The studies described in this protocol are all performed within the framework of PROTECT
(Pharmacoepidemiological Research on Outcomes of Therapeutics by a European ConsorTium)
Workpackage 2 (WP2) and Workgroup 1. The primary aim of these studies is to develop, test and
disseminate methodological standards for the design, conduct and analysis of
Pharmacoepidemiological (PE) studies applicable to different safety issues and using
different data sources. To achieve this, results from PE studies on 5 key adverse events
(AEs) performed in different databases will be evaluated. Therefore, emphasis will be on the
methodological aspects of the studies in this protocol and not on the clinical consequences
of the association under investigation. The standards to develop will contribute to
decreasing the discrepancies in results from different studies in the future and increase the
usefulness and reliability of these studies for benefit-risk assessment in the EU.
Within WP2, five possible adverse event - drug pairs have been selected for analyses; one of
these includes the possible role of calcium channel blockers (CCBs) in the risk of cancer.
Analyses will address the hypothesis that CCBs modify the risk of cancer (all forms of cancer
combined and various groups of cancers).
This hypothesis will be investigated using two sources of data: the UK General Practice
Research Database (GPRD) and the Danish national databases. Investigations in the UK may also
use The Health Improvement Network (THIN).
The primary objective of the study is to investigate the possible association between use of
CCBs and risk of all forms of cancer combined, among adult patients (18 to 79 years of age
during the study period, January 1, 1996 to December 31, 2009). The study will be conducted
using three databases with different study designs (descriptive, cohort, population based
cohort study and nested case-control) across different databases (GPRD, THIN, Danish
databases) and to compare the results between databases, across designs to evaluate the
impact of design/database/population differences on the outcome of the studied association.
Secondary objectives are to investigate the potential association between use of CCBs and
risk of all forms of breast cancer in women; all forms of prostate cancer; and all forms of
colon cancer using the same age groups and databases).