Lung cancer study points to new and improved therapies
Squamous cell carcinoma of the lung is a common type of lung cancer; it is responsible for approximately 400,000 deaths per year worldwide. Researchers affiliated with the Eli and Edythe L. Broad Institute of Massachusetts Institute of Technology and Harvard University Cambridge, Massachusetts are engaged in studying genetic abnormalities.
The current study is part of the Cancer Genome Atlas, which is a large project by the National Institutes of Health. They published their results online on September 9 in the journal Nature. The researchers note that their results are promising because they could lead to a new type of treatment in which drugs are tailored to match the genetic abnormality in each patient.
The study authors note that genomic alterations in squamous cell lung cancers have not been comprehensively characterized, and no molecularly targeted agents have been specifically developed for its treatment. Therefore, more than 300 researchers conducted what they describe as the first large and comprehensive study of lung squamous cell carcinoma. They found that more than half these tumors have mutations that might be treated by new drugs that are already in the pipeline or that could be easily developed.
The researchers profiled 178 lung squamous cell carcinomas to provide a comprehensive landscape of genomic and epigenomic alterations. (While genomic information is uniform in the different cells of complex organisms, the epigenome controls the differential expression of genes in specific cells.) The researchers found that this type of lung cancer is characterized by complex genomic alterations, with a mean of 360 exonic mutations (mutations in a DNA sequence.), 165 genomic rearrangements, and 323 segments of copy number alteration per tumor. They found statistically recurrent mutations in 11 genes, including mutation of TP53 in nearly all specimens.
In addition to identifying the mutations, the researchers identified a potential therapeutic target in most tumors; thus, they have provided new avenues of investigation for the treatment of squamous cell lung cancers. In looking at lung cancer from a genetic perspective, they found that no one mutation in this study of squamous cell lung cancer dominated: different patients had different mutations. Therefore, the usual way of testing drugs by giving them to everyone with a particular type of cancer no longer makes sense. In view of their findings, the investigators are planning a new type of testing program for squamous cell cancer that will match the major genetic abnormality in each patient with a drug designed to attack it. They note that their findings are likely to lead to a new focus for cancer research.
According to the Centers for Disease Control and Prevention (CDC), more people in the United States die from lung cancer than any other type of cancer. This is true for both men and women. That is more people than are killed in the nation by breast cancer, colon cancer or prostate Squamous cell lung cancer is responsible for approximately 50,000 Americans each year. More than 90% of squamous cell cancer patients are or were smokers.