Siu-Long Yao

Outcomes of Localized Prostate Cancer Following Conservative Management

CONTEXT Most newly diagnosed prostate cancers are clinically localized, and major treatment options include surgery, radiation, or conservative management. Although conservative management can be a reasonable choice, there is little contemporary prostate-specific antigen (PSA)-era data on outcomes with this approach. OBJECTIVE To evaluate the outcomes of clinically localized prostate cancer managed without initial attempted curative therapy in the PSA era. DESIGN, SETTING, AND PARTICIPANTS A population-based cohort study of men aged 65 years or older when they were diagnosed (1992-2002) with stage T1 or T2 prostate cancer and whose cases were managed without surgery or radiation for 6 months after diagnosis. Living in areas covered by the Surveillance, Epidemiology, and End Results (SEER) program, the men were followed up for a median of 8.3 years (through December 31, 2007). Competing risk analyses were performed to assess outcomes. MAIN OUTCOME MEASURES Ten-year overall survival, cancer-specific survival, and major cancer related interventions. RESULTS Among men who were a median age of 78 years at cancer diagnosis, 10-year prostate cancer-specific mortality was 8.3% (95% confidence interval [CI], 4.2%-12.8%) for men with well-differentiated tumors; 9.1% (95% CI, 8.3%-10.1%) for those with moderately differentiated tumors, and 25.6% (95% CI, 23.7%-28.3%) for those with poorly differentiated tumors. The corresponding 10-year risks of dying of competing causes were 59.8% (95% CI, 53.2%-67.8%), 57.2% (95% CI, 52.6%-63.9%), and 56.5% (95% CI, 53.6%-58.8%), respectively. Ten-year disease-specific mortality for men aged 66 to 74 years diagnosed with moderately differentiated disease was 60% to 74% lower than earlier studies: 6% (95% CI, 4%-8%) in the contemporary PSA era (1992-2002) compared with results of previous studies (15%-23%) in earlier eras (1949-1992). Improved survival was also observed in poorly differentiated disease. The use of chemotherapy (1.6%) or major interventions for spinal cord compression (0.9%) was uncommon. CONCLUSIONS Results following conservative management of clinically localized prostate cancer diagnosed from 1992 through 2002 are better than outcomes among patients diagnosed in the 1970s and 1980s. This may be due, in part, to additional lead time, overdiagnosis related to PSA testing, grade migration, or advances in medical care.

Survival following primary androgen deprivation therapy among men with localized prostate cancer.

CONTEXT Despite a lack of data, increasing numbers of patients are receiving primary androgen deprivation therapy (PADT) as an alternative to surgery, radiation, or conservative management for the treatment of localized prostate cancer. OBJECTIVE To evaluate the association between PADT and survival in elderly men with localized prostate cancer. DESIGN, SETTING, AND PATIENTS A population-based cohort study of 19,271 men aged 66 years or older receiving Medicare who did not receive definitive local therapy for clinical stage T1-T2 prostate cancer. These patients were diagnosed in 1992-2002 within predefined US geographical areas, with follow-up through December 31, 2006, for all-cause mortality and through December 31, 2004, for prostate cancer-specific mortality. Instrumental variable analysis was used to address potential biases associated with unmeasured confounding variables. MAIN OUTCOME MEASURES Prostate cancer-specific survival and overall survival. RESULTS Among patients with localized prostate cancer (median age, 77 years), 7867 (41%) received PADT, and 11,404 were treated with conservative management, not including PADT. During the follow-up period, there were 1560 prostate cancer deaths and 11,045 deaths from all causes. Primary androgen deprivation therapy was associated with lower 10-year prostate cancer-specific survival (80.1% vs 82.6%; hazard ratio [HR], 1.17; 95% confidence interval [CI], 1.03-1.33) and no increase in 10-year overall survival (30.2% vs 30.3%; HR, 1.00; 95% CI, 0.96-1.05) compared with conservative management. However, in a prespecified subset analysis, PADT use in men with poorly differentiated cancer was associated with improved prostate cancer-specific survival (59.8% vs 54.3%; HR, 0.84; 95% CI, 0.70-1.00; P = .049) but not overall survival (17.3% vs 15.3%; HR, 0.92; 95% CI, 0.84-1.01). CONCLUSION Primary androgen deprivation therapy is not associated with improved survival among the majority of elderly men with localized prostate cancer when compared with conservative management.

Effect of age and surgical approach on complications and short-term mortality after radical prostatectomy--a population-based study.

