Not all cancers are equally lethal: cancer in your prostate means a longer survival rate than a malignancy in your brain, for example. But even prostate cancer comes in multiple flavors ranging from manageable to very bad. By analyzing the mutated genome of a tumor, doctors can now pinpoint whether a cancer is sensitive to a certain chemotherapy, or one that doesn’t respond at all to current treatments. Knowing the subtype might mean jumping directly to a clinical trial that could save your life.
Cancer is a disease of the genome. It arises when genes involved in promoting or suppressing cell growth sustain mutations that disturb the normal stop and go signals. There are more than 100 different types of cancer, most of which derive their names and current treatment based on their tissue of origin—breast, colon, or brain, for example. But because of advances in DNA sequencing and analysis, that soon may be about to change.
A new method to take the DNA fingerprint of individual cancer cells is uncovering the true extent of cancer’s genetic diversity. A single cancer cell may help oncologists anticipate tumor growth. A genetic “fingerprint” taken from a cancerous cell can reveal the extent of the cancer’s genetic diversity — its “family tree.” By highlighting key mutations, the method could help doctors develop more effective, personalized therapies.
There is a huge potential to identify key genomic changes shared by certain subsets of tumors, regardless of where they arise in the body. Such information is vital to our efforts to develop more individualized approaches for helping people with cancer—called personalized medicine, or precision medicine. For example, if a patient’s tumor has a genomic fingerprint that indicates it is likely to spread to other areas of the body, or metastasize, doctors may suggest a more aggressive treatment strategy than they would for someone whose tumor had a different profile.
Genomic information might also help us figure out if a drug originally approved for use in one type of cancer might be useful in treating other types. For example, if a drug works for colon cancer, it might also work for a lung cancer with a similar genetic fingerprint.