Comparison of clinical and pathologic findings of prostate cancers detected through screening versus conventional referral in Brazil

Abstract

Introduction: Data regarding prostate cancer screening in Brazil are limited. We compared features of prostate cancers detected through screening versus those referred for treatment in Brazil.

Patients and methods: Group I included 500 of 13,754 men whose cancers were detected through screening, and Group II included 2731 men referred for treatment through the habitual public health system. We used Mann-Whitney and χ(2) tests to compare clinical and pathologic findings, considering significant any P < 0.05.

Results: Median prostate-specific antigen (PSA) was lower among screened patients (5.5 ng/mL versus 10.0 ng/mL; P < 0.001). Of the screened patients, 170 (34%) had biopsy Gleason score ≥ 7, compared with 1265 (46.3%) in the referred group (P < 0.001). Lymph node metastases were suspected in 8.6% of the referred versus 3.2% of the screened men (P = 0.002). Distant metastases were more common in the referred men (9.3% vs. 3.0%; P < 0.001). Only 6.0% of the screened cancers were locally advanced at diagnosis (T3 or T4) versus 26.5% of the referred (P < 0.001). Screened patients had a higher proportion of localized tumors after surgery (67.7% vs. 54.2%; P = 0.002). Pathology Gleason scores were also lower among screened men (P < 0.01). Lymphadenectomies were performed in 166/636 men (26.1%). No nodal metastases were found in screened cancers (0/28; 0.0%), while 6/138 referred cancers (4.3%) presented nodal involvement (P = 0.3).

Conclusion: Clinical and pathologic characteristics of screen-detected cancers are more favorable than those of tumors diagnosed through the Brazilian health system.