Dr. Callahan is board certified in Internal Medicine and Medical Oncology.

Education and Experience

Dr. Callahan was born and raised in Philadelphia, PA. His early years were influenced by his Jesuit Education first at St. Joseph's Preparatory School and, subsequently at St. Joseph's College in Philadelphia, Pa. where he earned a BS in Biology. Upon graduation from College, he worked at the University of Pennsylvania, initially in the clinical lab, but then transferred to work as a Research Technologist at the University of Pennsylvania Cancer Research Center.

He earned his Doctor of Osteopathy at UNE in Biddeford, Maine in 1987. He completed his internship at the University of Medicine and Dentistry of NJ/Kennedy Health System where he served as Chief Intern in 1988. He completed his Internal Medicine Residency at UMDNJ/Kennedy Health System/Our Lady of Lourdes in 1990. He went on to Hahnemann University Hospital in Philadelphia to complete his Fellowship in Hematology/Oncology in 1992.

He went into practice in South Jersey and then relocated to Portsmouth, NH. He returned to New Jersey in 2000 and joined The Center for Cancer and Hematologic Disease. He is the Director of The Center's satellite office in Woodbury and the managing partner for The Center for Cancer.

Affiliations