How Targeted Therapy Is Used to Treat Prostate Cancer

In this article, the expert medical oncologists and hematologists of Regional Cancer Care Associates (RCCA), one of the nation’s largest networks of oncology specialists, explain how targeted therapy works and how it can help treat prostate cancer.   

Is Targeted Therapy Different from Chemotherapy?

Like chemotherapy, targeted therapy uses drugs to attack cancer cells or disrupt their function and reproduction. However, these medications specifically affect malignant cells while generally leaving healthy cells intact. By contrast, standard chemotherapy may harm both healthy and cancerous cells.

Which Prostate Cancer Patients Benefit from Targeted Therapy? 

Some targeted therapies for prostate cancer have very broad applicability because the processes they disrupt are common features of prostate cancer. This is particularly true of hormonal treatments that block the production of androgens or prevent their synthesis.

Other targeted therapies are options only when a patient has metastatic disease, meaning that the cancer has spread beyond the prostate. Two radiopharmaceutical agents fall into this category. Both are given by infusion. One travels to sites of bone metastases are releases alpha particles – a form of radiation – at those sites to kill cancerous cells in the bone. The other travels to the locations of both bone and soft-tissue metastases and concentrates radiation in those spots.

Still other targeted therapies employed in advanced prostate cancer work only when there are specific genetic mutations that these therapies can affect.

Given the different mechanisms of action of these agents, physicians need to carefully assess each patient to determine who is or is not a candidate for a given therapy. This evaluation typically includes imaging studies and genetic testing.

What to Expect with Targeted Therapy  

Every patient’s experience with targeted therapy is different. For example, patients may receive drugs orally or intravenously (through a needle placed in a vein). The frequency of treatment and route of administration will depend on the type and stage (severity) of prostate cancer. Patients may receive treatment daily, weekly, or monthly, or have a more specifically tailored schedule. There might also be periods when patients stop treatment.

Success with targeted therapy also varies depending on the type and stage of prostate cancer. Patients will have regular follow-up visits with their physicians to measure the effectiveness of targeted therapy. These visits may include questions about side effects, as well as blood and imaging tests.

Side effects of targeted therapy vary depending on the drug used and whether it stimulates the immune system, changes or interferes with proteins on the surface of cells, shuts off chemical signals, releases radiation, or acts in some other manner. Some patients experience no side effects. If adverse effects do arise, they typically go away within a few months of completing treatment. Patients, however, should notify their oncologist if an adverse medication effect persists or becomes intolerable. 

Understanding Prostate Cancer Signs and Symptoms

Detecting prostate cancer can be difficult because symptoms may not be present in the disease’s early stages. Rather, signs and symptoms of prostate cancer may not be apparent until the disease has progressed. Some symptoms that may signal prostate cancer include:

• Frequent or urgent urination, particularly at night
• Inconsistent stream of urine (difficulty starting or stopping urination)
• Burning or stinging with urination
• Straining or pushing during urination
• Loss of bladder control
• Rectal pressure or pain
• Changes in bowel movements
• Blood with urine or ejaculation
• Pain during ejaculation
• Less fluid is produced during ejaculation
• Difficulty maintaining an erection
• Pain or stiffness in the pelvis, hips, thighs, or lower back

It is important to note that the symptoms described above may be indicative of many conditions. For example, frequent urination at night and an inconsistent urine stream can be caused by a benign, age-related increase in the size of the prostate, while difficulty maintaining an erection can be a consequence of diabetes or cardiovascular disease, and stiffness in the hips or lower back may be due to arthritis. So, while none of these symptoms is a cause for panic, each is a reason to see a physician for prompt evaluation.

Prostate Cancer Screening

Screening for prostate cancer can help clinicians detect and treat the disease in its early stages, increasing the chance of a favorable outcome. Screening typically is performed by means of a simple blood test that measures the level of a protein called prostate-specific antigen (PSA) in a man’s blood. Levels of this protein may be elevated for several reasons, including not only prostate cancer but also infections or a common, non-cancerous condition called benign prostatic hyperplasia (BPH). Some physicians augment PSA screening with a digital rectal examination, briefly inserting a gloved, lubricated finger into the anus to feel the man’s prostate gland and assess its size and firmness.

