What causes head and neck cancer recurrence?

Presence of HPV after treatment

Head and neck cancers are a group of cancers that develop in the nose, tongue, cheeks, throat, tonsils, larynx, salivary glands, and thyroid gland. HPV infection can cause head and neck cancers, especially oral and pharyngeal cancer. HPV-related cancers have a better prognosis than HPV-related ones; approximately 20% of patients will experience recurrence and die within the first 5 years after treatment.

Several studies have shown that the continued presence of HPV-16 DNA in the oral cavity is a factor contributing to disease recurrence. Whether HPV persists after treatment can be determined by testing for HPV DNA in the patient's mouthwash.

After treatment, the rate of HPV infection decreases significantly, potentially down to 1%. The average time to clear the infection is 42 days. If HPV infection recurs, it increases the risk of recurrence and reduces survival time. After cancer treatment, patients need to maintain good oral hygiene and practice healthy sexual habits to avoid reinfection. If HPV persists after treatment, the doctor will consider additional treatment using other methods.

Smoking after treatment

Smoking is the leading cause of head and neck cancer. After treatment, patients are usually advised to quit smoking completely. Continuing to smoke not only increases the likelihood of recurrence and reduces survival time, but also increases the risk of developing a second cancer in a different location.

Dry mouth, tooth decay, and mucosal damage after radiation therapy will worsen if the patient continues to smoke. Smoking combined with alcohol addiction will further reduce the patient's survival time.

Nutritional status

Many patients follow post-treatment diets that reduce sugar and protein intake, especially red meat, in an attempt to limit the return of cancer cells. In reality, these practices lack scientific basis and evidence.

Numerous studies worldwide confirm that malnutrition before, during, and after treatment leads to a worse prognosis. Up to 30-50% of patients will die due to relapse, progression, or irreversible severe wasting. Adequate nutrition improves quality of life and reduces mortality rates after treatment. Poor nutrition also causes anemia, characterized by low hemoglobin (Hb) levels. If Hb < 12 g/dl before radiotherapy, the local control and overall survival rates after radiotherapy or surgery will be very low.