Screening for prostatic carcinoma

Clinical Utility of Epigenetic Changes in Pancreatic Adenocarcinoma

Pancreatic cancer is a molecularly heterogeneous disease. Epigenetic changes and epigenetic regulatory mechanisms underlie at least some of this heterogeneity and contribute to the evolution of aggressive tumor biology in patients and the tumor's intrinsic resistance to therapy. Here we review our current understanding of epigenetic dysregulation in pancreatic cancer and how it is contributing to our efforts in early diagnosis, predictive and prognostic biomarker development and new therapeutic approaches in this deadly cancer.

The changing face of central chondrosarcoma of bone. One UK-based orthopaedic oncology unit's experience of 33 years referrals

AIM

To ascertain the changing incidence over time of the three commonest primary sarcomas of bone. Data obtained with particular reference to central chondrosarcoma from the annual referral rate to a large UK-based specialist orthopaedic oncology unit. To discuss how the "barnyard pen" analogy of cancers previously applied to certain commoner cancers can also be applicable to central chondrosarcoma (CS) of bone.

MATERIALS AND METHODS

A retrospective review was conducted of a computerised database identifying all central cartilage tumours (CCT) of bone, including enchondroma and CS subtypes, between 1985 and 2018. These were compared with the referrals of the other two commonest primary sarcomas of bone, osteosarcoma and Ewing sarcoma.

RESULTS

There was a total of 1507 CS showing a 68% overall increase in annual referral rate/incidence over the study period. 68% cases were the borderline malignant lesions now known as atypical cartilaginous tumour (ACT). The annual referral rate/incidence of this entity increased by 194% over the 30 years. Whereas, the annual referral rate/incidence for osteosarcoma and Ewing sarcoma was static for the past 20 years.

CONCLUSION

The annual incidence of central CS of bone showed a marked increase over the 33-year period as compared with both osteosarcoma and Ewing sarcoma. This is especially in the ACT category and is thought to be due to the increased provision of MRI scanning flagging up a rise in incidental findings. The spectrum of CCTs from benign to highly malignant elegantly fits the "barn yard" pen analogy and could prove useful as an explanatory tool for patients and clinicians unfamiliar with these diseases.

The Use of Monoclonal Antibodies for Radioscintigraphic Detection of Cancer

Beginning with Ehrlich's original “magic bullet” concept of 1904, the pioneering human trials in the late 1970s of Goldenberg and Mach using polyclonal antibodies, and the Nobel Prize-winning work of Kohler and Milstein in 1975 for developing monoclonal antibody (MAb) technology, there has been much interest in the use of antibodies for detecting and treating cancer. Although not the revolutionary breakthrough that was initially hoped for, marked progress has been made. The Food and Drug Administration (FDA) has recently approved the intact murine IgG, 111-indium CYT-103 (satumomoab, Oncoscint™ Cytogen, Princeton, NJ) for clinical use in detecting colorectal and ovarian cancer. However, the agent has been approved for only a single, one-time use, because patients developed an immune response (human anti-mouse antibody, or HAMA) that alters MAb biodistribution and may limit the clinical effectiveness of this agent when repeat studies are performed. Other MAbs reacting with a variety of antigens and targeting numerous tumors, including breast, lung, prostate, and melanomas, are currently undergoing large-scale clinical trials. To reduce induction of immune responses, many of the agents use immunoglobulin fragments [Fab, or F(ab)2] labeled with the short-lived isotope 99m-technetium used for most routine nuclear medicine diagnostic testing. Future developments will use even smaller fragments such as single chain antibodies or custom synthesized molecular recognition units (small peptides containing only the specific antigen combining site). Presented herein is an overview of the past results and an assessment of the current status of radioimmunoscintigraphy for various neoplasms.

Pharmacokinetics of dehydroepiandrosterone and its metabolites after long-term daily oral administration to healthy young men

OBJECTIVE

To determine the effects of dehydroepiandrosterone (DHEA) supplementation on the pharmacokinetics of DHEA and its metabolites and the reproductive axis of healthy young men.

DESIGN

A prospective, randomized, double-blind, placebo-controlled pharmacokinetic study.

