William J. Catalona

Measurement of prostate-specific antigen in serum as a screening test for prostate cancer

BACKGROUND Prostate-specific antigen (PSA) is secreted exclusively by prostatic epithelial cells, and its serum concentration is increased in men with prostatic disease, including cancer. We evaluated its usefulness in the detection and staging of prostate cancer. METHODS We measured serum PSA concentrations in 1653 healthy men 50 or more years old. Those with PSA values greater than or equal to 4.0 micrograms per liter then underwent rectal examination and prostatic ultrasonography. Ultrasound-directed prostatic needle biopsies were performed in the men with abnormal findings on rectal examination, ultrasonography, or both. The results were compared with those in 300 consecutively studied men 50 or more years old who underwent ultrasound-directed biopsy because of symptoms or abnormal findings on rectal examination. RESULTS Serum PSA levels ranged from 4.0 to 9.9 micrograms per liter in 6.5 percent of the 1653 men (107). Nineteen of the 85 men in this group (22 percent) who had prostatic biopsies had prostate cancer. Serum PSA levels were 10.0 micrograms per liter or higher in 1.8 percent of the 1653 men (30). Eighteen of the 27 men in this group (67 percent) who had prostatic biopsies had cancer. If rectal examination alone had been used to screen the men who had biopsies, 12 of the 37 cancers (32 percent) would have been missed. If ultrasonography alone had been used to screen these men, 16 of the 37 cancers (43 percent) would have been missed. Serum PSA measurement had the lowest error rate of the tests, and PSA measurement plus rectal examination had the lowest error rate of the two-test combinations. CONCLUSIONS The combination of measurement of the serum PSA concentration and rectal examination, with ultrasonography performed in patients with abnormal findings, provides a better method of detecting prostate cancer than rectal examination alone.

Comparison of Digital Rectal Examination and Serum Prostate Specific Antigen in the Early Detection of Prostate Cancer: Results of a Multicenter Clinical Trial of 6,630 Men

&NA; To compare the efficacy of digital rectal examination and serum prostate specific antigen (PSA) in the early detection of prostate cancer, we conducted a prospective clinical trial at 6 university centers of 6,630 male volunteers 50 years old or older who underwent PSA determination (Hybritech Tandom‐E or Tandem‐R assays) and digital rectal examination. Quadrant biopsies were performed if the PSA level was greater than 4 &mgr;g./l. or digital rectal examination was suspicious, even if transrectal ultrasonography revealed no areas suspicious for cancer. The results showed that 15% of the men had a PSA level of greater than 4 &mgr;g./l., 15% had a suspicious digital rectal examination and 26% had suspicious findings on either or both tests. Of 1,167 biopsies performed cancer was detected in 264. PSA detected significantly more tumors (82%, 216 of 264 cancers) than digital rectal examination (55%, 146 of 264, p = 0.001). The cancer detection rate was 3.2% for digital rectal examination, 4.6% for PSA and 5.8% for the 2 methods combined. Positive predictive value was 32% for PSA and 21% for digital rectal examination. Of 160 patients who underwent radical prostatectomy and pathological staging 114 (71%) had organ confined cancer: PSA detected 85 (75%) and digital rectal examination detected 64 (56%, p = 0.003). Use of the 2 methods in combination increased detection of organ confined disease by 78% (50 of 64 cases) over digital rectal examination alone. If the performance of a biopsy would have required suspicious transrectal ultrasonography findings, nearly 40% of the tumors would have been missed. We conclude that the use of PSA in conjunction with digital rectal examination enhances early prostate cancer detection. Prostatic biopsy should be considered if either the PSA level is greater than 4 &mgr;g./l. or digital rectal examination is suspicious for cancer, even in the absence of abnormal transrectal ultrasonography findings.

Genome-wide association study identifies a second prostate cancer susceptibility variant at 8q24

Prostate cancer is the most prevalent noncutaneous cancer in males in developed regions, with African American men having among the highest worldwide incidence and mortality rates. Here we report a second genetic variant in the 8q24 region that, in conjunction with another variant we recently discovered, accounts for about 11%–13% of prostate cancer cases in individuals of European descent and 31% of cases in African Americans. We made the current discovery through a genome-wide association scan of 1,453 affected Icelandic individuals and 3,064 controls using the Illumina HumanHap300 BeadChip followed by four replication studies. A key step in the discovery was the construction of a 14-SNP haplotype that efficiently tags a relatively uncommon (2%–4%) susceptibility variant in individuals of European descent that happens to be very common (∼42%) in African Americans. The newly identified variant shows a stronger association with affected individuals who have an earlier age at diagnosis.

