Scientists have begun researching and developing gene-specific treatments to treat and cure advanced prostate cancer. Until recently, prostate cancers that were discovered in advanced stages were most often treated with radical prostatectomy—surgery to remove all of the prostate gland and some of the surrounding tissue. Radiation and chemotherapy were sometimes used in conjunction with the surgery and sometimes as the first-line of treatment. Hormone therapy, which halts the production of testosterone, is also frequently used in patients who opt for radiation and chemotherapy. (Testosterone feeds the tumor and speeds up its growth and development.)
But compared to some other treatments, like those for breast cancer, the treatments for prostate cancer left a lot to be desired. Gene therapy has been used for some time, and with great success, in treating other types of cancer. Now, prostate cancer treatment is catching up.
A Tumor’s Genetic Signature
Tumors have their own genes, their own map of how they function, their own DNA. These genetic maps determine if a cancer is going to be aggressive, how susceptible it will be to treatment, and if the tumor is likely to return. Researchers call these biomarkers “DNA methylation profiles,” and the more they understand about each man’s profiles, the better they can treat him.
Using these DNA profiles, doctors can create treatments designed to treat each man’s specific tumor genetic map. If a man’s cancer profile shows it will be very aggressive, doctors can return with an equally aggressive treatment plan. If the profiles suggest that the cancer will be very slow growing, doctors may suggest the patient do nothing and wait to see how the cancer progresses.
On the diagnosing and early detection side of things, DNA profiles may also help physicians diagnose prostate cancer early. DNA profiles may be able to determine whether a man will get prostate cancer, how bad it will be, and when it makes sense to start treatment.
The Role of Androgen
In males, testosterone (a type of androgen hormone) aids growth and development, fuels the sex drive, and promotes mental health. But testosterone can also be bad for the body—specifically when it helps cancer cells grow and divide.
Tumors can be sensitive to hormones in the body. These hormones may stimulate tumor cell growth. Most prostate cancer tumors are sensitive to testosterone, just as many breast and uterine cancers are sensitive to the hormone estrogen.
Doctors have known for some time that slowing or blocking testosterone production can help slow prostate cancer growth. However, in recent years, research shows that slowing testosterone production may not be enough. Some tumors continue developing despite low levels of testosterone and hormone therapy. Some tumors simply outsmart the treatment. They’re able to grow new receptors; become more sensitive so any existing testosterone is more powerful; and in some cases, the tumors begin producing their own testosterone.
Gene-specific therapies are exploring ways to combat the morphing tumor. These new avenues of research are looking at studying how tumors grow and adapt to the lower-hormone levels. When the mechanisms behind these changes are understood, doctors may be able to prevent these tumors from outsmarting the treatment.
A Vaccine That Alters Genes
In 2010, the U.S. Food and Drug Administration (FDA) approved Provenge, the first-ever cancer treatment vaccine. The vaccine is customized to each patient, using his own genes, and it’s designed for use in men with advanced-stage prostate cancer.
The vaccine was successful in several trials, and it was shown to prolong a patient’s life. However, it added an average of only four months—which left many doctors unsure if the treatment was worth the cost. The vaccine costs $93,000, and that’s not including costs from physicians, hospitals, and labs. Many private insurance companies cover the expense, as does Medicare. While the vaccine has not been shown to actually shrink the tumor, the FDA chose to approve it because of the survival benefit.