Public Release:  Research from the 2013 Genitourinary Cancers Symposium highlights new insights on high-risk prostate cancer prevalence and treatment, compares benefit of surveillance and surgery for management of small kidney tumors

American Society of Clinical Oncology

ALEXANDRIA, Va. - Research on promising new therapies and data on the relative benefits of established treatments for genitourinary cancers were released today, in advance of the fourth annual Genitourinary Cancers Symposium, being held February 14-16, 2013, at the Rosen Shingle Creek in Orlando, FL.

The results of three studies were highlighted in a media presscast (press briefing via live webcast):

  • High-Risk Prostate Cancer Affects African-American Men and Older Men of Any Race: Findings from a large population-based study show men older than 75 years account for about 40 percent of all patients with high-risk, PSA-detected prostate cancer and have a 9.4 fold higher likelihood of having high-risk disease at diagnosis compared with men younger than 50. African Americans of any age are more likely to have high-risk disease than white men. Asymptomatic men should discuss the relative risk and benefits of PSA screening to make an informed decision.
  • Duration of Androgen Blockade Therapy Can be Cut in Half without Jeopardizing Survival: A prospective randomized clinical trial demonstrates that survival rates are the same in men with high-risk prostate cancer who receive radiation therapy and either 18 or 36 months of androgen blockade. The finding implies that the standard course of androgen blockade, 24-36 months, could be safely shortened, potentially decreasing side effects and costs to patients and society.
  • Surveillance of Small Renal Masses Is a Safe Alternative to Surgery for Elderly Patients: A retrospective analysis of more than 8,300 elderly patients diagnosed with small masses in their kidneys shows that kidney cancer-related death rates are comparable whether a patient undergoes surveillance or surgery to remove the mass. The analysis also found that patients who underwent surveillance had a lower risk of suffering a cardiovascular complication and dying of any cause.

"Two studies presented today will help guide our use of established treatment and surveillance approaches for prostate and kidney cancers, ensuring that more patients have the best possible outcome while avoiding dangerous side effects and reducing costs," said Bruce J. Roth, MD, who moderated today's presscast. "The third study brings important new insight on increased prevalence of high-risk prostate cancer among elderly men and African Americans."

Genitourinary cancers include those of the prostate, kidney, bladder and testis, as well as less common cancers such as those of the penis, ureters and other urinary organs. In 2013, more than 388,000 people in the United States are expected to be diagnosed with genitourinary cancers, with more than an estimated 60,000 deaths. The most common genitourinary cancer is prostate cancer, which according to estimates, will be diagnosed in more than 238,000 men in the United States in 2013, and claim more than 29,000 lives. *

The 2013 Genitourinary Cancers Symposium is co-sponsored by the American Society of Clinical Oncology (ASCO), the American Society for Radiation Oncology (ASTRO) and the Society of Urologic Oncology (SUO).

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More information for media: www.asco.org/GUpresskit

Relevant Links From Cancer.Net, the oncologist-approved cancer information website from the American Society of Clinical Oncology:

Guide to Prostate Cancer: http://www.cancer.net/patient/Cancer+Types/Prostate+Cancer

Prostate-Specific Antigen (PSA) Testing: http://www.cancer.net/cancer-news-and-meetings/expert-perspective-cancer-news/prostate-specific-antigen-psa-testing-prostate-cancer-screening

Hormone Therapy for Advanced Prostate Cancer: http://www.cancer.net/publications-and-resources/what-know-ascos-guidelines/what-know-ascos-guideline-hormone-therapy-advanced-prostate-cancer

Guide to Kidney Cancer: http://www.cancer.net/cancer-types/overview-55

An interactive history of cancer research advances, including those in prostate and kidney cancers, can be found at ASCO's Cancer Progress website at www.cancerprogress.net.

Follow updates from the 2013 Genitourinary Cancers Symposium on Twitter: #GU13

General Poster Session A

Hong Zhang, MD, PhD
Thursday, February 14, 2013, 11:45 AM - 1:15 PM EST
University of Rochester
Gatlin Ballroom B
Rochester, NY

Large Study Shows Elderly and African-American Men Are at Increased Risk of Having Aggressive Prostate Cancer

A large, population-based, retrospective study demonstrated that the odds of detecting high- to intermediate-risk prostate cancer for men with stage T1cN0M0 are much higher for men over the age of 75 and African-American men. The findings represent the first indication that a significant number of elderly men and African Americans may have an aggressive form of prostate cancer diagnosed because of PSA testing.

