PATIENTS ADVISED TO CAREFULLY WEIGH RISKS OF PROSTATE CANCER TREATMENT

Toronto, ON (January 16, 2014, 6:30 p.m. EST) - The type of prostate cancer treatment a man chooses at diagnosis is the strongest predictor for complications found to have new, significant impact, says a Sunnybrook study published in The Lancet Oncology.

Dr. Robert Nam, the study's lead investigator and urologic-oncologist at Sunnybrook's Odette Cancer Centre says before patients choose a treatment path, it is important for them to understand all the specific related risks alongside other complicating factors such as age and pre-existing medical conditions.

"This is the first, large-scale study of over 32,000 men to examine rates of other important complications associated with primary treatment, beyond the well-known ones of incontinence and erectile dysfunction, that can substantially affect a patient's quality of life," says Dr. Nam, who is also a Professor in the Department of Surgery at the University of Toronto.

Primary treatment options involve surgery or radiotherapy. The researchers used five outcome measures or procedures specifically needed to address complications developed due to treatment:

• hospital admission rates
• urological procedures rates
• rectal or anal procedures rates
• open surgical procedures rates
• development of new, second cancers.

Conducted in collaboration with radiation oncologists, the study reports increasing age and the level of pre-existing medical conditions (comorbidity) at the time of either treatment were associated with higher rates of complications.

The strongest predictor of these complications was the type of treatment received. Patients treated with radiotherapy had fewer minimally invasive urological procedures, but had higher incidence of complications in all other categories of hospital admissions, rectal or anal procedures, open surgical procedures, and secondary cancers. 

After accounting for differences of age and comorbidity, patients who underwent radiotherapy experienced 2 to 10-fold higher rates of these types of complications compared to those who had surgery.  Higher rates from the radiotherapy group included complications such as being admitted to hospital to treat bladder or rectal bleeding, or to undergo major operative procedures such as bladder removal.

The cumulative incidence of secondary cancers in years 5 to 9 was 4.5% in the radiotherapy group, and 1.8% in the surgery group.  The most common site of secondary cancers was the gastrointestinal tract.  When comparing cancer incidence rates to the general population, the younger patients in the radiotherapy group experienced up to a 3.5-fold higher rate of developing secondary cancers, while rates in the surgery group were the same as for the general population. 

Of the 32,465 patients, 15,870 underwent surgery with a median age at 62 years, and 16,595 had radiotherapy with a median age of 70 years.

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Media contact;

Natalie Chung-Sayers, Communications Advisor, Sunnybrook, 416-480-4040