In a recent OncLive article, Andrew D. Smith highlighted a scientific talk from Gregory J. Riely, MD, PhD, vice chair of the Clinical Trials Office in the Department of Medicine at Memorial Sloan Kettering Cancer Center, during the 9th Annual New York Lung Cancer Symposium, which focused on tyrosine kinase inhibitor (TKI) regimen for EGFR-mutant or ALK-positive lung cancer patients who no longer respond to treatment.
The best course of action, according to Dr. Riely, is often to maintain the same TKI treatment, since progression by some measures is not synonymous that the therapy is not working still.
Dr. Riely went on to explain when to leave treatment protocols unchanged and what measures to take when treatment alterations are necessary. “If there’s asymptomatic progression at multiple sites, I generally do nothing. If we let things go, we can keep people alive and well for a year or more after disease reaches the RECIST definition for progression”, he explained.
The reason why this strategy works is due to the fact that lung cancer progresses in a very slow fashion. To support this explanation, a research study on lung cancer patients who received TKI erlotinib (Tarceva) found that median progression-free survival (PFS) defined by the patients’ physicians was 3 months longer than that defined by RECIST (Response Evaluation Criteria In Solid Tumors).
Before changing protocols or abandoning treatments, Dr. Riely first evaluates each individual patient to look for the first signs of progression, such as tumor growth or number of lesions, prescribing local therapy when some form of lesions exists.
The most fitting form of local therapy will vary depending on the patient, but can include adrenalectomy, radiation therapy, lobectomy, or radiofrequency ablation.
Clinical studies have demonstrated that several different types of local therapies can provide excellent benefits for patients diagnosed with EGFR-mutant lung cancer that has acquired resistance to erlotinib, with a median time to progression after local treatment of 10 months compared to a median overall survival after local therapy of 41 months.
“If you ignore the rest of the body by dropping erlotinib, you risk disease flare. The local treatment is, by definition, localized to individual lesions that have become resistant. You have to continue to treat the rest of the body,” Dr. Riely advised.