The significance of relapse monitoring lies in 'preventing problems before they occur.' By using CTCs in the blood for early warning, patients have the opportunity to take intervention during the early stages of relapse, turning passive response into active management.

Ms. D was diagnosed with right ovarian cancer and high-grade serous tubal carcinoma at stage IIIC. During treatment, blood was drawn for CTC testing, which showed 27 CTCs and 1 CTC cluster. The CTC cluster consists of multiple tumor cells, which may be heterogeneous, presenting epithelial, mesenchymal, mixed, or stem cell types. Each subtype has its own abilities for survival, evasion, differentiation, and metastasis. Therefore, the presence of a CTC cluster is closely related to cancer recurrence and metastasis and is a very high-risk indicator. Ms. D's test results indicated an extremely high risk of metastatic recurrence, and subsequent clinical diagnosis confirmed tumor recurrence.

Case Summary

• Through CTC detection, doctors are able to assess the risk of recurrence and metastasis, make early diagnoses, and avoid delaying treatment.

• The presence of CTC clusters is the culprit of tumor recurrence and metastasis, and has important clinical value.