Lung Cancer and melanoma relapsed frequently whereas its very sensitive to treatment such as chemotherapy or radiotherapy. The purpose of this study is to have a better understanding of why those patients are relapsing using next generation sequencing to identify rare mutations and assessed their predictive value.

Inclusion Criteria:

1. Cytological or histological diagnosis of SCLC, NSCLC or melanoma
2. Patients age >/= 18 years old
3. Indication of treatment using platinum salts for lung cancer except for patient with NSCLC treated by surgery for whom platinum salts is not indicated
4. If a biopsy is proposed, lesion lust be easily accessible
5. Signed informed consent

Exclusion Criteria:

1. Patients unable to follow the protocol
2. Consent refusal