Proton Therapy Limits Prostate Cancer Recurrence
Survey finds 97% of patients remain cancer free after treatment
Approximately 97% of patients who received only proton therapy for prostate cancer reported that they had not experienced a recurrence of their disease, according to a survey of nearly 4,000 patients presented at the National Proton Conference in Arlington, Virginia.
The survey was commissioned by the National Association for Proton Therapy (NAPT) as a follow-up to a 2013 report designed to investigate clinical outcomes and patient satisfaction. This year's survey captured data from 3,798 proton therapy patients treated at 12 centers — an almost twofold increase from the 1,961 former patients who completed the 2013 survey. Approximately 17% of all men treated in the U.S. with proton therapy for prostate cancer participated in the survey. Many of the cancer-free patients completed treatment as long as 10 years ago.
The 2013 and 2014 studies “show that the overwhelming majority of proton therapy patients surveyed are free from recurrence, enjoying an excellent quality of life, and so happy with their choice of treatment that they have recommended it to others," said Leonard Arzt, Executive Director of the NAPT.
Proton therapy uses a high-energy beam of protons, instead of conventional high-energy X-rays, to deliver a precise dose of radiation therapy. The treatment destroys cancer cells but does not affect adjacent healthy tissue, eliminating certain side effects of conventional radiation and lowering the risk of radiation-induced secondary tumors.
In contrast to the results reported by proton therapy patients, an estimated 10% to 30% of men who have a prostatectomy experience a recurrence of cancer, according to the NAPT. Moreover, a 2006 study showed that 11% of patients treated with a conventional form of radiation experience a recurrence within 8 years.
The new survey showed that most men who choose proton therapy over other treatment modalities (such as surgery and conventional X-ray radiation) do so based on their desire for fewer side effects.
To measure patients’ post-treatment condition, the study used the Expanded Prostate Cancer Index Composite (EPIC), which measures health-related quality of life (HRQOL) among men with prostate cancer. In both surveys, prostate cancer patients who received only proton therapy as treatment did not have significantly different HRQOL scores post-treatment compared with a control group of subjects who were free of prostate cancer in the four categories of urinary incontinence, urinary irritative, bowel, and sexual.
In the survey:
- Of 3,632 patients who responded, 98% believed they had made the best treatment decision for themselves.
- Of 3,636 patients who responded, 96% recommended proton therapy to others.
- Of 3,642 patients who responded, 85% reported that their quality of life was “better than” (27%) or “the same as” (58%) before their treatment.
Source: NAPT; April 2, 2014