T1cN0M0 stage prostate cancer can only be detected through PSA testing, as the tumor causes no symptoms, cannot be felt during a physical exam and is not seen during imaging. While this provides insight into when PSA testing may be warranted and why, more research is needed to verify that early detection and intervention is beneficial for those patients.

"If we stop PSA screening altogether, we have no other way to detect this form of prostate cancer sufficiently early to have the best chance of helping this group of high-risk patients," said lead author Hong Zhang, MD, PhD, Associate Professor of Radiation Oncology at the University of Rochester. "The findings of this study will help physicians and certain patients make more informed decisions on whether or not they want to proceed with PSA testing, although more research (and longer follow-up) is needed to determine the effect of early detection and intervention on outcome in these high-risk patients."

There is convincing evidence that a substantial proportion of men who have asymptomatic, PSA-detected prostate cancer will remain asymptomatic throughout their life and have good outcomes even without treatment. Given the harms associated with "over treatment," the U.S. Preventative Services Task Force (USPSTF) recommended against PSA screening for men in the general U.S. population. While at any given time, the percentage of all men who have either intermediate- or high-risk prostate cancer diagnosed exclusively because of PSA is small (about 1 in 8000 men), for those patients, early diagnosis and treatment might be life-saving, particularly if they have a life expectancy of more than 10 years.

Among the 70,345 U.S. men with T1cN0M0 prostate cancer evaluated in the study, 47.6 percent, 35.9 percent, and 16.5 percent had low-, intermediate-, and high-risk disease, respectively. Men older than 75 years accounted for 40 percent of all patients with high-risk disease. Patients aged 75 and older had a 4.4-fold higher probability of developing intermediate-risk disease and 9.4-fold higher probability of developing high-risk disease compared with patients younger than 50. In addition, African Americans of all ages had a 1.8-fold higher likelihood of developing high-risk disease compared with white men.

The present study identifies two subpopulations of patients - men older than 75 years and African Americans - in which the potential benefit of PSA screening may need further investigation. Prior research has shown that over 50 percent of deaths due to prostate cancer occur in men initially diagnosed when older than 75 years and that African Americans of all ages are twice as likely to die of prostate cancer compared with other men in the United States. The USPSTF did not have enough evidence to assess the ratio of potential benefits and harms of PSA screening in the African American population specifically.

Since the release of the USPSTF recommendations, there has been a decline in PSA screening for all age groups. ASCO issued guidance in 2012 recommending that physicians discuss the benefits and risks of PSA screening with their asymptomatic male patients who have a life expectancy of more than 10 years. ASCO recommended against screening for men expected to live less than 10 years because the harms appear to outweigh potential benefits. Physicians should therefore assess life expectancy before offering PSA screening to their elderly patients. ASCO's decision aid for patients explains available data and important considerations about PSA testing in lay language.

The average 10-year survival rates are 91 percent for low-risk, 84 percent for intermediate-risk and 80 percent for high-risk disease. The risk levels are defined based on clinical stage, PSA level and Gleason score. Patients have different treatment options depending on the aggressiveness of their cancer. For example, while active surveillance is appropriate for low-risk disease, intermediate- and high-risk patients are typically offered radiation, surgery, and/or androgen deprivation therapy.

Abstract # 50

Title: PSA-detected prostate cancer in the United States: A population-based study of 70,345 men with AJCC stage T1cN0M0 disease.

Authors: Hong Zhang, Lois B. Travis, Edward M. Messing, Ollivier Hyrien, Rui Chen, Michael T. Milano, Ralph Anthony Brasacchio, Yuhchyau Chen

Background: The U.S. Preventive Services Task Force (USPSTF) recently recommended against prostate-specific antigen (PSA)-based screening for prostate cancer. This recommendation has heightened the debate about risks and benefits of prostate cancer screening, and underscored our limited understanding of PSA-detected prostate cancer. The purpose of this study was to determine the frequency of various risks of prostate cancer based on patient characteristics and PSA levels.

