Prostate Cancer Symptoms and Treatment

by Sarah Guy | MedwireNews | 11.11.2009

Patients with high-risk prostate cancer whose tumors are located in the transitional zone (TZ) have better outcomes than men with tumors located in the peripheral zone (PZ), except if they have high-grade disease, report U.S. researchers.

Researchers found that prostate cancer patients with large tumors, a high pre-operative prostate-specific antigen (PSA) level, low Gleason score, and high PSA velocity have better 5-year rates of biochemical relapse-free survival (bRFS) rates if these tumors are located in the TZ rather than the PZ.

“Our findings suggest that accurate characterization of tumor location could contribute to prediction of bRFS after radical prostatectomy,” say Christopher King and team, from Stanford University School of Medicine in California, USA, in the journal Urologic Oncology.

However, location had no effect on the bRFS if prostate cancer patients had small tumors, low pre-operative PSA, low PSA velocity, or high Gleason score.

The researchers reviewed the medical records of 494 radical prostatectomy patients. They compared all TZ and PZ tumors according to known clinical and pathologic prognostic factors including stage, pre-operative PSA level, pathologic Gleason grade, and total cancer volume.

Biochemical failure occurred in 23% of PZ patients and 16% of TZ patients, after a median period of 1.5 years. Compared with patients with PZ cancers, TZ cancer patients had a higher median pre-operative PSA value (10.8 vs 7.4 ng/ml) and tumor volume (4.4 vs 2.3 cc), and were more likely to have nonpalpable disease (T1c, 78% vs 51%).

The researchers found that men whose TZ tumors were greater than 2 cc in volume had an 81% 5-year bRFS rate compared with 65% in men with PZ tumors of the same volume.

Furthermore, 5-year bRFS rates were worse for TZ cancer patients with a pre-operative PSA level above 10 ng/ml, and those with a PSA velocity of more than 2 ng/ml, compared with PZ cancer patients, at 80% vs 59%, and 85% vs 66%, respectively.

However, patients with a high Gleason score, indicating high-grade disease, had low bRFS rates irrespective of where their tumors were located.

“Our study confirms the prevalence of TZ cancers and their clinical and biologic difference with PZ prostate cancers,” say King et al.

“It also demonstrates the relative importance in identifying these cancers, both within the context of analyzing outcomes after primary therapy and in the context of assessing individual prognostic groups at the time of patient counseling,” they conclude.

Copyright Medwire News 2009