Prostate Cancer
With the exception of skin cancer, prostate cancer is the most common cancer in men. It is the second most common cancer killer in men. It is estimated that 40,000 men will die from prostate cancer this year, and this figure was rising until recently. Death rates seem to be falling due to early detection and treatment. Currently, prostate cancer is the cause of death in 3% of men ages 55 to 74, and 4.4% of men age 75 and over. Hopefully, the mortality rate will decrease as more and more men are having the disease detected at an earlier stage when it can be cured.
Management of prostate cancer is very controversial in medicine. Most of the scientific studies on this problem are very poorly done and a great amount to bias exists. An additional “problem” is that the tumors are so slow growing. Fifty percent of patients with prostate cancer live ten years, but over sixty percent of patients living beyond ten years eventually die from cancer. IF a patient is diagnosed before age 74, he has a greater than 50% chance of dying from prostate cancer if left untreated. Conversely, in the United States, where most patients receive treatment, only 25-33% of patients die from the cancer.
Early treatment in our country has vastly decreased the mortality rate as compared to the Swedish population. That is why it is vitally important for men to undergo the necessary screening exams. The group at risk included all men over age 50, African-American men over age 40, and all men with a family history of prostate cancer over age 40. Testing involves a blood test called a PSA (prostate specific antigen) and a digital rectal exam of the prostate; both of which must be repeated annually. PSA is produced by normal prostate tissue, but can signify cancer if present in excessive amounts. There are other disease states, which can raise the PSA; not everyone with an elevated PSA has cancer.
There is a great amount of controversy in medicine about the choice of therapy for patients with prostate cancer. The options include observation, hormone therapy, cryosurgery, external beam radiation, Brachytherapy (radioactive seed implantation), and surgery which can be performed through an abdominal incision (retropubic) or perineal incision (incision between the scrotum and anus). A wise saying in medicine is that when there are multiple treatments for a problem, there are no good treatments. I don’t think this is true for prostate cancer. While it is true that no one treatment is ideal for everyone with prostate cancer, most patients are able to make and informed decision and select an efficacious therapy with which the feel comfortable.
There are three major factors that determine treatment. The first is the age of a patient. In our country, the average 70-year-old male has about 13 years to live and the average 75-year-old has 10 years to live. As previously stated, the typical patient may live 10 years if left untreated, so observation may be an alternative for older patients who have multiple medical problems. Again, from the Swedish studies, it appears that men under age 74 will have better than 50% chance of dying from prostate cancer if left untreated. Even at age 80, there may be up to a 45% mortality rate in untreated patients.
The second factor to be considered is the stage of the cancer. Stage refers to the size and extent of the tumor. In general, the entire discussion in this manuscript is for localized cancer that has not spread beyond the prostate. Stage A (or T1) is cancer that is found during a procedure to unobstruct a patient who was believed to have only benign growth of the prostate tissue. Usually patients who are found to have cancer because of an elevated PSA in their blood are also placed in this category. State B tumors (or T2) are palpable, but are believed to be confined to the prostate itself. These tumors are subdivided into B-1, B-2, B-3, based on size and extent. Patients with B-1 tumors are best treated by surgery. Patients with B2 and B3 lesions are usually treated with surgery or radiation. However, these larger tumors do not have as good a prognosis regardless of management. It should also be kept in mind that staging the extent of the tumor is only completely done for those patients who have undergone surgery, and many state B-2 and B-3 lesions are upgraded following surgery. In fact, only 34% to 40% of these patients will have organ-confined disease after surgery. For radiation patients, the actual extent of the disease is only a “guesstimate” base on physical exam. The relatively poor cure rate for these larger lesions is a reason that some patients choose cyrosurgery, which does not have long-term data to evaluate.
Stage C (or T-3) tumors have grown outside of the prostate. These tumors are aggressive and rarely curable by standard therapies, so patients may choose from a wide variety of treatments.
Stage D tumors have distant spread in the body, rather than just local growth as in the stage C population. These tumors are usually treated with hormonal management to slow their growth, but cure is rare (occasionally, hormonal reduction of growth will be permanent, but usually the cancer eventually progresses)
The third factor to be considered is the grade of the tumor. Grade refers to the appearance of the individual glands in the malignant tissue under a microscope. Prostate cancer is graded from 1 to 5. The cancer is usually heterogeneous (that is multiple types from the same specimen) and the two most common types are added to give the Gleason’s sum, which can go from 2 to 10. Patients with lower grades (2-4) will likely do well whereas higher grades (8-10) are unlikely to be curable despite aggressive measures.
Treatment options for Localized Cancer (Stage A and B)
Observation
Observation implies doing nothing. In selected patients with advanced age and/or other significant medial problems, no treatment may be the best treatment. Because the tumor grows slowly and the treatments may have unacceptable side effects, some patient may elect to do nothing other than be seen occasionally to make sure they are not developing any complications from cancer growth. Untreated, the cancer may spread to the bones causing pain (or paralysis if the spinal cord is involved), may cause obstructing urinary symptoms, can block the ureters causing renal failure or even grow into the rectum causing bowel obstruction. Patients undergoing observation are monitored and treatment is instituted if progression is detected, based also on symptoms. Keep in mind that while prostate cancer is slow growing, your cancer will never again be as small as it is right now.
