Results Summary

What was the research about?

Men treated for prostate cancer usually have prostate-specific antigen, or PSA, blood tests as part of their follow-up care. This test helps detect if prostate cancer has returned. But doctors differ in how often they recommend that men have follow-up PSA tests.

In this project, the research team did two studies that looked at men with prostate cancer who differed in how often they received PSA tests in the first year after treatment. They studied whether more PSA tests led to better health outcomes.

What were the results?

Study 1. The research team compared groups of men who had either zero or one, two, or three or more PSA tests in the first year. The three groups didn’t differ in

  • Survival
  • Rate of prostate cancer returning
  • How soon doctors detected cancer that came back

Study 2. Anxiety, overall quality of life, and quality of life related to their cancer didn’t differ based on the number of PSA tests men had in the first year.

Who was in the study?

Study 1. The research team used records from the National Cancer Data Base. The records included 10,479 men diagnosed with prostate cancer between 2005 and 2010. These men had radiation or surgery to treat the cancer. Of the men, 72 percent were white, 13 percent were African American, and 15 percent were another race or Hispanic. The average age was 63.

Study 2. The team used surveys from 835 men diagnosed with prostate cancer between 2011 and 2013 who participated in the North Carolina Prostate Cancer Comparative Effectiveness and Survivorship Study. These men had radiation or surgery to treat the cancer. Of these men, 66 percent were white, 30 percent were African American, and 4 percent were another race or Hispanic. The average age was 63.

What did the research team do?

Study 1. The research team grouped men based on whether they were at low, medium, or high risk of their cancer coming back, and if they had surgery or radiation. The team then sorted men into three categories based on how many PSA tests they had the first year. Then they compared health outcomes across these categories.

Study 2. Men completed surveys about anxiety related to prostate cancer and quality of life once a year for five years. The research team sorted men based on how many PSA tests they had the first year. The team then compared changes in anxiety and quality of life across the three categories.

Prostate cancer survivors and cancer doctors helped plan the study.

What were the limits of the study?

Patients may have had more or fewer tests in later years than they did in the first year. The first study had fewer men than planned, making it hard to find differences in survival or cancer return rates. In the second study, fewer men answered surveys over time, which could make results less accurate.

Future research could follow patients for longer.

How can people use the results?

Prostate cancer survivors and their doctors can use these results when considering how often to schedule PSA testing after treatment.

Final Research Report

View this project's final research report.

More About This Research

Peer-Review Summary

Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study.

The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments. 

Peer reviewers commented and the researchers made changes or provided responses. Those comments and responses included the following:

  • The reviewers asked why overall survival was chosen as the primary outcome to measure rather than counting deaths specifically caused by prostate cancer. The researchers explained that the database they used provided data on overall survival only and not the cause of death.
  • The reviewers asked for more discussion about the effects of race, ethnicity, and socioeconomic status on the frequency of prostate-specific antigen (PSA) surveillance. The researchers agreed that post-cancer treatment surveillance should reflect risk factors that affect recurrence rates. The researchers commented that race appears to be an independent risk factor and added a paragraph about the effects of race to the report’s background section. However, the researchers declined to add a discussion about socioeconomic status, which they said does not appear to be an independent risk factor when race and other factors are also considered.
  • The reviewers asked how the researchers accounted for changes in treatment modality in their cohorts. The researchers stated that in one cohort, they did not record specific treatment characteristics and would not have been able to compare groups based on these characteristics because of small numbers in each group. In the second cohort, the researchers did collect treatment modality information, but they found that the time period for tracking that cohort was too short to see significant changes in treatment modality over time.
  • The reviewers asked if the study looked at how frequency of clinic visits affected PSA surveillance and outcomes. The researchers said that they did not have data regarding patients’ physician visits, so they could not evaluate whether the frequency of visits correlated with testing frequency, cancer recurrence, or survival.
  • The reviewers said that an important problem with this study is that they powered the study to detect a 7 to 10 percent difference in mortality between groups of patients. The reviewers pointed out that this is a very ambitious expectation in a sample of patients who already had prostate cancer and had viable options to treat co-occurrences and prevent death. The researchers stated that they had originally planned the study to include about 14,000 patients and to have the ability to detect a 5 percent difference in survival. Unfortunately, the researchers were unable to recruit a sample of that size, so they needed a larger difference between groups to find it to be statistically significant.

Conflict of Interest Disclosures

View the COI disclosure form.

Peer-Review Summary

Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study.

The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments. 

Peer reviewers commented and the researchers made changes or provided responses. Those comments and responses included the following:

  • The reviewers asked why overall survival was chosen as the primary outcome to measure rather than counting deaths specifically caused by prostate cancer. The researchers explained that the database they used provided data on overall survival only and not the cause of death.
  • The reviewers asked for more discussion about the effects of race, ethnicity, and socioeconomic status on the frequency of prostate-specific antigen (PSA) surveillance. The researchers agreed that post-cancer treatment surveillance should reflect risk factors that affect recurrence rates. The researchers commented that race appears to be an independent risk factor and added a paragraph about the effects of race to the report’s background section. However, the researchers declined to add a discussion about socioeconomic status, which they said does not appear to be an independent risk factor when race and other factors are also considered.
  • The reviewers asked how the researchers accounted for changes in treatment modality in their cohorts. The researchers stated that in one cohort, they did not record specific treatment characteristics and would not have been able to compare groups based on these characteristics because of small numbers in each group. In the second cohort, the researchers did collect treatment modality information, but they found that the time period for tracking that cohort was too short to see significant changes in treatment modality over time.
  • The reviewers asked if the study looked at how frequency of clinic visits affected PSA surveillance and outcomes. The researchers said that they did not have data regarding patients’ physician visits, so they could not evaluate whether the frequency of visits correlated with testing frequency, cancer recurrence, or survival.
  • The reviewers said that an important problem with this study is that they powered the study to detect a 7 to 10 percent difference in mortality between groups of patients. The reviewers pointed out that this is a very ambitious expectation in a sample of patients who already had prostate cancer and had viable options to treat co-occurrences and prevent death. The researchers stated that they had originally planned the study to include about 14,000 patients and to have the ability to detect a 5 percent difference in survival. Unfortunately, the researchers were unable to recruit a sample of that size, so they needed a larger difference between groups to find it to be statistically significant.

Conflict of Interest Disclosures

Project Information

Ronald C. Chen, MD, MPH
The Alliance for Clinical Trials In Oncology Foundation
$1,712,057
10.25302/05.2020/CER.150329220

Key Dates

45 months
September 2015
June 2020
2015
2020

Study Registration Information

^This project was previously titled: Determining How Often Prostate Cancer Survivors Should Get Follow-up Testing

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Last updated: October 20, 2021