Introduction to Prostate Cancer
Prostate cancer is the most common type of cancer in men in the United States (other than skin cancer). The National Cancer Institute (NCI) has written this booklet to help patients with prostate cancer and their families and friends better understand this disease. We hope others will read it as well to learn more about prostate cancer.
The prostate is a male sex gland. It produces a thick fluid that forms part of the semen. The prostate is about the size of a walnut. It is located below the bladder and in front of the rectum. The prostate surrounds the upper part of the urethra, the tube that empties urine from the bladder.
The prostate needs male hormones to function. The main male hormone is testosterone, which is made mainly by the testicles. Some male hormones are produced in small amounts by the adrenal glands.
What Is Cancer?
Cancer is a group of many different diseases that have some important things in common. They all affect cells, the body's basic unit of life. To understand cancer, it is helpful to know about normal cells and what happens when cells become cancerous. The body is made up of many types of cells. Normally, cells grow and divide to produce more cells only when the body needs them. This orderly process helps keep the body healthy. If the cells keep dividing when new cells are not needed, they form too much tissue. Excess tissue can form a mass, called a tumor. Excess tissue can be benign or malignant.
- Benign tissue is not cancer. The cells do not invade nearby tissue or spread to other parts of the body.
- Malignant tissue is cancer. The cancer cells divide out of control. They can invade and destroy nearby healthy tissue. Also, cancer cells can break away from the tumor they form and enter the bloodstream and lymphatic system, This is how cancer spreads from the original (primary) tumor to form new tumors in other parts of the body. The spread of cancer is called metastasis.
Benign prostatic hyperplasia (BPH) is the abnormal growth of benign prostate cells. In BPH, the prostate grows larger and pushes against the urethra and bladder, blocking the normal flow of urine. More than half of the men in the United States between the ages of 60 and 70 and as many as 90 percent between the ages of 70 and 90 have symptoms of BPH. Although this condition is seldom a threat to life, it may require treatment to relieve symptoms.
Most cancers are named for the type of cell or organ in which they begin. Cancer that begins in the prostate is called primary prostate cancer (or prostatic cancer). Prostate cancer may remain in the prostate gland, or it may spread to nearby lymph nodes. Prostate cancer may also spread to the bones, bladder, rectum, and other organs.
When cancer spreads to other parts of the body, the new tumor has the same malignant cells and the same name as the primary tumor. For example, if prostate cancer spreads to the bones, the cancer cells in the new tumor are prostate cancer cells. The disease is metastatic prostate cancer; it is not bone cancer.
Early prostate cancer often does not cause symptoms. When symptoms of prostate cancer do occur, they may include some of the following problems:
- A need to urinate frequently, especially at night;
- Difficulty starting urination or holding back urine;
- Inability to urinate;
- Weak or interrupted flow of urine;
- Painful or burning urination;
- Painful ejaculation;
- Blood in urine or semen; and/or
- Frequent pain or stiffness in the lower back, hips, or upper thighs.
Any of these symptoms may be caused by cancer or by other, less serious health problems, such as BPH or an infection. Only a doctor can tell the cause. A man who has symptoms like these should see his family doctor or a urologist (a doctor who specializes in treating diseases of the genitourinary system). Do not wait to feel pain; early prostate cancer does not cause pain.
If symptoms occur, the doctor asks about the patient's medical history, performs a physical exam, and may order laboratory tests. The exams and tests may include the following:
- Digital rectal exam--the doctor inserts a gloved, lubricated finger into the rectum and feels the prostate through the rectal wall to check for hard or lumpy areas.
- Blood tests--a lab measures the levels of prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP) in the blood. The level of PSA in the blood may rise in men who have prostate cancer, BPH, or an infection in the prostate. The level of PAP rises above normal in many prostate cancer patients, especially if the cancer has spread beyond the prostate. The doctor cannot diagnose prostate cancer with these tests alone because elevated PSA or PAP levels may also indicate other, noncancerous problems. However, the doctor will take the results of these tests into account in deciding whether to check the patient further for signs of cancer.
- Urine test--a lab checks the urine for blood or infection.
