Obese Patients at Higher Risk of Prostate Cancer Spreading, Study Says

Obese Patients at Higher Risk of Prostate Cancer Spreading, Study Says

Obese prostate cancer patients may be at higher risk of having the disease spread to other organs, according to a joint German and Canadian study.

Radical prostatectomy not only seems to reduce that risk, but also the risk of prostate cancer recurring after surgery. Radical prostatectomy involves removing the prostate gland and tissue around it.

The findings in the study “Radical prostatectomy neutralizes obesity-driven risk of prostate cancer progression” were published in Urologic Oncology.

In addition to being a major contributor to cardiovascular disease and diabetes, obesity is associated with higher death rates in several cancers, including prostate cancer.

Changes in the micro-organism makeup of an obese man can increase his risk of prostate cancer. It also can lead to a more aggressive form of disease and to increased risk of biochemical recurrence — or a rise in PSA levels after treatment — along with spread of the disease to other organs, and death.

Despite robust evidence supporting an association between obesity and prostate cancer, some results have been contradictory. That has prompted doctors to debate the reliability of evidence suggesting a connection.

Researchers sought to assess obesity’s impact on two prostate cancer metrics. One was the rate of non-organized-confined disease — or the spread of the cancer to other organs — at the time of surgery. Another was the rate of biochemical recurrence after radical prostatectomy.

The term non-organ-confined disease means the cancer has spread to tissue just outside the prostate or to the pelvic lymph nodes.

The research collaboration involved teams from the Academic Hospital Braunschweig and University Medical Center Hamburg-Eppendorf and from the University of Montreal Health Center.

Researchers found that 2,403 or 15% of the 16,014 prostate cancer patients in the Martini-Klinik Prostate Cancer Center database were obese, meaning their body mass index (BMI) was 30 or higher. Obese men were younger, had higher PSA levels, and a more aggressive disease than their non-obese counterparts, researchers found.

The team discovered that obese men were 27 percent more likely to have non-organ-confined disease at the time of surgery than non-obese patients. However, obese patients were no more likely to have biochemical recurrence following radical prostatectomy than non-obese patients.

Similarly, there was no difference in the time to biochemical recurrence among the two groups, suggesting that radical prostatectomy eliminated the obesity-related risk of recurrence.

“In consequence, lack of association between obesity and BCR may be interpreted as a valid surrogate proof of absence of association between obesity and metastatic progression or PCa death,” the researchers wrote.

The team noted that their study had limitations: There was selection bias because they used a single-center database, and the study was retrospective.

In addition, all patients in the study had been selected for surgery. The results might not reflect the outcome of patients treated with approaches such as active surveillance or radiation therapy, the team said.