Potency, continence and complication rates in 1,870 consecutive radical retropubic prostatectomies.

PURPOSE We update results in a series of consecutive patients treated with anatomic radical retropubic prostatectomy regarding recovery of erections, urinary continence and postoperative complications. MATERIALS AND METHODS One surgeon performed anatomic radical retropubic prostatectomy on 1,870 men, using the nerve sparing modification when feasible. We evaluated recovery of erections and urinary continence in men followed for a minimum of 18 months. Patients who were not reliably potent before surgery, did not undergo a nerve sparing procedure, or received hormonal therapy or postoperative adjuvant radiotherapy were excluded from the analysis of potency rates but not of continence rates. Other postoperative complications were evaluated for the entire patient population. RESULTS Recovery of erections occurred in 68% of preoperatively potent men treated with bilateral (543 of 798) and 47% treated with unilateral (28 of 60) nerve sparing surgery. Recovery of erections was more likely with bilateral than with unilateral nerve sparing surgery in patients less than 70 years old (71 versus 48%, p<0.001) compared with patients with age 70 years old or older (48 versus 40%, p = 0.6). Recovery of urinary continence occurred in 92% (1,223 of 1,325 men) and was associated with younger age (p<0.0001) but not with tumor stage (p = 0.2) or nerve sparing surgery (p = 0.3). Postoperative complications occurred in 10% of patients overall and were associated with older age (p<0.002) but the incidence declined significantly with increasing experience of the surgeon (p<0.0001). There was no operative mortality. CONCLUSIONS Anatomic radical retropubic prostatectomy with the nerve sparing modification can be performed with favorable results in preserving potency and urinary continence. Better results are achieved in young men with organ confined cancer. Other complications can be reduced with increasing surgeon experience.

A common variant associated with prostate cancer in European and African populations

With the increasing incidence of prostate cancer, identifying common genetic variants that confer risk of the disease is important. Here we report such a variant on chromosome 8q24, a region initially identified through a study of Icelandic families. Allele −8 of the microsatellite DG8S737 was associated with prostate cancer in three case-control series of European ancestry from Iceland, Sweden and the US. The estimated odds ratio (OR) of the allele is 1.62 (P = 2.7 × 10−11). About 19% of affected men and 13% of the general population carry at least one copy, yielding a population attributable risk (PAR) of ∼8%. The association was also replicated in an African American case-control group with a similar OR, in which 41% of affected individuals and 30% of the population are carriers. This leads to a greater estimated PAR (16%) that may contribute to higher incidence of prostate cancer in African American men than in men of European ancestry.

Two variants on chromosome 17 confer prostate cancer risk, and the one in TCF2 protects against type 2 diabetes

We performed a genome-wide association scan to search for sequence variants conferring risk of prostate cancer using 1,501 Icelandic men with prostate cancer and 11,290 controls. Follow-up studies involving three additional case-control groups replicated an association of two variants on chromosome 17 with the disease. These two variants, 33 Mb apart, fall within a region previously implicated by family-based linkage studies on prostate cancer. The risks conferred by these variants are moderate individually (allele odds ratio of about 1.20), but because they are common, their joint population attributable risk is substantial. One of the variants is in TCF2 (HNF1β), a gene known to be mutated in individuals with maturity-onset diabetes of the young type 5. Results from eight case-control groups, including one West African and one Chinese, demonstrate that this variant confers protection against type 2 diabetes.

Incidence and Treatment of Complications of Bacillus Calmette-Guerin Intravesical Therapy in Superficial Bladder Cancer

Intravesical therapy with bacillus Calmette-Guerin (BCG) has proved to be more effective in the prophylaxis and treatment of superficial bladder tumors and carcinoma in situ than most chemotherapeutic agents. Compared to intravesical chemotherapy, instillations with BCG provoke more local and systemic reactions. In addition to the commonly induced granulomatous inflammatory changes in the bladder, which produce irritative symptoms, this therapy may cause systemic side effects varying from mild malaise and fever to, in rare instances, life-threatening or fatal sepsis. We report the incidence and varieties of toxicities in 2,602 patients treated with intravesical BCG. Side effects are classified according to local and systemic toxicity. Treatment options vary according to the severity of toxicity from delaying or withholding instillations to treatment with antituberculous drugs for up to 6 months. In general, 95% of the patients have no serious side effects. Recognition of risk factors, particularly traumatic catheterization or concurrent cystitis, that result in systemic BCG absorption, as well as the prompt and appropriate treatment of early side effects should significantly decrease the incidence of severe toxicity.

