Pathologists Corner – Dr. Kosko Molecular Testing in Non-Small Cell Lung Cancer

Posted: February 02. 2015

Lung cancer is the number one cause of cancer related deaths for both men and women in the United States.  It is the second most commonly diagnosed cancer in both sexes in the United States.  The incidence of lung cancer is declining in both men and women however; the incidence in women is declining at a slower rate than in males.

The majority of patients diagnosed with lung cancer present with advanced disease and treatment is increasingly being based on results of small biopsies or cytology specimens rather than larger resection specimens.  Drugs which act as EGFR tyrosine kinase inhibitors and ALK inhibitors have shown significant clinical responses in a subset of patients whose tumors have activating mutations in either EGFR or ALK genes making identification of patients who would benefit from treatment with these medications a priority.  Current clinical approaches to treating lung cancer now rely on both identification of the histologic type of tumor and the molecular findings to select the optimal treatment for the individual patient.  It is no longer sufficient to stop at a diagnosis of Non-Small Cell Lung Cancer (NSCLC), NOS if adequate tumor tissue is present to take the diagnosis further with the understanding that there will always be some cases in which a diagnosis of NSCLC, NOS is necessary owing to specimen/sample size or quality.  In these instances, re-biopsy may be needed to perform molecular testing if a larger resection will not be available. Read more