Dr. Edward Lewis Jr., 50, who had been in charge of the Drug Enforcement Administration, died of cancer Monday at Suburban Hospital.

The programs were geared to the specialized needs of DEA personnel, including special agents and laboratory workers. Dr. Lewis also was responsible for the health and safety inspections at the agency's regional laboratories, which handle both toxic and explosive substances.

He had joined the Bureau of Narcotics and Dangerous Drugs, a predecessor of DEA, in 1968. He left DEA in 1977 to work as a medical officer at the radar clinic at Fort Meyer. He also had been medical officer of Caroline County, Md., since 1977.

Dr. Lewis was born in Washington. He graduated from Wilson High School and earned a bachelor's degree from George Washington University, where he also graduated from the school of medicine.

His internship and residency were taken at the old Garfield Memorial Hospital. He also was a fellow in internal medicine at the Georgetown University Medical school and a resident in public health with the Maryland State Department of Health.

He had been on the staff of D.C. General Hospital and was chief of the tuberculosis and chronic disease division of the Montgomery County Health Department.

Dr. Lewis was medical director of the United Cerebral Palsy Nursery Treatment Center in Silver Spring and a consulting physician to the C&P Telephone Co.

He is survived by his wife, Kathryn, and two children, Edward III and Jonathan, all of the homes in Bethesda and Leonardtown, Md., and his parents, Dr. and Mrs. Edward Lewis, Sr., and a sister, Dorothy Auerbach, all of Washington.

The family suggests that expressions of sympathy be in the form of contributions to the Dr. Edward Lewis Memorial Fund at the Caroline Country Health Department in Denton, Md.