Methods: This population-based study used the Surveillance, Epidemiology, and End Results (SEER) program to identify men with AJCC stage T1cN0M0 disease diagnosed between 1/2004 and 12/2008. Multivariate logistic regression was conducted to model the probability of developing low (PSA <10 mg/L and Gleason score ≤6), intermediate (PSA between 10 mg/L to 20 mg/L and/or Gleason score 7), and high risk diseases (PSA ≥20 mg/L, and/or Gleason score ≥8). Results: A total of 70,345 men with PSA-detected T1cN0M0 prostate cancer were evaluated. Among them, 47.6%, 35.9% and16.5% had low, intermediate, or high risk disease, respectively. Odds ratios (OR) of having intermediate or high risk disease in patients ≥75 years old were 4.47 (95% confidence interval (CI) 3.81 to 5.26, p<0.01) and 9.39 (95% CI 7.25 to 12.16, p<0.01), respectively, when compared with patients aged <50. Also, black men had increased ORs for intermediate and high risk disease compared with white men (OR 1.50, 95% CI 1.42 to 1.58, p<0.01 for intermediate risk disease; OR 1.84, 95% CI 1.72 to 19.97, p<0.01 for high risk disease). While men aged >75 accounted for 11.8% of the population at risk, they accounted for 24.3% of intermediate and 26.1% of high risk disease.

Conclusions: A substantial number of PSA-detected prostate cancer patients have either intermediate or high risk disease at diagnosis. Men age >75 or of black race have the highest risk of presenting with intermediate or high risk disease. Disclosures: Nothing to disclose

Oral Abstract Session A

Abdenour Nabid, MD, FRCP(C)
Thursday, February 14, 2013, 1:15 PM - 1:27 PM EST
Centre Hospitalier Universitaire
de Sherbrooke
Gatlin Ballroom C
Sherbrooke, QC

Duration of Hormone Therapy for High-Risk Prostate Cancer Can be Shortened without Compromising Treatment Efficacy

A Phase III study showed that patients with high-risk prostate cancer who received 18 months of hormone therapy lived as long as patients treated for 36 months. The finding suggests that the currently recommended duration of hormone therapy - also known as androgen blockade therapy - of 24-36 months can be safely shortened without affecting survival.

"Shorter-term hormone therapy could have a big impact on the lives of men with prostate cancer, reducing the quantity and intensity of its unpleasant side effects as well as treatment costs," said lead author Abdenour Nabid, MD, Fellow of the Royal College of Physicians of Canada and associate professor at Centre Hospitalier Universitaire de Sherbrooke in Sherbrooke, Canada. "For the benefit of the patients, we hope these results will convince doctors that they can stop hormone therapy after one and a half year instead of two to three years."

In the study, 630 patients with high-risk, node-negative (localized) prostate cancer were randomly assigned to receive either 36 or 18 months of androgen blockade therapy (bicalutamide and goserelin) before, during, and after pelvic and prostate radiotherapy. At a median follow-up of 77 months, comparable numbers of patients were still alive in the two treatment groups - 77.1 percent in the 36-month group and 76.2 percent in the 18-month group. Five-year and 10-year overall survival rates were also comparable in the 36-month and 18-month groups - 92.1 percent vs. 86.8 percent and 63.6 percent vs. 63.2 percent for the two groups, respectively. Assessment of cancer-specific survival showed that halving the duration of androgen blockade therapy didn't affect the odds of dying of prostate cancer (10-year disease-specific survival was 87.2 percent in both groups).

Long-term androgen blockade therapy is a standard treatment for men diagnosed with localized prostate cancer. The goal of this therapy is to block the body's ability to produce the hormone testosterone, which fuels the growth of prostate cancer. Prolonged suppression of testosterone production, however, causes a wide range of physical, mental, and emotional side effects in men, including hot flashes, loss of libido, erectile dysfunction, weight gain, loss of bone density, loss of muscle mass, and depression. Many of those side effects worsen over the duration androgen blockade therapy. It is therefore expected that shorter-course treatment will result in improved quality of life. A quality of life analysis for this study, still in progress, marks the longest quality of life follow-up among patients with prostate cancer to date.

Abstract #3

Title: High-risk prostate cancer treated with pelvic radiotherapy and 36 versus 18 months of androgen blockade: Results of a phase III randomized study.