SETTING

General Clinical Research Center and laboratories at the Keck School of Medicine of the University of Southern California, Los Angeles, California.

PATIENT(S)

Fourteen healthy men, ages 18-42 years.

INTERVENTION(S)

Daily oral administration of placebo (n = 5), 50 mg DHEA (n = 4), or 200 mg DHEA (n = 5) for 6 months. Blood samples were collected at frequent intervals on day 1 and at months 3 and 6 of treatment.

MAIN OUTCOME MEASURE(S)

Quantification of DHEA, DHEA sulfate (DHEAS), androstenedione, T, E(2), dihydrotestosterone (DHT), and 5alpha-androstane-3alpha-17beta-diol glucuronide (ADG). Physical examination, semen analysis, serum LH, FSH, prostate-specific antigen, and general chemistries were carried out.

RESULT(S)

Baseline DHEA, DHEAS, and ADG levels increased significantly from day 1 to months 3 and 6 in the DHEA treatment groups but not in the placebo group. No significant changes were observed in pharmacokinetic values. Clinical parameters were not affected.

CONCLUSION(S)

DHEA, DHEAS, and ADG increased significantly during 6 months of daily DHEA supplementation. Although the pharmacokinetics of DHEA and its metabolites are not altered, sustained baseline elevation of ADG, a distal DHT metabolite, raises concerns about the potential negative impact of DHEA supplementation on the prostate gland.

Using gray-scale and two different techniques of color Doppler sonography to detect prostate cancer

OBJECTIVES

To correlate the findings of prostate color Doppler sonography (CDS) with those of site-specific transrectal ultrasound-guided core biopsy; to evaluate the significance of two different color presets in detecting prostate cancer compared with gray-scale transrectal ultrasonography; and to compare the accuracy of conventional gray-scale transrectal ultrasound (CGS)-guided biopsy with CDS-guided biopsy.

METHODS

Seventy patients were enrolled in this prospective study. CDS was performed before biopsy. Two color presets were used: CDS-1 (high sensitivity) and CDS-2 (high specificity). The color flow was graded on a scale from 0 to 2+. At the completion of the color grading, color maps were constructed. In each case, CDS-guided biopsy was performed followed by CGS-guided biopsy (six sextant biopsies and focal lesional biopsies).

RESULTS

The cancer detection rate was 33%, 31%, and 27% for CGS-guided biopsy, CDS-1, and CDS-2, respectively. CDS-1 was more sensitive than CDS-2 (81% versus 60%) but both presets had similar specificities (79% versus 82%). CGS-guided biopsy yielded a sensitivity of 90%, a specificity of 38%, and a positive and negative predictive value of 34% and 83%, respectively. A biopsy strategy combining hypoechoicity with increased color flow increased the specificity to 97%, positive predictive value to 68%, and negative predictive value to 84%, but its sensitivity was low (18%).

CONCLUSIONS

Our experience suggests that low-velocity, high-sensitivity color is superior to all other CDS settings. The presence of focal peripheral zone hypervascularity at CDS is associated with a high likelihood of prostate cancer. However, only a combination of CDS guidance with six sextant biopsies may achieve maximal sensitivity and specificity.

A quantitative analysis of the costs and benefits of prostate cancer screening

The present study attempts to quantitate in an economically and clinically meaningful manner the cost and cost-effectiveness of prostate cancer screening and subsequent treatment, including complications from that treatment. Outcome data from large prostate cancer screening trials using prostate specific antigen (PSA) and digital rectal examination (DRE) and PSA alone were used to construct the screening model. The benefit of screening is expressed in years of life saved by screening, which is calculated by comparing the survival rate of men with prostate cancer to the survival rate of men in the general population. The cost of screening, treatment, and complications were estimated using the Medicare data base and published reports on the cost, morbidity and mortality for radical prostatectomy. The cost per year of life saved by prostate cancer screening with PSA and DRE was $2339-3005 for men aged 50-59, $3905-5070 for men aged 60-69, and $3574-4627 overall for men aged 50-69. The cost per year of life saved by prostate cancer screening with PSA alone for men aged 50-70 was $3822-4956. A sensitivity analysis demonstrates that the cost per year of life saved by prostate cancer screening will not change substantially even if the assumptions in this model have been underestimated or overestimated by 100%. This study quantifies only those parameters which can be reliably compared in concrete terms such as dollars, treatment impact on survival, published complication rates and published treatment costs. Using this type of analysis, prostate cancer screening appears to be a cost-effective intervention. However, the issue of whether prostate cancer screening is cost-effective will be decided definitively only when randomized, controlled trials are available to quantify the costs and benefits of prostate cancer screening.Prostate Cancer and Prostatic Diseases (2001) 4, 138-145.

