Is primary prostate cancer treatment influenced by likelihood of extraprostatic disease? A surveillance, epidemiology and end results patterns of care study

Abstract

Purpose: To examine the patterns of primary treatment in a recent population-based cohort of prostate cancer patients, stratified by the likelihood of extraprostatic cancer as predicted by disease characteristics available at diagnosis.

Methods and materials: A total of 157,371 patients diagnosed from 2004 to 2008 with clinically localized and potentially curable (node-negative, nonmetastatic) prostate cancer, who have complete information on prostate-specific antigen, Gleason score, and clinical stage, were included. Patients with clinical T1/T2 disease were grouped into categories of <25%, 25%-50%, and >50% likelihood of having extraprostatic disease using the Partin nomogram. Clinical T3/T4 patients were examined separately as the highest-risk group. Logistic regression was used to examine the association between patient group and receipt of each primary treatment, adjusting for age, race, year of diagnosis, marital status, Surveillance, Epidemiology and End Results database region, and county-level education. Separate models were constructed for primary surgery, external-beam radiotherapy (RT), and conservative management.

Results: On multivariable analysis, increasing likelihood of extraprostatic disease was significantly associated with increasing use of RT and decreased conservative management. Use of surgery also increased. Patients with >50% likelihood of extraprostatic cancer had almost twice the odds of receiving prostatectomy as those with <25% likelihood, and T3-T4 patients had 18% higher odds. Prostatectomy use increased in recent years. Patients aged 76-80 years were likely to be managed conservatively, even those with a >50% likelihood of extraprostatic cancer (34%) and clinical T3-T4 disease (24%). The proportion of patients who received prostatectomy or conservative management was approximately 50% or slightly higher in all groups.

Conclusions: There may be underutilization of RT in older prostate cancer patients and those with likely extraprostatic disease. Because more than half of prostate cancer patients do not consult with a radiation oncologist, a multidisciplinary consultation may affect the treatment decision-making process.