Strategies to Improve Treatment - Stage III Prostate Cancer

This content has been reviewed and approved by

Daniel P. Petrylak, MD
Associate Professor of Medicine
Director, Genitourinary Oncology Program
Columbia University Medical Center

Researchers are currently investigating new treatments for stage III prostate cancer. Participation in trials of these treatments will lead to improved therapies. If you wish to participate in a clinical trial, please talk to your doctor about the potential benefits and side effects of the treatment.

Strategies to improve systemic therapy -Surgery and radiation are local therapies directed at treating cancer in and around the prostate gland. Treatment administered before local therapy is called neoadjuvant therapy. Administering systemic therapies, such as hormonal therapy and chemotherapy, before local therapy is a strategy that is being actively investigated. This technique can shrink the cancer so that it is more treatable with local therapies. Over the past several years, many new more active anticancer drugs have been discovered. Administration of these newer anticancer agents in addition to radiation or surgical removal of prostate cancer may improve the treatment of locally advanced prostate cancer.

Neoadjuvant hormone therapy -Hormone therapy deprives a man’s body of male hormones necessary for prostate cancer to grow. The use of hormone therapy to shrink the prostate cancer before radical prostatectomy or radiation therapy is being evaluated for patients with prostate cancer. Some urologists are trying to make radical prostatectomy more successful for stage III prostate cancer by shrinking the cancer before surgery with hormone therapy. Hormonal therapy before local treatment appears to decrease the size of the prostate cancer by approximately 20 percent to 50 percent. The use of neoadjuvant hormone therapy before radical prostatectomy is being evaluated in clinical studies.

Neoadjuvant chemotherapy -Administration of chemotherapy before either surgery or radiation is called neoadjuvant chemotherapy. It can shrink the cancer so that it is more treatable with local therapies. Chemotherapy also provides the benefit of killing cancer cells that have already spread away from the prostate and are not treated with local radiation or hormonal therapy. Cancer cells that have spread are thought to be the most likely cause of cancer recurrence or relapse after local therapy.

Combination chemotherapy and hormone therapy -Research indicates that combining chemotherapy and hormone therapy may improve survival in patients with locally advanced prostate cancer. Ninety-five percent of patients who received the combination treatment in a clinical trial experienced a complete or partial disappearance of their cancer compared with only 53 percent of patients who received hormone therapy alone. The average duration of survival following therapy was also better, nearly 7½ years compared with 3 years for patients receiving only hormone therapy.

Advances in local treatment - Several strategies to improve local treatment of prostate cancer are under evaluation. All of these strategies either increase the dose of radiation delivered to the cancer or expand the field of radiation. They treat cancer confined to the prostate and do not treat cancer cells beyond the radiation or surgical field.

Combination radiation therapy -Some radiation oncologists are combining EBRT and interstitial seed brachytherapy for patients with stage II or III cancers. The purpose of the EBRT is to treat the tissue surrounding the prostate gland and lymph nodes where cancer cells may have spread. The interstitial seeds serve to deliver extra radiation doses to the prostate, where the cancer cells are greatest. The combination of internal and external radiation is being evaluated to allow for higher doses of radiation to the cancer while minimizing side effects to surrounding organs.

Whole pelvic radiation therapy -Because certain patients are at higher risk of cancer involving the pelvic lymph nodes, some physicians have advocated expanding the radiation field to include the pelvic lymph nodes. This is referred to as whole pelvic radiation therapy (WPRT). Some, but not all, comparisons of WPRT to prostate-only radiation therapy suggest that WPRT may improve survival rates and is not more toxic than radiation. Many physicians believe, however, that if cancer has spread to the pelvic lymph nodes, it has probably spread elsewhere in the body and expanding the radiation field will be of little benefit. Efforts to improve treatment might be better focused on systemic treatment approaches versus local treatment with radiation. Physicians in the United States are currently conducting a clinical study comparing WPRT to prostate only radiation.

Newer radiation techniques -EBRT can be delivered more precisely to the prostate gland by using a special CT scan and targeting computer. Efforts to improve the cure rate of prostate cancer with radiation therapy are under investigation. One exciting technique is the use of three-dimensional (3-D) computer targeting systems to precisely aim the radiation beam at the prostate gland. This technique appears to reduce side effects to the surrounding organs, thereby allowing higher radiation doses. Clinical studies using 10 percent to 20 percent higher radiation doses for prostate cancer with 3-D radiation therapy are under way.

Newer radiation machines -Most EBRT uses high energy x-rays to kill cancer cells. Some radiation cancer centers use different types of radiation that require special machines. These different types of radiation, such as protons or neutrons, appear to kill more cancer cells with the same dose. Combining protons or neutrons with conventional x-rays is one method of radiation therapy being evaluated in clinical trials.