PROSTATE CANCER – WHAT’S NEW. A Short Synopsis of Recent Developments of Clinical Interest. (November 2010)
Compiled by Edward L. Weber, MD, Medical Oncologist, Retired, Swedish Hospital Cancer Institute, Seattle, WA.
Author of PCa Commentary, an analysis of new information and management options in prostate cancer found at Seattleprostate.org, click on “News and Events.”
1) ASPIRIN: Studies show improvement in prostate cancer outcome, a significant decrease in risk for disease-specfic mortality in a 10-year analysis of users versus non-users. The absolute risk decrease for Aspirin users was 1% at 5 years; 2% at 10. This was seen particularly in men with high-risk prostate cancer. CapSure data on 5295 men with localized disease treated with radiation therapy (RT) had better biochemical control. The relative risk of recurrence at 5 years was 22% lower in the Aspirin users; and 33% lower at 10 years. Source: American Society of Therapeutic Radiologists (ASTRO) Abstract, 2010 #270.
Another study also showed that the risk of getting prostate cancer was reduced by 21% in Aspirin users. Long-term use of less than 5 years showed a 24% decrease while daily low-dose, “baby” aspirin lessened the risk by 29%. This data was based on a study from the Fred Hutchinson Cancer Research Center (FHCRC) of 1001 cases and 942 controls. (Published Sept 1, 2010)
2) STATINS (cholesterol lowering drugs such as Lipitor, Pravacol): (Reviewed in PCa Commentary, Jul/Aug 2010) Statin usage reduces risk of a diagnosis of advanced prostate cancer by 40% if used for less than 5 years; and by 74% for usage greater than 5 years. Also seen was a 30% reduction of recurrence. All-cause mortality decreased 65% after radical prostatectomy, and 41% after radiation therapy.
3) POLYUNSATURATED FATS: A FHCRC study on diet and supplement use based on data from the Prostate Cancer Prevention Trial showed that the risk of high-grade prostate cancer (Gleason 8-10) was increased 2.41 X in association with a high intake of polyunsaturated fats. No effect was seen in cancer prevention from lycopene, long-chain-3 fatty acids, Vit. D, Vit. E, and selenium. N-6 fatty acids (found in red meat) may increase prostate cancer risk. (Article: Sept 1, 2010 )
4) PSA SCREENING: Despite the brisk controversy on the benefits of PSA screening, an ASTRO report (Oct, 2010) found that routine screening improved quality of life and decreased the occurrence of metastatic disease at 10 years in all risk groups compared to men who were not screened. The analysis was based on 1700 prostate cancer patients.
(See PCa Commentary article, Sept/Oct 2010, reviewing the Swedish Goteberg study which showed a 20% decrease in prostate cancer-specific mortality (PCSM).
Dr. Crawford, a prominent urologic surgeon, Denver, CO, reported at the 2010 ASCO meeting that after 10-years of follow-up a “significant decrease in the risk of PCSM (22/164 v. 38/164) was “observed in men with no or minimal co-morbidity. This was based on analysis of prostate cancer deaths in the major screening study (the international Lung, Colon, Ovarian, Prostate study) wherein no overall benefit was seen for PSA screening. However, when results were analyzed in reference to co-morbidities of the prostate patients (mainly cardiovascular disease and diabetes), screening in these healthy men showed a benefit as regards the risk of a diagnosis of prostate cancer.
5) DIAGNOSIS: (PCa Commentary Nov/Dec, 2010 ) Five-year usage of a statin reduces PSA by 13% and thiazide diuretics ( e.g. hydrochorothiazide, Diuril, or Enduron) reduce PSA by 26%. Used together for five years, the reduction is 36%.
6) ANDROGEN DEPRIVATION THERAPY (ADT)
a) FDA asked manufacturers to add new label warnings for GnRH agonists
(i.e. Lupron and Zoladex) linking the drugs to increased
cardiovascular risks, i.e. myocardial infarction and cardiac deaths.
b) Bicalutamide (Casodex) 150 mg/qd monotherapy is an established
alternative to GnRH agonists in Europe and provides comparable
outcome in men with non-metastatic cancer, but preserves bone mineral
density, muscle strength, and other quality of life (QOL) aspects. An
American Society of Clinical Oncology 2010 reported that “Endurance,
upper extremity strength and physical components of QOL are affected
within 3 months of starting ADT