Endocrine and lipid responses to chronic androstenediol-herbal supplementation in 30 to 58 year old men

OBJECTIVE

The effectiveness of an androgenic nutritional supplement designed to enhance serum testosterone concentrations and prevent the formation of dihydrotestosterone and estrogen was investigated in healthy 3 to 58 year old men.

DESIGN

Subjects were randomly assigned to consume a nutritional supplement (AND-HB) containing 300-mg androstenediol, 480-mg saw palmetto, 450-mg indole-3-carbinol, 300-mg chrysin, 1,500 mg gamma-linolenic acid and 1.350-mg Tribulus terrestris per day (n = 28), or placebo (n = 27) for 28 days. Subjects were stratified into age groups to represent the fourth (30 year olds, n = 20), fifth (40 year olds, n = 20) and sixth (50 year olds, n = 16) decades of life.

MEASUREMENTS

Serum free testosterone, total testosterone, androstenedione, dihydrotestosterone, estradiol, prostate specific antigen and lipid concentrations were measured before supplementation and weekly for four weeks.

RESULTS

Basal serum total testosterone, estradiol, and prostate specific antigen (PSA) concentrations were not different between age groups. Basal serum free testosterone concentrations were higher (p < 0.05) in the 30- (70.5 +/- 3.6 pmol/L) than in the 50 year olds (50.8 +/- 4.5 pmol/L). Basal serum androstenedione and dihydrotestosterone (DHT) concentrations were significantly higher in the 30- (for androstenedione and DHT, respectively, 10.4 +/- 0.6 nmol/L and 2198.2 +/- 166.5 pmol/L) than in the 40- (6.8 +/- 0.5 nmol/L and 1736.8 +/- 152.0 pmol/L) or 50 year olds (6.0 +/- 0.7 nmol/L and 1983.7 +/- 147.8 pmol/L). Basal serum hormone concentrations did not differ between the treatment groups. Serum concentrations of total testosterone and PSA were unchanged by supplementation. Ingestion of AND-HB resulted in increased (p < 0.05) serum androstenedione (174%), free testosterone (37%), DHT (57%) and estradiol (86%) throughout the four weeks. There was no relationship between the increases in serum free testosterone, androstenedione, DHT, or estradiol and age (r2 = 0.08, 0.03, 0.05 and 0.02, respectively). Serum HDL-C concentrations were reduced (p < 0.05) by 0.14 mmol/L in AND-HB.

CONCLUSIONS

These data indicate that ingestion of androstenediol combined with herbal products does not prevent the formation of estradiol and dihydrotestosterone.

The usefulness of power Doppler ultrasonography for diagnosing prostate cancer: histological correlation of each biopsy site

OBJECTIVE

To correlate the findings of power Doppler ultrasonography (PDUS) of the prostate with those of site-specific transrectal ultrasonography (TRUS)-guided biopsy.

PATIENTS AND METHODS

The study comprised 28 patients referred to our institution for TRUS-guided prostate biopsy because of an elevated PSA level and/or abnormal digital rectal examination. PDUS findings were graded 0, 1 or 2; grades 0-1 were considered as negative and grade 2 as positive. The blood volume of each biopsy site was also determined using the mean number (MN) value that represents the average vascularity in a 5-mm square sample. PDUS values were correlated with the histological findings of 147 biopsies with 19 focal lesions.

