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CHICAGO – Black men with advanced prostate cancer have survival with chemotherapy that rivals or surpasses that of white men with advanced disease, and black men with castration-resistant prostate cancer have better outcomes with abiraterone than white men.
Those conclusions come from two studies presented here at the annual meeting of the American Society of Clinical Oncology. Taken together, they suggest that although there may be genetic or biologic differences in cancer presentation among different racial groups, receiving the appropriate care can level out those differences.
In the first study, Susan Halabi, PhD, from Duke University in Durham, N.C., and colleagues pooled data from nine randomized phase 3 chemotherapy trials in men with advanced prostate cancer and found that black and white men had the same median survival, 21 months, but black men had an adjusted hazard ratio [HR} for death of 0.81, compared with white men.
For the subpopulation of African Americans who were enrolled in trials funded by the National Cancer Institute (NCI), the HR for death was 0.76 (P less than .0001).
“The bottom line, in a sense, is that African American men with advanced prostate cancer need to get to an oncologist and ideally need to get on a clinical trial, and if they do, their outcomes are every bit as good as Caucasian men, if not even a little bit better,” Richard Schilsky, MD, chief medical officer of ASCO, said at a briefing prior to presentation of the studies.
In the second study, a prospective clinical trial of abiraterone (Zytiga) in 100 men with metastatic castration-resistant prostate cancer (mCRPC), black men were more likely to have a decline in prostate-specific antigen (PSA), and a longer median time to PSA rise than white men (16.6 vs. 11.5 months), reported Daniel George, MD, also from Duke.
“There’s a 1.6 times greater likelihood that African Americans are diagnosed with prostate cancer, but a 2.4 times greater chance they die from that disease, and although there very well may be multi-factorial reasons for that, I think some of this is genetic,” he said.
Pooled analysis
In the United States, black men are more likely to be diagnosed with prostate cancer in their 40s and 50s than white men and are often diagnosed with advanced-stage and higher grade cancers. Black men also have double the rate of prostate cancer-specific deaths as white men.
Black men, however, are underrepresented in clinical trials, making it difficult to draw firm conclusions about racial differences due to small sample sizes.
To overcome this problem, Dr. Halabi and colleagues pooled data on 8,452 patients with mCRPC - including 7,528 white men and 500 African American men – from nine randomized phase 3 trials of docetaxel and prednisone or a regimen containing those agents.
Median overall survival, the primary endpoint, was 21.0 months for black men and 21.2 months for white men.
In multivariate analysis adjusted for age, PSA, performance status, alkaline phosphatase, hemoglobin, and metastatic sites, the pooled hazard ratio (HR) for black vs. white men was 0.81 (P = .001) for all patients in the study, and when the analysis was restricted to those patients who received only docetaxel and prednisone (4,172), the results were similar, Dr. Halabi said.
“I would argue that what this tells us is pretty striking: that African-American men have potentially better survival by getting conventional therapy,” commented ASCO expert Robert Dreicer, MD, MS, from the University of Virginia in Charlottesville.
“The nihilism associated with prostate cancer in African-American men is not supported by this really interesting work,” he continued. “What it says to us is when we treat those with bad prostate cancer, African Americans, they do well.”
Abiraterone Study
In the abiraterone study, 50 men who self-identified as white and 50 as black were enrolled and treated with abiraterone acetate and prednisone until disease progression or intolerable toxicity.
Radiographic progression-free survival, the primary endpoint, was 16.8 months in each group. As previously noted, however, median PFS was 16.6 months for black patients, vs. 11.5 months for white men. Black men also had a longer median PSA PFS, with 82% of black men having a 30% or greater PSA decline, compared with 78% of white patients. Respective proportions of men having higher declines were 74% vs. 66% experiencing a PSA decline of at least 50%, and 48% vs. 38% having a decline of at least 90%.
Rates of tumor flare, however, were higher among African Americans, at 16% vs. 4%.
Adverse event rates were generally similar between the study arms, although more white than black patients experienced fatigue, and more black than white patients had hypokalemia.
Single-nucletoide polymorphism (SNP) profiling showed differences between the two groups in key genes involved in androgen metabolism and transport, which may explain the improved responses to abiraterone among African Americans.
“We talk about access to care; we have now demonstrated that if you treat African Americans with standard-of-care drugs for advanced prostate cancer, there’s compelling evidence that they respond as well or maybe better than white men,” Dr. Dreicer commented.
“[We are] beginning to understand the differences that drive differential responses,” he continued. “When African-American men are under-represented in clinical trials, the trial outcomes might be different, frankly, because people respond differently to drugs. I think those are the take homes.”
SOURCE: Halabi et al, George et al. ASCO 2018 Abstracts LBA5005 and LBA5009
CHICAGO – Black men with advanced prostate cancer have survival with chemotherapy that rivals or surpasses that of white men with advanced disease, and black men with castration-resistant prostate cancer have better outcomes with abiraterone than white men.
Those conclusions come from two studies presented here at the annual meeting of the American Society of Clinical Oncology. Taken together, they suggest that although there may be genetic or biologic differences in cancer presentation among different racial groups, receiving the appropriate care can level out those differences.
