The Association of the Pandemic With Prostate Biopsy and Prostate Cancer Diagnosis Rates Among Black vs White Patients in the Veterans Affairs Health Care System Journal Club - Zachary Klaassen
February 23, 2023
In this UroToday Journal Club, Zachary Klaassen discusses the publication “Association of the COVID-19 Pandemic With Rates of Prostate Cancer Biopsy and Diagnoses in Black Versus White US Veterans.”. The study used a retrospective analysis of all prostate biopsies performed in the VA system between January 2018 and March 2021, excluding men with a pre-existing diagnosis of prostate cancer. The study used interrupted time-series analysis and Poisson generalized linear models to assess the association between the pandemic onset and prostate biopsy and prostate cancer incidence. The results showed a sharp decrease in both the number of positive and negative biopsies obtained during the strict lockdown period after the declaration of the pandemic, with a recovery period in the latter part of 2020 and 2021. The number of negative biopsies had come back to the expected count while the number of positive biopsies had not quite reached the expected count had there not been a pandemic interruption.
Biographies:
Zachary Klaassen, MD, MSc, Urologic Oncologist, Assistant Professor Surgery/Urology at the Medical College of Georgia at Augusta University, Georgia Cancer Center
Biographies:
Zachary Klaassen, MD, MSc, Urologic Oncologist, Assistant Professor Surgery/Urology at the Medical College of Georgia at Augusta University, Georgia Cancer Center
Read the Full Video Transcript
Christopher Wallis: Hello, and thank you for joining us for this UroToday Journal Club discussion. We're discussing, today, a recent publication entitled, Association of the COVID-19 Pandemic With Rates of Prostate Cancer Biopsy and Diagnoses in Black Versus White US Veterans. I'm Chris Wallis, an assistant professor in the Division of Urology at the University of Toronto, and joining me today is Zach Klaassen, an assistant professor in the Division of Urology at the Medical College of Georgia. You can see here, the citation for this recent publication of JAMA Oncology that Dr. Klaassen led along with the team of Dr. Freedland.
COVID-19 has disrupted not just our lives and our social fabric, but clearly the practice of medicine, and this is not spared urology or urologic oncology. You can see to the right of this screen, changes in patient encounters and new patient encounters associated with the initial onset of the pandemic, and across all oncologic sites, but including prostate cancer, we saw traumatic decreases in cancer diagnosis, in large part due triaging patients for screening as well as treatment.
We have seen from work in other groups, including Andres Correa's group, that the effects of the pandemic on urologic care may be a differential according to race. And so he, along with his team, showed that Black men were considerably less likely to undergo radical prostatectomy during the pandemic compared to White men. And so you can see at the bottom right here, that White men during the pandemic did not have a significantly different change in their likelihood of undergoing surgery, but Black men had a substantial decrease in their chance of undergoing radical prostatectomy. And so these authors sought to assess whether the pandemic was associated with changes in prostate cancer biopsy volume and diagnoses in the context of the equal access VA system, which may mitigate some racial effects.
To do this, they undertook a retrospective study of all prostate biopsies performed in the VA system between January 2018 and March 2021. They excluded men who had a preexisting diagnosis of prostate cancer, that is where the diagnosis date was at least 30 days prior to the included biopsy date. The base population included all living men who had at least one visit to a veteran's healthcare center during the 3 years prior to each month that was included in the study. Racial stratification was performed dividing men into Black and White racial groups and omitting other racial groups just to focus on this dichotomous comparison.
The two outcomes of interest were the of number of prostate biopsies performed and the number of incident prostate cancer diagnoses. The authors use interrupted time-series analysis to assess the association between the pandemic onset and prostate biopsy and prostate cancer incidence. They used Poisson generalized linear models to assess linear time trends from the initiation of their cohort in January 2018 to a level change at the start of the pandemic in January 2020, an interaction term to allow for changes in the trend following this recovery. So we have, essentially, three intervals. We have the pre-pandemic time trends, we have a level change at the start of the pandemic, and then we have a new time trend following the start of the pandemic. Differences between Black and White men were assessed by adding a racial indicator variable to the model, with interaction terms between this variable and each of those trends I just described. Now going to hand it over to Zach to walk us through the results of their analysis.
Zachary Klaassen: Thanks very much, Chris, for that great introduction. This is the first figure in the paper, and this looks at prostate biopsies and newly diagnosed cases of prostate cancer stratified by month. So just taking a minute to set this figure up, which will be important for subsequent figures as well, on the y-axis we have time starting in January 2018, all the way down to March 2021, and the color scheme is for positive biopsies in orange and negative biopsies in this gray-blue color. The bars on this figure are the observed counts are both positive and negative biopsies.
