If not detected quickly, cancer cells often spread to other organs in a process called metastasis. Lymph nodes (LNs) are the organs most at risk of developing malignancy. Malignancy in LNs also influences cancer stage and treatment planning, and its detection is associated with an increased risk of recurrence and death.
The most reliable sign of a malignant, early-stage, non-enlarged tumor is when perfusion — the passage of blood through the lymphatic system — shows defects, something that can be detected by CT scans, MRIs, and ultrasound machines.
Now, Professor Tetsuya Kodama and his research group from Tohoku University’s Graduate School of Biomedical Engineering have revealed that the lack of small blood vessels in tumors may be the cause of poor perfusion in non-enlarged and early stage LNs.
To achieve this breakthrough, the research group injected cancer cells into mice bearing LNs of similar size to humans (about 10 mm). LNs are injected with metastatic cancer cells into the connected LNs, where researchers carefully track the progression of the cancer using contrast-enhanced high-frequency ultrasound and micro-computed tomography.
We found that tumors that form with few microvasculature are associated with defective perfusion.”
Tetsuya Kodama, Professor, Tohoku University Graduate School of Biomedical Engineering
This finding could explain the low efficacy of systemic chemotherapy for LN metastases.
Their study also highlighted the importance of improving the spatial resolution and density of diagnostic imaging equipment to improve the diagnosis and detection of LN metastasis, thus reducing cancer-related mortality.
Yamaki, T.; et al. (2021) Characterization of perfusion defects in early stage metastatic lymph nodes using high-frequency ultrasound and computed tomography. Clinical and experimental malignancy. doi.org/10.1007/s10585-021-10127-6.