NCT00712647

Brief Summary

The Carotene and Retinol Efficacy Trial (CARET) was a randomized, double-blind, placebo-controlled trial of the cancer prevention efficacy and safety of a daily combination of 30 mg of beta-carotene and 25,000 IU of retinyl palmitate in 18,314 persons at high risk for lung cancer. CARET began in 1985, and the intervention was halted in January 1996, 21 months ahead of schedule, with the twin conclusions for definitive evidence of no benefit and substantial evidence of a harmful effect of the intervention on both lung cancer incidence and total mortality. CARET continued to follow and collect endpoints on their participants through 2005. During the active intervention phase of CARET, serum, plasma, whole blood, and lung tissue specimens were collected on participants. These biospecimens make up the CARET Biorepository. The CARET Biorepository is a valuable resource for population-based studies of the major human cancers. During CARET's twenty years of follow-up (1985-2005), we have received reports of 1,445 participants with lung cancer, 901 with prostate cancer, 433 with breast cancer, 334 with bladder cancer, 332 with colon cancer, and 1,429 with other cancers. CARET is one of the few trials that has prospectively collected serum, plasma, whole blood, blood spots (for DNA), and lung cancer tumor specimens, as well as smoking history and serial food frequency questionnaires (in some individuals for up to 12 years) in populations at high risk for lung cancer. This wealth of information in over 18,000 individuals makes the CARET Biorepository a special resource for cancer researchers.

Trial Health

100
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
18,314

participants targeted

Target at P75+ for phase_4 lung-cancer

Timeline
Completed

Started May 1985

Longer than P75 for phase_4 lung-cancer

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

May 1, 1985

Completed
19.6 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 1, 2004

Completed
6 months until next milestone

Study Completion

Last participant's last visit for all outcomes

June 1, 2005

Completed
3.1 years until next milestone

First Submitted

Initial submission to the registry

July 8, 2008

Completed
2 days until next milestone

First Posted

Study publicly available on registry

July 10, 2008

Completed
Last Updated

September 26, 2012

Status Verified

September 1, 2012

Enrollment Period

19.6 years

First QC Date

July 8, 2008

Last Update Submit

September 25, 2012

Conditions

Outcome Measures

Primary Outcomes (1)

  • Lung Cancer Incidence

    bi-annual

Secondary Outcomes (1)

  • Other cancers

    bi-annual

Study Arms (2)

1

ACTIVE COMPARATOR

Asbestos-exposed participants and heavy smokers

Drug: Beta Carotene and Retinol

2

PLACEBO COMPARATOR

Asbestos-exposed participants and heavy smokers

Other: Placebo

Interventions

Pilot participants (ppts): Asbestos-Exposed--15 mg/day beta-carotene + 25,000 IU/day retinol Heavy Smokers--30 mg/day beta-carotene + 25,000 IU/day retinol Vanguard \& Efficacy ppts: Asbestos-exposed AND heavy smokers--30 mg/day beta-carotene + 25,000 IU/day retinol

1
PlaceboOTHER

Two placebos, one each/day

2

Eligibility Criteria

Age45 Years - 69 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Asbestos-exposed men who were:
  • current smokers or quit within 15 years prior to enrollment
  • had first exposure to asbestos on the job at least 15 years prior to enrollment
  • had chest X-ray positive for changes compatible with asbestos exposure according to ILO criteria; or had been employed in a protocol-defined high-risk trade for at least 5 years, at least 10 years prior to enrollment.
  • Heavy Smokers, men and women:
  • cigarette smoking history of 20+ pack-years
  • either current smokers or had quit within previous 6 years

You may not qualify if:

  • Pre-menopausal women
  • History or cirrhosis or hepatitis within 12 months prior to enrollment
  • Taking \> 5500 IU daily vitamin A supplement
  • Taking any beta-carotene supplement
  • History of cancer within 5 years prior to enrollment
  • SGOT \> than 2.5X upper limit of normal, or alkaline phosphatase \> 1.5X upper limit of normal
  • taking less than 50% of study vitamins during the enrollment period between the First and Second Visits.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

MeSH Terms

Conditions

Lung Neoplasms

Interventions

beta CaroteneVitamin A

Condition Hierarchy (Ancestors)

Respiratory Tract NeoplasmsThoracic NeoplasmsNeoplasms by SiteNeoplasmsLung DiseasesRespiratory Tract Diseases

Intervention Hierarchy (Ancestors)

CarotenoidsPolyenesAlkenesHydrocarbons, AcyclicHydrocarbonsOrganic ChemicalsCyclohexenesCyclohexanesCycloparaffinsHydrocarbons, AlicyclicHydrocarbons, CyclicTerpenesPigments, BiologicalBiological FactorsRetinoidsDiterpenes

Study Officials

  • Gary E Goodman, MD

    Fred Hutchinson Cancer Center

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
phase 4
Allocation
RANDOMIZED
Masking
QUADRUPLE
Who Masked
PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
Purpose
PREVENTION
Intervention Model
PARALLEL
Sponsor Type
OTHER

Study Record Dates

First Submitted

July 8, 2008

First Posted

July 10, 2008

Study Start

May 1, 1985

Primary Completion

December 1, 2004

Study Completion

June 1, 2005

Last Updated

September 26, 2012

Record last verified: 2012-09