RESULTS

Grade 2 was assigned to 19 sites, grade 1 to 52 sites, and grade 0 to 76 sites. Fourteen of the 19 PDUS findings of grade 2 sites revealed carcinoma and five were grade 1. Ten of 35 TRUS-positive sites were carcinomas, three benign prostatic hyperplasia (BPH) and 22 normal. The MN value for prostatic carcinoma was 4.33, for BPH 11.7 and for normal tissue 4.7. The overall sensitivity of PDUS was 74%, the specificity 96% and the positive predictive value 74%.

CONCLUSIONS

Because TRUS alone cannot detect all cancers, PDUS should be used routinely in all patients undergoing TRUS-guided biopsy, to improve the diagnostic yield of prostate cancer.

Screening for prostate cancer is neither appropriate nor cost-effective

Seen from a societal perspective, the health gains that might result from prostate screening are too uncertain to justify the substantial associated costs and adverse health effects. Clinicians who rely on observational screening studies to justify current screening practices should be aware of the potential biases that render conclusions suspect. Medical history documents numerous cases of medical interventions that appeared reasonable at the time, but ultimately proved worthless and even harmful. Before embarking on an ambitious screening program for prostate cancer, clinicians should demand that five basic criteria are satisfied: (1) that prostate cancer is a significant health burden, (2) that screening can identify localized disease, (3) that tests used in screening programs have acceptable performance among the population being tested, (4) that the potential for cure is greater among patients with screen-detected disease, and (5) that screen-detected patients have improved health outcomes compared with those who are not screened. Randomized trials provide the best methodology for determining the efficacy of screening and treatment. Clinicians are often too quick to credit medical intervention for successful outcomes and blame tumor biology for disease progression. Furthermore, when faced with a decision of administering or withholding therapy, physicians generally wish to err on the side of having done everything possible. Data modeling can provide critical insights concerning these issues using currently available information. Three recently published models suggest that the overall benefit to a population of men screened for prostate cancer can be measured in days of additional time of life gained, not months or years. Furthermore, models suggest that a substantial number of men need to undergo treatment in order to avert a single cancer death. The costs of implementing a screening program are enormous and deflect resources away from alternative uses, such as increased basic science funding to identify a cure for this disease. Therefore, based on the evidence presented, I believe that without more substantial data supporting the efficacy of screening programs, screening for prostate cancer is neither appropriate nor cost-effective.

Incidental Prostatic Carcinoma

Incidental carcinoma of the prostate is defined as an incidentally detected cancer without any clinical manifestation, i.e. latent. Clinically, it is diagnosed mostly by TUR and is staged as T1a and T1b according to the TNM classification. There is clinical understaging, however, of up to 27% for T1a and 68% for T1b. Although the subdivision seems justifiable on the basis of the progression rates (8% and 63% respectively), it is not a useful indicator of the natural history of the incidental carcinoma. Pathological staging of TUR specimens is far from standardized, with regard to both the different sampling methods and the commonly-used classifications. Since the T1 staging system is based more on how the cancer is identified than on classifying its pathology, different methods should be used for a full clinical understanding of an incidental carcinoma. Distinguishing cancers as clinically important or not allows a better prognostic indication compared to the staging systems, which can still not be considered as precise indicators of whether to treat the cancer or wait and see. Unfortunately the true prognostic factors cannot be directly deduced from the currently used sampling methods of TUR specimens. A complete diagnostic assessment should be carried out after initial diagnosis of incidental prostatic cancer in order to appreciate its clinical importance. Basically both revision of the material by the pathologist and further clinical investigation are useful. Lastly, the need for close co-operation between urologists and pathologists should be stressed.

Geriatric health maintenance

OBJECTIVE

To highlight articles pertaining to geriatric health maintenance and provide clinicians with current evidence supportive of or opposed to screening or treatment for various diseases and conditions.

METHOD

We conducted a computer-assisted search of the relevant medical literature and summarized the results of pertinent studies in the elderly population.

RESULTS

The geriatric population is progressively increasing in numbers. Unfortunately, no consensus exists about health maintenance in this population. To date, the United States Preventive Services Task Force has made several recommendations about preventive services; however, they did not specifically focus on the geriatric age-group. We outline their guidelines and discuss our clinical practices in a wide variety of encounters with geriatric patients.

