The link between time to disease progression and survival after progression in patients with advanced lung cancer

This study looked at a link between time to disease progression and longer survival after progression in patients with advanced BRAF V600E non-small-cell lung cancer. The authors concluded that a longer time to disease progression after treatment was linked to longer survival in these patients. 

Some non-small-cell lung cancers (NSCLC) are caused by a mutation (change) in a gene called BRAF V600E. Patients with this mutation have a worse response to chemotherapy than other cancers. Recent research, therefore, focuses on therapy to target this mutation specifically. Dabrafenib (Tafinlar) and trametinib (Mekinist) are such targeted therapies.

Doctors are looking for factors which would predict longer survival for patients with BRAF V600E advanced NSCLC. For other advanced NSCLCs, longer time to progression (TTP; the time from the start of the treatment until disease progression) indicates a longer survival after progression (SAP; time patients are alive after disease progression following treatment start). It is possible therefore that longer TTP would suggest longer survival in patients with BRAF V600E mutations. 

This trial included 84 patients with advanced NSCLC. They received either dabrafenib alone (57 patients) or in combination with trametinib (27 patients). All patients have progressed during the study period. TTP and SAF were the main outcomes evaluated.

Patients who had disease progression after more than 6 months following treatment had significantly longer SAP (9.5 – 20.2 months) compared to those who had disease progression before 6 months following treatment (2.7 – 4.8 months).

Every 3-month increase in TTP was associated with a 32% lower risk of death following disease progression. 

The authors concluded that a longer time to progression after targeted treatment was associated with longer survival in patients with advanced NSCLC. 

This study was part of a larger trial and survival data is still being collected. The authors did not factor in the use of treatments after progression in the analysis which could alter the results. The sample size was also small.