Authors: Abdenour Nabid, Nathalie Carrier, André-Guy Martin, Jean-Paul Bahary, Luis Souhami, Marie Duclos, François Vincent, Sylvie Vass, Boris Bahoric, Robert Archambault, Céline Lemaire

Background: Radiotherapy (RT) and long term androgen blockade (AB) is standard treatment for patients with high risk prostate cancer. However, the optimal duration of AB is not yet defined. The purpose of this randomized study was to compare outcomes between 36 vs. 18 months of AB in high risk prostate cancer treated with RT (PCS IV trial, Clinical Trials.gov, #NCT00223171).

Methods: PCS IV randomized patients with node negative high risk prostate cancer (T3-4, PSA >20 ng/ml or Gleason score >7), to pelvic RT (whole pelvis 44 Gy/4 ½ weeks, prostate 70 Gy/7 weeks) and 36 (arm 1) vs. 18 months (arm 2) of AB (neo adjuvant, concomitant, adjuvant). AB consisted of bicalutamide 50 mg for one month plus goserelin 10.8 mg every three months for 36 vs. 18 months. Overall survival was the primary end point. Overall and cancer specific survival rates were compared between arms with Kaplan-Meier log rank test and Cox regression. Results: From October 2000 to January 2008, 310 patients were randomized to arm 1 and 320 to arm 2. Patients' characteristics were well balanced between the two arms (median age 71 years, median PSA 16 ng/ml, median Gleason score 8). Most patients had T2-3 disease. At a median follow-up of 77 months, 71/310 patients (22.9%) in arm 1 and 76/320 (23.8%) in arm 2 had died (p=0.802). Overall, 116 patients died of causes other than prostate cancer. Overall and cancer specific survival hazard ratios were 1.15 (0.83-1.59), p=0.398 and 1.13 (0.61-2.08), p=0.153, respectively. 5 year overall and disease specific survival rates were 92.1% (89.1-95.1) vs. 86.8% (83.0-90.6), p=0.052 and 97.6% (95.9-99.4) vs. 96.4% (94.2-98.6), p=0.473 and 10 year overall and disease specific survival rates were 63.6% (55.7-71.5) vs. 63.2% (54.7-71.7), p=0.429 and 87.2% (81.0-93.3) vs. 87.2% (80.9-93.6), p=0.838 for arm 1 and arm 2, respectively. There were no significant differences in the rates of biochemical, regional or distant failure between arms.

Conclusions: Our study shows that long term AB can be safely reduced from 36 to 18 months without compromising outcomes. Analysis of treatment impact on quality of life is now under review. Source of Funding: AstraZeneca Pharmaceuticals Grant.

Disclosures: Nothing to disclose

Oral Abstract Session C

William C. Huang, MD
Saturday, February 16, 2013, 10:12 AM - 10:24 AM EST
New York University
Gatlin Ballroom C
New York, NY

Large Population-Based Study Suggests Surveillance is a Safe Alternative to Surgery for Older Patients with Small Kidney Tumors

A large retrospective study of older patients diagnosed with small kidney tumors - less than 1.5 inches in diameter - showed that patients who undergo surgery to remove these tumors have the same risk of dying of kidney cancer over a five-year period as those who undergo surveillance. Additionally, elderly patients treated with surgery for these small masses may be at greater risk for suffering a cardiovascular event and an earlier death from any cause. The findings suggest that surveillance with imaging, such as MRI, ultrasound, and CT, is a safe option for the management of small renal masses in the elderly.

"Our analysis indicates that physicians can comfortably tell an elderly patient, especially a patient that is not healthy enough to tolerate general anesthesia and surgery, that the likelihood of dying of kidney cancer is low and that kidney surgery is unlikely to extend their lives," said lead author William C. Huang, MD, Assistant Professor of Urologic Oncology at New York University Medical Center in New York. "However, since it is difficult to identify which tumors will become lethal, elderly patients who are completely healthy and have an extended life expectancy, may opt for surgery."

In 3 out of 4 cases, small renal tumors are detected incidentally - when a patient undergoes ultrasound, CT, or MRI imaging for an unrelated condition, such as gallstones, abdominal pain, or back pain. Currently, the majority of patients diagnosed with a small renal mass receive surgery, which entails removal of either part of the kidney or the entire kidney. However, emerging evidence has suggested that, for elderly patients or patients with co-morbid conditions and limited life expectancy, the risk of surgery may outweigh the benefit.