CONCLUSION

The efficacy of many screening tests and interventions for preventing illness in elderly patients is unclear. As the general population continues to age, further research in this area will be important.

Ruolo dell'ER e del PSA nello screening per la diagnosi precoce del carcinoma prostatico:The role of ER and PSA in screening for early diagnosis of prostatic carcinoma

From September 1992 to February 1994, 1441 men aged between 50 and 70 years underwent screening with PSA and ER measurement for early diagnosis of prostatic carcinoma. A neoplasm was diagnosed in 1.73% (25/1441) of cases, which being found at an early stage, made it possible to perform prostatectomy and radical radiotherapy on 37.5% and 16.6% of patients respectively. The incidence of the disease was higher than in a previous screening with just ER dosage (1.73% vs 1.1%). Combined PSA and ER also gave higher sensitivity, specificity, overall accuracy and predictiveness compared to the methods taken individually. This combination seems preferable, in view of the greater efficacy and “practicability” compared to protocols which involve the use of USTR, which is less practicable on a large scale due to the length of time required and high costs. The utility of periodic determination of PSA levels in those over fifty years old is emphasised, both for oncological screening controls and to increase the diagnostic accuracy of other clinical tests.

The use of prostate specific antigen for prostate cancer screening: a managed care perspective

A large nonprofit staff model Health Maintenance Organization experienced increased use of prostate specific antigen (PSA) as a screening test for prostate cancer beginning in May 1991. A critical evaluation of the evidence in support of PSA screening was done and concluded that the use of PSA to screen for prostate cancer did not meet the criteria for an effective screening program. A guideline stating that PSA was not recommended as a screening test was implemented focusing on a model of shared decision making. PSA test ordering decreased significantly when patients were fully informed about the evidence for PSA screening. If PSA screening had continued at the peak rate, the cascade of intervention initiated by screening would have resulted in significant complications and approximately $4,800,000 in increased costs.

Influence of initial presentation on treatment outcome of clinically localized prostate cancer treated by definitive radiation therapy

PURPOSE

The increasing proportion of early stage prostate cancer diagnosed by various early detection methods together with reports espousing watchful waiting as a management option raise the possibility that patients may be selected for surveillance according to their initial presentation.

METHODS AND MATERIALS

The outcome for 427 men with clinical stages T1 to T4 localized prostate cancer treated with radiation therapy was evaluated according to their presentation: elevated prostate-specific antigen (PSA) level; abnormal digital rectal examination; or, urologic symptomatology.

RESULTS

With a median follow-up of 30 months, there were no significant differences in disease outcome according to initial presentation. The actuarial incidence of relapse at 5 years was: PSA-detected (54 patients), 24%; digital rectal-detected (173 patients) 29%; and, symptom-detected (200 patients) 31% (p = 0.79). Likewise, there were no significant differences in the incidence of postradiation rising PSA profiles among the three groups. The actuarial incidence of relapse and/or rising PSA at 5 years was: PSA-detected 35%; digital rectal-detected 42%; symptom-detected, 48% (p = 0.72). On the other hand, T-stage, Gleason grade, pretreatment PSA, pretreatment acid phosphatase, and transurethral resection in T3/T4 disease were each highly correlated with outcome. In multivariate proportional hazards regression pretreatment PSA (p = 0.0003), Gleason grade (p = 0.045), and transurethral resection in T3/T4 disease (p = 0.0562) correlated with outcome, but initial presentation did not (p = 0.25).

CONCLUSION

The absence of a prognostic gradient, good to bad, from PSA-detected through digital rectal-detected to symptom-detected cancer suggests that the initial presentation of patients with localized prostate cancer is not a valid basis for selecting watchful waiting vs. initial treatment.

