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Methods and rationale used in a matched cohort study of the incidence of new primary cancers following prostate cancer
OBJECTIVES: We describe several methodological issues that were addressed in conducting a Danish population-based matched cohort study comparing rates of new primary cancers (NPCs) in men with and without prostate cancer (PC). METHODS: We matched 30,220 men with PC to 151,100 men without PC (compara...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Dove Medical Press
2013
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3817011/ https://www.ncbi.nlm.nih.gov/pubmed/24204172 http://dx.doi.org/10.2147/CLEP.S49713 |
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author | Cronin-Fenton, Deirdre P Antonsen, Sussie Cetin, Karynsa Acquavella, John Daniels, Andre Lash, Timothy L |
author_facet | Cronin-Fenton, Deirdre P Antonsen, Sussie Cetin, Karynsa Acquavella, John Daniels, Andre Lash, Timothy L |
author_sort | Cronin-Fenton, Deirdre P |
collection | PubMed |
description | OBJECTIVES: We describe several methodological issues that were addressed in conducting a Danish population-based matched cohort study comparing rates of new primary cancers (NPCs) in men with and without prostate cancer (PC). METHODS: We matched 30,220 men with PC to 151,100 men without PC (comparators) on age (±2 years) and PC diagnosis/index date. We focused on several methodological issues: 1) to address survival differences between the cohorts we compared rates with and without censoring comparators on the date their matched PC patient died or was censored; 2) to address diagnostic bias, we excluded men with a history of cancer from the comparator cohort; 3) to address prostate cancer immunity, we graphed the hazard of NPC in both cohorts, with and without prostate cancer as an outcome; 4) we used empirical Bayes methods to explore the effect of adjusting for multiple comparisons. RESULTS: After 18 months of follow-up, cumulative person-time was lower in the PC than comparator cohort due to higher mortality among PC patients. Terminating person-time in comparators at the matched PC patient’s death or loss to follow-up resulted in comparable person-time up to 30 months of follow-up and lower person-time among comparators thereafter. The hazard of NPC was lower among men with PC than comparators throughout follow-up. There was little difference in rates beyond the first four years of follow-up after removing PC as an outcome. Empirical Bayes adjustment for multiple comparisons had little effect on the estimates. CONCLUSION: Addressing the issues of competing risks, treatment interference or diagnostic bias, prostate cancer immunity due to radical prostatectomy, and multiple comparisons lowered the deficit rate of NPCs among men with a history of PC compared with those without PC. However, the differing rates of NPCs may also be due to risk factor differences between the cohorts. |
format | Online Article Text |
id | pubmed-3817011 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2013 |
publisher | Dove Medical Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-38170112013-11-07 Methods and rationale used in a matched cohort study of the incidence of new primary cancers following prostate cancer Cronin-Fenton, Deirdre P Antonsen, Sussie Cetin, Karynsa Acquavella, John Daniels, Andre Lash, Timothy L Clin Epidemiol Original Research OBJECTIVES: We describe several methodological issues that were addressed in conducting a Danish population-based matched cohort study comparing rates of new primary cancers (NPCs) in men with and without prostate cancer (PC). METHODS: We matched 30,220 men with PC to 151,100 men without PC (comparators) on age (±2 years) and PC diagnosis/index date. We focused on several methodological issues: 1) to address survival differences between the cohorts we compared rates with and without censoring comparators on the date their matched PC patient died or was censored; 2) to address diagnostic bias, we excluded men with a history of cancer from the comparator cohort; 3) to address prostate cancer immunity, we graphed the hazard of NPC in both cohorts, with and without prostate cancer as an outcome; 4) we used empirical Bayes methods to explore the effect of adjusting for multiple comparisons. RESULTS: After 18 months of follow-up, cumulative person-time was lower in the PC than comparator cohort due to higher mortality among PC patients. Terminating person-time in comparators at the matched PC patient’s death or loss to follow-up resulted in comparable person-time up to 30 months of follow-up and lower person-time among comparators thereafter. The hazard of NPC was lower among men with PC than comparators throughout follow-up. There was little difference in rates beyond the first four years of follow-up after removing PC as an outcome. Empirical Bayes adjustment for multiple comparisons had little effect on the estimates. CONCLUSION: Addressing the issues of competing risks, treatment interference or diagnostic bias, prostate cancer immunity due to radical prostatectomy, and multiple comparisons lowered the deficit rate of NPCs among men with a history of PC compared with those without PC. However, the differing rates of NPCs may also be due to risk factor differences between the cohorts. Dove Medical Press 2013-10-31 /pmc/articles/PMC3817011/ /pubmed/24204172 http://dx.doi.org/10.2147/CLEP.S49713 Text en © 2013 Cronin-Fenton et al. This work is published by Dove Medical Press Ltd, and licensed under Creative Commons Attribution – Non Commercial (unported, v3.0) License The full terms of the License are available at http://creativecommons.org/licenses/by-nc/3.0/. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Ltd, provided the work is properly attributed. |
spellingShingle | Original Research Cronin-Fenton, Deirdre P Antonsen, Sussie Cetin, Karynsa Acquavella, John Daniels, Andre Lash, Timothy L Methods and rationale used in a matched cohort study of the incidence of new primary cancers following prostate cancer |
title | Methods and rationale used in a matched cohort study of the incidence of new primary cancers following prostate cancer |
title_full | Methods and rationale used in a matched cohort study of the incidence of new primary cancers following prostate cancer |
title_fullStr | Methods and rationale used in a matched cohort study of the incidence of new primary cancers following prostate cancer |
title_full_unstemmed | Methods and rationale used in a matched cohort study of the incidence of new primary cancers following prostate cancer |
title_short | Methods and rationale used in a matched cohort study of the incidence of new primary cancers following prostate cancer |
title_sort | methods and rationale used in a matched cohort study of the incidence of new primary cancers following prostate cancer |
topic | Original Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3817011/ https://www.ncbi.nlm.nih.gov/pubmed/24204172 http://dx.doi.org/10.2147/CLEP.S49713 |
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