A sore spot in your mouth can be easy to overlook, especially when it doesn’t hurt. Many mouth changes have harmless causes, but a change that persists deserves attention. Oral cancer can develop in areas such as your tongue, gums, inner cheeks, or the floor of your mouth. Finding it before it grows deeper or spreads can improve the chances of successful treatment. Routine screening and detection of oral cancer will improve the long term prognosis.