Researchers develop prostate cancer testing, treatment guidelines

September 29, 2012

Julio M. Pow-Sang, M.D., chair of Moffitt Cancer Center's Department of Genitourinary Oncology, and colleagues have published two prostate cancer articles in the September issue of JNCCNThe Journal of the National Comprehensive Cancer Network. The articles review and clarify recent updates made to the National Comprehensive Cancer Network's (NCCN) guidelines for the screening and treatment of prostate cancer.

According to the NCCN, nearly 242,000 cases of prostate cancer will be diagnosed in 2012, accounting for 29 percent of new cancers among men. It is estimated that more than 28,000 men will die from the disease this year.

According to the journal, prostate cancer is "over diagnosed and over treated" and is subject to a controversy "fueled by large screening studies." This month, Prostate Cancer Awareness Month, the NCCN has offered support for , a strategy by which men with low-risk tumors, often classified as clinically insignificant, are monitored over time.

"Depending on the disease characteristics and the patient's life expectancy and personal preference, active surveillance may be a viable alternative to immediate and radical treatment," Pow-Sang said. "For others with high-risk, localized tumors or locally advanced disease, there are recent treatment advances that should be considered."

New agents and therapy combinations

According to the NCCN, and androgen deprivation therapy have been the traditional treatments for patients with high-risk tumors. However, the NCCN reports that brachytherapy, either permanent seed implant or temporary placement (high ), combined with external beam radiation and androgen deprivation therapy is increasingly being used for these patients.

The first article, Prostate Cancer, version 3.2012, noted that two new agents – abiraterone acetate and immunotherapy sipuleucel-T – are welcome therapeutic additions for patients with late-stage disease and .

Abiraterone acetate, which inhibits a key enzyme related to prostate cancer, can be given to patients after their chemotherapy. Studies have shown that it can also be used in chemotherapy-naïve patients.

Sipuleucel-T, a second line therapy, is a live cancer vaccine approved in 2010 for treating asymptomatic or minimally symptomatic patients with metastatic prostate cancer. The NCCN has recommended the new drug for use after chemotherapy failure or as treatment along with chemotherapy.

"The new NCCN guidelines highlight important updates to the management of prostate cancer," concluded Pow-Sang and his co-authors. "These protocols are updated annually and more often when new, high-quality clinical data become available. The guidelines are based on evidence from clinical trials combined with expert consensus."

Active surveillance and PSA density, percent free, and biopsy cores

In a second article, Enrollment Criteria Controversies for Active Surveillance and Triggers for Conversion to Treatment in Prostate Cancer, Pow-Sang and co-author David D. Buethe, M.D., a urologic oncology fellow at Moffitt, examine the controversy and criteria for implementing active surveillance for patients with asymptomatic prostate cancer and identify the triggers that would convert active surveillance patients to active treatment status.

The authors note that for those patients with prostate cancers at low-risk for progression, the active surveillance strategy was proposed a decade ago but is recently receiving more attention as a viable management option.

"However, critical uncertainties still surround active surveillance," Pow-Sang said. "The criteria that qualify a patient as low or very low risk are not clear, nor is the definition of disease progression."

In this article, Pow-Sang and Buethe reviewed recent literature regarding those uncertainties, examining criteria for assisting in selecting men for active surveillance, including PSA density, percent free versus percent total PSA, biopsy positive core results and "volume of involvement" data.

"A PSA density of greater than 0.08 ng/mL/g has been identified as a significant predictor of future disease progression in those with low-risk prostate cancer," reported Pow-Sang. "However, some clinicians use a level of 0.15 ng/mL/g as a threshold."

Percent-free PSA has been found to be a significant predictor of organ-confined disease, said Pow-Sang and Buethe, noting that some reports have shown a significant indirect correlation between percent-free PSA and prostate cancer volume; but as yet this parameter is "not widely accepted as a predictor of cancer extent."

They also looked at studies on positive cores from biopsies and the extent to which core results could be used to develop criteria for treatment. Reports have shown the predictive value of positive biopsy cores, but the frequency for performing prostate biopsies remains controversial for outcomes of active surveillance patients, Pow-Sang said.

"Biopsies are not without consequences," he said. "Rectal bleeding and serious infectious complications from frequent biopsies need to be considered."

Additionally, no standard protocol exists, and controversy remains, for the frequency of PSA testing and the digital rectal exam for patients who are under active surveillance.

"Current guidelines vary," Pow-Sang said. "There are recommendations that the PSA and digital rectal exam should be performed every three to six months, or the PSA every three months and the digital rectal exam every six months. The frequency of biopsies is also variable, from once a year to up to every three years."

New potential tools

Pow-Sang and Buethe also report that a new tool, the PCA3 urinary marker, may be useful. PCA3 is a urine test used to quantify copies of the known prostate cancer gene 3. A PCA3 score of 35 or greater is considered possibly malignant. The test is prostate cancer specific and unaffected by prostatitis or benign prostatic hyperplasia, both of which have confounded the results of PSA testing.

The future of active surveillance

"Most studies report that 30 percent of active surveillance-classified men will be reclassified in the short term to clinically significant cancer that may require treatment," noted Pow-Sang. "Once more, PSA velocity (how quickly the PSA score rises) or PSA doubling time (how often the score doubles) has no clear role in active surveillance."

When counseling men with early prostate cancer, all treatment options, risks and complications should be discussed, Pow-Sang confirmed.

"Active surveillance is a reasonable management strategy for low-risk and very low risk , but allows for continual reassessment and identification of progressive tumors."

Explore further: More aggressive treatment not necessary for men with a family history of prostate cancer

Related Stories

More aggressive treatment not necessary for men with a family history of prostate cancer

October 5, 2011
Approximately 10-20 percent of prostate cancer patients have a family history of the disease. There are three major factors that are used to evaluate the extent and aggressiveness of prostate cancer, help make treatment decisions, ...

PSA test valuable in predicting biopsy need, low-risk prostate cancer

October 21, 2011
The prostate-specific antigen test, commonly known as the PSA test, is valuable in predicting which men should have biopsies and which are likely to be diagnosed with low-risk prostate cancer, a Mayo Clinic study has found. ...

Investigational urine test can predict high-risk prostate cancer in men who chose 'watchful waiting'

February 2, 2012
Initial results of a multicenter study coordinated by researchers at Fred Hutchinson Cancer Research Center indicates that two investigational urine-based biomarkers are associated with prostate cancers that are likely to ...

Recommended for you

Anti-cancer chemotherapeutic agent inhibits glioblastoma growth and radiation resistance

July 24, 2017
Glioblastoma is a primary brain tumor with dismal survival rates, even after treatment with surgery, chemotherapy and radiation. A small subpopulation of tumor cells—glioma stem cells—is responsible for glioblastoma's ...

New therapeutic approach for difficult-to-treat subtype of ovarian cancer identified

July 24, 2017
A potential new therapeutic strategy for a difficult-to-treat form of ovarian cancer has been discovered by Wistar scientists. The findings were published online in Nature Cell Biology.

Immune cells the missing ingredient in new bladder cancer treatment

July 24, 2017
New research offers a possible explanation for why a new type of cancer treatment hasn't been working as expected against bladder cancer.

Shooting the achilles heel of nervous system cancers

July 20, 2017
Virtually all cancer treatments used today also damage normal cells, causing the toxic side effects associated with cancer treatment. A cooperative research team led by researchers at Dartmouth's Norris Cotton Cancer Center ...

Molecular changes with age in normal breast tissue are linked to cancer-related changes

July 20, 2017
Several known factors are associated with a higher risk of breast cancer including increasing age, being overweight after menopause, alcohol intake, and family history. However, the underlying biologic mechanisms through ...

Immune-cell numbers predict response to combination immunotherapy in melanoma

July 20, 2017
Whether a melanoma patient will better respond to a single immunotherapy drug or two in combination depends on the abundance of certain white blood cells within their tumors, according to a new study conducted by UC San Francisco ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.