016
Progression-Free Survival and Overall Survival Beyond 5 Years of NSCLC Patients With Synchronous Oligometastases
Dirk De Ruysscher1, Rinus Wanders2, Lizza E Hendriks3
1Department of Radiation Oncology (Maastro Clinic), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands.
Introduction:
Two randomized studies have shown an increased progression-free survival (PFS) by adding a radical local treatment to systemic therapy in responding patients with oligometastatic NSCLC, but long-term data are lacking. We updated the results of our previous phase II trial with a minimal follow-up exceeding 7 years.
Methods:
This is a prospective single-arm phase II trial. The main inclusion criteria were pathologically proven NSCLC stage IV with less than five metastases at primary diagnosis, amendable for radical local treatment (surgery or radiotherapy). No previous response to systemic treatment was needed.
Results:
Forty patients were enrolled, 39 of whom were evaluable (18 men, 21 women); mean age was 62.1 ± 9.2 years (range, 44 to 81 years). Twenty-nine (74%) had N2 or N3 disease; 17 (44%) brain, 7 (18%) bone, and 4 (10%) adrenal gland metastases. Thirty-five (87%) had a single metastatic lesion. Thirty-seven (95%) of the patients received chemotherapy as part of their primary treatment. Median overall survival (OS) was 13.5 months (95% confidence interval: 7.6-19.4 months); 1-, 2-, 3-, 5-, and 6- year OS was 56.4%, 23.3%,12.8%, 10.3%, 7.7%, and 5.1%, respectively. Median PFS was 12.1 months (95% confidence interval: 9.6-14.3 months); 1-, 2-, 3-, 5-, and 6- year OS was 51.3%, 13.6%, %,12.8%, 7.7%, 7.7%, and 2.5%, respectively. Only three patients (7.7%) had a local recurrence.
Conclusions:
In patients who were not selected according to response to systemic treatment, the PFS at 5 years was 8%. Entering patients in trials combining local therapy with novel systemic agents (e.g., immunotherapy) remains mandatory.
Related Concept Videos
Survival Curves
The Kaplan-Meier estimator is the most common method for constructing survival curves. This...
Survival Tree
Building a Survival Tree
Constructing a...
Introduction To Survival Analysis
The primary goal of survival analysis is to estimate survival time—the time...
Comparing the Survival Analysis of Two or More Groups
Truncation in Survival Analysis
Left truncation occurs when individuals who experienced the event of interest before a certain time are not included in the study. This is often due to a "delayed entry" into the study where only those who survive until a certain entry point are...
Assumptions of Survival Analysis

