The purpose of this study is to evaluate the effect of ALDH2 mutation in radiation associating dermatitis or mucositis in head and neck cancer patients who accept chemoradiation therapy

• One-site audit. The enrolled subject is confirmed by PIs

  ◦◦Source data is compared to external data sources medical records, either paper or electronic case report forms.

• NCI CTCAE v5.0 for AE records

• Patient recruitment according to inclusion criteria: 1. Newly diagnosed locally head and neck squamous cell carcinoma; 2. Apply for primary chemoradiation or adjuvant chemoradiation; 3. Signed informed consent

• Sample size assessment: 60 subjects will be included in one year for total 120 subjects

• Missing data to address situations where variables are reported as missing, unavailable, "non-reported," uninterpretable, or considered missing because of data inconsistency or out-of-range results

• Fisher's exact test is for category comparison. Kaplan-Meier analysis is for survival analysis. AE grades will be analyzed according to NCI guideline. Two-side p < 0.05 is suggested significant.

Inclusion Criteria:

• Age >20, <70
• Newly diagnosed head and neck squamous cell carcinoma
• Tissue proved
• Signed informed consent
• Suitable for chemoradiation

Exclusion Criteria:

• Uncontrolled underlying diseases
• Allergy to chemotherapy
• Uncontrolled skin diseases or mucosa diseases
• Previously radiation therapy over head and neck
• Combined with other cancer currently

Locally advanced Taiwanese head and neck squamous cell carcinoma patients who intend to accept primary chemoradiation or surgery with adjuvant chemoradiation, without previous treatment