DC-CIK Immunotherapy Combined With Concurrent Chemoradiation for Locally Advanced Esophageal Cancer

Patients required a confirmed diagnosis of locally advanced esophageal carcinoma established by cytology or histology — including squamous cell carcinoma and adenocarcinoma of the esophagus. Metastatic disease was not eligible.

There was no upper age limit, but patients required adequate organ function to tolerate both chemoradiation and cell therapy infusion.

Patients needed a Karnofsky performance score of ≥ 70% — reflecting the ability to carry on normal activity with effort, and a minor degree of signs or symptoms of disease.

Per RECIST criteria, patients required at least one measurable tumour lesion assessable for response evaluation throughout the study.

Normal functions of heart, lung, liver, kidney, and bone marrow were required. Specific haematological thresholds included: haemoglobin ≥ 9 g/dL, neutrophil ≥ 1.5×10⁹/L, platelet ≥ 100×10⁹/L, and creatinine ≤ 1.5× ULN.

Patients with CNS metastatic disease, complete esophageal obstruction, deep esophageal ulcer, mediastinal fistula, haematemesis, pregnancy or nursing, or co-morbidities considered unsuitable for chemoradiation were excluded.

Concurrent chemoradiation is profoundly immunosuppressive — it depletes lymphocytes and impairs NK and T cell function. DC-CIK infusions have been shown to restore CD3+, CD4+, CD8+, and NK cell populations during treatment, potentially counteracting chemoradiation-induced immunosuppression and enabling the immune system to contribute to tumour control alongside the cytotoxic treatment.

CIK cells kill tumour targets through NKG2D, DNAX accessory molecule-1 (DNAM-1), and Fas/FasL pathways — mechanisms independent of MHC class I expression. This allows them to attack tumour cells that have downregulated HLA molecules as an immune escape strategy, a common feature of esophageal squamous cell carcinoma.

Co-culturing CIK cells with autologous dendritic cells loaded with tumour antigens generates a product in which DCs direct CIK cytotoxicity toward tumour-associated targets. This antigen-specific element of DC-CIK therapy may produce more durable tumour-directed immune responses than CIK cells alone.

Published evidence from related DC-CIK plus radiotherapy studies in esophageal cancer patients shows improved quality of life, reduced bone marrow suppression, and better immune function compared with radiotherapy alone — suggesting a potential protective effect during treatment that directly benefits patients' daily functioning.

Meta-analyses covering 1,416 patients across 17 trials found no fatal adverse reactions associated with CIK/DC-CIK immunotherapy. Side effects are typically mild — low-grade fever, transient fatigue, and occasional headache — and hematological, hepatorenal, and gastrointestinal toxicity profiles are comparable to chemoradiation alone.

DC-CIK infusion does not require prior lymphodepletion conditioning. It is designed to complement, not replace, chemoradiation — making it one of the most practically combinable adoptive cell therapies with standard oncology treatment backbones.