OBJECTIVES To use population-based data to accurately delineate the types and incidence of complications, risk of readmission, and influence of age and surgical approach on short-term mortality after radical prostatectomy. METHODS Medicare claims from 1991 to 1994 were used to identify and quantify the types and risks of complications, rehospitalization within 90 days, and mortality at 30 and 90 days after perineal or retropubic prostatectomy. Logistic regression was used to determine the relationships between age, surgical approach, and short-term outcomes while adjusting for potential confounders. RESULTS On the basis of data from 101,604 men, complications affected 25.0% to 28.8% of patients treated with the perineal or retropubic approach. The retropubic approach had a higher risk of respiratory complications (relative risk [RR] = 1.53, 95% confidence interval [CI] 1.37 to 1.71) and miscellaneous medical complications (RR = 1.77, 95% CI 1.60 to 1.97) and a lower risk of miscellaneous surgical complications (RR = 0.86, 95% CI 0.78 to 0.94). Differences in medically related gastrointestinal complications partially accounted for the differences in miscellaneous medical complications. Rectal injury with the perineal approach was only approximately 1% to 2%. Readmission within 90 days was necessary for 8.5% to 8.7% of patients who underwent the retropubic or perineal approach. The 30-day mortality was less than 0.5% for men aged 65 to 69; it approached 1% for men aged 75 and older. CONCLUSIONS Complications and readmission after prostatectomy are substantially more common than previously recognized. Notable differences exist in the incidence of respiratory and nonsurgical gastrointestinal complications, although many short-term outcomes are comparable for the two approaches. Older age is associated with elevated surgical mortality and complications.

Characterization of a Novel Prostate-Specific Antigen–Activated Peptide-Doxorubicin Conjugate in Patients With Prostate Cancer

PURPOSE To evaluate safety and pharmacokinetics (PK), and determine the recommended dose for efficacy studies, of L-377202, a novel peptide conjugate of doxorubicin (Dox) that releases the active metabolites leucine-doxorubicin (Leu-Dox) and Dox on cleavage by membrane-bound prostate-specific antigen (PSA). PATIENTS AND METHODS Nineteen patients with advanced hormone-refractory prostate cancer were treated intravenously with 71 cycles of L-377202 at escalating dose levels of 20 (n = 1), 40 (n = 3), 80 (n = 4), 160 (n = 3), 225 (n = 6), and 315 mg/m(2) (n = 2) once every 3 weeks. Toxicity, response, and PK of L-377202 were assessed. RESULTS L-377202 was well tolerated. Dose-limiting grade 4 neutropenia was noted in two of two patients administered 315 mg/m(2) (both patients were able to resume therapy at 225 mg/m(2)). The recommended dose for efficacy studies was 225 mg/m(2), which induced grade 4 neutropenia in one of six patients. PK studies demonstrated that L-377202 was metabolized to Leu-Dox and Dox. PK were linear; after administration of single doses of 225 mg/m(2), the mean area under the concentration-time profiles of L-377202, Leu-Dox, and Dox were 6 micromol x L/h, 4 micromol x L/h, and 1 micromol x L/h, and peak concentrations were 14 micromol/L, 5 micromol/L, and 120 nmol/L, respectively. At 225 and 315 mg/m(2), five patients completed at least three cycles of therapy; two patients had a greater than 75% decrease in PSA, and one patient had a stabilized PSA. No response was noted at dose levels less than 225 mg/m(2). CONCLUSION This is the first study of selective drug delivery in humans using a novel PSA-activated agent. L-377202 was cleaved to produce detectable levels of the active metabolites Leu-Dox and Dox. L-377202 was well tolerated and established a safe dose level for further study.

Fifteen-Year Survival Outcomes Following Primary Androgen-Deprivation Therapy for Localized Prostate Cancer

