For those who might be interested but who don't happen to see all of the new posts listed on the home page, here's a post I just did featuring a short video that describes some new information on the association between rash and clinical outcome for NSCLC patients on Tarceva (erlotinib).
http://cancergrace.org/lung/2012/11/25/topical-rash-and-egfr-outcome/
In combination with the significant amount of consistent results from other trials, and with findings suggestive that patients who don't develop a rash on Tarceva may actually be harmed rather than helped by this agent, I'm beginning to revisit my long-held view that rash is too iffy of a prognostic or predictive variable to be used for clinical decisions right now.
I'm very interested in your thoughts, either on this thread or as a comment after the post itself.
-Dr. West
Reply # - November 27, 2012, 03:12 AM
Reply To: Rash and Clinical Outcome on EGFR inhibitors
Dear Dr. West, thank you for keeping us up to date. Is it possible for rash to develop as a side effect of taking Tarceva in non-EGFR mutant patients? If yes, does this rule apply too?
NJ
Reply # - November 27, 2012, 06:19 AM
Reply To: Rash and Clinical Outcome on EGFR inhibitors
Yes, 93% of the people in this trial who had EGFR mutation testing done didn't have an EGFR mutation, so this association of rash with better outcome is absolutely in patients who have EGFR wild type (no mutation). In fact, if there is one group in which I definitely wouldn't be inclined to discontinue an EGFR tyrosine kinase inhibitor in the absence of a rash, it's someone with an EGFR mutation, since they in particular have such a high probability of a response. So EGFR mutation patients are probably the very group in which I'd be least interested in following their rash or absence of a rash as a key clinical factor.
-Dr. West