In the first study, Susan Halabi, PhD, from Duke University in Durham, N.C., and colleagues pooled data from nine randomized phase 3 chemotherapy trials in men with advanced prostate cancer and found that black and white men had the same median survival, 21 months, but black men had an adjusted hazard ratio [HR} for death of 0.81, compared with white men.
For the subpopulation of African Americans who were enrolled in trials funded by the National Cancer Institute (NCI), the HR for death was 0.76 (P less than .0001).
“The bottom line, in a sense, is that African American men with advanced prostate cancer need to get to an oncologist and ideally need to get on a clinical trial, and if they do, their outcomes are every bit as good as Caucasian men, if not even a little bit better,” Richard Schilsky, MD, chief medical officer of ASCO, said at a briefing prior to presentation of the studies.
In the second study, a prospective clinical trial of abiraterone (Zytiga) in 100 men with metastatic castration-resistant prostate cancer (mCRPC), black men were more likely to have a decline in prostate-specific antigen (PSA), and a longer median time to PSA rise than white men (16.6 vs. 11.5 months), reported Daniel George, MD, also from Duke.
“There’s a 1.6 times greater likelihood that African Americans are diagnosed with prostate cancer, but a 2.4 times greater chance they die from that disease, and although there very well may be multi-factorial reasons for that, I think some of this is genetic,” he said.
Pooled analysis
In the United States, black men are more likely to be diagnosed with prostate cancer in their 40s and 50s than white men and are often diagnosed with advanced-stage and higher grade cancers. Black men also have double the rate of prostate cancer-specific deaths as white men.
Black men, however, are underrepresented in clinical trials, making it difficult to draw firm conclusions about racial differences due to small sample sizes.
To overcome this problem, Dr. Halabi and colleagues pooled data on 8,452 patients with mCRPC - including 7,528 white men and 500 African American men – from nine randomized phase 3 trials of docetaxel and prednisone or a regimen containing those agents.
Median overall survival, the primary endpoint, was 21.0 months for black men and 21.2 months for white men.
In multivariate analysis adjusted for age, PSA, performance status, alkaline phosphatase, hemoglobin, and metastatic sites, the pooled hazard ratio (HR) for black vs. white men was 0.81 (P = .001) for all patients in the study, and when the analysis was restricted to those patients who received only docetaxel and prednisone (4,172), the results were similar, Dr. Halabi said.
“I would argue that what this tells us is pretty striking: that African-American men have potentially better survival by getting conventional therapy,” commented ASCO expert Robert Dreicer, MD, MS, from the University of Virginia in Charlottesville.
“The nihilism associated with prostate cancer in African-American men is not supported by this really interesting work,” he continued. “What it says to us is when we treat those with bad prostate cancer, African Americans, they do well.”
Abiraterone Study
In the abiraterone study, 50 men who self-identified as white and 50 as black were enrolled and treated with abiraterone acetate and prednisone until disease progression or intolerable toxicity.
Radiographic progression-free survival, the primary endpoint, was 16.8 months in each group. As previously noted, however, median PFS was 16.6 months for black patients, vs. 11.5 months for white men. Black men also had a longer median PSA PFS, with 82% of black men having a 30% or greater PSA decline, compared with 78% of white patients. Respective proportions of men having higher declines were 74% vs. 66% experiencing a PSA decline of at least 50%, and 48% vs. 38% having a decline of at least 90%.
Rates of tumor flare, however, were higher among African Americans, at 16% vs. 4%.
Adverse event rates were generally similar between the study arms, although more white than black patients experienced fatigue, and more black than white patients had hypokalemia.
Single-nucletoide polymorphism (SNP) profiling showed differences between the two groups in key genes involved in androgen metabolism and transport, which may explain the improved responses to abiraterone among African Americans.
“We talk about access to care; we have now demonstrated that if you treat African Americans with standard-of-care drugs for advanced prostate cancer, there’s compelling evidence that they respond as well or maybe better than white men,” Dr. Dreicer commented.
“[We are] beginning to understand the differences that drive differential responses,” he continued. “When African-American men are under-represented in clinical trials, the trial outcomes might be different, frankly, because people respond differently to drugs. I think those are the take homes.”
SOURCE: Halabi et al, George et al. ASCO 2018 Abstracts LBA5005 and LBA5009
CHICAGO – Black men with advanced prostate cancer have survival with chemotherapy that rivals or surpasses that of white men with advanced disease, and black men with castration-resistant prostate cancer have better outcomes with abiraterone than white men.
Those conclusions come from two studies presented here at the annual meeting of the American Society of Clinical Oncology. Taken together, they suggest that although there may be genetic or biologic differences in cancer presentation among different racial groups, receiving the appropriate care can level out those differences.
In the first study, Susan Halabi, PhD, from Duke University in Durham, N.C., and colleagues pooled data from nine randomized phase 3 chemotherapy trials in men with advanced prostate cancer and found that black and white men had the same median survival, 21 months, but black men had an adjusted hazard ratio [HR} for death of 0.81, compared with white men.
For the subpopulation of African Americans who were enrolled in trials funded by the National Cancer Institute (NCI), the HR for death was 0.76 (P less than .0001).
