The specific medical abbreviation (prefix and/or root word) that refers to the chest is "pector-" when used in medicine. You also will hear this said in body building and weight training, where the "pecs" abbreviation is used to refer to the chest muscles, the pectoralis major and pectoralis minor muscles.
There are many other terms that are also used to refer to the chest in medicine, such as:
Thoracic Cavity, also known as the Chest Cavity or Thorax. The Thorax is the section of the body that includes the thoracic vertebrae, sternum, and ribs and contains the heart and lungs in the thoracic cavity.
Ventral thorax (the front side of the chest cavity, ventral refers to the front side of the human body.)
Torso could also be a word used to refer to the chest, although normally its definition includes everything between the neck and hips (a larger body section than just the Thorax or chest), so it is sometimes clarified as "Upper torso" to mean the chest only.
Pectus carinatum is the medical term meaning pigeon chest.
Pectus excavatum is the medical term meaning sunken-in chest.Pneumothorax
Mastitis is the medical term meaning inflammation of the breast.
Cancer
Intrathoracic is the medical term meaning inside the chest. The heart and lungs are intrathoracic.
angina
thoracectomy (excision). The cutting into the chest, or opening of the chest, is known as a thoracotomy.
Torso
thoracostomy or CTI
Gynecomastia is the medical term meaning female-like breast growth in a man.
Upper thoracic region
Chest X-ray