Meta-analysis of previous studies have shown that melatonin is a beneficial adjutant for reducing chemotherapy-induced toxicity; however no randomized, double-blind, placebo controlled trials have been conducted. This study evaluates the effect of melatonin in improving quality of life and reducing chemotherapy-induced toxicity in advanced cancer patients. This is a multi-center, randomized, double-blind, placebo controlled trial conducted in patients with histologically proven advanced non small cell lung, breast, head and neck or sarcoma cancer. Mixed-block randomization, stratified by center and treatment scheme is used to divide eligible patients into three groups: melatonin 20 mg, 10 mg or matched placebo. The patients are required to take the studied drugs at night (after 21.00 pm) on the first day of chemotherapy and continue daily for six months. Standard treatment is chemotherapy according to each center's standard protocol. Study endpoints are QOL (FACT), adverse event frequency (CTCAE), oxidative stress status, melatonin level, and survival.

Inclusion Criteria:

• histologically proven advanced NSCLC, breast, head and neck, sarcoma cancer Eastern Cooperative Oncology Group (ECOG) performance status (PS) ≤ 2
• platelet count ≥100,000 cells/mm3
• white blood cell count ≥ 3,000 cell/mm3
• hemoglobin ≥ 10 g/dL
• serum creatinine ≤ 1.5 mg/dL
• bilirubin ≤ 2 mg/dL
• AST ≤ 2.5 times upper limit of normal(ULN)for subjects without metastases or AST ≤ 2.5 times UNL for those with liver metastases
• New York Heart Association grade ≤ 2
• written consent

Exclusion Criteria:

• Patients who receive prior chemotherapy or biotherapy, radiotherapy or surgery within 1 month preceding randomization
• Patients who have more than one type of cancer or brain metastasis were excluded from the trial.
• Patients with moderate neuropathy (CTCAE grade ≥ 2)
• Patients with an active infection, or uncontrolled complications (i.e. blood glucose > 200 mg/dL, uncontrolled hypertension, unstable angina, history of congestive heart failure or history of myocardial infarction within one year).