Symptoms of recurrence of gum cancer after surgery are gum lumps, bleeding ulcers on gums and gum pain. 1. Gingival mass: new growths appear on the gums, forming a localized mass and accompanied by obvious pain. 2. Gingival bleeding ulcers: new large ulcers appear on the gums, accompanied by bleeding symptoms, and long-term persistent non-healing. 3. Gingival pain: after the operation, there is unexplained persistent and severe pain in the gums, which does not improve after various treatments. If the above symptoms appear, it is necessary to be highly alert to the possibility of recurrence of gingival cancer, and it is necessary to go to the hospital in time for relevant examination, such as CT, MRI, etc., to find out whether there is any new bone destruction or encroachment of the surrounding tissues, and actively carry out targeted treatment.