Back to 2025 Posters
VALUE OF CIRCULATING TUMOR DNA (CTDNA) FOR HEPATIC NEUROENDOCRINE TUMOR MANAGEMENT
Alyssa Field
*1, Vasu Moparty
2, Alejandro Mejia
31Methodist Dallas Medical Center, Dallas, TX; 2Texas Oncology, Dallas, TX; 3The Transplant Institute at Methodist Dallas, Dallas, TX
Introduction:
Neuroendocrine tumors (NETs) are a heterogeneous group of malignancies that often present diagnostic and therapeutic challenges due to their varied behavior and potential for both slow growth and metastasis. Monitoring these tumors, especially after treatment, is essential for detecting recurrence and guiding management. Circulating tumor DNA (ctDNA), consisting of cell-free DNA fragments released by tumor cells into the plasma, is emerging as a valuable biomarker for this purpose. Here, we present a case of a patient with a NET of the liver that was treated by surgical resection, lanreotide, and chemotherapy, with treatment response monitored by ctDNA analysis.
Case Description:
A healthy 52-year-old female presented with a large mass in the right hepatic lobe, measuring approximately 16 x 12 x 16 cm. Biopsy confirmed a high-grade NET (Ki-67 index: 25%). After appropriate workup, she underwent a right trisegmentectomy. Final pathology revealed a 22.5 x 18.5 x 9.5 cm well-differentiated Grade 3 NET with areas suspicious for lymphovascular invasion. Her preoperative ctDNA was positive at 1719.59 MTM/mL. One month post-surgery, ctDNA was undetectable. A dotatate positron emission tomography (PET) scan and biopsy at five months post-surgery revealed pulmonary metastasis. At six months post-surgery, her ctDNA level was positive below analytical levels. She was started on lanreotide, but her ctDNA levels continued to be positive. A PET scan revealed mixed response in the pulmonary nodules and new liver masses. CapTem therapy was started one month later. Two months after CapTem initiation, her ctDNA level was below detection. A follow-up PET scan four months after CapTem initiation showed a reduction in the size of both pulmonary and liver metastases. Her ctDNA levels have since remained undetectable.
Discussion:
This case highlights the potential of using ctDNA as a non-invasive tool to monitor treatment response and tumor recurrence in NETs. Monitoring ctDNA levels throughout this patient’s treatment provided real-time insights into disease status, enabling informed and timely therapeutic decisions. Chromogranin A is a biomarker historically used to assess NETs. However, Chromogranin A in our patient was negative. Additionally, chromogranin A has low specificity and can be elevated in other disease processes. Circulating tumor DNA offers a more individualized test to monitor a specific tumor response to treatment.
Conclusions:
For NET and especially high grade tumors, ctDNA provides a very useful tool to monitor the response to therapy and underscores the importance of personalized medicine for cancer management.
The patient’s circulating tumor DNA level and milestones throughout the course of treatment.
Back to 2025 Posters