Hormonal Therapy
Testosterone is produced by the testicles causes the cancer to grow more rapidly. Removing the testicles stops testosterone production, and it causes the cancer to shrink. This can be accomplished with medications that can be injected every one, three, or four months or even annually. It must be stressed that this treatment is not curative because the cancers will usually eventually grow again. In addition to slowing the growth of advanced cancers, hormonal therapy is sometimes used for larger prostate tumors to shrink them for surgery, radiation or cryosurgery. In men initially treated with observation only, hormonal therapy is begun should these individual develop complications. Hormonal therapy side effects can include hot flashes, impotence, and decreased libido, but can also include mood changes and osteoporosis. Rarely the medication can cause a skin rash.
External Beam Radiation
External beam radiation is delivered by sending radiation through a patient into the prostate. This is accomplished on a daily basis for six weeks. Usually the radiation itself is painless. The most common complications are transient diarrhea and irritative symptoms in the bladder. Sometimes the symptoms can become severe and disabling. Impotence and incontinence and even fistula formation (a fistula is a connection between tow epithelial tissues in the body and here implies the bladder opening into the rectum) are possible. Impotence seems to increase over time and eventually affects 50% of irradiated patients. Patients treated with radiation do not seem to do as well as those treated with surgery. The only study that directly compared the two showed a divergence at seven years, but this study does have some flaws in it. However in multiple trials and review studies it does not appear that radiation has as favorable of in impact. It must be kept in mind that many patients re selected for radiation because they are not good candidates for surgery and this fact may have an impact as well.
Over 50% of patients treated with radiation will continue to have cancer when biopsies are repeated. Radiation also causes mutations within the tissue making the use of PSA less reliable in following patients. PSA is a very reliable marker for surgically treated patients. Another disadvantage of radiation is that surgery cannot be performed should the patient have a relapse, whereas some patients who have surgery may also have radiation.
Brachytherapy
Brachytherapy involves placing radioactive seeds into the prostate. This procedure involves the use of ultrasound to monitor placement of seeds, which allows for a uniform treatment. Results are promising but long-term results are not yet available. We have extensive experience with this procedure. Patients tolerate it well. I am most concerned that the initial results are biased because they include a large proportion of patients with minimal amounts of disease. These patients would likely do well regardless of treatment. Up till now, patients treated with Brachytherapy are doing well when properly selected even up to 10 years out from therapy. Side effects and the other problems as outlined for external beam radiation apply to this technique as well.
Cryosurgery
Cryosurgery involves freezing the prostate through small tubes, which are placed through the skin beneath the scrotum. Liquid nitrogen, or argon, is coursed through the tubes thereby destroying the cancer. There is essentially no pain ant the patient is discharged after one day. The technique can be repeated if necessary. This procedure was first used in the 70’s and showed a ten-year survival rates that were comparable to surgery. However, initially the procedure had to be abandoned because of unacceptable complications arising from the destruction of tissue other that the prostate. Recent technological advances have drastically reduced the complication rate. Preliminary results are promising, but many doctors characterize the procedure as experimental since there are no long-term results with the newest modification of the technique. Cryosurgery is probably the best treatment for patients who have failed radiation, as this group will not do well with surgery.
Surgery
Surgery is generally regarded as the standard of care for healthy patients with localized disease. It is the only treatment in which the extent of the disease is ultimately known with certainty, which helps to predict outcome and allow for additional treatment. In doing surgery, one can also evaluate the lymph nodes where the cancer is most likely to spread. If the tumor has spread to the lymph nodes, an open surgical procedure would be abandoned, sparing the patient from additional morbidity, unlike irradiated patients (lymph nodes would also be evaluated as part of a cryosurgical procedure). A retropubic surgery, the most common surgical procedure, is performed through an abdominal incision. Blood loss is a complication, (although I have not seen a transfusion in over 5 years) and more pain is involved than with the other treatments. In addition, there is also a 2 to 4 day hospital stay. Potency is often preserved in patients 60 or younger providing the patient is not already having erectile problems. I have seen patients as old as 75 maintain potency following the operation.
A perineal prostatectomy is performed through an incision behind the scrotum. There is less pain and blood loss through this operation as opposed to the retropubic incision. Lymph nodes are not evaluated and potency is less likely. This operation is ideal for the older patient with a moderate Gleason sum and PSA (when these are not high, lymphatic spread is not likely).
Summary
Prostate cancer is a common killer but many treatments are available when the disease is detected early. Choice of treatment depends on a given patient’s age, histological tumor grade (Gleason sum), and extent of disease (stage A, B, or C). Our goal is to educated the patient as much as possible and help him make the best possible choice.