This dashed line is March 11th, 2020 when the World Health Organization declared a global pandemic and the solid lines are the expected counts from the interrupted time series analyses. And so, as we see here, this is the trend for 2018, 2019, into early 2020, when we see a sharp decrease in both the number of positive and negative biopsies that were obtained, with a recovery period in the latter part of 2020 and 2021. The final point for this figure is the dashed lines, which are the projected expected counts had there not been a COVID pandemic interruption. We can see this line here at the bottom of this figure. And so as we look at the very bottom in March and February 2021, we see that the number of negative biopsies has come back to the expected and the number of positive biopsies has not quite reached the expected had there not been a pandemic interruption.
This is the observed prostate biopsies and new prostate diagnosis expected had there not been a pandemic interruption. And I've highlighted here in the green box, the particular strict lockdown period after the March 2020 declaration of the pandemic. And we can see here in April, number of observed biopsies was 344 compared to what was expected of 1,362, number of new prostate cancer diagnoses, 221 with an expected of 794, and again, in May, 491 observed biopsies with an expected 1,350, and number of new prostate diagnoses, 317 with an expected of 788. And as we look through the remaining portion of this table, we do see these numbers slowly start to increase to the early part of 2021 when we were either close or at the level of expected number of biopsies and not quite to the level of expected number of diagnoses, but certainly trending in the direction pre-pandemic.
This is a similar looking figure as the one I previously showed, but this is looking at prostate biopsy rates stratified by race. Again, this blue line is the March 11th, 2020 delineation and these dots that we see here are the observed rates of prostate biopsies, and this is stratified by White patient in the dark blue line and Black patients in the orange line. The solid line, expected counts from the interrupted time series analysis, again, moving along through 2018 and 2019 into the early part of 2020, when we see a sharp decrease in the number of biopsies in both Black and White men. And this dash line is the projected counts had there not been a pandemic interruption. And so we see over the course of time after the strict lockdowns, the number of biopsies did reach or come very close to reaching what they would've been had there not been a pandemic interruption for both races.
A similar figure, but now switching prostate biopsies for prostate cancer diagnoses, again, the blue line being the March 11th, 2020 pandemic and the dots being the observed rates of prostate cancer diagnoses. We see here in the solid line, a solid trend for both Black and White men, and then a sharp decrease again at the time of the strict lockdowns, and then the recovery period afterwards, not quite to the level of what would be expected if there was not a pandemic interruption. As you can see, the solid and the dash lines did not quite reach each other as we move into March 2021.
This is the observed and expected number of prostate biopsies and new prostate cancer diagnoses that had not had there not been a pandemic interrupted stratified by race. So looking first at number of prostate biopsies, again, I've highlighted in the green box, the strict lockdown period of April and May 2020. So for White patients in terms of number of biopsies, drastically down from the observed and the expected for both of these months, but also seen again, similarly for the Black patients, the observed as much lower than expected, as well as a similar trend in the prostate cancer diagnoses. As we move down to February and March 2021, we see recovery for both prostate biopsies and prostate cancer diagnoses for both Black and White men. So again, similar trends to the overall trends that we saw not stratified by race.
This is the incident rate ratios from the Poisson generalized linear model., And I've highlighted two asterisks here. The first is that there was more prostate biopsies and prostate cancer diagnoses for Black versus White men. But I think the most important take home message from this table is this joint test, and this is a test evaluating the changes in race effects during the pandemic onset and recovery periods, and we see that this was not statistically significant, suggesting there was no differences in the prostate biopsy rate or the prostate cancer diagnoses rate during the pandemic or the recovery period stratified by race.
Several discussion points from this study, this study showed that the COVID-19 pandemic was associated with fewer biopsies and fewer new prostate cancer cases, which was particularly pronounced during the initial pandemic peak. This is the first study, to our knowledge, to assess cancer screening and diagnosis rates in the VA healthcare system. Collectively, this study and other studies have suggested that the pandemic has negatively affected cancer diagnosis rates, regardless of jurisdiction or payment model. Importantly, Black men had statistically significantly higher biopsy and prostate cancer diagnosis rates compared to White men prior to the pandemic with no significant changes by race during the pandemic peak or during the recovery period. This suggests that the pandemic did not result in a differential marginalization of care for Black men treated in the VA system.