The doctor may order other tests to learn more about the cause of the symptoms and to help determine whether conditions of the prostate are benign or malignant, such as:
- Transrectal ultrasonography--sound waves that cannot be heard by humans (ultrasound) are sent out by a probe inserted into the rectum. The waves bounce off the prostate, and a computer uses the echoes to create a picture called a sonogram.
- Intravenous pyelogram--a series of x-rays of the organs of the urinary tract.
- Cystoscopy --a procedure in which a doctor looks into the urethra and bladder through a thin, lighted tube.
If test results suggest that cancer may be present, the patient will need to have a biopsy. A biopsy is the only sure way to know whether a problem is cancer. During a biopsy, the doctor removes a small amount of prostate tissue, usually with a needle. A pathologist looks at the tissue under a microscope to check for cancer cells. If cancer is present, the pathologist usually reports the grade of the tumor. The grade tells how closely the tumor resembles normal prostate tissue and suggests how fast the tumor is likely to grow. One way of grading prostate cancer, called the Gleason system, uses scores of 2 to 10. Another system uses G1 through G4. Tumors with lower scores are less likely to grow or spread than tumors with higher scores.
A man who needs a biopsy may want to ask the doctor some of the following questions:
- How long will the procedure take? Will I be awake? Will it hurt?
- How soon will I know the results?
- If I do have cancer, who will talk to me about treatment? When?
If the physical exam and test results do not suggest cancer, the doctor may recommend medicine to reduce the symptoms caused by an enlarged prostate. Surgery is another way to relieve these symptoms. The surgery used in such cases is transurethral resection of the prostate (TURP or TUR). In TURP, an instrument is inserted through the penis to remove prostate tissue that is pressing against the upper part of the urethra.
If cancer is found in the prostate, the doctor needs to know the stage, or extent, of the disease. Staging is a careful attempt to find out whether the cancer has spread and, if so, what parts of the body are affected. The doctor may use various blood and imaging tests to learn the stage of the disease. Treatment decisions depend on these findings.
The results of staging tests help the doctor decide which stage best describes a patient's disease:
- Stage I (A)--The cancer cannot be detected by rectal exam and causes no symptoms. The cancer is usually found during surgery to relieve problems with urination. State I tumors may be in more than one area of the prostate, but there is no evidence of spread outside the prostate.
- Stage II (B)--The tumor is felt in a rectal exam or detected by a blood test, but there is no evidence that the cancer has spread outside the prostate.
- Stage III (C)--The cancer has spread outside the prostate to nearby tissues.
- Stage IV (D)--Cancer cells have spread to lymph nodes or to other parts of the body.
Treating Prostate Cancer
Getting a Second Opinion
Decisions about prostate cancer treatment are complex. It may be helpful to have the opinion of more than one doctor. Before starting treatment, men may want to have a second doctor review their diagnosis and treatment options. A short delay will not reduce the chance that treatment will be successful. Some health insurance companies require a second opinion; many others will cover a second opinion if the patient requests it. There are a number of ways to find a doctor who can give a second opinion:
- The doctor may be able to recommend a specialist. Doctors who specialize in treating prostate cancer are urologists, radiation oncologists, and medical oncologists.
- The Cancer Information Service, at 1-800-4-CANCER, can tell callers about treatment facilities, including cancer centers and other programs supported by the National Cancer Institute.
- People can get the names of doctors from their local medical society, a nearby hospital, or a medical school.
- The Directory of Medical Specialists lists doctors by state and specialty and gives information about their background. This resource is in most public libraries.
Preparing for Treatment
The doctor develops a treatment plan to fit each patient's needs. Treatment for prostate cancer depends on the stage of the disease and the grade of the tumor (how fast the cells are likely to grow or spread to other organs). Other important factors in planning treatment are the man's age and general health and his feelings about the treatments and their possible side effects.