When a PSA level is mildly elevated in a man with no symptoms and known risk factors for prostate cancer, physicians often will track the PSA level over time. If the PSA level is significantly beyond the normal range, or if the patient reports symptoms or has risk factors for prostate cancer, physicians generally conduct further assessments, such as taking a small sample of prostate tissue at biopsy for examination under a microscope or ordering imaging tests.

The American Cancer Society recommends that physicians discuss prostate cancer screening with patients starting at age 50 for men at average risk for the disease. The organization advises that this discussion take place at age 45 for men at high risk, including African Americans men and men who have a first-degree relative who was diagnosed with prostate cancer before 65 years of age. The society recommends having that conversation at age 40 for men at particularly high risk, such as those with more than one first-degree relative who had prostate cancer at an early age.

Prostate Cancer Risk Factors

As referenced above, several factors can affect a man’s risk of developing prostate cancer. The main prostate cancer risk factors include:

• Age: Prostate cancer is much more common among men aged 65 and older than among younger men.
• Race/ethnicity: African American men are more likely to get prostate cancer than white men, Asian American, and Hispanic/Latino men. Caribbean men of African descent are also at a higher risk.
• Family history: Men with a family history of prostate cancer are at increased risk, especially if their father or brother had the disease.
• Inherited genetic mutations: Having Lynch syndrome or inherited mutations of the genes BRCA1 and BRCA2 increases the risk of prostate cancer.
• Additional risk factors also may increase prostate cancer risk, but the links in these cases are unclear. These include:
  • Being exposed to certain chemicals
  • Eating diets heavy in high-fat dairy products and red meats and low in fruits and vegetables
  • Smoking
  • Being overweight
  • Having prostatitis
  • Undergoing a vasectomy
  • Contracting sexually transmitted infections (e.g., chlamydia, gonorrhea)

Prostate Cancer Stages and Targeted Therapy

A cancer’s stage often dictates the type of treatment that is best for the patient. Targeted therapies ted to be prescribed in higher-stage prostate cancer, particularly in cases in which the cancer has metastasized, or spread. Prostate cancer stages range from I to IV, with higher stages correlating with further spread.

• Stage I: Prostate cancer is slow-growing and found only in the prostate gland. Many patients have no noticeable symptoms at this stage.
• Stage II: Prostate cancer has grown significantly, and the chance of recurrence following treatment is greater.
• Stage III: Cancer has spread outside the prostate gland to surrounding lymph nodes and tissues, and possibly to distant organs.
• Stage IV: Prostate cancer has progressed to nearby organs, such as the bladder and rectum, and possibly more distant organs, such as the bones, lungs, and liver.

Prostate Cancer Treatment at RCCA

Regional Cancer Care Associates (RCCA) provides the full range of medical therapies for patients with prostate cancer and coordinates closely those patients urologists, radiation oncologists, and primary care physicians.

In addition to targeted therapy, RCCA offers prostate cancer treatments such as:

• Chemotherapy: Chemotherapy uses powerful medications to attack and kill cancer cells or prevent them from spreading. By reducing the size of tumors, these drugs may also alleviate pain and other symptoms.Chemotherapy may be administered orally or intravenously.
• Hormone therapy: Androgens are male hormones that can cause cancer cells to grow. The goal of hormone therapy is to decrease androgen levels or prevent them from functioning.
  Vaccines: A vaccine specially formulated for each patient from his white blood cells helps stimulate the immune system to attack cancer cells. This method is used to treat advanced prostate cancer.

Rely on RCCA for Comprehensive Prostate Cancer Care

Patients diagnosed with prostate cancer can find the compassionate, comprehensive treatment they need at RCCA. With 22 conveniently located, community-based locations throughout New Jersey, Connecticut, Maryland, and the Washington, DC area, RCCA offers patients care close to home. Contact RCCA to learn more or schedule an appointment at a nearby location.