Several important limitations are associated with this study. The data are limited by lacking information on cancer stage and grade AT diagnosis, as well as the present study of race being limited to Black and White men. Thus, it is unknown if other racial and ethnic groups have different biopsy or prostate cancer diagnosis trends.
So in conclusion, this cohort study demonstrates that during the COVID-19 pandemic, prostate biopsy and prostate cancer diagnosis rates decreased, particularly during the peak of the pandemic. However, importantly, there was no statistically significant changes in rates of either of these metrics by race. And finally, with COVID-19 variant strains, it is possible that continued on ongoing delays in prostate cancer screening may occur. Thank you very much for your attention and we hope we enjoyed this UroToday Journal Club discussion.
Christopher Wallis: Hello, and thank you for joining us for this UroToday Journal Club discussion. We're discussing, today, a recent publication entitled, Association of the COVID-19 Pandemic With Rates of Prostate Cancer Biopsy and Diagnoses in Black Versus White US Veterans. I'm Chris Wallis, an assistant professor in the Division of Urology at the University of Toronto, and joining me today is Zach Klaassen, an assistant professor in the Division of Urology at the Medical College of Georgia. You can see here, the citation for this recent publication of JAMA Oncology that Dr. Klaassen led along with the team of Dr. Freedland.
COVID-19 has disrupted not just our lives and our social fabric, but clearly the practice of medicine, and this is not spared urology or urologic oncology. You can see to the right of this screen, changes in patient encounters and new patient encounters associated with the initial onset of the pandemic, and across all oncologic sites, but including prostate cancer, we saw traumatic decreases in cancer diagnosis, in large part due triaging patients for screening as well as treatment.
We have seen from work in other groups, including Andres Correa's group, that the effects of the pandemic on urologic care may be a differential according to race. And so he, along with his team, showed that Black men were considerably less likely to undergo radical prostatectomy during the pandemic compared to White men. And so you can see at the bottom right here, that White men during the pandemic did not have a significantly different change in their likelihood of undergoing surgery, but Black men had a substantial decrease in their chance of undergoing radical prostatectomy. And so these authors sought to assess whether the pandemic was associated with changes in prostate cancer biopsy volume and diagnoses in the context of the equal access VA system, which may mitigate some racial effects.
To do this, they undertook a retrospective study of all prostate biopsies performed in the VA system between January 2018 and March 2021. They excluded men who had a preexisting diagnosis of prostate cancer, that is where the diagnosis date was at least 30 days prior to the included biopsy date. The base population included all living men who had at least one visit to a veteran's healthcare center during the 3 years prior to each month that was included in the study. Racial stratification was performed dividing men into Black and White racial groups and omitting other racial groups just to focus on this dichotomous comparison.
The two outcomes of interest were the of number of prostate biopsies performed and the number of incident prostate cancer diagnoses. The authors use interrupted time-series analysis to assess the association between the pandemic onset and prostate biopsy and prostate cancer incidence. They used Poisson generalized linear models to assess linear time trends from the initiation of their cohort in January 2018 to a level change at the start of the pandemic in January 2020, an interaction term to allow for changes in the trend following this recovery. So we have, essentially, three intervals. We have the pre-pandemic time trends, we have a level change at the start of the pandemic, and then we have a new time trend following the start of the pandemic. Differences between Black and White men were assessed by adding a racial indicator variable to the model, with interaction terms between this variable and each of those trends I just described. Now going to hand it over to Zach to walk us through the results of their analysis.
Zachary Klaassen: Thanks very much, Chris, for that great introduction. This is the first figure in the paper, and this looks at prostate biopsies and newly diagnosed cases of prostate cancer stratified by month. So just taking a minute to set this figure up, which will be important for subsequent figures as well, on the y-axis we have time starting in January 2018, all the way down to March 2021, and the color scheme is for positive biopsies in orange and negative biopsies in this gray-blue color. The bars on this figure are the observed counts are both positive and negative biopsies.
This dashed line is March 11th, 2020 when the World Health Organization declared a global pandemic and the solid lines are the expected counts from the interrupted time series analyses. And so, as we see here, this is the trend for 2018, 2019, into early 2020, when we see a sharp decrease in both the number of positive and negative biopsies that were obtained, with a recovery period in the latter part of 2020 and 2021. The final point for this figure is the dashed lines, which are the projected expected counts had there not been a COVID pandemic interruption. We can see this line here at the bottom of this figure. And so as we look at the very bottom in March and February 2021, we see that the number of negative biopsies has come back to the expected and the number of positive biopsies has not quite reached the expected had there not been a pandemic interruption.