In the study, researchers analyzed SEER registry data linked to Medicare claims for patients aged 66 years or older who were diagnosed with small renal masses. Out of 8,317 patients, 5,706 (70 percent) underwent surgery and 2,611 (31 percent) underwent surveillance. During a median follow up of 4.8 years, 2,078 (25 percent) patients died overall, 277 (3 percent) of kidney cancer. The rates of kidney cancer-related death were the same among patients who received surgery and those who underwent surveillance. Surveillance was also associated with a markedly lower risk of death from any cause as well as a lower risk of having a cardiovascular event, such as chronic heart failure, ischemic stroke, and vascular disease.

The study found that during the years 2000 through 2007, the percentage of patients managed with surveillance increased between 25 to 37 percent. It appears that doctors are beginning to realize that many small tumors do not pose a threat even if they are malignant. There is also increased awareness that removal of the kidney may lead to chronic kidney disease, which is associated with kidney failure, cardiovascular problems, and early death.

While 8 out of 10 small renal masses are malignant tumors, they generally don't pose an immediate threat because they normally grow slowly and only a small number of them metastasize. Surveillance allows doctors to intervene if the tumor exhibits an aggressive growth rate or reaches a size that indicates a greater potential for spreading. "The risk of dying of kidney cancer in a person diagnosed with a small renal mass is small but real," cautions Huang. "So, treatment considerations are different for healthy individuals, because they have a long life expectancy and a greater chance of having progression and spread of the disease."

Abstract #343

Title: Surveillance for the management of small renal masses: Utilization and outcomes in a population-based cohort.

Authors: William C. Huang, Laura C. Pinheiro, Paul Russo, William Thomas Lowrance, Elena B. Elkin

Background: Small renal masses (SRM) are comprised of a heterogeneous group of tumors with some having malignant potential. Although surgery is the standard treatment for SRMs, emerging data suggests that surgery in the elderly or morbidly ill patients, may be unnecessary and may adversely impact non-oncologic outcomes. We analyzed a population-based cohort of patients to identify predictors of surveillance and assess the impact of surveillance on overall survival, kidney cancer-specific survival and cardiovascular (CV) events, compared with surgery.

Methods: From surveillance, epidemiology, and end results (SEER) cancer registry data linked with Medicare claims, we performed a retrospective cohort study of patients, 66 years of age or older who received surgery or surveillance for SRM (< 4 cm) diagnosed between 2000 to 2007. Propensity score methods were used to control for potential confounders in multivariable analysis.

Results: Of 8,317 patients, 5,706 (70%) underwent surgery and 2,611 (31%) underwent surveillance. The use of surveillance increased from 25% in 2000 to 37% in 2007 (p < 0.001). During a median follow-up of 58 months, 2,053 (25%) patients had at least one CV event and 2,078 (25%) patients died, including 277 (3%) who died of kidney cancer. Compared with surgery, surveillance was associated with a significantly lower risk of death from any cause (hazard ratio [HR], 0.84; CI, 0.75-0.94) and of suffering a CV event (HR, 0.79; CI 0.70-0.89), controlling for patient and disease characteristics. Kidney cancer-specific survival did not differ by treatment approach (HR, 0.89; CI, 0.66-1.21).

Conclusions: There is increasing utilization of surveillance as an initial treatment strategy for patients with SRMs. For older patients with SRM, surveillance does not appear to adversely affect kidney cancer-specific survival, while surgery may be associated with CV complications and an increased risk of death from any cause. Surveillance should be considered an option for patients with SRM who are not otherwise acceptable candidates for surgical treatment.

Disclosures: Nothing to disclose

2013 Genitourinary Cancers Symposium News Planning Team
Mark K. Buyyounouski, MD, American Society for Radiation Oncology (ASTRO); Bruce J. Roth, MD, American Society of Clinical Oncology (ASCO); Leonard G. Gomella, MD, Society for Urologic Oncology (SUO)

Click the link to view the disclosures for the News Planning Team: http://gucasym.asco.org/sites/gucasym.org/files/GU13_Cmte_Disclosures1.pdf

ATTRIBUTION TO THE 2013 GENITOURINARY CANCERS SYMPOSIUM IS REQUESTED IN ALL NEWS COVERAGE.

* American Cancer Society, Cancer Facts and Figures 2013

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