The probability that a point of pain in the left back is cancer is very low. A point of pain in the back may be caused by inflammation of the fascia, or it may be caused by strain, such as prolonged ambulatory work, which causes inflammation of the fascia in the neck and shoulders, which can cause pain. In addition, some diseases can also cause pain, such as damage to the ligaments in the thoracic spine, or trauma caused by other reasons, can cause pain in the back. Muscle strains or injuries in the back may also cause pain at one point.