“The bottom line, in a sense, is that African American men with advanced prostate cancer need to get to an oncologist and ideally need to get on a clinical trial, and if they do, their outcomes are every bit as good as Caucasian men, if not even a little bit better,” Richard Schilsky, MD, chief medical officer of ASCO, said at a briefing prior to presentation of the studies.
In the second study, a prospective clinical trial of abiraterone (Zytiga) in 100 men with metastatic castration-resistant prostate cancer (mCRPC), black men were more likely to have a decline in prostate-specific antigen (PSA), and a longer median time to PSA rise than white men (16.6 vs. 11.5 months), reported Daniel George, MD, also from Duke.
“There’s a 1.6 times greater likelihood that African Americans are diagnosed with prostate cancer, but a 2.4 times greater chance they die from that disease, and although there very well may be multi-factorial reasons for that, I think some of this is genetic,” he said.
Pooled analysis
In the United States, black men are more likely to be diagnosed with prostate cancer in their 40s and 50s than white men and are often diagnosed with advanced-stage and higher grade cancers. Black men also have double the rate of prostate cancer-specific deaths as white men.
Black men, however, are underrepresented in clinical trials, making it difficult to draw firm conclusions about racial differences due to small sample sizes.
To overcome this problem, Dr. Halabi and colleagues pooled data on 8,452 patients with mCRPC - including 7,528 white men and 500 African American men – from nine randomized phase 3 trials of docetaxel and prednisone or a regimen containing those agents.
Median overall survival, the primary endpoint, was 21.0 months for black men and 21.2 months for white men.
In multivariate analysis adjusted for age, PSA, performance status, alkaline phosphatase, hemoglobin, and metastatic sites, the pooled hazard ratio (HR) for black vs. white men was 0.81 (P = .001) for all patients in the study, and when the analysis was restricted to those patients who received only docetaxel and prednisone (4,172), the results were similar, Dr. Halabi said.
“I would argue that what this tells us is pretty striking: that African-American men have potentially better survival by getting conventional therapy,” commented ASCO expert Robert Dreicer, MD, MS, from the University of Virginia in Charlottesville.
“The nihilism associated with prostate cancer in African-American men is not supported by this really interesting work,” he continued. “What it says to us is when we treat those with bad prostate cancer, African Americans, they do well.”
Abiraterone Study
In the abiraterone study, 50 men who self-identified as white and 50 as black were enrolled and treated with abiraterone acetate and prednisone until disease progression or intolerable toxicity.
Radiographic progression-free survival, the primary endpoint, was 16.8 months in each group. As previously noted, however, median PFS was 16.6 months for black patients, vs. 11.5 months for white men. Black men also had a longer median PSA PFS, with 82% of black men having a 30% or greater PSA decline, compared with 78% of white patients. Respective proportions of men having higher declines were 74% vs. 66% experiencing a PSA decline of at least 50%, and 48% vs. 38% having a decline of at least 90%.
Rates of tumor flare, however, were higher among African Americans, at 16% vs. 4%.
Adverse event rates were generally similar between the study arms, although more white than black patients experienced fatigue, and more black than white patients had hypokalemia.
Single-nucletoide polymorphism (SNP) profiling showed differences between the two groups in key genes involved in androgen metabolism and transport, which may explain the improved responses to abiraterone among African Americans.
“We talk about access to care; we have now demonstrated that if you treat African Americans with standard-of-care drugs for advanced prostate cancer, there’s compelling evidence that they respond as well or maybe better than white men,” Dr. Dreicer commented.
“[We are] beginning to understand the differences that drive differential responses,” he continued. “When African-American men are under-represented in clinical trials, the trial outcomes might be different, frankly, because people respond differently to drugs. I think those are the take homes.”
SOURCE: Halabi et al, George et al. ASCO 2018 Abstracts LBA5005 and LBA5009
REPORTING FROM ASCO 2018
Key clinical point: Apparent racial disparities in prostate cancer care may be reduced or eliminated with proper care and access to clinical trials.
Major finding: In a pooled analysis, black men with advanced prostate cancer treated with docetaxel prednisone had a 19% lower risk for death than white men,
Study details: Pooled analysis of 9 randomized phase III trials with a total of 8,452 men and a prospective trial with 100 men with advanced prostate cancer.
Disclosures: The study by Halabi et al was funded by Congressionally Directed Medical Research Programs. The study by George et al was funded by Janssen. Dr. Halabi disclosed a consulting or advisory role with Tokai Pharmaceuticals, Eisai, and Bayer, and travel expenses from Bayer. Dr. George disclosed consulting/advising with Janssen and several other pharmaceutical companies, in addition to speakers’ bureau, travel expenses, and honoraria from various companies. He has also received institutional research funding from Exelixis, Genentech/Roche, Janssen Oncology, Novartis, Pfizer, Astellas Pharma, Bristol-Myers Squibb, Millennium, Acerta Pharma, Bayer, Dendreon, and Innocrin Pharma.
Source: Halabi et al, George et al. ASCO 2018 Abstracts LBA5005 and LBA5009.