Detection of prostate cancer in males with prostatism

The present study was designed to compare the prostate cancer detection rate, sensitivity, specificity, and positive predictive value of digital rectal examination (DRE) and serum prostatic specific antigen (PSA) in a consecutive cohort of males presenting to a single institution with clinically significant prostatism. The study population was comprised of 224 consecutive males with clinically significant prostatism referred to the Prostate Center at the Medical College of Wisconsin between June 1990 and December 1991. Subjects were considered to have clinically significant prostatism if they elected to pursue medical or surgical therapy following exclusion of carcinoma of the prostate. The initial examination consisted of a Boyarsky symptom score assessment, DRE, uroflowmetry, postvoid residual determination, serum PSA level, and transrectal prostatic ultrasonography. Subjects with an abnormality on DRE or serum PSA > 4 ng/dl were advised to undergo transrectal prostatic biopsy. Of the 224 subjects, 40 (17.9%) had an abnormal DRE and 57 (25.4%) had an elevated serum PSA > 4 ng/dl. The overall detection rate of prostate cancer in the study population was 6.7%. The prostate cancer detection rates for PSA alone and DRE alone were 5.8% and 5.3%, respectively. The sensitivity, specificity, and positive predictive values of PSA alone were 86.7%, 80.9%, and 25.0% and of DRE alone 80.0%, 86.3%, and 30.0%, respectively. Receiver operator characteristic (ROC) curves were constructed for the entire study population in order to compare the screening measures serum PSA and PSA density. The area under the curves was 0.88 for both tests, indicating that these screening tests for prostate cancer were not significantly different. The present study demonstrated that males with clinically significant prostatism represent a high risk cohort for detecting prostate cancer. DRE and PSA are equally effective measures for detecting prostate cancer. PSA density does not offer any advantage over serum PSA in screening for prostate cancer, except in the subset of patients with a normal DRE and serum PSA levels between 4.0 and 9.9 ng/dl.

Chemoprevention of prostate cancer

Primary prevention of prostate cancer is a relatively new concept. Through large-scale studies it is possible that we may be able to define better the risk for prostate cancer and identify those who would benefit from an intervention to lower their risk of disease. As risk for prostate cancer is better defined, a number of interventions may eventually be tested. Several interventions are sufficiently mature that they can be implemented in large-scale trials. Diet modification is an intervention that is ready for evaluation. It may also have additional benefits by decreasing mortality from other malignancies and cardiac disease. 5 alpha-reductase inhibitors are also ready for testing. The National Cancer Institute and its clinical cooperative groups have begun a large trial to assess finasteride in the prevention of prostate cancer.

Characteristics of men reporting for prostate cancer screening

A survey to determine demographics, prostate cancer screening practices, and prostate cancer-related knowledge and beliefs was administered to over 1,700 participants at five sites during Prostate Cancer Awareness Week (1991) screening events. Findings are presented by site since significant differences in demographics existed. Results suggest that screenings conducted at the major medical centers attract primarily white males, a number of whom already practice adequate secondary prevention. Thus, if optimal benefit is sought through mass prostate cancer screening, innovative strategies to reach populations that are currently underserved and at risk are necessary.

Prostate cancer: screening and early detection update

Many questions still exist about the etiology of prostate cancer. Prostate cancer screening methods continue to evolve. The following four findings are important to remember: (1) PSA is organ specific, not cancer specific, (2) DRE remains the standard method for screening, (3) TRUS continues to evolve but is currently too expensive to use as a screening modality, and (4) a combination of DRE and PSA is the most effective and cost-efficient screening method. Although screening methods are controversial, mass screening for prostate cancer is already occurring in several cities in the United States. An understanding of the value and limitations of the available screening tools is essential.

Prostate cancer. Finding and managing it

Despite development of new technology for the diagnosis and treatment of prostate cancer, the age-adjusted mortality rate for the disease has not declined for nearly half a century. Physicians now have the ability to diagnose very small tumors in asymptomatic patients, but it remains to be determined which subset of patients would benefit most from early identification and treatment. Studies that are currently under way hopefully will clarify what screening protocols, if any, actually reduce the mortality and morbidity that are associated with prostate cancer and its treatment. Until such evidence becomes available, screening measures for the general population are unwarranted, with the possible exception of digital rectal examination performed as part of other healthcare services. Prostate-specific antigen (PSA) determination may have a place in screening patients whose family history puts them at increased risk. In patients with symptoms or findings suggestive of prostate cancer, diagnosis and staging can be accomplished more accurately and easily than ever before with a combination of PSA determination, transrectal ultrasound, ultrasound-guided tissue sampling using a biopsy gun, and the judicious use of imaging techniques such as bone scans, magnetic resonance imaging, and computed tomography. New treatment methods are being studied, and the options available, especially for management of disease progression, are expected to increase. Monitoring of treated patients has been greatly facilitated by determination of PSA levels, which are predictive of both long- and short-term prognosis. Although much work remains to be done, we may finally be on the verge of making real progress in control of prostate cancer.