IMPORTANCE One in 6 American men will be diagnosed as having prostate cancer during their lifetime. Although there are no data to support the use of primary androgen-deprivation therapy (ADT) for early-stage prostate cancer, primary ADT has been widely used for localized prostate cancer, especially among older patients. OBJECTIVE To determine the long-term survival impact of primary ADT in older men with localized (T1/T2) prostate cancer. DESIGN, SETTING, AND PARTICIPANTS This was a population-based cohort study of 66,717 Medicare patients 66 years or older diagnosed from 1992 through 2009 who received no definitive local therapy within 180 days of prostate cancer diagnosis. The study was conducted in predefined US geographical areas covered by the Surveillance, Epidemiology, and End Results (SEER) Program. Instrumental variable analysis was used to assess the impact of primary ADT and control for potential biases associated with unmeasured confounding variables. The instrumental variable comprised combined health services areas with various usage rates of primary ADT. The analysis compared survival outcomes in the top tertile areas with those in the bottom tertile areas. MAIN OUTCOMES AND MEASURES Prostate cancer-specific survival and overall survival. RESULTS With a median follow-up of 110 months, primary ADT was not associated with improved 15-year overall or prostate cancer-specific survival following the diagnosis of localized prostate cancer. Among patients with moderately differentiated cancers, the 15-year overall survival was 20.0% in areas with high primary ADT use vs 20.8% in areas with low use (difference: 95% CI, -2.2% to 0.4%), and the 15-year prostate cancer survival was 90.6% in both high- and low-use areas (difference: 95% CI, -1.1% to 1.2%). Among patients with poorly differentiated cancers, the 15-year cancer-specific survival was 78.6% in high-use areas vs 78.5%, in low-use areas (difference: 95% CI, -1.8% to 2.4%), and the 15-year overall survival was 8.6% in high-use areas vs 9.2% in low-use areas (difference: 95% CI, -1.5% to 0.4%). CONCLUSIONS AND RELEVANCE Primary ADT is not associated with improved long-term overall or disease-specific survival for men with localized prostate cancer. Primary ADT should be used only to palliate symptoms of disease or prevent imminent symptoms associated with disease progression.

Fifteen-year Outcomes Following Conservative Management Among Men Aged 65 Years or Older with Localized Prostate Cancer.

BACKGROUND To understand the threat posed by localized prostate cancer and the potential impact of surgery or radiation, patients and healthcare providers require information on long-term outcomes following conservative management. OBJECTIVE To describe 15-yr survival outcomes and cancer therapy utilization among men 65 years and older managed conservatively for newly diagnosed localized prostate cancer. DESIGN, SETTINGS, AND PARTICIPANTS This is a population-based cohort study with participants living in predefined geographic areas covered by the Surveillance, Epidemiology, and End Results program. The study includes 31 137 Medicare patients aged ≥65 yr diagnosed with localized prostate cancer in 1992-2009 who initially received conservative management (no surgery, radiotherapy, cryotherapy, or androgen deprivation therapy [ADT]). All patients were followed until death or December 31, 2009 (for prostate cancer-specific mortality [PCSM]) and December 31, 2011 (for overall mortality). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Competing-risk analyses were used to examine PCSM, overall mortality, and utilization of cancer therapies. RESULTS AND LIMITATIONS The 15-yr risk of PCSM for men aged 65-74 yr diagnosed with screening-detected prostate cancer was 5.7% (95% confidence interval [CI] 3.7-8.0%) for T1c Gleason 5-7 and 22% (95% CI 16-35%) for Gleason 8-10 disease. After 15 yr of follow-up, 24% (95% CI 21-27%) of men aged 65-74 yr with screening-detected Gleason 5-7 cancer received ADT. The corresponding result for men with Gleason 8-10 cancer was 38% (95% CI 32-44%). The major study limitations are the lack of data for men aged <65 yr and detailed clinical information associated with secondary cancer therapy. CONCLUSIONS The 15-yr outcomes following conservative management of newly diagnosed Gleason 5-7 prostate cancer among men aged ≥65 yr are excellent. Men with Gleason 8-10 disease managed conservatively face a significant risk of PCSM. PATIENT SUMMARY We examined the long-term survival outcomes for a large group of patients diagnosed with localized prostate cancer who did not have surgery, radiotherapy, cryotherapy, or androgen deprivation therapy in the first 6 mo after cancer diagnosis. We found that the 15-yr disease-specific survival is excellent for men diagnosed with Gleason 5-7 disease. The data support conservative management as a reasonable choice for elderly patients with low-grade localized prostate cancer.

Does Primary Androgen-Deprivation Therapy Delay the Receipt of Secondary Cancer Therapy for Localized Prostate Cancer?