Serial Prostatic Biopsies in Men with Persistently Elevated Serum Prostate Specific Antigen Values

The objective of this study was to determine the need for repeat prostatic biopsies in men whose initial biopsy results revealed no evidence of cancer or atypia. We evaluated 1,136 men who underwent 1 or more prostatic biopsies in a longitudinal prostate specific antigen (PSA) based prostate cancer screening study that called for biopsy if the serum PSA level was greater than 4.0 ng./ml. (Hybritech assay) and findings on rectal examination or ultrasonography were abnormal or suspicious for cancer. Of the 1,136 men who underwent prostatic biopsy 391 (34%) had prostate cancer on the initial biopsy. Of 427 men who had negative initial biopsy results, a persistent serum PSA level of greater than 4.0 ng./ml. and abnormal rectal or ultrasound examination findings 82 (19%) had cancer on biopsy 2. Of 203 men with persistent abnormalities 16 (8%) had cancer on biopsy 3 and 6 of 91 (7%) had cancer on biopsy 4 or later. Thus, 96% of the cancers were detected through either biopsy 1 or 2. The median initial PSA level, followup PSA levels and the yearly rate of change in PSA were significantly greater in men whose cancer was detected compared with those of men whose cancer was not detected (6.4 versus 5.4 ng./ml., 7.4 versus 6.6 ng./ml. and 1.1 versus 0.7 ng./ml. per year, respectively). There was a trend for a higher percentage of tumors detected through serial screening to be pathologically organ confined with those detected through initial screening (73% versus 62%, p = 0.07). We conclude that men with a persistently elevated serum PSA value after an initial negative prostatic biopsy should routinely undergo at least 1 repeat biopsy to exclude adequately the presence of detectable prostate cancer.

Sequence variants at the TERT-CLPTM1L locus associate with many cancer types

The common sequence variants that have recently been associated with cancer risk are particular to a single cancer type or at most two. Following up on our genome-wide scan of basal cell carcinoma, we found that rs401681[C] on chromosome 5p15.33 satisfied our threshold for genome-wide significance (OR = 1.25, P = 3.7 × 10−12). We tested rs401681 for association with 16 additional cancer types in over 30,000 cancer cases and 45,000 controls and found association with lung cancer (OR = 1.15, P = 7.2 × 10−8) and urinary bladder, prostate and cervix cancer (ORs = 1.07−1.31, all P < 4 × 10−4). However, rs401681[C] seems to confer protection against cutaneous melanoma (OR = 0.88, P = 8.0 × 10−4). Notably, most of these cancer types have a strong environmental component to their risk. Investigation of the region led us to rs2736098[A], which showed stronger association with some cancer types. However, neither variant could fully account for the association of the other. rs2736098 corresponds to A305A in the telomerase reverse transcriptase (TERT) protein and rs401681 is in an intron of the CLPTM1L gene.

5-Year Tumor Recurrence Rates After Anatomical Radical Retropubic Prostatectomy For Prostate Cancer

The new anatomical approach to radical retropubic prostatectomy with its nerve sparing option allows for preservation of erections, improved urinary continence, decreased blood loss, and lower operative mortality and morbidity rates. We sought to evaluate cancer control with this operation by determining the 5-year tumor recurrence rates using detectable serum prostate specific antigen levels as a criterion for tumor recurrence in a series of 925 consecutive men with clinical stage T1 or T2 prostate cancer. Overall, the 5-year probability of nonprogression was 78% (95% confidence limits 74 to 82%). The 5-year nonprogression rate was higher in patients whose tumors were not palpable (90% for impalpable tumors detected through transurethral resection of the prostate, 97% for impalpable prostate specific antigen detected tumors and 74% for palpable tumors). Nonprogression correlated with pathological tumor stage (91% for organ confined disease, 74% for positive margins or microscopic capsular perforation, 32% for seminal vesical invasion and virtually nil for lymph node metastases) and tumor grade (89% for well, 78% for moderately and 51% for poorly differentiated tumors). We conclude that anatomical radical prostatectomy achieves excellent cancer control for patients with organ confined prostate cancer.