Prostate cancer

Overview

Cancer begins when normal cells in the prostate begin to change and grow uncontrollably, forming a mass called a tumor. A tumor can be benign (noncancerous) or malignant (cancerous, meaning it can spread to other parts of the body).

Prostate cancer is a malignant tumor that begins in the prostate gland of men. The prostate is a walnut-sized gland located behind the base of the penis, in front of the rectum, and below the bladder. It surrounds the urethra, the tube-like channel that carries urine and semen through the penis. The prostate's main function is to produce seminal fluid, the liquid in semen that protects, supports, and helps transport sperm.

Some prostate cancers grow very slowly and may not cause symptoms or problems for years. In this situation, the cause of death is usually not from prostate cancer, but other causes. However, if cancer does metastasize (spread) to other parts of the body, it can cause pain, fatigue, and other symptoms. Prostate cancer is somewhat unusual from other types of cancer, in that many tumors that are diagnosed do not spread from the prostate. And often, even metastatic prostate cancer can be successfully treated, with the person surviving in good health for some years.

More than 95% of prostate cancers are adenocarcinomas, cancer that develops in glandular tissue. A rare type of prostate cancer known as neuroendocrine cancer or small cell anaplastic cancer tends to spread earlier, but usually does not produce prostate-specific antigen (PSA), a tumor marker discussed later in this section. Read more about neuroendocrine tumors.
Treatment options overview

There are many treatment options for prostate cancer that is confined to the prostate gland. Each option should be considered carefully, balancing the advantages against the disadvantages as they relate to the individual man's age, overall health and personal preferences.

Historical standard options include:

* Surgery (radical prostatectomy): An incision is made in the lower abdomen or through the perineum (between the anus and the scrotum), and the prostate is removed. Incomplete surgery, in which the entire tumor cannot be removed, may need to be followed by radiation therapy. Possible side effects of surgery can include incontinence (inability to control urination) and impotence (inability to achieve erection). More recently, several centers are using three small incisions to do robot assisted prostatectomy that results in shorter hospitalization and faster recuperation. This may be preferable for selected patients, but not for all.
* External beam therapy (EBT): a method for delivering a beam of high-energy x-rays to the location of the tumor. The beam is generated outside the patient (usually by a linear accelerator) and is targeted at the tumor site. These x-rays can destroy the cancer cells and careful treatment planning allows the surrounding normal tissues to be spared. No radioactive sources are placed inside the patient's body. See the External Beam Therapy page (www.RadiologyInfo.org/en/info.cfm?pg=ebt) for more information.
* Watchful waiting: No treatment, with careful observation and medical monitoring.

Newer, advanced options have been developed in the past 10 to 15 years. These newer options avoid or minimize some of the unpleasant side effects sometimes associated with the standard therapies. These options include:

* Nerve-sparing radical prostatectomy: Surgical procedure in which the prostate gland is removed without severing the critical nearby nerves that send signals between the brain and penis to allow normal sexual functioning. A skilled and experienced surgeon may be able to preserve sexual function for some patients by successfully using this procedure.
* Conformal external beam radiation therapy: Uses advanced technology to tailor the radiation therapy to an individual's body structures. Relying on computerized three-dimensional images of the prostate, bladder and rectum, the x-ray radiation beam is aimed precisely ("conformed") to affect the diseased area. In this way, less radiation reaches the surrounding normal tissues. Today there are two levels of conformal radiation therapy: 3-D conformal radiation therapy and intensity modulated radiation therapy (IMRT). Both allow for increased doses to the tumor while protecting the normal surrounding organs. IMRT is considered the more conformal of the two but is not necessary or appropriate for all patients. For more detailed information see the Intensity-Modulated Radiation Therapy page (www.RadiologyInfo.org/en/info.cfm?pg=imrt).
* Image-guided radiation therapy: For either 3-D conformal or IMRT, daily image guidance is increasingly used to improve the setup due to organs movement. Since the prostate position varies day-to-day depending on bladder and rectal filling, the prostate position must be localized and verified prior to each treatment. Typically several fiducial markers, or tiny pieces of metal, are placed in the prostate before the simulation. Digital x-ray images are taken either with the same beam as that of the treatment or an add-on low energy x-ray beam aligned to the linear accelerator. The metallic markers will be visible on the x-ray images. This is done to check the position of the prostate on a daily basis just before the treatment and appropriate adjustment and alignment of prostate to the planned high-dose radiation treatment field.
* Proton beam therapy: a type of conformal therapy that bombards the diseased tissue with protons instead of x-rays. See the Proton Therapy page (www.RadiologyInfo.org/en/info.cfm?PG=protonthera) for more information.
* Cryotherapy: A procedure that uses extremely low temperatures (-190°C) to freeze and destroy cancer cells. Some experienced physicians have had good results with low complication rates using cryotherapy; however, others have not. This should be considered experimental at this time as upfront treatment for prostate cancer, until there is longer follow-up for patients treated with this modality. This technique was developed as an alternative to surgery for patients who have recurrent cancer in the prostate after radiation treatments. For more detailed information, see the Cryotherapy page (www.RadiologyInfo.org/en/info.cfm?pg=cryo).
* Brachytherapy: The temporary placement of radioactive materials. See the Brachytherapy page (www.RadiologyInfo.org/en/info.cfm?PG=brachy) for more information.
* Low-dose rate (LDR) brachytherapy or permanent seed implant treatment: hundreds of small radioactive seeds are inserted into the prostate. These radioactive seeds deliver radiation continuously over about a month then become inactive. These seeds remain in the prostate forever. While the implant technique has been around for decades, recent advances in imaging technology have made it more effective. Using ultrasound to see the prostate gland better, physicians can place each seed in the prostate more carefully and better control the effect on surrounding tissues. Long-term results are available for up to 10—15 years at some institutions. These results show that in experienced centers, ultrasound-guided radioactive seed implantation is highly effective in controlling prostate cancer and has essentially the same result as surgery or external beam radiation for appropriately selected prostate cancer patients.
* High Dose Rate (HDR) Brachytherapy: This technique was developed to supplement external beam therapy to treat patients with high risk prostate cancer. In skilled hands, this is an effective regimen to treat such cancers. Patients receive about five weeks of external beam radiation therapy, followed by one to three HDR sessions. These sessions require anesthesia and placement of about a dozen needles into the prostate. The patient is then hooked up to the HDR machine, where a radioactive source moves up and down within each needle, delivering radiation. When the HDR treatment is finished, the needles are removed from the patient. This type of brachytherapy leaves no permanent radiation in the patient. Use of this technique by itself (i.e., without the external beam treatments) for low-risk patients is still in the experimental stages.

How can I choose from among the options?

In addition to talking with family and friends, you will need a team of physicians to help advise you. By the time of diagnosis, you will already have met two of the three or four doctors you will need for your cancer treatment planning: your primary care physician (an internist or family practice doctor) and a urologist, who probably performed the biopsy. (In some cases, a radiologist performs the biopsy.) If you have an early-stage cancer or moderately advanced cancer and there is no evidence of spread to other organs (non-metastatic), you need to talk to one more doctor: a radiation oncologist. The two major options for treatment are surgery (performed by your urologist) and radiation therapy (performed by a radiation oncologist).

If your cancer is advanced and you require chemotherapy, then you will also need a medical oncologist, who administers chemotherapy. Hormones, which are often used to treat prostate cancer, can be administered by your internist, urologist, radiation oncologist or medical oncologist. Depending on the stage of the cancer, hormones may be used in addition to radiation therapy to help control the cancer.
If I choose surgery, will radiation treatment still be required?

If your surgery is incomplete (meaning that some cancer still remains), additional radiation therapy within three to six months can prevent reoccurrence in many men. You will want to discuss this option with your physician team.
How effective is modern radiation treatment of prostate cancer?

With modern technology and recent advances in software, radiation therapy can give more radiation dose directly to the prostate than to surrounding healthy tissues. Physicians use various imaging techniques to see the prostate and surrounding tissues in three dimensions, so that the radiation beams can be tailored more precisely to the individual patient's unique needs. Physicians can estimate and minimize the dose of radiation that will be received near the rectum, small bowel, bladder and hips during the course of radiation treatment to reduce the risk of side effects and complications. The goal is to safely provide a higher dose of radiation than even five years ago, which helps to improve the chances of cure.

source : http://www.cancer.net/patient/cancer+types/prostate+cancer
http://www.radiologyinfo.org/en/info.cfm?pg=pros_cancer