Many people with cancer want to learn all they can about their disease, their treatment choices, and possible side effects of treatment, so they can take an active part in decisions about their medical care. There are a number of available treatments for men with prostate cancer (surgery, radiation therapy, and hormone therapy). Not all men require treatment. The patient and his doctor may want to consider both the benefits and possible side effects of each option, especially the effects on sexual activity and urination, and other concerns about quality of life. Patients may find helpful information in Methods of Treatment, Side Effects of Treatment, and Support for Cancer Patients. Also, the patient may want to talk with his doctor about taking part in a research study to help determine the best approach or to study new kinds of treatment. To find more information about such studies, see the Clinical Trials section.
When a person is diagnosed with cancer, shock and stress are natural reactions. These feelings may make it difficult for patients to think of everything they want to ask the doctor. Often it helps to make a list of questions. Also, to help remember what the doctor says, patients may take notes or ask the doctor whether they may use a tape recorder. Some patients also may want to have a family member or friend with them when they talk to the doctor--to take part in the discussion, to take notes, or just to listen.
Questions may arise throughout the treatment process. From time to time, patients may wish to ask members of their health care team to explain things further. These are some questions a patient may want to ask the doctor before treatment begins:
- What is the stage of the disease?
- What is the grade of the disease?
- Do I need to be treated? What are the treatment choices? What do you recommend for me?
- What are the expected benefits of each kind of treatment?
- What are the risks and possible side effects of each treatment?
- Is treatment likely to affect my sex life?
- Am I likely to have urinary problems?
- Are new treatments being studied in clinical trials? Would a trial be appropriate for me?
Methods of Treatment
Many men whose prostate cancer is slow growing and found at an early stage may not need treatment. Also, treatment may not be advised for older men or men with other serious medical problems. For these men, the possible side effects and the risks of treatment may outweigh the possible benefits of treatment; instead, the doctor may suggest "watchful waiting"--following the patient closely and treating the patient later for symptoms that may arise. Researchers are studying men with early stage prostate cancer to determine when and in whom treatment may be necessary and effective.
Treatment for prostate cancer may involve surgery, radiation therapy, or hormone therapy. Sometimes, patients receive a combination of these treatments. In addition, doctors are studying other methods of treatment to find out whether they are effective against this disease.
Surgery is a common treatment for the early stages of prostate cancer. Surgery to remove the entire prostate is called radical prostatectomy. It is done in one of two ways. In retropubic prostatectomy, the prostate and nearby lymph nodes are removed through an incision in the abdomen. In perineal prostatectomy, the prostate is removed through an incision between the scrotum and the anus. Nearby lymph nodes are sometimes removed through a separate incision in the abdomen. If the pathologist finds cancer cells in the lymph nodes, it may mean that the disease has spread to other parts of the body.
These are some questions a patient may want to ask the doctor before having surgery:
- What kind of operation will it be?
- How will I feel after the operation?
- If I have pain, how will you help?
- Will I have any lasting side effects?
Radiation therapy is another way to treat prostate cancer. In radiation therapy (also called radiotherapy), high-energy rays are used to damage cancer cells and stop them from growing and dividing. Like surgery, radiation therapy is local therapy; it can affect cancer cells only in the treated area. In early stage prostate cancer, radiation can be used instead of surgery, or it may be used after surgery to destroy any cancer cells that may remain in the area. In advanced stages, it may be given to relieve pain or other problems. Radiation may be directed at the body by a machine (external radiation), or it may come from a small container of radioactive material placed directly into or near the tumor (internal radiation). Some patients receive both kinds of radiation therapy.
For external radiation therapy for prostate cancer, the patient is treated in an outpatient department of a hospital or clinic. Treatment generally is given 5 days a week for about 6 weeks. This schedule helps protect healthy tissues by spreading out the total dose of radiation. The rays are aimed at the pelvic area. At the end of treatment, an extra "boost" of radiation is often directed at a smaller area, where the tumor developed.
For internal (or implant) radiation therapy, a brief stay in the hospital may be needed when the radioactive material is implanted. The implant may be temporary or permanent. When a temporary implant is removed, there is no radioactivity in the body. The amount of radiation in a permanent implant is not generally dangerous to other people, but patients may be advised to avoid prolonged close contact with others for a period of time.
These are some questions a patient may want to ask the doctor before having radiation therapy:
- What is the goal of this treatment?
- How will the radiation be given?
