Carbon Black Deposition in Regional Lymph Nodes Is Associated with Disease Control after Immune Checkpoint Inhibitor-Based Therapy in Recurrent Esophageal Squamous Cell Carcinoma
In brief
Greater carbon-black deposition in nodes predicts better disease control with immunotherapy
In a retrospective series of 47 patients with recurrent esophageal squamous cell carcinoma treated with checkpoint inhibitors, those with a higher proportion of carbon-black-filled regional lymph nodes had a significantly higher disease-control rate and a trend toward longer progression-free survival. The finding was independent of tumor-infiltrating immune cells or PD-L1 status, suggesting that simple histologic assessment of nodal anthracosis may help identify patients more likely to benefit from ICI therapy.
- Journal
- Acta histochemica et cytochemica (Q2)
- Published
- 22 August 2026
- Study design
- Cohort / observational study
- Evidence level
- Level 3, Low (CEBM 3b)
- Authors
- Teruki Sakoh, Kosuke Kanemitsu, Yoshihiro Komohara, Daiki Yoshii, Cheng Pan, Rin Yamada, et al.
- PMID
- 42718905
- DOI
- 10.1267/ahc.26-00018
Why clinicians should know about it
- Picked for Histology (top studies of the week, 13 September 2026).
Abstract
Carbon black (CB) deposition, or anthracosis, is frequently observed in the regional lymph nodes (RLNs) of patients with thoracic malignancies, particularly those with a history of smoking; however, its clinical significance in immune checkpoint inhibitor (ICI)-based therapy remains unclear. This retrospective study aimed to investigate the association between CB deposition in RLNs and response to ICI-based therapy in recurrent esophageal squamous cell carcinoma (ESCC). The study included 47 patients with recurrent ESCC who underwent curative-intent esophagectomy and subsequently received ICI-based therapy. The proportion of CB-containing RLNs (%CB) was histologically evaluated, and patients were divided into high- and low-CB groups according to the median %CB value. CB was mainly detected in lymph node sinus macrophages. Patients in the high-CB group showed a significantly higher disease control rate than those in the low-CB group. Progression-free survival tended to be longer in the high-CB group, although the difference did not reach statistical significance. CB-containing sinus macrophages expressed CD68 and CD163, whereas CD169 expression was markedly reduced or absent. No significant association was observed between %CB and tumor-infiltrating immune cell densities or HLA class I/PD-L1 expression. By contrast, ectopic HLA-DR expression in cancer cells was more frequent in the high-CB group. These findings suggest that a higher proportion of CB-containing RLNs is associated with disease control following ICI-based therapy in recurrent ESCC. Histological assessment of CB deposition in RLNs may provide useful information regarding clinical benefit from ICI-based immunotherapy.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.