Calcified foci in the lungs that are more than ten years old are very unlikely to be cancerous. Calcified foci in the lungs are usually formed by the accumulation of calcium salts in the body tissues when necrosis occurs or when there is a tumor. Most cases of lung calcification are caused by old tuberculosis and chronic inflammation, or the presence of calcification in the lesion, so the possibility of cancer is very small. However, it should be noted that some lung cancerous lesions may also have calcium deposits, so when finding calcified foci in the lungs, it is necessary to make a comprehensive judgment according to the location and size of the lesion as well as the lesions in the surrounding tissues. If necessary, some pathological biopsy is also needed to confirm the diagnosis, so as to better understand whether the calcified foci are due to cancer cells. Therefore, it is recommended to go for regular lung checkups to rule out malignant tumors in the lungs. At the same time, it is also necessary to quit the habit of smoking, pay attention to healthy diet and daily routine, and go to the hospital in time if you feel unwell to avoid adverse effects.