- When will the treatment begin? When will it end?
- How will I feel during therapy?
- What can I do to take care of myself during therapy?
- How will we know if the radiation therapy is working?
- Will I be able to continue my normal activities during treatment?
Hormone therapy prevents the prostate cancer cells from getting the male hormones they need to grow. When a man undergoes hormone therapy, the level of male hormones is decreased. This drop in hormone level can affect all prostate cancer cells, even if they have spread to other parts of the body. For this reason, hormone therapy is called systemic therapy.
There are several forms of hormone therapy. One is surgery to remove the testicles. This operation, called orchiectomy, eliminates the main source of male hormones. The use of luteinizing hormone-releasing hormone (LHRH) agonist is another type of hormone therapy. LHRH agonists prevent the testicles from producing testosterone. In another form of hormone therapy, patients take the female hormone estrogen to stop the testicles from producing testosterone.
After orchiectomy or treatment with an LHRH agonist or estrogen, the body no longer gets testosterone from the testicles. However, the adrenal glands still produce small amounts of male hormones. Sometimes, the patient is also given an antiandrogen, a drug that blocks the effect of any remaining male hormones. This combination of treatment is known as a total androgen blockade.
Prostate cancer that has spread to other parts of the body usually can be controlled with hormone therapy for a period of time, often several years. Eventually, however, most prostate cancers are able to grow with very little or no male hormones. When this happens, hormone therapy is no longer effective, and the doctor may suggest other forms of treatment that are under study.
Many men with prostate cancer take part in clinical trials (treatment studies). Doctors conduct clinical trials to learn about the effectiveness and side effects of new treatments. In some clinical trials, all patients receive the new treatment. In the trials, doctors compare different therapies by giving the new treatment to one group of patients and the standard therapy to another group; or they may compare one standard treatment to another.
People who take part in these studies have the first chance to benefit from treatments that have shown promise in earlier research. They also make an important contribution to medical science.
Many clinical trials of treatments for prostate cancer are under way. For example, researchers are comparing treatment against careful observation of men with early stage prostate cancer. The results of this work will help doctors to know whether to treat early stage prostate cancer immediately or only later on, if symptoms occur.
Doctors are studying new ways of using radiation therapy and hormone therapy. Some doctors also are exploring the use of cryosurgery, which uses extreme cold to destroy cancer cells, as an alternative to surgery and radiation therapy. In cryosurgery, an instrument called a cryoprobe is placed in direct contact with the tumor to freeze it, sparing nearby healthy tissue.
Researchers also are testing the effectiveness of chemotherapy and biological therapy for patients whose cancer does not respond or stops responding to hormone therapy. In addition, scientists are looking for new ways of combining various types of treatment.
Men with prostate cancer who are interested in taking part in a clinical trial should discuss this option with their doctor. Taking Part in Clinical Trials: What Cancer Patients Need To Know is a National Cancer Institute booklet that explains the possible benefits and the risks of participating in treatment studies.
One way to learn about clinical trials is through PDQ, a computerized resource developed by the National Cancer Institute. This resource contains information about cancer treatment and about clinical trials in progress all over the country. The Cancer Information Service can provide PDQ information to patients and the public.
Side Effects of Treatment
Although doctors plan treatment very carefully, it is hard to limit the effects of treatment so that only cancer cells are removed or destroyed. Because treatment also damages healthy cells and tissues, it often causes unwanted, and sometimes serious, side effects.
The side effects of cancer treatment depend mainly on the type and extent of the treatment. Also, each patient reacts differently. Doctors and nurses can explain the possible side effects of treatment, and they can often suggest ways to help relieve symptoms that may occur during and after treatment. It is important to let the doctor know if any side effects occur.
Although patients are often uncomfortable during the first few days after surgery, their pain can be controlled with medicine. Patients should feel free to discuss pain relief with the doctor or nurse. It is also common for patients to feel tired or weak for a while. The length of time it takes to recover from an operation varies for each patient.