BACKGROUND Despite evidence that shows no survival advantage, many older patients receive primary androgen-deprivation therapy (PADT) shortly after the diagnosis of localized prostate cancer (PCa). OBJECTIVE This study evaluates whether the early use of PADT affects the subsequent receipt of additional palliative cancer treatments such as chemotherapy, palliative radiation therapy, or intervention for spinal cord compression or bladder outlet obstruction. DESIGN, SETTING, AND PARTICIPANTS This longitudinal population-based cohort study consists of Medicare patients aged ≥ 66 yr diagnosed with localized PCa from 1992 to 2006 in areas covered by the Surveillance Epidemiology and End Results (SEER) program. SEER-Medicare linked data through 2009 were used to identify the use of PADT and palliative cancer therapy. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Instrumental variable analysis methods were used to minimize confounding effects. Confidence intervals were derived from the bootstrap estimates. RESULTS AND LIMITATIONS This study includes 29 775 men who did not receive local therapy for T1-T2 PCa within the first year of cancer diagnosis. Among low-risk patients (Gleason score 2-7 in 1992-2002 and Gleason score 2-6 in 2003-2006) with a median age of 78 yr and a median follow-up of 10.3 yr, PADT was associated with a 25% higher use of chemotherapy (hazard ratio [HR]: 1.25; 95% confidence interval [CI], 1.08-1.44) and a borderline higher use of any palliative cancer treatment (HR: 1.07; 95% CI, 0.97-1.19) within 10 yr of diagnosis in regions with high PADT use compared with regions with low PADT use. Because this study was limited to men >65 yr, the results may not be applicable to younger patients. CONCLUSIONS Early treatment of low-risk, localized PCa with PADT does not delay the receipt of subsequent palliative therapies and is associated with an increased use of chemotherapy.

An evidence-based approach to prostate cancer follow-up

The follow-up required for patients with prostate cancer is critically dependent upon the stage of disease and the ultimate goal for treatment. A major difficulty in follow-up in prostate cancer is the lack of data on outcome of various treatment modalities. Additionally, there is a lack of data on the use of treatment modalities early in the course of prostate cancer. Despite these limitations, there is a need to develop an approach to follow these patients pending further study. In this review, we critically assess the natural course of untreated prostate cancer, the complications of local therapy, and the controversy over early versus delayed hormonal therapy. As a result of this discussion, common themes emerge. Most patients diagnosed with prostate cancer die of causes other than prostate cancer such as cardiovascular disease and therefore require additional follow-up. Since patients experience local problems such as urinary obstruction more commonly than symptomatic metastatic disease, instruments to assess urinary symptoms are discussed. Finally, follow-up as a means to determine eligibility for clinical studies is discussed.

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To the Editor: The analysis of prostate cancer–specific and overall survival by Dr Lu-Yao and colleagues concluded that primary androgen deprivation therapy (PADT) offered no benefit compared with conservative management in elderly men with localized prostate cancer. Since their comparison was based on epidemiologic data rather than those obtained in a prospective randomized trial, there is a possibility that confounding variables may have influenced patient outcomes. Serum prostate-specific antigen (PSA) has been shown to be an independent predictor of outcome in newly diagnosed patients and may often be used by clinicians to choose recommended therapy. It seems likely that men with higher PSA levels (and thus worse prognoses) were those who were given PADT. However, the study by Lu-Yao et al does not include an analysis of PSA data and their possible influence on treatment recommendations. In the absence of this information, it is not possible to conclude that PADT confers no benefit, especially to a high–PSA-level subpopulation of patients.

Primary radiotherapy vs conservative management for localized prostate cancer—a population-based study

Background:Radiotherapy is the most common curative cancer therapy used for elderly patients with localized prostate cancer. However, the effectiveness of this approach has not been established. The purpose of this study is to evaluate the long-term outcomes of primary radiotherapy compared with conservative management in order to facilitate treatment decisions.Method:This population-based study consisted of 57 749 patients with T1–T2 prostate cancers diagnosed during 1992–2007. We utilized an instrumental variable (IV) analytical approach with competing risk models to evaluate the outcomes of primary radiotherapy vs conservative management. The IV was comprised of combined health service areas with high- and low-use areas corresponding to the top and bottom tertile in radiotherapy usage rates.Results:In patients with low-/intermediate-risk prostate cancer, 10-year prostate cancer-specific and overall survival was similar in high- and low-radiotherapy use areas (96.1 vs 95.4% and 56.6 vs 56.3%, respectively). In patients with high-risk disease, however, areas with high-radiotherapy use had a higher 10-year cancer-specific survival (90.2 vs 88.1%, difference 2.1%; 95% CI 0.3–4.0%) and 10-year overall survival (53.3 vs 50.2%, difference 3.1%; 95% CI 1.3–6.3%). Results were similar irrespective of the type of radiotherapy used. To assess the robustness of our choice of IV, we repeated the IV analytical approach using different IVs (using the median utilization rate as the cutoff) and found the results to be similar.Conclusions:Among men >65 years of age, the benefit of primary radiotherapy for localized disease is largely confined to patients with high-risk prostate cancer (Gleason scores 7–10).