In order to guide patients in choosing an appropriate treatment, doctors depend in part on an understanding of prognostic factors that suggest how extensive or aggressive the cancer may actually be. Such factors include digital rectal examination (DRE), PSA Test, Gleason score and biopsy. Given the impact on prognosis that each of these factors may have, a combination of these factors is often more useful in understanding the potential for treatment success or failure that the use of any one factor alone. Within the realm of clinically localized cancer, a combination of these factors may be used to categorize patients as “low risk”, “intermediate risk” and “high risk” in terms of treatment failure. It is important to note that while prognostic factors are helpful in guiding treatment choices, there is no “cookbook” for selection of treatment, and other factors including age, overall health, urinary and bowel function and each patient’s own concerns about treatment need to be taken into account. Therefore, a thorough discussion with an individual’s urologist and oncologist is an important part of the decision-making process.
Prostate cancer that has not spread outside the immediate area around the prostate is often referred to as clinically localized cancer. An important distinction within the realm of clinically localized cancer is between prostate cancers confined to the prostate, referred to as organ-confined disease, and prostate cancer that has spread directly outside the prostate or into the seminal vesicles. The term “clinical” is applied to the setting where the determination that cancer has not spread to other site, including lymph nodes or distant tissues and organs, is based on the findings of physical exam and diagnostic imaging tests that may include CT scan, MRI and/or bone scan. Proof of cancer stage is only obtained by invasive procedures such as surgical removal of the prostate or biopsy.
Treatment of low-risk clinically localized prostate cancer: The “low-risk” category generally includes patients with E1 or T2a cancer (normal examination or small abnormality limited to one side of the prostate), PSA levels less than 10 ng/ml and/or Gleason grade less than or equal to six. These men are the most likely to have cancer confined to the prostate. Treatment options may include radical prostatectomy, external beam radiation therapy (EBRT), prostate brachytherapy or in certain circumstances observation. Given that almost all men with early detection of prostate cancer are without symptoms, the impact that treatment may have on quality of life is an important consideration.
Treatment of intermediate-risk clinically localized prostate cancer: The “intermediate-risk” category includes patients with bulky T2a disease, PSA greater than 10 ng/ml but less than or equal to 20 ng/ml and/or Gleason grade seven. In addition, recent studies have suggested that the extent of tumor on biopsy, often referred to as “percent positive biopsies” may help sort out which men in this category have outcomes more similar to the low or high-risk group. Men with just a little cancer found on biopsy might have outcomes more in line with low risk patients while men with extensive cancer may be greater risk for treatment failure. Overall, many men in this category may still have cancer confined to the prostate or along the edge of the prostate. The risk of spread outside the prostate is greater, however, than that for men with all low-risk features.
Given the many nuances in the presentation of intermediate-risk disease a number of treatment options may be appropriate. These options may include radical prostatectomy, EBRT, prostate brachytherapy or a combination of EBRT and brachytherapy. Androgen suppression therapy, commonly referred to as hormonal therapy, may also have a role in treatment of intermediate-risk prostate cancer when combined with radiation. While in men with high-risk prostate cancer the role of hormonal therapy with radiation is now established, the role in treatment of intermediate-risk prostate cancer remains to be fully defined. The results of two large clinical studies now completed are awaited in the next several years and hopefully will provide answers. In the meantime, a large study of previously treated patients at the Dana-Farber Cancer Institute did suggest a benefit to the addition of six months of hormonal therapy to EBRT in this patient group and therefore at least warrants consideration when radiation therapy is used.
Treatment of high-risk clinically localized prostate cancer: The “high-risk” category includes men with any of the following features: T2c, T2 or T4 disease (abnormal examination on both sides of the prostate or cancer that has spread outside of the prostate as determined by digital rectal examination), PSA greater then 20 ng/ml, and/or Gleason grade between eight and ten. Men in this category have a substantial risk of spread of cancer outside of the prostate. Nevertheless, some men in this category do have cancer confined to the prostate and therefore local treatment including prostatectomy may be appropriate. In men deemed to be at greater risk for disease spread, the most standardized radiotherapeutic approach to treatment is the combination of EBRT and hormonal therapy. Other treatments, including combination of EBRT and brachytherapy with or without hormonal therapy may be considered but the long-term results of newer approaches remain to be fully defined. Two national studies started in the 1980s in the United States and a third large study in Europe all showed benefit to the use of hormonal therapy when combined with EBRT in men with various high-risk features. The European study was the first to show an overall survival benefit to the addition of hormonal therapy to radiation. Early results of another study indicate a benefit to longer duration hormonal therapy in men with high-risk prostate cancer. The use of chemotherapy in this group of men remains to be defined and is now the focus of a few national studies. Given the variety of presentations within the high-risk group, the right treatment for any given individual needs to be carefully considered in consultation with a urologist and/or oncologist.