ASCO issues Provisional Clinical Opinion on EGFR testing in Non-Small-Cell Lung Cancer
Posted Apr 29 2011 12:50pm
Hot off the electronic press is the PCO issued by ASCO recommending that patients with advanced stage NSCLC should have their tumors tested for EGFR mutation if they are being considered candidates for EGFR-TKI therapy. Read here for the abstract or Download ASCO EGFR testing in NSCLC for more deets.
Provisional Clinical Opinion On the basis of the results of ﬁve phase III randomized controlled trials, patients with NSCLC who are being considered for ﬁrst-line therapy with an EGFR TKI (patients who have not previously received chemotherapy or an EGFR TKI) should have their tumor tested for EGFR mutations to determine whether an EGFR TKI or chemotherapy is the appropriate ﬁrst-line therapy.
If you haven't been following this topic, the paper nicely summarizes the clinical trials forming the basis for this recommendation.
Of especial interest to pathologists is the issue of adequate tissue for testing in patients with advanced stage disease:
the ad hoc panel commented that there is often a limited amount of tissue for mutation testing and, therefore, endorses a relevant recommendation in ASCO’s stage IV NSCLC guideline update: “In order to obtain tissue formore accurate histologic classiﬁcation or for investigational purposes, theUpdate Committee supports reasonable efforts to obtain more tissue than what is contained in a routine cytology specimen.” Properly ﬁxed material from cytology cell block preparations is generally required for analysis, as opposed to cytology smear preparations.
Finally, note that this PCO only addresses mutation analysis for activating mutations. Giving recent literature showing concommitant EGFR T790M resistance mutation in 30%-35% of patients at the time of diagnosis, I think we should take this into consideration when looking at testing pathways. This PCO specifically does not recommend EGFR testing by FISH or IHC at this time. By the way, testing issues are discussed in the companion journal, Journal of Oncology Practice. I'll hunt down the link and post later.