"Selinexor+Pegaspargase+Dexamethasone"in Ⅰ/Ⅱ NKTCL

1. Age 18-70 years old, ECOG score 0-2; (including those aged 18 and 70);
2. Pre-survival time > 6 months;
3. The pathological tissue was confirmed as NK/T cell lymphoma (the pathological report of the first three months of enrollment could be accepted) (Note: If there is any doubt about the pathological diagnosis, domestic third-party consultation could be organized);
4. Clinical stage Ⅰ to Ⅱ (CA stage) with at least one measurable lesion;
5. Acceptable hematological indicators, no contraindications to chemotherapy; Neutrophil absolute value ≥1.0×10\^9 /L, platelet ≥75×10\^9 /L, hemoglobin ≥80g/L (except patients with lymphoma bone marrow infiltration);
6. Liver function: direct bilirubin ≤1.5× upper limit reference value; Glutamic pyruvic transaminase or glutamic oxalacetic transaminase ≤2.5× upper limit reference value; Alkaline phosphatase ≤3×ULN in non-bone invaded patients;
7. Renal function: serum creatinine ≤1.5×ULN;
8. Female and male patients of reproductive age and their spouses are willing to use adequate contraception throughout the study period, and female patients of reproductive age must have a negative serum pregnancy test within 7 days before the first dose;
9. The newly treated patient had not received other tumor-related treatment in the past;
10. Subjects voluntarily participate in the clinical trial, sign informed consent, and cooperate with follow-up;

Exclusion Criteria:

1. Refuse to collect blood samples;
2. Previous allergy to any of the drugs in the program;
3. Pregnant and lactating women;
4. Major diseases that the investigator believes can cause interference with the test;
5. Combined with other tumors;
6. There are contraindications related to therapeutic drugs in the program;
7. Persons with serious mental illness;
8. Participating in other clinical trials;
9. Previous anti-tumor therapy (such as radiotherapy, chemotherapy, hormone therapy, biotherapy, immunotherapy);
10. Other serious medical conditions that may limit participants\' participation in the trial, such as uncontrolled diabetes; Severe cardiac insufficiency (NYHA grade II or above); Acute coronary syndrome within the last 6 months; Coronary revascularization such as stenting, coronary artery bypass surgery, and other heart and large vessel related procedures within the last 6 months; Severe arrhythmias include frequent ventricular early, ventricular tachycardia, rapid atrial fibrillation/flutter, and severe bradycardia. Uncontrolled hypertension: systolic blood pressure >150mmHg, diastolic blood pressure >100mmHg. Gastric ulcers (stomach ulcers that researchers have determined are at risk of perforation); Active autoimmune diseases (e.g. systemic lupus erythematosus, rheumatoid arthritis, multiple sclerosis, Sjogren\'s syndrome, autoimmune thrombocytopenia, etc.); Severe respiratory disease (such as obstructive pulmonary disease and a history of bronchospasm);
11. Hemophagic cell syndrome;
12. Researchers do not consider it suitable for inclusion;
13. Hepatitis B core antibody (HBcAb) positive and peripheral blood hepatitis B virus (HBV) DNA titer detection is not within the normal reference value range; Hepatitis C virus (HCV) antibody positive and peripheral blood hepatitis C virus (HCV) RNA positive; Human immunodeficiency virus (HIV) antibody positive; Syphilis test positive.