D. Ross Camidge, MD, PhD, from the University of Colorado Cancer Center, discusses the selective administration of targeted therapies in the adjuvant setting for patients with non-small cell lung cancer.
D. Ross Camidge, MD, PhD, director of the Thoracic Oncology Clinical Program at the University of Colorado Cancer Center, discusses the selective administration of targeted therapies in the adjuvant setting for patients with non-small cell lung cancer (NSCLC).
In the phase II SELECT study, 36 patients with stage I-III EGFR mutation-positive NSCLC received adjuvant treatment with the EGFR TKI erlotinib, following completion of standard adjuvant treatments. After 2 years, treatment with erlotinib was discontinued. The initial disease-free survival (DFS) rate was 94%, which seems impressive, Camidge states; however, after 3 years DFS dropped to around 60% and at 4 years it was 40%.
Overall, these findings suggest that adjuvant use of EGFR-targeted treatments is not killing cancer cells in the same fashion as chemotherapy. As in advanced NSCLC, these agents seem to control the disease but, due to toxicity and costs, lifetime treatment with these agents is not an option.
Since sensitive cells survive, merely targeting cells that illicit growth is not sufficient, Camidge suggests. As a result, researchers must pinpoint the genes that allow cancer cells to enter a "siege" state that allows them to survive these treatments. Once found, it is likely that synthetic lethal approaches will be required to maximize the cancer kill rate. However, until these new agents are found, Camidge does not believe targeted therapies should be used in the adjuvant space to treat NSCLC.