Surgery to remove the prostate may cause permanent impotence and sometimes causes urinary incontinence. These side effects are somewhat less common than in the past. Some surgeons use new methods, especially when removing small tumors. These techniques, called nerve-sparing surgery, may prevent permanent injury to the nerves that control erection and damage to the opening of the bladder. When this surgery is fully successful, impotence and urinary incontinence are only temporary. However, men who have a prostatectomy no longer produce semen, so they have dry orgasms.
Radiation therapy may cause patients to become very tired as treatment continues. Resting is important, but doctors usually advise patients to try to stay as active as they can. Patients may have diarrhea or frequent and uncomfortable urination. In addition, when patients receive external radiation therapy, it is common for the skin in the treated area to become red, dry, and tender. Radiation therapy can also cause hair loss in the pelvic area. The loss may be temporary or permanent, depending on the amount of radiation used.
Radiation therapy causes impotence in some men. This does not occur as often with internal radiation therapy as with external radiation therapy; internal radiation therapy is not as likely to damage the nerves that control erection.
The National Cancer Institute publication Radiation Therapy and You offers helpful suggestions about coping with the side effects of this form of treatment.
Orchiectomy, LHRH agonists, and estrogen often cause side effects such as loss of sexual desire, impotence, and hot flashes. When first taken, an LHRH agonist tends to increase tumor growth and may make the patient's symptoms worse. This temporary problem is called "tumor flare." Gradually, however, the drug causes a man's testosterone level to fall. Without testosterone, tumor growth slows down and the patient's condition improves. Prostate cancer patients who receive estrogen or an antiandrogen may have nausea, vomiting, or tenderness and swelling of the breasts. (Estrogen is used less now than in the past because it increases a man's risk of heart problems. This form of treatment is not appropriate for men who have a history of heart disease.)
The side effects of chemotherapy depend mainly on the specific drugs that are used. The National Cancer Institute publication Chemotherapy and You may be helpful to patients experiencing the side effects of chemotherapy.
Biological therapy may cause flu-like symptoms such as chills, fever, muscle aches, weakness, loss of appetite, nausea, vomiting, or diarrhea. Patients may also bleed or bruise easily, and some get a rash. Some of these problems can be severe, but they go away after the treatment stops.
Nutrition for Cancer Patients
Good nutrition is important. Patients who eat well often feel better and have more energy. Eating well during cancer treatment means getting enough calories and protein to prevent weight loss, regain strength, and rebuild normal tissues.
Some patients find it hard to eat well during treatment. They may lose their appetite. In addition to loss of appetite, common side effects of treatment, such as nausea and vomiting, can make eating difficult. Foods taste different to some patients. Also, people undergoing treatment may not feel like eating when they are uncomfortable or tired.
Doctors, nurses, and dietitians can offer advice for healthy eating during cancer treatment. Patients and their families also may want to read the National Cancer Institute booklet Eating Hints for Cancer Patients, which has helpful information about cancer treatment and coping with side effects.
Regular followup exams are important for any man who has had prostate cancer. The doctor will suggest an appropriate followup schedule. The doctor will examine the patient regularly to be sure that the disease has not returned or progressed, and decide what other medical care may be needed. Followup exams may include x-rays, scans, and laboratory tests, including the PSA blood test.
Support for Cancer Patients
Living with a serious disease is not easy. People with cancer and those who care about them face many problems and challenges. Coping with these problems is often easier when people have helpful information and support services. Several useful booklets, including the National Cancer Institute booklet Taking Time, are available from the Cancer Information Service.
Friends and relatives can be very supportive. Also, patients may find it helpful to discuss their concerns with others who have or have had cancer. Cancer patients often get together in support groups, where they can share what they have learned about coping with cancer and the effects of treatment. It is important to keep in mind, however, that each patient is different. Treatments and ways of dealing with cancer that work for one person may not be right for another--even if they both have the same kind of cancer. It is a good idea to discuss the advice of friends and family members with the doctor.
People with cancer may worry about holding their job, caring for their family, or keeping up with daily activities. Worries about tests, treatments, hospital stays, and medical bills are common. Doctors, nurses, and other members of the health care team can answer questions about treatment, working, and other activities. Also, meeting with a social worker, counselor, or member of the clergy can be helpful to patients who want to talk about their feelings and discuss their concerns.