The association of benign prostatic hyperplasia and cancer of the prostate

There are a number of similarities between benign prostatic hyperplasia (BPH) and cancer. Both display a parallel increase in prevalence with patient age according to autopsy studies (86.2% and 43.6%, respectively, by the ninth decade), although cancer lags by 15-20 years. Both require androgens for growth and development, and both respond to antiandrogen treatment regimens. Most cancers arise in prostates with concomitant BPH (83.3%), and cancer is found incidentally in a significant number of transurethral prostatectomy (TURP) specimens (10%). The clinical incidence of cancer arising in patients with surgically treated BPH is approximately 3%. BPH may be related to a subset of prostate cancer which arises in the transition zone, perhaps in association with atypical adenomatous hyperplasia (AAH). It is important to exclude cancer in patients presenting with symptoms of bladder outlet obstruction presumably due to BPH. For such patients, we recommend digital rectal examination (DRE) and, at least in high-risk patients, serum prostate specific antigen (PSA) determination. Transrectal ultrasound (TRUS) should be employed in patients with elevated PSA levels to determine the volume of the prostate, the relative contribution of BPH to volume, and the PSA density (ratio of PSA level to volume). Biopsy should be obtained from any area suspicious for cancer. Early detection and treatment of cancer when it is localized offers the greatest chance for cure.

Prostate-specific antigen and digital rectal examination in long-term follow-up of stage A1 prostatic carcinoma

Twenty-six individuals with Stage A1 carcinoma of the prostate (less than or equal to 5%, Gleason score less than or equal to 4) diagnosed from 1969 to 1980 were evaluated with digital rectal examination (DRE) and prostate-specific antigen (PSA). This unique cohort, sixty-one to eight-two years of age (median 72 years), had a mean interval from diagnosis of thirteen years (median 12.5 years). Abnormal findings on DRE were found in 6 individuals, whereas only one elevated PSA was detected. Ninety-six percent of the PSA levels were less than 3.0 ng/mL and nearly 60 percent of the group had 1.0 ng/mL or less. These levels compare favorably with healthy control subjects under forty years of age and with the limited data available for PSA in healthy men over seventy years of age (87% and 26%, respectively). While biopsy showed persistent or recurrent carcinoma in 2 of 5 individuals, further evaluation disclosed only localized disease. Though the PSA provided little additional information to DRE in the individual patient, it appears from an overview of this group that a low level of PSA in Stage A1 prostatic carcinoma may be associated with long-term survival.

Validity of Transrectal Ultrasonography in the Early Diagnosis and Staging of Prostatic Cancer

In 3 years of mass screening for early diagnosis of prostatic cancer, 57 tumors were found (57/5000, for a detection rate of 1.2%). Patients first underwent digital rectal examination (DRE): at present the least expensive, least invasive and most effective way to diagnose prostatic cancer. 420 men underwent transrectal ultrasonography (TRUS) with a 5 MHz transverse and longitudinal transducer for pathological digital rectal findings, obstructive symptoms and other reasons. Prostatic biopsy was performed in 190 patients with DRE findings and/or hypoechoic zones of the prostatic gland (transrectal digitally directed or ultrasonically perineal guided biopsies). The specificity, sensitivity and prediction capacity of DRE and TRUS in this group of patients was evaluated. Sensitivity of DRE was 92%, specificity 42% (usual finding for mass screening); predictive positive value was 41 %, negative 93%. Sensitivity of TRUS was 77%, specificity 57%, predictive positive value was 44%, negative 86%. Data seem to confirm the ability of TRUS to reduce the number of “false positives” after DRE (and consequently the number of biopsies). However, contraindications for use in mass screenings are: sensitivity lower than with DRE, high false positive rate and prohibitive cost for systematic use. Validity of TRUS is confirmed in clinical staging for the selection of patients undergoing radical retropubic prostatectomy, by comparison with local pathological staging.

Early detection of prostate cancer

Prostate cancer is unique among the potentially lethal human malignancies in the wide discrepancy between the high prevalence of histologic changes recognizable as cancer and the much lower prevalence of the clinical disease. Despite the availability of effective tests for early detection and of effective treatment for cancers so detected, the diagnosis usually is not established until the tumor is locally advanced or metastatic. Yet, physicians hesitate to use these tests for fear that many cancers found would be latent, of little threat to the life or health of the host, and treatment could introduce inappropriate morbidity. Latent or "clinically unimportant" cancers can be distinguished from those that are clinically important by the larger volume, higher grade, and greater invasiveness of the latter. The available tests can detect only those cancers large enough to be palpable, visible on ultrasound, or capable of elevating the serum level of prostate-specific antigen. Such cancers are clinically important and should be treated for cure if the life expectancy of the patient is sufficiently long and the morbidity rate of therapy is low. Early detection of prostate cancer using the tests that are available today may widen the window of opportunity so that treatment indeed becomes possible in those for whom it is necessary.

Repeated screening for carcinoma of the prostate by digital rectal examination in a randomly selected population

Of 9,026 males aged 50-69 years, 1,494 were randomly selected and invited to participate in a programme including two screenings for carcinoma of the prostate by digital rectal examination performed in 1987 and 1990. The remaining 7,532 served as a control group. Of the selected persons, 78% accepted the invitation to the first screening round and 70% to the second one. Carcinoma of the prostate was suspected in 45 of 1,163 men examined at the first screening round and in 42 of 953 at the second round. Carcinoma was confirmed by fine-needle aspiration biopsy in 13 cases from the first and in 7 from the second round. In the study group, 17.4 carcinomas were diagnosed per 1,000 men and in the control group 8.6 per 1,000 men. The screening cost was 1,640 pounds per detected cancer and 2,343 pounds per detected and potentially cured cancer. Screening for carcinoma of the prostate by digital rectal examination can be organised with a high population acceptance, and at a reasonable cost. The impact of screening on mortality in prostatic cancer remains uncertain.

The American Cancer Society National Prostate Cancer Detection Project. Findings on the detection of early prostate cancer in 2425 men

The American Cancer Society National Prostate Cancer Detection Project (ACS-NPCDP) is a multidisciplinary, multicenter effort to assess the feasibility of early prostate cancer detection by digital rectal examination (DRE), transrectal ultrasound (TRUS), and prostate specific antigen (PSA) assay. By June 1990, 2425 men not previously suspected of having prostate cancer had been examined in ten participating clinical centers according to the project protocol. Three hundred ninety-six men (16.3%) were recommended for biopsy on the basis of TRUS or DRE. An analysis of the results of 330 completed biopsies showed 52 cancers detected by DRE and/or TRUS. Forty-four (84.6%) of the men with cancer had positive TRUS examination results compared with 33 (63.5%) with positive DRE. Five additional cancers were discovered as a result of elevated PSA levels. The overall detection rate was 2.4% and this rate varied by age. The detection rate in men 55 to 60 years of age was 1.3% and this rose to 3.3% in men older than 65 years of age. The estimated sensitivity was significantly greater for TRUS compared with DRE (77.2% versus 57.9%; P less than 0.05). The estimated specificity of DRE was greater than that of TRUS (96.3% versus 89.4%; P less than 0.01). The positive predictive value (PPV) for the tests varied as a function of patient and disease characteristics. The overall PPV was 28.0% for DRE and 15.2% for TRUS. The occurrence of elevated PSA levels significantly increased the PPV of both TRUS and DRE. The majority of cancers detected were at early stages. These preliminary data suggest the feasibility of using these techniques to promote cancer control, but additional data and follow-up are needed to assess the significance of the results.