Posted: July 7, 2014

The treatment of advanced lung cancer has changed radically in the last year.  In an article in the May 21, 2014 issue of the Journal of the American Medical Association Mark Kris from Memorial Sloan Kettering Cancer Center in New York and Bruce Johnson, from Dana Farber at Harvard, have teamed up with others to publish the results of the most important study on lung cancer in years.  The link above will get you to the abstract.  Dr. Stark can provide the entire article; just email him using the form on the right.  Using techniques originally developed to sequence the normal human genome, but refined and automated to the point where they are rapidly and cheaply performed, they tested over 700 lung cancer specimens for the presence of ten different genes, any of which could influence the behavior of the tumor.   Two of the genes, for EGFR (the Epidermal Growth Factor Receptor) and Alk (for Anaplastic Lymphoma Kinase, a gene originally described in lymphomas) are treatable with drugs that only affect the tumor cells, not the rest of the body, at least not much (side effects are there but minimal, not like chemotherapy).   This paper showed two things primarily: that such testing is feasible and transportable to the commercial laboratory — either in-hospital or outside reference lab — and that such testing makes a difference.  They looked at patients whose tumor possessed those mutations to see how they fared.  Patients who received so-called targeted therapy — with a drug designed to disrupt the protein product of the mutation but not the rest of the body — in these cases either Erlotinib (for EGFR) or Crizotinib (for Alk) lived on average a year longer than patients whose tumors had those mutation but were treated with conventional chemotherapy.  Given that two-thirds of the patients had stage 4 cancer, where median survival had been less than a year, the survival in the targeted group, 3.5 years, is remarkable.  As new genes are identified and new drugs to target them are developed the therapy of advanced lung cancer can only get much better.  Stay tuned.

Update 2020: the so-called targeted therapy has to some extent replaced chemotherapy in the treatment of advanced lung cancer.  As more drugs are developed that target different mutations, the entire landscape of lung cancer therapy will be changed forever.  All of this has been driven by the ease with which total sequencing of the genome of the cancer cell can now be done.