You may recall that Steve Jobs, the founder of Apple Computer, died October 2011 of pancreatic cancer, but you may not know how he and his doctors battled his cancer using futuristic genetic techniques. Now, this year, genetic research has advanced to the point that these techniques are starting to become available to people who aren’t CEOs of major corporations.
What is being hailed as a landmark research paper was published in the journal Nature on September 23, and brought together 348 researchers who presented findings on the genetic coding of breast cancer. However, the genetic procedures have implications for eventual treatment of all types of cancer.
To see what cancer therapy will probably look like in the relatively near future, let’s look at Mr. Jobs’ case. He had a rare—and difficult to cure—pancreatic cancer that actually may have been cured (since it was small when found), but for about nine months, Mr. Jobs avoided his doctors’ advice regarding treatment. Rather, he pursued a course of “alternative treatments: fruit juices, acupuncture, herbal remedies….some of which he found on the Internet”.
Not surprisingly, the alternative treatments did not work. His tumor grew, and after nine months he agreed to the recommended surgery. Later when the tumor had spread to his liver, he underwent a liver transplant.
What made his case remarkable was that during his several years of chemotherapy that accompanied the surgeries, his doctors chose the chemotherapy drugs based on an elaborate and expensive ($100,000) genetic analysis or sequencing of the structure of his normal cells, as well as of his tumor cells. At the time, only 20 people in the world had undergone this type of cancer genetic examination.
His doctors compared the genes of his normal cells with those in the cancer cells, and found the cancer cell mutations that fueled the growth of the cancer. Cancers are believed to grow when there is a defect (mutation) in one or more genes within the cancer. Normally, the function of some of our genetic material is to inhibit the growth of potential cancer cells.
Based on the mutations they found, his doctors could match the best chemotherapy drug known to attack that specific genetic defect. One reason some cancers are so difficult to cure is that their abnormal genes mutate again and again over time. In a sense the tumor is trying to escape being killed by the chemotherapy drugs. So Mr. Jobs had the sequencing analysis done multiple times, and each time the doctors adjusted his chemotherapy agents to select the best one(s) for the mutations found.
In Steve Jobs’ case, ultimately the cancer won, and he died from metastatic pancreatic cancer. That does not mean genetic cancer sequencing is not effective. He probably lived much longer than he would have without the genetic studies, and pancreatic cancer is one of the worst types of cancers, so his outcome was no surprise to his doctors.
Back to the recent Nature breast cancer study. The researchers studied 825 women with cancer in the same manner as in Steve Jobs’ case. They found that breast cancers can be categorized into one of four genetic types based on the tumor mutations found. So sometime within the next decade, doctors can select the best drug(s) that will best attack the woman’s specific tumor type.
Traditional cancer chemotherapy is more of a “shotgun” approach, using standard drugs based on what the tumor looks like under the microscope. But in the future doctors will be able to use a more “silver bullet” approach to selecting the best drug(s): the most effective with the least side effects.
It will take several more years of research before these “silver bullet” techniques are commonly used. However one finding from the study will likely be applicable sooner—one of the most difficult to treat breast cancers (the “triple negative”) actually is genetically more like ovarian cancer than breast cancer, so perhaps ovarian cancer drugs will work better than traditional breast cancer drugs for this tumor.
Tumor sequencing is a fascinating and hopeful research course. Here in Mais Saúde we will present more information as it comes out.
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