Prostate Cancer

Is your treatment what more than 1,100 Oncologists recommend?

The information provided below is meant to help you understand the role of your cancer biology treatment decisions, as well as the role of other tools used in determining your ability to receive chemotherapy or targeted therapy (precision medicine).

In 2016, it is estimated that about 180,890 new cases of prostate cancer diagnosed in in the United States (CA Cancer J Clin 2016; 66(1):7-30). It is the most common cancer in men in the United States with the risk for developing prostate cancer increases with age as following

• <49 years old (1 in 325)
• 50-59 years old (1 in 48)
• 60-69 years old ( 1 in 17)
• >70 years old (1 in 10)

Risk Factors

• Having family history of the disease
• Being of African descent
• Lifestyle factors such as high dietary fat intake

Screening

Testing healthy men for prostate cancer with PSA screening remains extremely controversial. The median PSA was 0.68ng/mL (40-49 years old group), 0.8 ng/mL (50-54 years old group, 0.96 ng/mL (55-59 years old group). Men with PSA levels above the median had 7.3-10.1 times increased risk for developing prostate cancer. It is worth noting, however, that one of the reasons that screening for prostate cancer is so controversial is that many men diagnosed with prostate cancer will never have their disease spread to other parts of the body, even if they receive no treatment.

Treatment

Three different approaches to treating prostate cancer are available.

• Surgery (remove the prostate gland with radical prostatectomy)
• Radiation therapy to the prostate, or if you have surgery, you may still benefit from radiation to the prostate bed (the portion of the pelvis from which the prostate was removed) mostly in cases where the surgical margins were not negative (i.e. there is some cancer at the edge of the specimen)
• Chemotherapy with or without targeted therapy (precision medicine)

This website is designed to outline in detail your chemotherapy and/or targeted therapy options and offer you personalized information about the best options to yield optimal survival and quality of life. Multiple factors affect your treatment options including:

• Cancer is recurring (you have had cancer before) or your cancer is a first time diagnosis: The treatment for recurrence is determined by what type of treatment you received for your first diagnosis. Certain chemotherapies can only be given once in your lifetime, so if you have already received one type of chemotherapy with your first cancer, then that chemotherapy will not be recommended for you again.
• The characteristics of the tumor (Gleason grade or PSA level) will greatly affect treatment decisions. The Gleason grade, or Gleason score, is a measure of how abnormal, i.e. how different from the normal prostate tissue from which it arose, the cancer is. While this score originally was reported as a number between 2 and 10, the Gleason system was revised in 2005 (Am J Surg Pathol 2005; 29: 1228) and under the revised system scores less than 6 are almost never reported, and even scores of 6 have become much less common.
• Cancer stage at the time of the diagnosis. Your treating physicians will do imaging tests (CT, bone scan or PET/CT) to determine your stage.

Therefore, if you have been newly diagnosed with prostate cancer, but have no symptoms and no evidence of spread of the cancer to other parts of the body, the first decision to be made is whether to start treatment at all. Prostate cancer tends to be slow-growing and remains dormant and clinically unimportant for decades. This decision will be based upon your estimated life expectancy and the risk that your prostate cancer will worsen and spread to other parts of your body. Thus, if your prostate cancer is considered high risk for eventually spreading to other parts of your body, you should get therapy. If it is low risk, it may be reasonable to watch you closely for any evidence of the cancer becoming more aggressive over time. Factors that influence this risk assessment decision include the Gleason grade of your cancer, how high your PSA is, and how extensive the tumor is, i.e. does it invade through the capsule that surrounds the prostate or does it invade the seminal vesicles (two small glands that are right behind the prostate). The life expectancy for an average healthy 65 years old American man is 16 years.

If you have prostate cancer and it is decided to pursue treatment, the recommendation for therapy will depend upon whether there is spread of the cancer to other organs or not. For prostate cancer that has not spread, treatment will be either surgery (radical prostatectomy) or radiation therapy to the prostate. For most men, either choice is reasonable, and your decision will depend upon what set of risks and side effects you are most willing to accept. Your urologist will have this discussion with you depending on your overall health.

If you choose to have radiation, it may be beneficial to give you treatment to bring down your testosterone level (so-called androgen deprivation therapy, or ADT). This will again depend upon how high the risk of recurrence of the cancer is. It should be noted that ADT alone is NOT appropriate therapy for cancer that is confined to the prostate (JAMA 2008; 300: 173).

Types of ADT

• Testosterone lowering is accomplished by taking medication, either a gonadotropin-releasing hormone (GnRH) agonist (e.g. degarelix) or a GnRH antagonist (e.g. leuprolide, goserelin, triptorelin). There are no effects to cure rates or survival with either drugs.
• Bilateral orchiectomy (i.e. surgical removal of the testes) is an alternative.
• Another approach in addition to ADT, androgen receptor blockers (e.g. flutamide, bicalutamide, nilutamide) are also often used; these medications prevent testosterone form interacting with its receptor within the prostate cancer cell. The receptor is a protein which testosterone binds to, and the combination of testosterone and its receptor then act on the cell, stimulating it to grow and divide.

Your physician may offer ADT after surgery for cancer that confined to the prostate if it is cosidered high risk for recurrence (N Engl J Med 1999; 341: 1781). However, the available data regarding this approach are still surprisingly limited, so this is still not the standard of care.

If the cancer has spread to other organs (metastatic) and thus it is considered advanced prostate cancer, initially therapy is usually some form of ADT until the cancer stops responding to ADT. When this happens, this is referred to as castrate resistant prostate cancer (CRPC). When CRPC develops, there are a variety of other treatments that can be utilized. It is important to know whether the cancer has spread primarily to bone, or whether it affects vital organs such as the lungs or liver. Drugs for advanced prostate cancer (CRPC):

• Abiraterone is a drug that blocks the formation of testosterone by inhibiting CYP17A1 enzyme
• Provenge (sipuleucel-T) is the first vaccine for prostate cancer treatment
• Chemotherapy i.e. docetaxel

This website gives you about 90% of straight forward prostate cancer treatment. All cancer treatment is recommended based on expertise ‘s opinions from multiple national guidelines (NCCN, ASCO, ESMO, ASTRO). However, your treating physician will use your overall health status (whether you have any significant weight loss) and other medical illness to determine your best personalized treatment for you.

Finally, chemotherapy and targeted therapies can result in unpleasant side effects such as hair loss, numbness of fingers or toes, cardiac toxicity, nausea, vomiting, diarrhea, abnormal liver function or low white blood cell count that could cause infection, and fatigue. However, advances in the oncology field have led to numerous supportive measures, such as white blood cell growth support (i.e. Neulasta) or anti-nausea medications (such as Zofran, Emend), that help to control most side effects when used as prescribed.

The best time to use this service (based on more than 1,100 cancer experts) is after you have learned the details of your cancer and treatment plan from your treating physicians, and would like to clarify and confirm that your treatment is the best option for your cancer. This questionnaire is used mainly for drug treatment in medical oncology.