This is the observed prostate biopsies and new prostate diagnosis expected had there not been a pandemic interruption. And I've highlighted here in the green box, the particular strict lockdown period after the March 2020 declaration of the pandemic. And we can see here in April, number of observed biopsies was 344 compared to what was expected of 1,362, number of new prostate cancer diagnoses, 221 with an expected of 794, and again, in May, 491 observed biopsies with an expected 1,350, and number of new prostate diagnoses, 317 with an expected of 788. And as we look through the remaining portion of this table, we do see these numbers slowly start to increase to the early part of 2021 when we were either close or at the level of expected number of biopsies and not quite to the level of expected number of diagnoses, but certainly trending in the direction pre-pandemic.
This is a similar looking figure as the one I previously showed, but this is looking at prostate biopsy rates stratified by race. Again, this blue line is the March 11th, 2020 delineation and these dots that we see here are the observed rates of prostate biopsies, and this is stratified by White patient in the dark blue line and Black patients in the orange line. The solid line, expected counts from the interrupted time series analysis, again, moving along through 2018 and 2019 into the early part of 2020, when we see a sharp decrease in the number of biopsies in both Black and White men. And this dash line is the projected counts had there not been a pandemic interruption. And so we see over the course of time after the strict lockdowns, the number of biopsies did reach or come very close to reaching what they would've been had there not been a pandemic interruption for both races.
A similar figure, but now switching prostate biopsies for prostate cancer diagnoses, again, the blue line being the March 11th, 2020 pandemic and the dots being the observed rates of prostate cancer diagnoses. We see here in the solid line, a solid trend for both Black and White men, and then a sharp decrease again at the time of the strict lockdowns, and then the recovery period afterwards, not quite to the level of what would be expected if there was not a pandemic interruption. As you can see, the solid and the dash lines did not quite reach each other as we move into March 2021.
This is the observed and expected number of prostate biopsies and new prostate cancer diagnoses that had not had there not been a pandemic interrupted stratified by race. So looking first at number of prostate biopsies, again, I've highlighted in the green box, the strict lockdown period of April and May 2020. So for White patients in terms of number of biopsies, drastically down from the observed and the expected for both of these months, but also seen again, similarly for the Black patients, the observed as much lower than expected, as well as a similar trend in the prostate cancer diagnoses. As we move down to February and March 2021, we see recovery for both prostate biopsies and prostate cancer diagnoses for both Black and White men. So again, similar trends to the overall trends that we saw not stratified by race.
This is the incident rate ratios from the Poisson generalized linear model., And I've highlighted two asterisks here. The first is that there was more prostate biopsies and prostate cancer diagnoses for Black versus White men. But I think the most important take home message from this table is this joint test, and this is a test evaluating the changes in race effects during the pandemic onset and recovery periods, and we see that this was not statistically significant, suggesting there was no differences in the prostate biopsy rate or the prostate cancer diagnoses rate during the pandemic or the recovery period stratified by race.
Several discussion points from this study, this study showed that the COVID-19 pandemic was associated with fewer biopsies and fewer new prostate cancer cases, which was particularly pronounced during the initial pandemic peak. This is the first study, to our knowledge, to assess cancer screening and diagnosis rates in the VA healthcare system. Collectively, this study and other studies have suggested that the pandemic has negatively affected cancer diagnosis rates, regardless of jurisdiction or payment model. Importantly, Black men had statistically significantly higher biopsy and prostate cancer diagnosis rates compared to White men prior to the pandemic with no significant changes by race during the pandemic peak or during the recovery period. This suggests that the pandemic did not result in a differential marginalization of care for Black men treated in the VA system.
Several important limitations are associated with this study. The data are limited by lacking information on cancer stage and grade AT diagnosis, as well as the present study of race being limited to Black and White men. Thus, it is unknown if other racial and ethnic groups have different biopsy or prostate cancer diagnosis trends.
So in conclusion, this cohort study demonstrates that during the COVID-19 pandemic, prostate biopsy and prostate cancer diagnosis rates decreased, particularly during the peak of the pandemic. However, importantly, there was no statistically significant changes in rates of either of these metrics by race. And finally, with COVID-19 variant strains, it is possible that continued on ongoing delays in prostate cancer screening may occur. Thank you very much for your attention and we hope we enjoyed this UroToday Journal Club discussion.