The purpose of this study is to evaluate the effectiveness of circulating DNA from peripheral blood for predicting the prognosis and relapse in DLBCL and PTCL patients.

The investigators plan to prospectively involve 300 Non-hodgkin Lymphoma patients, including both diffuse large B cell lymphomas and peripheral T cell lymphomas without previous treatment from Peking Union Medical College Hospital.

The following parameters were collected: age, sex, subtype, Eastern Cooperative Oncology Group (ECOG) performance status (PS), Ann Arbor stage (I-IV), presence of B symptoms, number and type of involved sites, prognostic index including International Prognostic Index (IPI) for DLBCLand PIT for PTCL based on medical record review.

All patients would have regular treatment and follow up in PUMCH. During the follow up, treatment response was evaluated by contrast enhanced computed tomography or PET-CT.

The peripheral blood would be collected and circulating DNA would be tested at the time of diagnosis, interim of treatment, end of treatment, 1 year follow-up, 1.5 year of follow-up, 2 year of follow up, 3 year of follow-up and disease progression or relapse. TCR/BCR domain would be sequenced by high-throughput sequencing.

Inclusion Criteria:

1. pathologically confirmed diffuse large B cell lymphoma (DLBCL nos, PCNSL, ALK+ DLBCL, DLBCL/BL) or peripheral T cell lymphoma (AITL, ALCL, PTCL nos, NK/T nasal type, EATL, HSTL)
2. no treatment before
3. hCG(-)
4. 18 years old to 80 years old

Exclusion Criteria:

1. other tumors
2. severe infections

Patients diagnosed to be diffuse large B cell lymphoma or peripheral T cell lymphoma without any previous treatment in Peking Union Medical College Hospital (PUMCH) would be included.