Clinical trial NCT01236053: Cancer in Patients With Gabapentin (GPRD)
Official title: Risk of Cancer in Patients Exposed to Gabapentin in the GPRD
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Pain, Neuropathic
Epilepsy
Renal Pelvis Cancer
Pancreatic Cancer
Breast Cancer
Nervous System Cancer
Chronic Pancreatitis
Stomach Cancer
Renal Cell Carcinoma
Diabetes
Bladder Cancer
Bone and Joint Cancer
Penis Cancer
Anal Cancer
Cancer
Renal Cancer
Keywords: renal cancer
pancreatic cancer
epidemiology
renal cell carcinoma
nervous system cancer
lung cancer
breast cancer
case-control
GPRD
Gapabentin
cancer
anal cancer
bone and joint cancer
renal pelvis cancer
penis cancer
stomach cancer
bladder cancer
Lead sponsor: GlaxoSmithKline
Sponsor class: INDUSTRY
First posted: 2010-11-07
Enrollment: 2323608
Sex: ALL
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_CONTROL
Time perspective: RETROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: The study cohort from which cases and controls are drawn is all subjects in the UK GPRD 1993-2008. Entry into the study cohort begins Jan 1, 1993 for all those who are registered in GPRD before that time, and at the time of registration if later than Jan 1, 1993. Subjects are excluded from the GPRD cohort if they have a cancer diagnosis or a history of cancer prior to the cohort entry date. Follow-up ends Dec 31, 2008, or earlier if the subject leaves the GPRD for any reason including death. There are several advantages to the GPRD dataset for this study. It is a large dataset with detailed longitudinal prescription data, and long term follow-up (mean 7 years) to allow for latency in carcinogenicity. It provides good representation of the elderly who are disproportionately affected by cancer, and routinely includes data recorded by general practitioners on potential risk factors such as smoking, alcohol consumption and body mass index.

Brief summary: High doses of gabapentin are associated with pancreatic acinar cell tumors in rats, but there has been no post marketing pancreatic carcinogenicity signal with gabapentin as reported by spontaneous reports in AERS or in the published literature. In a published case-control screening study of the association of gabapentin with 55 cancers, the only cancer that met the screening criteria for possibly increased cancer risk with gabapentin exposure was renal (including renal pelvis) cancer. This association was judged to be likely due to or substantially accentuated by confounding by cigarette smoking, hypertension, and lifestyle (Cancer Causes Control 2009;20:1821-1835).

The relationship between gabapentin exposure and pancreatic cancer and renal cancer is studied in NCT01138124, and supplemental analyses for these cancers are performed in the current study. The FDA recommended GSK also study the relationship between gabapentin and all-cancer sites, as well as cancer at the following specific sites: 1) stomach, 2) anus, anal canal, and anorectum, 3) lung and bronchus, 4) bones and joints, 5) breast, 6) penis, 7) urinary bladder, and 8) other nervous system.

The primary objective of this study is to determine whether exposure to gabapentin is associated with an increased risk of developing all-cancer, and these specific cancers in the United Kingdom (UK) General Practice Research Database (GPRD). Each member of the UK population is registered with a General Practice, which centralizes the medical information not only from the general practitioners themselves but also from specialist referrals and hospital attendances. Over 487 General Practices contribute data to the GPRD.

The study cohort from which cases and controls are drawn is all subjects in the GPRD 1993-2008. Gabapentin was approved in the UK in May 1993. Entry into the study cohort begins Jan 1, 1993 for all those who are registered in GPRD before that time, and at the time of registration if later than Jan 1, 1993. Subjects are excluded from the GPRD cohort if they have a cancer diagnosis or a history of cancer prior to the cohort entry date. Patients with a first diagnosis of the respective cancer 1995-2008 are risk set matched with up to 10 controls within the same General Practice for age at cohort entry (within two years), sex, and year of entry into the study cohort (within one year). For cases, the index date is the date of first diagnosis of the respective cancer. The index date for controls is set as the date at which the follow-up time from cohort entry is the same as the case. The index date is chosen so as to give the control equal follow-up time to that of the case for ascertainment of use of gabapentin. Cases and controls will be required to have at least 2 years of follow-up in the study cohort before their index date. Cases must have no history of any other cancer diagnosis prior to the index date. Controls are required to be free of cancer diagnosis in the database up to the control's index date.

Data on gabapentin prescriptions are obtained for cases and controls from study cohort entry to the index date. Gabapentin exposure will be assessed as ever/never, number of prescriptions, cumulative dose, and cumulative duration, with a 2 year lag period incorporated to control for protopathic bias (gabapentin prescription for initial pain symptoms of undiagnosed cancer) and latency (time between cancer onset and specific GPRD cancer diagnosis).

Crude and adjusted odds ratios and 95% confidence intervals (CI) will be produced from conditional logistic regression models, with additional analyses evaluating for dose-response. Covariates include indications for gabapentin use and risk factors for each cancer.

Detailed description: Actual number of patients may be less, as it is possible for a patient to be represented in more than one of the 22 arms (See "Participant Flow: Overall Study" Table) because of the risk set sampling.

