Eradication of a disease: how we cured symptomless prostate cancer

Prostate-specific antigen testing across the spectrum of prostate cancer

Prostate-specific antigen (PSA) is a protein produced by the prostate, and this protein may be elevated for several reasons, including prostatitis, benign prostatic hypertrophy and/or cancer. PSA is not cancer-specific, cannot be used as a cancer marker and it has been demonstrated that there is no level of PSA that is definitive for prostate cancer. The value of the PSA test varies when used for screening, diagnosis, prognosis or as a signal of disease recurrence. Misuse of the test for screening has created unnecessary anxiety and costs, and has led to the significant overdiagnosis and overtreatment of men. More important than whether or not to screen is how one acts upon the data from a single test; with the exception of extremely high double- or triple-digit levels of PSA, it is prudent only to use a single PSA determination as a baseline, with biopsy and cancer treatment reserved for those with significant PSA changes over time, or for those with clinical manifestations mandating immediate therapy. Using the PSA test to monitor disease progression or recurrence is appropriate, provided one understands that absolute levels of PSA are rarely meaningful; it is the relative change in PSA levels over time that provides insight, but not definitive proof of a cancerous condition necessitating therapy. PSA secretion is under hormonal control and thus PSA levels may be affected differently by the type of drug therapy, by the stage of a patients' disease, and by genetic factors suggesting some men are 'high PSA producers'. Until a validated alternative test for prostate cancer is found and adopted, the current flawed PSA test needs to be used more judiciously and not used for routine screening as studies have demonstrated that screening, as defined, does not lead to a reduction in patient mortality. All men, their families and their physicians need to understand the significant limitations of PSA testing.

Prostate cancer prevention by short-term anti-androgens: the rationale behind design of pilot studies

This paper sets out to review evidence that low-grade prostate inflammation is a precursor of prostate cancer development and the mechanisms by which it may account for the more than 50 years natural history from first infection to cancer. Though as yet there is no clear-cut specific associated infection, there is clear evidence that some sexually acquired infections damage the prostate and increase serum PSA with slow recovery back to normal. The demonstration that low-level solar exposure is protective provides a possible mechanism due to vitamin D's known benefit through action to boost macrophage-mediated immune surveillance. This observation and data demonstrating that non-steroidal anti-inflammatory drugs (NSAIDs) protect against prostate cancer provide the justification for trials of these two agents combined with short course intermittent anti-androgen therapy in populations at high risk of prostate cancer.

Escalated-dose versus standard-dose conformal radiotherapy in prostate cancer: first results from the MRC RT01 randomised controlled trial

BACKGROUND

In men with localised prostate cancer, conformal radiotherapy (CFRT) could deliver higher doses of radiation than does standard-dose conventional radical external-beam radiotherapy, and could improve long-term efficacy, potentially at the cost of increased toxicity. We aimed to present the first analyses of effectiveness from the MRC RT01 randomised controlled trial.

METHODS

The MRC RT01 trial included 843 men with localised prostate cancer who were randomly assigned to standard-dose CFRT or escalated-dose CFRT, both administered with neoadjuvant androgen suppression. Primary endpoints were biochemical-progression-free survival (bPFS), freedom from local progression, metastases-free survival, overall survival, and late toxicity scores. The toxicity scores were measured with questionnaires for physicians and patients that included the Radiation Therapy Oncology Group (RTOG), the Late Effects on Normal Tissue: Subjective/Objective/Management (LENT/SOM) scales, and the University of California, Los Angeles Prostate Cancer Index (UCLA PCI) scales. Analysis was done by intention to treat. This trial is registered at the Current Controlled Trials website http://www.controlled-trials.com/ISRCTN47772397.

FINDINGS

Between January, 1998, and December, 2002, 843 men were randomly assigned to escalated-dose CFRT (n=422) or standard-dose CFRT (n=421). In the escalated group, the hazard ratio (HR) for bPFS was 0.67 (95% CI 0.53-0.85, p=0.0007). We noted 71% bPFS (108 cumulative events) and 60% bPFS (149 cumulative events) by 5 years in the escalated and standard groups, respectively. HR for clinical progression-free survival was 0.69 (0.47-1.02; p=0.064); local control was 0.65 (0.36-1.18; p=0.16); freedom from salvage androgen suppression was 0.78 (0.57-1.07; p=0.12); and metastases-free survival was 0.74 (0.47-1.18; p=0.21). HR for late bowel toxicity in the escalated group was 1.47 (1.12-1.92) according to the RTOG (grade >/=2) scale; 1.44 (1.16-1.80) according to the LENT/SOM (grade >/=2) scales; and 1.28 (1.03-1.60) according to the UCLA PCI (score >/=30) scale. 33% of the escalated and 24% of the standard group reported late bowel toxicity within 5 years of starting treatment. HR for late bladder toxicity according to the RTOG (grade >/=2) scale was 1.36 (0.90-2.06), but this finding was not supported by the LENT/SOM (grade >/=2) scales (HR 1.07 [0.90-1.29]), nor the UCLA PCI (score >/=30) scale (HR 1.05 [0.81-1.36]).

INTERPRETATION

Escalated-dose CFRT with neoadjuvant androgen suppression seems clinically worthwhile in terms of bPFS, progression-free survival, and decreased use of salvage androgen suppression. This additional efficacy is offset by an increased incidence of longer term adverse events.

Pathways to the diagnosis of prostate cancer in a British city. A population-based study

OBJECTIVE

To identify the pathways leading to the diagnosis of prostate cancer from a UK population perspective, including the role of prostate-specific antigen (PSA) testing.

MATERIAL AND METHODS

We studied all 217 prostate cancers occurring in the region covered by Exeter Primary Care Trust, Devon, UK (population 128 700) between 1998 and 2002. The general practitioner's records for 2 years before diagnosis were used to identify the category of pathway to diagnosis.

RESULTS

Symptomatic presentation to primary care initiated the diagnostic process in 166/217 men (76%). The presenting symptoms were lower urinary tract symptoms (LUTS) in 151 men (70%), systemic symptoms and no LUTS in 12 (6%) and bowel symptoms with a rectal examination revealing an abnormal prostate in 3 (1%). Eighteen cases (8%) were diagnosed as a result of PSA screening in asymptomatic men. Diagnosis as an inpatient accounted for 33 cases (15%), 25 of whom (11%) had been admitted with urological problems, and 4% of cases had been admitted for non-urological problems. Of the 151 men who presented with LUTS, 91 (60%) had a PSA test in primary care, 15 (10%) had one in secondary care and 39 (17%) had a prostatectomy that revealed a cancer that had not previously been suspected. Most prostate cancers were diagnosed after presentation to primary care with LUTS. Presentation with disseminated disease was rare.

CONCLUSION

Screening by means of PSA testing remains uncommon in this area of the UK, in contrast to the situation in other countries. Most PSA tests performed in patients with prostate cancer were diagnostic rather than screening tests.

Race/ethnicity and the receipt of watchful waiting for the initial management of prostate cancer

INTRODUCTION

Several recent studies have noted that African Americans disproportionately receive "watchful waiting" for the initial management of their prostate cancer. To determine whether racial/ethnic differences in the receipt of watchful waiting are explained by differences in clinical presentation and life expectancy at the time of diagnosis, we examined Surveillance, Epidemiology, and End Results (SEER)-Medicare data for men diagnosed with prostate cancer in 1994 to 1996.

METHODS

Race/ethnicity, comorbidity, stage, grade, age, and expected lifespan and their association with the receipt of watchful waiting were examined in multivariate logistic regression analyses. Race-stratified logistic regression analyses were also used to examine racial/ethnic variation in the association of clinical and demographic factors with the receipt of watchful waiting among African-American, Hispanic, and non-Hispanic white men.

RESULTS

African-American (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.3 to 1.6) and Hispanic men (OR, 1.3; 95% CI, 1.1 to 1.5) were significantly more likely than non-Hispanic white men to receive watchful waiting in a multivariate model adjusted for age, comorbidity, stage, grade, and life expectancy. Advanced stage and grade, lower life expectancy, older age, and high comorbidity indices were also significantly associated with an increase in the odds of receipt of watchful waiting in multivariate analyses. In general, the association between the receipt of watchful waiting and the clinical characteristics (i.e., stage, grade, and age) were similar for the three racial/ethnic groups. In race-stratified logistic regression analyses, life expectancy was associated with an increase in the odds of receiving watchful waiting but results were statistically significant for whites only. There was also a statistically significant increase in the odds of receiving watchful waiting for African-American and white men with high comorbidity indices but not Hispanic men. The odds of receiving watchful waiting were also higher for African-American and Hispanic men who resided in census tracts where a large percentage of residents had not completed high school than for white men who resided in similar census tracts.

CONCLUSION

The disproportionate receipt of watchful waiting among African Americans and Hispanics is not completely explained by racial/ethnic variation in clinical characteristics or life expectancy as measured in this study. These data suggest that there are other factors that contribute to racial/ethnic differences in receipt of watchful waiting that warrant investigation.

Challenges to cancer control by screening

Population-based screening seems to be a common-sense strategy for controlling cancer, but recent reports have raised controversy concerning the benefits of common screening procedures. Intense efforts to develop and evaluate novel screening technologies are underway; however, effective use of any screening method must take into account any underlying biological considerations. What are these biological issues, and what challenges do clinicians face in screening for common cancers?

Trends in prostate cancer mortality among black men and white men in the United States

BACKGROUND

Prostate cancer mortality rates in the United States declined sharply after 1991 in white men and declined after 1992 in black men. The current study was conducted to investigate possible mechanisms for the declining prostate cancer mortality rates in the United States.

METHODS

The authors examined and compared patterns of prostate cancer incidence, survival rates, and mortality rates among black men and white men in the United States using the 1969-1999 U.S. prostate cancer mortality rates and the 1975-1999 prostate cancer incidence, survival, and incidence-based mortality rates from the Surveillance, Epidemiology, and End Results (SEER) Program for the U.S. population. The SEER data represent approximately 10% of the U.S. population.

RESULTS

Prostate cancer incidence and mortality rates showed transient increases after 1986, when the U.S. Food and Drug Administration approved the use of prostate specific antigen (PSA) testing. The age-adjusted prostate cancer mortality rates for men age 50-84 years, however, have dropped below the rate in 1986 since 1995 for white men and since 1997 for black men. In fact, for white men ages 50-79 years, the 1998 and 1999 rates were the lowest observed since 1950. Incidence-based mortality rates by disease stage revealed that the recent declines were due to declines in distant disease mortality. Moreover, the decrease in distant disease mortality was due to a decline in distant disease incidence, and not to improved survival of patients with distant disease.

CONCLUSIONS

Similar incidence, survival, and mortality rate patterns are seen in black men and white men in the United States, although with differences in the timing and magnitude of recent rate decreases. Increased detection of prostate cancer before it becomes metastatic, possibly reflecting increased use of PSA testing after 1986, may explain much of the recent mortality decrease in both white men and black men.

"PSA-itis": knowledge of serum prostate specific antigen and other causes of anxiety in men with metaststic prostate cancer

PURPOSE

High or increasing prostatic specific antigen (PSA) levels may be a source of anxiety in patients with metastatic prostate cancer.

MATERIALS AND METHODS

Patients with metastatic prostate cancer completed questionnaires, including the Prostate Cancer Specific Quality of Life Instrument, Hospital Anxiety and Depression Scale, and a questionnaire to assess the impact of the knowledge of PSA levels on anxiety. These were completed at home more than 3 days before or after a clinic appointment and returned by mail. Patient medical history was obtained from the record.

RESULTS

Of the 65 patients who consented to the study 52 returned the completed questionnaires. Median age was 70 years (range 55 to 86) and median time since diagnosis was 53 months. Of the patients 81% had hormone resistant disease. Most reported good overall quality of life with a median Prostate Cancer Specific Quality of Life Instrument score of 93 (maximum 100). Of the patients 77% indicated that PSA levels were one of the ways and 44% indicated they were the only way that they knew whether disease was progressing. When asked to rate preferences for treatment outcome, 25% of the men rated decreasing PSA and worse physical symptoms above increasing PSA and better physical symptoms. If measurement of PSA levels ceased, 52% of patients would believe that their doctor was giving up on them and only 1 would be relieved. Before receiving PSA results 76% reported some level of anxiety and 15% reported extreme anxiety.

CONCLUSIONS

PSA related anxiety represents a substantial problem in patients with metastatic prostate cancer.