Lung cancer patients, is MRD testing necessary?

MRD (Minimal Residual Disease), or Minimal Residual Disease, is a small number of cancer cells (cancer cells that do not respond or are resistant to treatment) that remain in the body after cancer treatment.
MRD can be used as a biomarker, with a positive result meaning that residual lesions can still be detected after cancer treatment (cancer cells are found, and residual cancer cells can become active and begin to multiply after cancer treatment, leading to a recurrence of the disease), while a negative result means that residual lesions are not detected after cancer treatment (no cancer cells are found);
It is well known that MRD testing plays an important role in identifying early-stage non-small cell lung cancer (NSCLC) patients at high risk of recurrence and in guiding adjuvant therapy after radical surgery.
Scenarios in which MRD can be applied:

For operable early stage lung cancer

1. After radical resection of early stage non-small cell lung cancer patients, MRD positivity suggests a high risk of recurrence and requires close follow-up management. MRD monitoring is recommended every 3-6 months;
2. It is recommended to carry out perioperative clinical trials of operable non-small cell lung cancer based on MRD, and provide perioperative precision treatment options as much as possible;
3. Recommend exploring the role of MRD in both types of patients, driver gene positive and driver gene negative, separately.

For locally advanced non-small cell lung cancer

1.MRD testing is recommended for patients in complete remission after radical chemoradiotherapy for locally advanced non-small cell lung cancer, which can help to determine the prognosis and formulate further treatment strategies;
2. Clinical trials of MRD-based consolidation therapy after chemoradiotherapy are recommended to provide accurate consolidation therapy options as much as possible.
For advanced non-small cell lung cancer
1. There is a lack of relevant studies on MRD in advanced non-small cell lung cancer;
2. It is recommended that MRD be detected in patients in complete remission after systemic therapy for advanced non-small cell lung cancer, which can help to judge the prognosis and formulate further therapeutic strategies;
3. It is recommended to carry out research on MRD-based treatment strategies in patients in complete remission to prolong the duration of complete remission as much as possible so that patients can maximize their benefits.

It can be seen that due to the lack of relevant studies on MRD detection in advanced non-small cell lung cancer, the application of MRD detection in the treatment of advanced non-small cell lung cancer patients has not been clearly indicated.
In recent years, advances in targeted and immunotherapy have revolutionized the treatment outlook for patients with advanced NSCLC.
Emerging evidence suggests that some patients achieve long-term survival and are even expected to achieve complete remission by imaging. Therefore, under the premise that some groups of patients with advanced NSCLC have gradually realized the goal of long-term survival, disease recurrence monitoring has become a major clinical issue, and whether MRD testing can also play an important role in it deserves to be explored in further clinical trials.