Toe calluses are not cancerous; however, there are callus-like bumps that can occur on the foot and are cancerous, according to the American Podiatric Medical Association and Dartmouth University. Squamous cell carcinoma, a kind of cancer, sometimes first appears as callus-like hard bumps on the feet, but normal calluses are more likely.
Regular toe calluses are not cancerous and are caused by the way that a person walks or moves, as reported by Dartmouth University. The pressure of the feet against shoes, socks or the floor causes the skin to thicken. Most calluses will dissolve on their own and do not require treatment.
Another type of hard and thick bump on the foot is a corn. Corns are not always hard, but they tend to occur between the toes more often than calluses and will also dissolve on their own without treatment. Most of the time, the corns start to heal and disappear once a patient changes their shoes.
Most people with calluses identify them when they see a hard lump or bump on their foot. Some calluses also have a gray or yellow color to them, and they may not be as sensitive as the rest of the foot. To keep calluses from developing, a person should wear toe separators, toe crest pads, toe caps, toe sleeves or moleskin.