Lymph nodes may be a source for immunetherapy in gastric cancer

Area of Science:

• Immunology
• Oncology
• Cancer Therapy

Background:

• Adoptive immunotherapy shows promise for cancer treatment but faces technical challenges in cell selection and expansion.
• Gastric cancer lymph nodes contain numerous immune cells already exposed to cancer antigens.
• The benefit of using cancer-negative lymph nodes for immunotherapy is unclear.

Purpose of the Study:

• To analyze the expression of immune checkpoints PD-1 and PD-L1 in gastric cancer lymph nodes.
• To determine if cancer-negative lymph nodes offer an advantage for adoptive immunotherapy.

Main Methods:

• Construction of tissue microarrays from 143 gastric adenocarcinoma lymph nodes.
• Automated immunostaining for PD-1 and PD-L1 expression.

Main Results:

• PD-L1 expression was found in 6% of cancer cells in positive nodes.
• PD-1 was positive in B lymphocytes (60%), T lymphocytes (70%), and rarely in cancer cells (2.5%).
• In cancer-negative nodes, PD-1 was highly expressed in B (73.1%) and T (71.65%) lymphocytes.

Conclusions:

• PD-1 and PD-L1 expression in gastric cancer lymph nodes was confirmed.
• PD-1 is expressed in both positive and negative nodes, potentially activating the PD-1 pathway.
• Lymphocytes from tumor-free nodes lacked PD-L1, suggesting their potential utility for adoptive immunotherapy.