What We Do

Why is the DCPP important?

In the DCPP, the primary participant-level data in the participating cohorts are harmonized and then analyzed using standardized criteria across cohorts as opposed to analyzing results extracted from the published literature. This approach reduces potential sources of heterogeneity between studies that may occur in the published literature. Analyzing the participant-level data also allows for inclusion of cohorts that have not published on the research question being evaluated and permits investigations of less common exposures, less common outcomes including cancer subtypes, and population subgroups that are challenging to examine in many individual cohorts. Further, the project evaluates whether associations are consistent across cohort studies comprised of different populations with a wide distribution of participant characteristics.

Can the DCPP inform cancer prevention strategies?

Investigations in the DCPP analyze the harmonized data from multiple cohorts using standardized criteria across cohorts to yield summary estimates of associations between dietary and other modifiable factors and risk of cancer or other chronic diseases. Results from DCPP projects may identify population subgroups that may particularly benefit from specific lifestyle interventions to reduce the risk of disease. These projects contribute to the body of evidence required to develop evidence-based cancer prevention recommendations.

In addition, as cancer is a heterogeneous disease, evaluation of whether associations vary by tumor subtype may lead to a better understanding of causes of that cancer. Projects in DCPP on less common cancers may yield new information on potentially modifiable factors to provide evidence for strategies to prevent their occurrence.

How are studies selected for inclusion in the DCPP?

To maximize the quality and comparability of the cohort studies in the DCPP, each cohort must meet several inclusion criteria. It must be a published cohort study which includes a minimum number of cases of the specific cancer being examined. For the dietary analyses, additional inclusion criteria include (1) a comprehensive dietary assessment method to measure usual diet and (2) an assessment of the validity of their dietary assessment instrument or a closely related instrument. Additional inclusion criteria have been specified for investigations of specific cancers.

Thirty-nine studies have participated in the consortium. Cohort studies that meet the inclusion criteria are eligible to join the consortium.