Normal    Prostate   vs   Cancerous   Prostate                                                            

 

Prostate cancer begins when cells in the prostate gland start to grow  uncontrollably. The prostate is a gland found only in males. The prostate is below the bladder and in front of the rectum. The size of the prostate changes with age. In younger men, it is about the size of a walnut, but it can be much larger in older men. The urethra, which is the tube that carries urine and semen out of the body, goes through the center of the prostate.

Prostate cancer is the most common cancer in American men. About 1 man  in 7 will be diagnosed with prostate cancer during his lifetime. It develops mainly in older  men. About 6 cases in 10 are diagnosed in men aged 65 or older, and it is rare before age 40. The average age at the time of diagnosis is about 66. Prostate cancer is the second leading cause of cancer death in American men, behind only lung cancer. About 1 man in 39 will die of prostate cancer. Prostate cancer can be a serious disease, but most men diagnosed with prostate cancer do not die from it. In fact, more than 2.9 million men in the United States who have been diagnosed with prostate cancer at some point are still alive today.

The 5-year survival rate for most men with prostate cancer is 99%. Ninety-eight percent (98%) are alive after 10 years, and 95%  live for at least 15 years. For men diagnosed with prostate cancer that has spread to other parts of the body, the 5-year survival rate drops to 28%. For more than  90% of men whose prostate cancer is localized to the prostate or just nearby, the prognosis is even better. Almost 100% of these men will live at least five years.

As statistics show people diagnosed with prostate cancer can survive, so which are the treatments used? There are many options, that depend on the progress or the stage of the disease.

Here are the conventional ways of treatment:

Active surveillance – In active surveillance, regular follow-up blood tests, rectal exams and possibly biopsies may be performed to monitor progression of the cancer.

Radiation therapy – Radiation therapy uses high-powered energy to kill cancer cells. 

Hormone  therapy – Hormone therapy is treatment to stop your body from producing the male hormone testosterone.

Surgery – Surgery for prostate cancer involves removing the prostate gland (radical prostatectomy), some surrounding tissue and a few lymph nodes. 

Cryosurgery – Cryosurgery involves freezing tissue to kill cancer cells.

Chemotherapy – Chemotherapy uses drugs to kill rapidly growing cells, including cancer cells. Chemotherapy can be administered through a vein in your arm, in pill form or both.

Biological  therapy – Biological therapy (immunotherapy) uses your body's immune system to fight cancer cells. 

Even though, scientists  continue to find new effective ways for treating prostate cancer. The latest research is a five year study  for treating people diagnosed with prostate cancer with SBRT (Stereotactic Body Radiotherapy ). It is a therapy that gives radiation from many different positions around the body. The beams meet at the tumor. So the tumor receives a high dose of radiation and the tissues around it only receive a low dose. This lowers the risk of side effects.

UT Southwestern served as the lead site for the multi-institutional clinical trial, which involved first-time prostate cancer patients diagnosed with stage I or stage II prostate cancer. A total of 91 patients were treated prospectively and followed for five years, with only one patient experiencing a recurrence of his cancer.

 The results has shown 98.6 % cure rate with SBRT. Stereotactic Body Radiation Therapy (SBRT) to treat prostate cancer offers a higher cure rate than more traditional approaches, according to researchers at UT Southwestern Medical Center Harold C. Simmons. The findings are published in the European Journal of Cancer.

The current form of radiation is 44 treatments given over nine weeks. In contrast, the SBRT therapy  used allows the delivery of highly focused radiation in only five treatments, allowing patients to return to their normal lives more quickly. SBRT is both more convenient and has increased potency. The delivery of SBRT is accomplished with image-guidance (IGRT) via 3 implanted gold seed markers in the prostate gland. This image-guidance is integrated with an intensity modulated beam that is shaped to fit and surround the prostate gland, aiming at the prostate gland continuously as the gantry rotates around the patient. This specialized state of the art beam is called RapidArc. A dedicated treatment machine, the Novalis Tx, is used to accomplish this.

 

There are many good reasons to consider and choose SBRT over the other potential options, including:

  • It is entirely non-invasive (unlike brachytherapy it does not involve the insertion of needles, risks of bleeding, risk of infection, general anesthesia, hospital stays, or wearing a catheter).
  • It is a very short treatment course (unlike conventional external beam which takes a total of 9 weeks) SBRT is a total of 5 treatment sessions, each taking approximately 15 minutes, all as an outpatient.
  • The cancer control rates of SBRT are equivalent to those of brachytherapy, conventional external beam radiotherapy, or surgery.
  • Sparing of radiation exposure to the rectum and bladder is equal to or better than with brachytherapy.
  • The side effects are less than those experienced with brachytherapy or conventional external beam radiotherapy.

In the short term, the side effects of SBRT can include urinary issues (urgency, frequency and burning) and rectal irritation, which are often temporary and reverse within four weeks of treatment. Researchers found a small risk of longer-term urinary and rectal complications, which is also comparable to conventional treatments

To reduce the side effects associated with SBRT, current clinical trials at UTSW are using a unique and biodegradable rectal spacer gel to protect the rectum. UTSW is currently the only accredited site in Texas at which this spacer gel can be used.

Other clinical trials at the UTSW Department of Radiation Oncology are seeking to expand the application of SBRT to high-risk (Stage III) prostate cancer patients.

UT Southwestern has been a leader in pioneering use of SBRT. Dr. Timmerman, Director of Image-Guided Stereotactic Radiation Therapy, Medical Director of Radiation Oncology, and holder of the Effie Marie Cain Distinguished Chair in Cancer Therapy Research, has served as the lead investigator in several national trials designed to evaluate the efficacy and safety of SBRT to treat other types of cancer, including cancer in the lung, liver, and spine. A range of clinical trials of SBRT therapy are under way at Simmons Cancer Center, including new investigations evaluating use of SBRT for cancers in the breast and larynx.

Since 2009, UT Southwestern has trained more than 300 physicians and peers interested in implementing SBRT in their clinical practice.

 

References:

https://www.sciencedaily.com/releases/2016/04/160418145458.htm

https://cancerstatisticscenter.cancer.org/?_ga=1.263995276.1219086055.1464856016#/cancer-site/Prostate

http://www.cancer.net/cancer-types/prostate-cancer/statistics

http://www.webmd.com/prostate-cancer/prostate-cancer-survival-rates-what-they-mean

http://www.mayoclinic.org/diseases-conditions/prostate-cancer/basics/treatment/con-20029597

http://radonc.ucla.edu/faqs-sbrt#whatis

www.cancerresearchuk.org/about-cancer/cancers-in-general/treatment/radiotherapy/external/stereotactic-body-radiotherapy-sabr

http://radonc.ucla.edu/prostate-cancer-sbrt#2