Diaphragm
The diaphragm is the muscle most responsible for the breathing in and out of air, or inspiration and expiration. It is a thin, dome-shaped sheet of muscle fibers located between the lower ribs. Through a process of expanding and contracting, it allows for proper respiration.
The diaphragm becomes vulnerable in cases of lung cancer, as cancer cells can invade the muscle and hinder its operation. Because it is essential for breathing, doctors treating lung cancer patients must maintain awareness of the health of the diaphragm, and respond to any threat with appropriate treatment. In cases of mesothelioma, depending on the staging system used, the cancer cells may have spread to the diaphragm as early as Stage 1.