Here is the design of a clinical trial:

Official Title: A Prospective Study of Longitudinal Monitoring in Surgical Lung Cancer Patients by Circulating Tumor DNA and Its Methylation

Included conditions:
- Carcinoma
- Lung Cancer
- NSCLC
- Lung Neoplasm

Study Armgroups:

Interventions:

Primary Outcomes:
- {'measure': "Correlation between patients' recurrence and quantitative detection of circulating tumor DNA (ctDNA) concentration, including the quantitative detection of ctDNA mutations and ctDNA aberrant methylation.", 'timeFrame': '3 years'}

Please estimate the sample size based on the assumption: 
The follow-up rate is assumed to be 85%. The significance level (alpha) is set at 0.05, and the power is over 90%.
Sample size calculation
        According to previous studies, the sensitivity of ctDNA methylation detection is above 70% in stage I lung adenocarcinoma [21]. So we assume our panel has a sensitivity of at least 70% in stage IA to III surgical patients. As our study focuses on early stage patients, we hypothesize the postoperative positive rate to be 15% during the 3-year follow-up, and assume a 85% follow-up rate. In the field of breast cancer and colon cancer, the recurrence rate within one year was over 50% in ctDNA-positive patients and less than 10% in ctDNA-negative patients [5, 7]. We assume ctDNA have similar prognostic prediction value in NSCLC patients. Given the information above, we plan to recruit 200 individuals for the final analysis. As a result, when alphaâ=â0.05, the two groups (postoperative positive vs. postoperative negative) would demonstrate statistical difference on DFS, with a power over 90%.