Article and Video CATEGORIES

Cancer Journey

Search By

EGFR Inhibitors: Personalization by "Snips"
dg

Please Note: New Treatments Have Emerged Since this Original Post
Author
Dr. Garfield

What we are striving for in cancer care today is personalized medicine. So, if a patient with newly diagnosed NSCLC has an activating epidermal growth factor receptor (EGFR) mutation, we give that patient Tarceva (erlotinib), a tyrosine kinase inhibitor (TKI). Right? Well, yes -- but it doesn’t always work (the response rate is in the 70-75% range). Why not? We’re not sure, but it would be nice to learn why we don't see near a 100% response rate among patients with EGFR mutations, so that we can know to recommend other alternatives. On the other hand, if a patient does not have the mutation, we don’t really expect much in the way of a dramatic response. Again, only partly right. In fact, some studies show a significant minority of patients with normal (“wild type”) EGFR will have at least some response to Iressa (gefitinib) or Tarceva. So, what’s going on here? A recent study out of China looked at blood rather than tumor in 84 patients with advanced NSCLC who were all treated with Iressa. The analysis looked at naturally occurring single-nucleotide polymorphisms (SNPs, and pronounced “snips”), in the EGFR gene. A polymorphism, which basically means “many forms”, can be thought of as small part of a gene which has a different part (nucleotide) from the general population, but is otherwise normal, as best we can tell. A minority of individuals will have the different nucleotide (polymorphism) while the general population will have the same gene but with a different nucleotide. In these patients, it was found that having a particular SNP could predict for a better response to Iressa and longer survival than the rest of the group, while different SNP could predict for a poorer response and shorter survival with the drug. Still another SNP could predict for a greater risk of developing a rash, which we know is also associated with a benefit from these TKIs. This has also been seen with Tarceva.

This study did, however, have some drawbacks, admitted by the authors. The study involved only Han Chinese, was retrospective, small (only 84 patients), did not list the subtypes of the tumors, and did not look for EGFR mutations in the tumors. However, the study was somewhat enriched because 57% were female, 82% were non-smokers, and 80% had adenocarcinomas; taken together, these characteristics in a group would be expected to get some benefit from Iressa. In fact, only 40% of patients had progressive disease while on the drug. We look forward to other such studies, hopefully in larger populations, and which would be prospective. But this is an interesting start, and you may hear more about SNPs in the future. In the meantime, this work begins to provide a hint about why some patients do better or worse than others, even with the same EGFR mutation status.

Next Previous link

Previous PostNext Post

Related Content

Article
Advance directives are a powerful way to take control of healthcare choices. These documents allow you to outline preferences for medical care and specify end-of-life wishes. These documents can also be a way to appoint loved ones who you would like to help with these decisions, such as a healthcare proxy (someone to make decisions on your behalf, if you cannot). As cancer treatments can involve aggressive treatments and/or complex medical management, having advance directives ensures that your desires regarding treatment options and end-of-life care are clearly communicated. 
Image
2024-25 patient perspectives header
Article
Tell your story and help us help others! Apply online now for this paid opportunity. This program gives a voice to those who have experience in participating in a clinical trial for a cancer diagnosis. Your voice helps to educate and advocate for others who are in or who may be considering a clinical trial.  We want to hear from you!
Image
Foro de Pacientes de Terapias Dirigidas de Cáncer de Pulmón
Video
¡El vídeo completo bajo demanda está disponible para verlo!

Forum Discussions

Hello Linda, my name is Alexandra Beneke, I'm the Outreach Manager for GRACE. Your willingness to share your experiences and knowledge with the cancer community is truly inspiring. Your dedication to...

Hi Bluebird,  Welcome to GRACE.  I'm sorry you're going through this scare and hope it's just inflammation or from an infection you didn't know you had. 

 

A CT would be...

Radiation + Brain Operation has just been discarded due to high risk. They will double Tagrisso dosis and then wait to see if it works, then try traditional Chemo. I would...

Hi and welcome to GRACE.  I'm sorry to know you are entering a new stage.  I'm not about to comment just now but wanted to let you know I see your...

Edit to say, we can't give advice but we can comment with views and facts.  :)

 

My first thought is to ask if she has been seen at a large...

Hi Barbro, Welcome to GRACE. I'm sorry you're worrying about this. We aren't able to give feedback on scan reports. Interpreting scan reports in this setting is not only unethical but...

Recent Comments

JOIN THE CONVERSATION
Tagrix FDA Approval
By mariachristian on
Hi Judy! It is so good to…
By JanineT GRACE … on
Tagrix vs Tagrisso
By Dipakchavan on
Hello Linda, my name is…
By AlexandraGBeneke on