Cancer Organizations: M
- Malteser Krankenhaus Bonn/Rhein-Sieg
- Malteser Krankenhaus St. Hildegardis
- Mamie McFaddin Ward Cancer Center at CHRISTUS St. Elizabeth Hospital
- Manatee Memorial Hospital
- Manchester Memorial Hospital
- Manchester Royal Infirmary
- Manhattan Colorectal Associates
- Manila Doctors Hospital
- Manimonides Medical Center Hematology/Oncology, FPP
- Manipal Hospital
- Manitoba Clinic
- Manitoba Medical Service Foundation
- MannKind Corporation
- Manning Base Hospital
- Manning Selvage & Lee
- Mansfield Center for Pacific Affairs
- Mansoura University Hospital
- Manstein Plastic Surgical Associates
- Maounat Hospital
- Maple Grove Surgical Specialists
- Maplewood Urological Associates, PA
- Mar del Plata Head and Neck Unit
- Marathon Ashland Petroleum Company LLC
- Marcial Radiation Oncology Center
- Margaret Mague Women's Health Institute
- Margaret and Charles Juravinski Cancer Centre
- Margaret and Howard Hall Radiation Center at Mercy Medical Center
- Maria Hospital
- Maria Middelares Hospital - Sint-Niklaas
- Maria Parham Medical Center
- Maria Sklodowska-Curie M.C.C.I.O. Krakow
- Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology - Warsaw
- Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology - Cracow
- Maria-Hilf-Krankenhaus
- Maria-Josef-Hospital Greven GmbH
- Marian Cancer Center at Marian Medical Center
- Marian Community Hospital
- Maricopa Medical Center
- Marien Hospital
- Marien Hospital - Duesseldorf
- Marien-Hospital Wesel gGmbH
- Marien-Hospital Witten
- Marien-Krankenhaus Luebeck
- Marienhaus Klinikum St. Elisabeth Neuwied
- Marienhospital Altenessen Akademie Lehrkrank
- Marienhospital Bottrop gGmbH
- Marienhospital Stuttgart
- Marienhospital at Ruhr University Bochum
- Marienkrankenhaus
- Marienkrankenhaus Schwerte gem. GmbH
- Marika Iliadis Hospital
- Marin Cancer Institute at Marin General Hospital
- Marin Gastroenterology
- Mario Negri Institute for Pharmacological Research
- Mario Negri Institute for Pharmacological Research
- Marion General Hospital
- Marion General Hospital Cancer Care Center
- Marion L. Shepard Cancer Center at Beaufort County Hospital
- Marion Regional Cancer Center
- Marion-Louise Saltzman Women's Center
- Maritime Hospital
- Marjorie G. Weinberg Cancer Care Center at Gottlieb Memorial Hospital
- Markham Stouffville Hospital
- Marlborough Hospital
- Marmara University Hospital
- Maroondah Hospital
- Maros Arznei GmbH
- Marseille Institute of Cancer - Institut J. Paoli and I. Calmettes
- Marselisborg University Hospital
- Marshall Edwards, Incorporated
- Marshall Hospital
- Marshall Medical Center South
- Marshall University Medical Center
- Marshfield Clinic - Chippewa Center
- Marshfield Clinic - Indianhead Center
- Marshfield Clinic - Lakeland Center
- Marshfield Clinic - Marshfield Center
- Marshfield Clinic - Wausau Center
- Marshfield Clinic - Weston Center
- Marshfield Clinic - Wisconsin Rapids Center
- Marshfield Clinic Cancer Care at Regional Cancer Center
- Marshfield Clinic at Saint Michael's Hospital
- Martha Davis Cancer Center
- Martha Jefferson Hospital Cancer Care Center
- Martha's Vineyard Hospital
- Martimbeau Gynecology Oncology, PA
- Martin - Luther Hospital
- Martin Anderson Cancer Center
- Martin Army Community Hospital
- Martin Faculty Hospital
- Martini Ziekenhuis
- Martini-Klinik at the University Medical Center Hamburg-Eppendorf
- Martinsville Urologic Clinic
- Mary Babb Randolph Cancer Center at West Virginia University Hospitals
- Mary Bird Perkins Cancer Center - Baton Rouge
- Mary Bird Perkins Cancer Center - Covington
- Mary Bird Perkins Cancer Center - Hammond
- Mary Black Memorial Hospital
- Mary Bridge Children's Hospital and Health Center - Tacoma
- Mary Crowley Medical Research Center at Sammons Cancer Center