ATLANTA - Pharmaceutical giant AstraZeneca is pledging $10 million to the American Cancer Society, the second-largest gift in the organization’s history, to help provide one-on-one support for cancer patients in U.S. hospitals, the American Cancer Society said Wednesday.

The society said the money will help it develop 50 new sites for its Patient Navigator Program. One of the first three sites was in AstraZeneca’s U.S. base of Wilmington, Del., at the Helen F. Graham Cancer Center at Christiana Care.

“While there are many uncertainties associated with cancer,” said Richard C. Wender, the national volunteer president of the American Cancer Society, “the Patient Navigator Program can relieve some of these anxieties by providing personalized support and education for the needs of each patient and their families.”

The program, started in 2005, focuses on underserved patients, and centers are “selected to reach those populations with the greatest need,” the society and the company said in a release. The program puts patients and their loved ones in contact with social services agencies, supplies cancer-related information and provides other types of support.

AstraZeneca, based in London, had health-care sales of more than $26 billion last year. The company developed the popular breast cancer drug tamoxifen, and makes about a half-dozen other breast cancer and prostate cancer medications