New study confirms that PROGENSA PCA3 can improve accuracy of prostate cancer diagnosis

Mar 20 2008

New clinical data from a study of 570 men published in the peer-reviewed Journal of Urology support the use of PROGENSA PCA3 as a tool for diagnosing prostate cancer. The study confirms that PROGENSA PCA3, the world's first gene-based urine test to help detect prostate cancer, can provide clinicians with valuable information that helps guide diagnosis.

As awareness and clinical support for PROGENSA PCA3 grows, a unique new resource regarding prostate cancer has been launched. http://www.PCA3.org is the first patient and professional website dedicated solely to PCA3, providing patients and healthcare professionals with information about how PCA3 can be used to help tackle the UK's most common cancer affecting males.

Launched last year in the UK, PROGENSA PCA3 addresses some of the limitations of existing diagnostic tools. For example, Prostate Specific Antigen (PSA) is commonly elevated for reasons not related to prostate cancer, and as a result, PSA testing produces many 'false positive' results, which can burden patients and the healthcare system. In contrast, the genetic marker PCA3 is elevated only in cancerous prostate tissue, making it a more specific indicator of cancer than PSA, potentially reducing the number of unnecessary biopsies.

"We found that the percent of biopsy-positive men identified directly increased with the PCA3 score," commented Dr. Jack Groskopf, Director of Oncology Research and Development at Gen-Probe Incorporated and co-author of the study. "We also confirmed that the PCA3 score was independent of prostate size; this is important because PSA levels can be elevated in men who have enlarged prostates due to non-cancerous conditions."

Men with a PCA3 score of less than five showed a positive biopsy rate of 14 percent; however, a PCA3 score greater than 100 showed a 69 percent biopsy positive rate. Results were similar regardless of a patient's PSA levels or whether they had undergone repeat biopsies.

"PROGENSA PCA3 provides physicians with valuable information to guide biopsy decisions." added Dr. Groskopf.

The study expands on findings from a previous study conducted by Dr. Leonard Marks of the Urological Sciences Research Foundation published in the March 2007 issue of Urology.

PROGENSA PCA3 is the first CE-Marked test to use the presence of PCA3 (a genetic marker for prostate cancer) to predict prostate cancer, and can be used in conjunction with current tests to confirm diagnosis.(2-7) PCA3 is overexpressed, relative to benign cells, by 60- to 100-fold in more than 90 percent of prostate tumors. DiagnoCure Inc. (TSX: CUR) is the exclusive worldwide licensee for all diagnostic and therapeutic applications of the gene. Gen-Probe acquired exclusive worldwide diagnostic rights to the PCA3 gene from DiagnoCure in November of 2003. The test is marketed across the European Union and is offered through the following laboratories in the UK:

Notes

• The prostate is a walnut-shaped gland that sits beneath the bladder and in front of the rectum. It is a fundamental part of the male reproductive system.
  
• Prostate cancer is the most common cancer in men in the UK - it accounts for nearly a quarter (23%) of all new male cancer diagnoses. In 2003, there were 31,900 new cases of prostate cancer diagnosed in the UK.(8)
  
• Prostate cancer accounts for around 13% of male deaths from cancer in the UK and is the second most common cause of cancer death in men, after lung cancer. In 2005 there were 10,000 deaths in the UK from prostate cancer.(9)
  
• The strongest known risk factor is age, with very low risk in men under 50 and rising risk with increasing age thereafter.(10)
  

About Gen-Probe

Gen-Probe Incorporated is a global leader in the development, manufacture and marketing of rapid, accurate and cost-effective nucleic acid tests (NATs) that are used primarily to diagnose human diseases and screen donated human blood. Gen-Probe has more than 24 years of NAT expertise, and received the 2004 National Medal of Technology, America's highest honor for technological innovation, for developing NAT assays for blood screening. Gen-Probe is headquartered in San Diego and employs approximately 1,000 people. For more information, go to http://www.gen-probe.com.

Reference List

(1) Deras IL, Aubin SM. PCA3: A Molecular Urine Assay for Predicting Prostate Biopsy Outcome. In: Blase A, Day JR, Koo S et al, editors. 2008: 1587-1592.

(2) The Prostate Cancer Charity. The PSA test. http://www.prostate-cancer.org.uk/info/tests_psa.asp. 2007.

(3) The Prostate Cancer Charity. PSA background. http://www.prostate-cancer.org.uk/news/features/psa_screening.asp. 2007.

(4) Groskopf J, Aubin SM, Deras IL et al. APTIMA PCA3 molecular urine test: development of a method to aid in the diagnosis of prostate cancer. Clin Chem 2006; 52(6):1089-1095.

(5) Kirby R. PCA3 improves diagnosis of prostate cancer KIRBY2007. Practitioner 2007; 251(1690):18, 21, 23.

(6) Marks LS, Fradet Y, Deras IL et al. PCA3 molecular urine assay for prostate cancer in men undergoing repeat biopsy. Urology 2007; 69(3):532-535.

(7) Schalken J. Interview with Jack Schalken. PCA3 and its use as a diagnostic test in prostate cancer. Interview by Christine McKillop. Eur Urol 2006; 50(1):153-154.

(8) Office for National Statistics. Cancer Statistics registrations: Registrations of cancer diagnosed in 2003, England. 2007.

(9) Office for National Statistics. Review of the Registrar General on deaths by cause, sex and age, in England and Wales, 2005. Series DH2 no.32. 2007.

(10) Cancer Research UK: CancerStats. Prostate cancer risk factors - Age and ethnicity. 2007.

The prostate

The prostate is a walnut-shaped gland that sits beneath the bladder and in front of the rectum. It is a fundamental part of the male reproductive system.

Prostate cancer

- Nearly all prostate cancers are adenocarcinomas (tumours that originate in glandular tissues), mainly occurring in the peripheral zone of the prostate gland. Benign prostate hyperplasia commonly arises in the central zone of the gland.

Symptoms

- Prostate cancer often has no symptoms, particularly in the early stages.

- When symptoms do develop, they can include: difficulty passing urine, frequent passing of urine, pain when urinating, blood in the urine, pain in the lower back, hips and upper thighs. However, other factors can cause these symptoms.

Incidence

- Prostate cancer is the most common cancer in men in the UK - it accounts for nearly a quarter (24%) of all new male cancer diagnoses, making it the second most common cancer overall, after lung cancer.(1) In 2004, there were 34,986 new cases of prostate cancer diagnosed in the UK.

- The lifetime risk of being diagnosed with prostate cancer is 1 in 14 for men in the UK.

Mortality

- In 2005, there were 10,000 deaths in the UK from prostate cancer - one man dies every hour from this disease.(2)

- Prostate cancer accounts for around 13% of male deaths from cancer in the UK and is the second most common cause of cancer death in men, after lung cancer.

Risk factors

- The strongest known risk factor is age. Men under 50 are considered to be at low risk; the risk increases with age thereafter.(3)

- African Caribbean men are three times more likely to be diagnosed with prostate cancer than their white counterparts.

Family History / Moleculars

- Risk increases two to three times for men with a family history of prostate cancer in a first-degree relative. The risk appears to be higher if the relative is a brother rather than a father, suggesting that the disease is linked to the X chromosome.(4)

- Risk is also increased if the affected relative is young or if more than one relative is affected. It has been estimated that a predisposing gene could be responsible for 43% of cases by age 55, and up to 10% of all cases.(5) Men whose families have an increased risk of breast cancer are also at higher risk of prostate cancer.

- Carriers of germline mutations in the breast cancer susceptibility gene BRCA2 are at five times greater risk of prostate cancer, but mutations in this gene account for only around 2% of all early-onset cases.(6;7)

Treatment of prostate cancer

- There are several strategies used in the management of prostate cancer:

Active monitoring

- Sometimes, particularly for slow-growing tumours, no treatment is the best course of action. This is often called active monitoring or watchful waiting.

Surgery

- Surgery is a common treatment option in prostate cancer. It is mostly used in otherwise healthy men (usually, those under 70) whose cancer has not spread beyond the prostate. The most common technique is a radical prostatectomy. This is a major operation, which removes the whole of the prostate, seminal vesicles and nearby lymph nodes.

Radiotherapy

- Radiotherapy uses radiation to destroy cancer cells. Techniques include conformal radiotherapy (CRT) and high-resolution intensity modulated radiotherapy (IMRT).

Brachytherapy

- Brachytherapy involves implanting radioactive seeds into, or next to, the tumour in the prostate, enabling radiation to be released slowly over time.

Hormone therapy

- Hormone therapy blocks the action of male sex hormones that help the cancer grow. This can slow the growth and spread of prostate tumours but will not kill the cancer cells. Surgical hormone therapy involves removing the testes, which permanently removes the main source of testosterone. This operation is called an orchidectomy.

New treatments

- New surgical developments include keyhole surgery (a laparoscopic prostatectomy), where the prostate is removed through small incisions.

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