Stage I and Stage II
If your prostate cancer is limited to the prostate (Stages I or II) and it is well or moderately differentiated (Gleason score 7 or below), the 5- year outcome is considered excellent for all three treatment options: watchful waiting, surgery, or radiation therapy. Even at the end of 10 years, few men with Stage I or II and a low Gleason score will have succumbed to prostate cancer.
With a median age of 72 at diagnosis, many men with prostate cancer die of a variety of other natural causes in the next 10 to 15 years. Few men with low-grade localized disease die of prostate cancer. The disease-specific survival rate-which excludes deaths from other causes-is close to 90 percent. In other words, regardless of treatment- watchful waiting, surgery, or radiation therapy-such a man can consider his cancer a chronic disease because he is much more likely to die of other causes than of prostate cancer.
Men with localized tumors who opt for watchful waiting, if they live long enough, may run a greater risk of eventually developing metastatic disease. In one series of studies, the chance of developing metastases within 10 years was 19 percent for men with well-differentiated tumors and 42 percent for men with moderately differentiated tumors.
Only one small study has directly compared watchful waiting with radical prostatectomy, and it found no significant differences in survival. More reliable answers should be forthcoming from ongoing trials. In a 15-year study known as PIVOT (Prostate Cancer Intervention versus Observation Trial), some 1,250 patients with clinically localized prostate cancer (Stage I or Stage II and low Gleason score) are being randomly assigned to either watchful waiting or radical prostatectomy. Similar trials comparing watchful waiting to surgery or to radiation therapy are under way in Europe.
Surgery or radiation therapy is chosen typically by those men whose tumors, although apparently localized, are more extensive or poorly differentiated (Gleason score of 8 to 10). Without aggressive therapy, around three-quarters of such men will have developed metastatic disease in the following 10 years, and twothirds will have died from prostate cancer. Whether or not treatment can change these outcomes is under study.
The reality is that not all seemingly localized cancers are, in fact, limited to the prostate gland. When examining excised biopsy tissue, pathologists find that as many as half show prostate cancer that has broken through the capsule, invaded the seminal vesicles, or spread into the surgical margins or lymph nodes. In other words, many cancers that are clinically Stage I or Stage II need to be reclassified as Stage III after the pathologist reports his findings. In other cases, even some cancers that are clinically staged and pathologically verified as Stage I or II apparently are still capable of spreading, since up to one-fourth of these patients will experience the recurrence of prostate cancer over the next few years. A review of Medicare records from around the country found that more than one-third of the men initially treated with radical prostatectomy needed additional cancer treatment in the next 5 years.
Stage III
If your prostate cancer is Stage III, it is a regionalized tumor that has spread beyond the prostate-through the capsule that encloses the prostate and perhaps into the seminal vesicles. However, it has not yet, as far as can be determined, reached the lymph nodes or any more distant sites in the body.
External beam radiation therapy is often used to treat Stage III cancers. Besides being less invasive than surgery, it is better suited for bulky tumors. A few men have surgery, while others rely on watchful waiting. Men whose tumors are reclassified as Stage III after surgery (because cancer is found to have spread through the capsule or into the lymph nodes) sometimes go on to have radiation therapy postoperatively. Studies are in progress to evaluate this approach.
Stage III tumors are often large enough to create difficulties with urination. These may be treated in a variety of ways, including radiation therapy, surgery, TURP, and hormonal therapy.
The long-term prospects for men with Stage III prostate cancer depend on the extent of disease. Once cancer has broken through the prostate capsule, chances that the disease will progress in the next 10 years are about 50-50. Spreading to the seminal vesicles further increases the likelihood of a recurrence. One study, following up on men who had been treated with radiation therapy 20 years earlier, found that close to half of them eventually died of prostate cancer, although nearly as many had died of some other cause with no sign of cancer recurrence.
Stage IV
If your prostate cancer has spread to the nearby lymph nodes or to distant parts of the body, it is called metastatic prostate cancer. Hormonal therapy will generally improve symptoms and delay the progress of disease for another 2 to 3 years. If just the lymph nodes are involved, a man may use hormonal therapy to delay the progress of prostate cancer even longer. However, the vast majority of those with positive lymph nodes at the time of getting hormonal therapy will remain at risk of developing additional metastatic disease within 10 years after the treatment. Bone metastases tend to be less responsive to hormonal therapy.
New Directions
Prostate cancer research is advancing on dozens of fronts. Scientists are probing the basic causes of disease, developing markers to distinguish slow-growing cancers from aggressive cancers, and testing drugs to control or reduce risk for prostate cancer. Most of the results are preliminary at present.
Genes and prostate cancer. Researchers are exploring numerous links between genes and the development of prostate cancer. They have identified several genes that may affect a prostate cancer’s ability to spread (metastasize), a gene change spurred by hormonal therapy, and a gene flaw that interferes with the body’s defenses against environmental carcinogens. The presence of multiple identical genetic segments (DNA repeats), which appear to intensify signals that order the cell to multiply, may provide a better way to predict a cancer’s aggressiveness.
Reduce risk. Since prostate cancer is less common in populations with low-fat, high-fiber, high-soy diets, scientists are also looking into the possibility of using diet to prevent prostate cancer from developing. There is still no evidence to show that switching to a healthy diet after years of eating high-fat foods will make a difference, but small studies are testing the effects of a low-fat, high-soy diet among men who have an increased risk of prostate cancer and men who have already been treated for prostate cancer. There is some evidence of a lower incidence of prostate cancer in men who eat lots of tomato-based foods, especially tomato sauce cooked with a little olive oil.
Followup Care
Depending upon your choice of treatment for prostate cancer, your doctor will make some recommendations for followup care. These recommendations may include more tests, and the results will be used to make choices that should improve your quality of life as a prostate cancer survivor. For example, you may be asked to have more PSA tests, bone scans, or palliative treatment. If you find any unusual changes in your body such as bone pain or swollen lymph nodes, you should call your doctor as soon as possible.