Is extracapsular extension linked to increased risk?

This study examined the link between locally advanced prostate cancer and the risk of poorer disease outcome.

Although prostate cancer is very common, most men do not die from it. This is because the cancer usually grows very slowly. The risk of death increase if the cancer has begun to spread through the prostate and into nearby areas (locally advanced; stage T3).

In some cases of locally advanced cancer the cancer has spread into and beyond the outer lining of the prostate gland (extracapsular extension; stage T3a). In other cases the cancer cells have spread into the seminal vesicles (glands positioned below the bladder; stage T3b). Although patients with locally advanced cancer are at increased risk, it is not known whether the prognosis is worse if the cancer has spread into the seminal vesicles and through the wall of the prostate.

This study evaluated 1,132 patients who had their prostates surgically removed (radical prostatectomy). All patients had locally advanced cancer that had spread to the seminal vesicles but not to the lymph nodes (stage T3bN0). The cancer had also spread through the lining of the prostate gland in 61% of patients (extracapsular extension).

Patients were followed-up for an average of ten years. During that time the cancer returned close to the original location (local recurrence) in 15.8% of patients, the cancer spread to other sites (systemic progression) in 18.8% of patients, and 11.4% died from prostate cancer. Patients with cancer in the seminal vesicles plus extracapsular extension had a 56% higher risk of the cancer spreading to other sites. They also had a 71% higher risk of dying from the cancer compared to patients with cancer in the seminal vesicles but no extracapsular extension.

Overall 29.5% of patients received hormone therapy after the prostate was removed. This decreased the risk of the cancer spreading by 50% and decreased the risk of death from the cancer by 43%.

The authors concluded that extracapsular extension is linked with an increased risk of the cancer spreading and of death from prostate cancer for patients with seminal vesicle invasion. They also suggest that these patients could benefit from hormone therapy after surgery.