Selenium in the Treatment of Arsenic Toxicity and Cancers (SETAC)

This study has been completed.
National Cancer Institute (NCI)
American Cancer Society, Inc.
Information provided by (Responsible Party):
Julian Spallholz, Texas Tech University Identifier:
First received: September 22, 2011
Last updated: October 6, 2011
Last verified: October 2011

Context: Approximately 100 million people throughout the world consume water contaminated with arsenic at levels above carcinogenic thresholds, including 40 million in Bangladesh alone, with up to one-fourth of deaths attributed to arsenic exposure in the worst-affected regions. There are no proven therapies for treating chronic arsenic toxicity or for preventing arsenical cancers. Selenium has been known to counter arsenic toxicity in a variety of animal models. The investigators have recently shown in animals and humans that this effect is mediated by the formation of [(GS)2AsSe]- , the seleno-bis(S-glutathionyl) arsinium ion, which is then rapidly excreted via the hepatobiliary system. Concurrently, two Phase II studies in China and Bangladesh have suggested clinical benefit to selenium supplementation in arsenicosis patients.

Objective: To assess whether daily selenium supplementation counters arsenic toxicity in patients exposed to drinking water arsenic. If proven effective, selenium supplementation might be safely and cost-effectively implemented in the worst-affected localities.

Condition Intervention Phase
Arsenical Melanosis
Arsenical Keratosis
Arsenical Cancers
Arsenic Exposure
Arsenic Toxicity
Arsenic Poisoning
Drug: sodium selenite
Drug: placebo
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator)
Primary Purpose: Treatment
Official Title: Selenite in the Detoxification of Arsenic and the Prevention of Arsenical Melanosis and Cancers Amongst Bangladeshi Arsenicosis Patients: A 48-week, Randomized, Double-blinded, Placebo-controlled Phase III Trial

Resource links provided by NLM:

Further study details as provided by Texas Tech University:

Primary Outcome Measures:
  • changes in arsenical melanosis [ Time Frame: 0 weeks (baseline), 24 weeks, and 48 weeks (end) ] [ Designated as safety issue: No ]
    Arsenical melanosis was recorded in 4 quadrants of each patients' torsos using the Dermlite epiluminescence microscopy system. The images were then scored in a blinded, randomized fashion by a dermatologist.

Secondary Outcome Measures:
  • changes in blood arsenic levels [ Time Frame: week 0, week 24 and week 48 ] [ Designated as safety issue: No ]
    The levels of arsenic in patients' blood was measured to determine whether intervention had a differential effect.

  • changes in urinary arsenic levels [ Time Frame: week 0, week 24 and week 48 ] [ Designated as safety issue: No ]
    The levels of arsenic in patients' urine was measured to determine whether intervention had a differential effect.

Enrollment: 819
Study Start Date: December 2006
Study Completion Date: April 2009
Primary Completion Date: April 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Placebo Comparator: Placebo
Patients who receive control (placebo)
Drug: placebo
dicalcium phosphate capsule matching the selenium capsule in appearance; consumed once daily with breakfast
Active Comparator: Selenium
Patients who receive treatment (selenium)
Drug: sodium selenite
200 micrograms (µg) of selenium in the form of sodium selenite; capsule form consumed once daily with breakfast.
Other Names:
  • selenium
  • selenite


Ages Eligible for Study:   12 Years to 55 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Resident of Bangladesh in an arsenic-affected region (Chandpur)
  • Age between 12 and 55
  • Exposure to arsenic in home drinking water greater than 50 ug/L.
  • Arsenical melanosis on the torso confirmed by epiluminescence microscopy

Exclusion Criteria:

  • Recent history or plans to consume selenium-containing supplements
  • Anticipated change in home drinking water supply during study period
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01442727

SETAC Trial Field Office
Kalibari town, Chandpur District, Bangladesh
Sponsors and Collaborators
Texas Tech University
National Cancer Institute (NCI)
American Cancer Society, Inc.
Principal Investigator: Julian E Spallholz, PhD Texas Tech University
Principal Investigator: Paul F La Porte, PhD Pritzker School of Medicine, The University of Chicago
Principal Investigator: Selim Ahmed, MBBS, FCPS Institute of Child & Mother Health, Dhaka, Bangladesh
  More Information

Additional Information:
Responsible Party: Julian Spallholz, Professor of Nutrition & Biochemistry, Division of Nutritional Sciences, College of Human Sciences, Texas Tech University., Texas Tech University Identifier: NCT01442727     History of Changes
Other Study ID Numbers: TTU-JES-1  1R21CA117111-01  ROG-06-098-01 
Study First Received: September 22, 2011
Last Updated: October 6, 2011
Health Authority: Bangladesh: Bangladesh Medical Research Council

Keywords provided by Texas Tech University:
arsenic poisoning
arsenical melanosis
arsenical melanoses
arsenical keratosis
arsenical keratoses
arsenical cancer
arsenic cancers
arsenic exposure
arsenic toxicity
drinking water
sodium selenite

Additional relevant MeSH terms:
Arsenic Poisoning
Heavy Metal Poisoning, Nervous System
Chemically-Induced Disorders
Nervous System Diseases
Neurotoxicity Syndromes
Pigmentation Disorders
Skin Diseases
Selenious Acid
Sodium Selenite
Growth Substances
Molecular Mechanisms of Pharmacological Action
Pharmacologic Actions
Physiological Effects of Drugs
Protective Agents
Trace Elements processed this record on April 27, 2016