Decision analysis for treatment of early stage prostate cancer

Information for Decision Making by Patients With Early-Stage Prostate Cancer

Purpose: To describe decisional roles of patients with early-stage prostate cancer in 9 countries and to compare the information they rated important for decision making (DM). Method: A survey of recently treated patients was conducted in Canada, Italy, England, Germany, Poland, Portugal, Netherlands, Spain, and Turkey. Participants indicated their decisional role in their actual decision and the role they would prefer now. Each participant also rated (essential/desired/no opinion/avoid) the importance of obtaining answers, between diagnosis and treatment decision, to each of 92 questions. For each essential/desired question, participants specified all purposes for that information (to help them: understand/decide/plan/not sure/other). Results: A total of 659 patients participated with country-specific response rates between 58%-77%. Between 83%-96% of each country’s participants recalled actually taking an active decisional role and, in most countries, that increased slightly if they were to make the decision today; there were no significant differences among countries. There was a small reliable difference in the mean number of questions rated essential for DM across countries. More striking, however, was the wide variability within each country: no question was rated essential for DM by even 50% of its participants but almost every question was rated essential by some. Conclusions: Almost all participants from each country want to participate in their treatment decisions. Although there are country-specific differences in the amount of information required, wide variation within each country suggests that information that patients feel is essential or desired for DM should be addressed on an individual basis in all countries.

Clinical stage T1c prostate cancer: evaluation with endorectal MR imaging and MR spectroscopic imaging

PURPOSE

To assess the diagnostic accuracy of endorectal magnetic resonance (MR) imaging and MR spectroscopic imaging for prediction of the pathologic stage of prostate cancer and the presence of clinically nonimportant disease in patients with clinical stage T1c prostate cancer.

MATERIALS AND METHODS

The institutional review board approved-and waived the informed patient consent requirement for-this HIPAA-compliant study involving 158 patients (median age, 58 years; age range, 40-76 years) who had clinical stage T1c prostate cancer, had not been treated preoperatively, and underwent combined 1.5-T endorectal MR imaging-MR spectroscopic imaging between January 2003 and March 2004 before undergoing radical prostatectomy. On the MR images and combined endorectal MR-MR spectroscopic images, two radiologists retrospectively and independently rated the likelihood of cancer in 12 prostate regions and the likelihoods of extracapsular extension (ECE), seminal vesicle invasion (SVI), and adjacent organ invasion by using a five-point scale, and they determined the probability of clinically nonimportant prostate cancer by using a four-point scale. Whole-mount step-section pathology maps were used for imaging-pathologic analysis correlation. Receiver operating characteristic curves were constructed and areas under the curves (AUCs) were estimated nonparametrically for assessment of reader accuracy.

RESULTS

At surgical-pathologic analysis, one (0.6%) patient had no cancer; 124 (78%) patients, organ-confined (stage pT2) disease; 29 (18%) patients, ECE (stage pT3a); two (1%) patients, SVI (stage pT3b); and two (1%) patients, bladder neck invasion (stage pT4). Forty-six (29%) patients had a total tumor volume of less than 0.5 cm(3). With combined MR imaging-MR spectroscopic imaging, the two readers achieved 80% accuracy in disease staging and AUCs of 0.62 and 0.71 for the prediction of clinically nonimportant cancer.

CONCLUSION

Clinical stage T1c prostate cancers are heterogeneous in pathologic stage and volume. MR imaging may help to stratify patients with clinical stage T1c disease for appropriate clinical management.

Do older men benefit from curative therapy of localized prostate cancer?

PURPOSE

Prior decision-analytic models are based on outdated or suboptimal efficacy, patient preference, and comorbidity data. We estimated life expectancy (LE) and quality-adjusted life expectancy (QALE) associated with available treatments for localized prostate cancer in men aged >/= 65 years, adjusting for Gleason score, patient preferences, and comorbidity.

METHODS

We evaluated three treatments, using a decision-analytic Markov model: radical prostatectomy (RP), external beam radiotherapy (EBRT), and watchful waiting (WW). Rates of treatment complications and pretreatment incontinence and impotence were derived from published studies. We estimated treatment efficacy using three data sources: cancer registry cohort data, pooled case series, and modern radiotherapy studies. Utilities were obtained from 141 prostate cancer patients and from published studies.

RESULTS

For men with well-differentiated tumors and few comorbidities, potentially curative therapy (RP or EBRT) prolonged LE up to age 75 years but did not improve QALE at any age. For moderately differentiated cancers, potentially curative therapy resulted in LE and QALE gains up to age 75 years. For poorly differentiated disease, potentially curative therapy resulted in LE and QALE gains up to age 80 years. Benefits of potentially curative therapy were restricted to men with no worse than mild comorbidity. When cohort and pooled case series data were used, RP was preferred over EBRT in all groups but was comparable to modern radiotherapy.

CONCLUSION

Potentially curative therapy results in significantly improved LE and QALE for older men with few comorbidities and moderately or poorly differentiated localized prostate cancer. Age should not be a barrier to treatment in this group.

Effectiveness and cost-effectiveness of prognostic markers in prostate cancer

This paper demonstrates how economic modelling can be used to derive estimates of the cost-effectiveness of prognostic markers in the management of clinically localised and moderately graded prostate cancer. The model uses a Markov process and is populated using published evidence and local data. The robustness of the results has been tested using sensitivity analysis. Three treatment policies of 'monitoring' (observation), radical prostatectomy, or a selection-based management policy using DNA-ploidy as an experimental marker, have been evaluated. Modelling indicates that a policy of managing these tumours utilising experimental markers has an estimated cost per quality-adjusted life year (QALY) of pound 12 068. Sensitivity analysis shows the results to be relatively sensitive to quality-of-life variables. If novel and experimental markers can achieve specificity in excess of 80%, then a policy of radical surgery for those identified as being at high risk and conservative treatment for the remainder would be both better for patients and cost-effective. The analysis suggests that a radical prostatectomy treatment policy for the moderately graded tumours (Gleason grades -7) modelled in this paper may be inferior to a conservative approach in the absence of reliable prognostic markers, being both more costly and yielding fewer QALYs.

Observation in the management of localized prostate cancer

Background

The widespread use of the prostate-specific antigen test, the availability of ultrasound, and improved techniques for prostate biopsy have led to the diagnosis of organ-confined prostate cancers at an earlier stage. An unknown number of these cancers will be incidental and will not impact the patient's quality or length of life.

Methods

The most recent published reports and decision analysis studies on observation management were reviewed. We also analyzed our own series of observed patients.

Results

Three contemporary series on observation and three reports on decision analysis for treatment of early prostate cancer define a group of patients who may be treated with observation. Our own preliminary experience, however, demonstrates that a significant number undergo definitive treatment within 3 years from diagnosis. The optimal treatment for men with early prostate cancer is currently unknown.

Conclusions

A subset of patients with newly diagnosed prostate cancer may be managed by observation. Standard protocols for selection and follow-up of patients on observation need to be developed.