Tracking down the gene that causes an inherited cancer
has implications for all cancers, inherited or not. A healthy allele of
the same gene, if it undergoes mutations triggered by the environment
during a person's lifetime, may lead to noninherited cancers. Thus, by
identifying a cancer gene, scientists are able to explore mechanisms
relevant to all people with cancer.
Genes and gene markers may also provide tools for improving cancer
diagnosis and treatment. By spotting a mutated gene (or its protein
product) in cells shed into stool, urine, or saliva, or in tissue
biopsies, doctors may be able to detect cancers years earlier than with
conventional diagnostic techniques. (It has even been suggested that some
day probes for a mutated gene could be injected, then traced on an x-ray.)
Evaluating cancer-preventing drugs, too, should prove more efficient
once the drugs can be tested in populations that are highly likely to
develop the cancer. Or, if a gene is found to produce some antitumor
protein, it might be possible to synthesize that protein and use it as a
drug. Ultimately, it may become possible to thwart disease with
gene therapy - inactivating the flawed gene or replacing it.