It is natural for a man and his partner to be concerned about the effects of prostate cancer and its treatment on their sexual relationship. They may want to talk with the doctor about possible side effects and whether these side effects are likely to be temporary or permanent. Whatever the outlook, it may be helpful for patients and their partners to talk about their concerns and to help one another find ways to be intimate during and after treatment.
Often, a social worker at the hospital or clinic can suggest local and national groups that can provide emotional support, financial aid, transportation, home care, or other services. The Cancer Information Service also has information on local resources. The American Cancer Society is one such resource. This nonprofit organization has many services for patients and their families and offers a free booklet on sexuality and cancer.
What the Future Holds
Researchers are finding better ways to treat prostate cancer, and the outlook for men with prostate cancer keeps improving. Still, it is natural for patients and their families to be concerned about what the future holds. Sometimes people use statistics to try to figure out the chances of being cured. It is important to remember, however, that statistics are averages based on large numbers of patients. They cannot be used to predict what will happen to a particular patient because no two patients are alike; treatments and responses vary greatly. The doctor who takes care of the patient is in the best position to discuss the patient's prognosis (chance of recovery or control of the disease).
When doctors talk about surviving cancer, they may use the term remission rather than cure. Even though many prostate cancer patients recover completely, doctors use this term because the disease can recur, or reappear after treatment.
Research To Understand Prostate Cancer
Prostate cancer is an important public health problem. Prostate cancer accounts for one of every three cancers among American men. Researchers are conducting studies to learn more about the causes and early detection of this common disease.
Causes and Prevention
The causes of prostate cancer are not yet understood. Researchers are looking at factors that may increase the risk of this disease. The more they can learn about these risk factors, the better the chance of finding ways to prevent and treat prostate cancer.
Studies in the United States show that prostate cancer is found mainly in men over age 55; the average age of patients at the time of diagnosis is 72. This disease is more common in black men than in white men. In fact, black men in the United States have the highest rate of prostate cancer in the world. Doctors cannot explain why one man gets prostate cancer and another does not, but they do know that no one can "catch" prostate cancer from another person. Prostate cancer is not contagious.
Some studies have shown that a man has a higher risk for prostate cancer if his father or brother has had the disease. However, researchers are uncertain why some families have a higher incidence of prostate cancer.
Scientists are studying the effects of diet. Some evidence suggests that a diet high in fat increases the risk of prostate cancer and a diet high in fruits and vegetables decreases the risk, but these links have not been proven.
Researchers have studied whether having a vasectomy increases a man's risk for prostate cancer. Some studies suggest there may be such a link, but other studies have not supported this claim.
Other studies show that farmers and workers exposed to the metal cadmium during welding, electroplating, or making batteries may have an increased risk of getting this disease. Also, workers in the rubber industry appear to develop prostate cancer more often than members of the general public. However, more research is needed to confirm these results.
Scientists are also doing studies to determine whether BPH or a sexually transmitted virus increases the risk for prostate cancer. At this time, they do not have clear evidence of increased risk in either case.
Men over age 55 are taking part in a study of finasteride (trade name Proscar), a drug used to treat BPH. This nationwide NCI study, called the Prostate Cancer Prevention Trial, is designed to help doctors learn whether finasteride can prevent prostate cancer. The Cancer Information Service can provide information about this study.
Researchers are studying ways to screen men for prostate cancer (check for the disease in men who have no symptoms). At this time, it is not known whether screening actually saves lives. The NCI-supported Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial is designed to show whether certain tests can detect these cancers early enough to reduce the number of deaths they cause. For prostate cancer, this trial is looking at the usefulness of screening with digital rectal exam and checking the PSA level in the blood in men ages 55 to 74. The results of this trial may change the way men are screened for prostate cancer. The Cancer Information Service can provide information about this trial.
Men should talk with their doctor about prostate cancer, the symptoms to watch for, and an appropriate schedule of checkups. The doctor's advice will be based on the risks and benefits of diagnosis and treatment, as well as a man's age, medical history, and other factors.
Source: National Cancer Institute, National Institutes of Health