Eligibility criteria: Inclusion Criteria:

* The study cohort from which cases and controls are drawn is all subjects in the UK GPRD 1993-2008. Entry into the study cohort begins Jan 1, 1993 for all those who are registered in GPRD before that time, and at the time of registration if later than Jan 1, 1993. Follow-up ends Dec 31, 2008, or earlier if the subject leaves the GPRD for any reason including death.

Exclusion Criteria:

* Subjects are excluded from the GPRD cohort if they have a cancer diagnosis or a history of cancer prior to the cohort entry date. Cases and controls will be required to have at least 2 years of follow-up in the study cohort before their index date (For cases, the index date is the date of first diagnosis of the respective cancer. The index date for controls is set as the date at which the follow-up time from cohort entry is the same as the case.) Cases must have no history of any other cancer diagnosis prior to the index date. Controls are required to be free of cancer diagnosis in the database up to the control's index date.

Primary outcomes:
measure: Number of All-Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin
timeFrame: The case index date was the date of incident cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of All-Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions
timeFrame: The case index date was the date of incident cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of All-Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of All-Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of All-Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin
timeFrame: The case index date was the date of incident cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Stomach Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin
timeFrame: The case index date was the date of incident stomach cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case
measure: Number of Stomach Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions
timeFrame: The case index date was the date of incident stomach cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case
measure: Number of Stomach Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident stomach cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case
measure: Number of Stomach Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident stomach cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case
measure: Number of Stomach Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin
timeFrame: The case index date was the date of incident stomach cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case
measure: Number of Anal Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin
timeFrame: The case index date was the date of incident anal cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Anal Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions
timeFrame: The case index date was the date of incident anal cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Anal Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident anal cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Anal Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident anal cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Anal Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin
timeFrame: The case index date was the date of incident anal cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Lung Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin
timeFrame: The case index date was the date of incident lung cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Lung Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions
timeFrame: The case index date was the date of incident lung cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Lung Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident lung cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Lung Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident lung cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Lung Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin
timeFrame: The case index date was the date of incident lung cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Bone/Joint Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin
timeFrame: The case index date was the date of incident bone/joint cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case.
measure: Number of Bone/Joint Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions
timeFrame: The case index date was the date of incident bone/joint cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case.
measure: Number of Bone/Joint Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident bone/joint cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case.
measure: Number of Bone/Joint Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident bone/joint cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case.
measure: Number of Bone/Joint Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin
timeFrame: The case index date was the date of incident bone/joint cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case.
measure: Number of Breast Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin
timeFrame: The case index date was the date of incident breast cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Breast Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions
timeFrame: The case index date was the date of incident breast cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Breast Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident breast cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Breast Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident breast cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Breast Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin
timeFrame: The case index date was the date of incident breast cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Penile Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin
timeFrame: The case index date was the date of incident penile cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Penile Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions
timeFrame: The case index date was the date of incident penile cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Penile Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident penile cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Penile Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident penile cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Penile Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin
timeFrame: The case index date was the date of incident penile cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Bladder Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin
timeFrame: The case index date was the date of incident bladder cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case
measure: Number of Bladder Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions
timeFrame: The case index date was the date of incident bladder cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case
measure: Number of Bladder Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident bladder cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case
measure: Number of Bladder Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident bladder cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case
measure: Number of Bladder Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin
timeFrame: The case index date was the date of incident bladder cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case
measure: Number of Other Nervous System Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin
timeFrame: The case index date was the date of incident other nervous system cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his cohort entry was the same as case.
measure: Number of Other Nervous System (ONS) Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions
timeFrame: The case index date was the date of incident other nervous system cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his cohort entry was same as for case.
measure: Number of Other Nervous System (ONS) Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident other nervous system cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was same as for case
measure: Number of Other Nervous System Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident other nervous system cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was same as for case
measure: Number of Other Nervous System (ONS) Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin
timeFrame: The case index date was the date of incident other nervous system cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was same as for case
measure: Number of Pancreatic Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin
timeFrame: The case index date was the date of incident pancreatic cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case.
measure: Number of Pancreatic Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions
timeFrame: The case index date was the date of incident pancreatic cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case.
measure: Number of Pancreatic Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident pancreatic cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case.
measure: Number of Pancreatic Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident pancreatic cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case
measure: Number of Pancreatic Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin
timeFrame: The case index date was the date of incident pancreatic cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case.
measure: Number of Renal Cancer Cases and Matched Controls With the Indicated Exposure to Gabapentin
timeFrame: The case index date was the date of incident pancreatic cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as for the case.
measure: Number of Renal Cancer Cases and Matched Controls With the Indicated Number of Gabapentin Prescriptions
timeFrame: The case index date was the date of incident renal cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Renal Cancer Cases and Matched Controls With the Indicated Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident renal cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Renal Cancer Cases and Matched Controls With the Indicated Long Duration of Exposure to Gabapentin
timeFrame: The case index date was the date of incident renal cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
measure: Number of Renal Cancer Cases and Matched Controls With the Indicated Cumulative Dose of Gabapentin
timeFrame: The case index date was the date of incident renal cancer diagnosis ascertained in the GPRD study cohort 1995-2008. The matched control index date was the date at which the follow-up time from his/her cohort entry was the same as that for the case.
Secondary outcomes:
Other outcomes:
Locations:
Study officials:
affiliation: GlaxoSmithKline
name: GSK Clinical Trials
role: STUDY_DIRECTOR
References: