Calcified foci are usually not a sign of cancer, and appropriate follow-up observation or treatment needs to be chosen depending on the specific calcified foci. Calcified foci usually form when a certain tissue in the body undergoes necrosis under certain factors, and then calcium salts from the body are deposited in the necrotic tissue, thus limiting the lesion. Calcification is usually the body’s defense response to the lesion, which facilitates the reduction of inflammation and the removal of necrotic foci. For example, calcified foci appear in the lungs after the improvement of tuberculosis, and calcified foci appear in the prostate after the improvement of prostate inflammation. Cancer in the human body is the malignant lesion and unlimited proliferation of normal cells under chemical, physical or genetic factors. Pre-cancerous lesions include chronic atrophic gastritis, colon or gastric polyps, and so on. To sum up, calcified foci are usually not signs of cancer, but in a few cases, calcified foci may be signs of cancer, for example, breast cancer may be accompanied by sand-like calcification. Therefore, there is no need to worry too much about the appearance of calcified foci, but necessary examination and follow-up are needed.