Immunotherapy (recombinant interleukin 2), hormone therapy (medroxyprogesterone acetate) and antioxidant agents as combined maintenance treatment of responders to previous chemotherapy

EGFR-Mutated Non-Small Cell Lung Cancer and Resistance to Immunotherapy: Role of the Tumor Microenvironment

Lung cancer is a leading cause of cancer-related deaths worldwide. About 10–30% of patients with non-small cell lung cancer (NSCLC) harbor mutations of the EGFR gene. The Tumor Microenvironment (TME) of patients with NSCLC harboring EGFR mutations displays peculiar characteristics and may modulate the antitumor immune response. EGFR activation increases PD-L1 expression in tumor cells, inducing T cell apoptosis and immune escape. EGFR-Tyrosine Kinase Inhibitors (TKIs) strengthen MHC class I and II antigen presentation in response to IFN-γ, boost CD8+ T-cells levels and DCs, eliminate FOXP3+ Tregs, inhibit macrophage polarization into the M2 phenotype, and decrease PD-L1 expression in cancer cells. Thus, targeted therapy blocks specific signaling pathways, whereas immunotherapy stimulates the immune system to attack tumor cells evading immune surveillance. A combination of TKIs and immunotherapy may have suboptimal synergistic effects. However, data are controversial because activated EGFR signaling allows NSCLC cells to use multiple strategies to create an immunosuppressive TME, including recruitment of Tumor-Associated Macrophages and Tregs and the production of inhibitory cytokines and metabolites. Therefore, these mechanisms should be characterized and targeted by a combined pharmacological approach that also concerns disease stage, cancer-related inflammation with related systemic symptoms, and the general status of the patients to overcome the single-drug resistance development.

Efficacy of intraperitoneal thermochemotherapy and immunotherapy in intraperitoneal recurrence after gastrointestinal cancer resection

AIM: To investigate the prophylactic and therapeutic efficacy of intraperitoneal IL-2 immunotherapy following intraperitoneal thermochemotherapy in the metastasis and recurrence of gastric and colorectal cancer after operation.

METHODS: Forty-two gastric cancer patients at T₃II-T₄III_B stages and 96 patients with colorectal cancer at B to D stages admitted from January 1996 to October 1998 were randomly divided into control group (group I, 65 cases) receiving intraperitoneal thermochemotherapy, and group II(73 cases) receiving both intraperitoneal thermochemotherapy and intraperitoneal IL-2 immunotherapy. Distilled water at 43-45 °C containing 5-Fu 0.5 g/L and MMC 8 mg/L was perfused into peritoneal cavity before closure at the end of operation for 1 h, and from the third day, IL-2 10 million IU in 500 mL 0.9% sodium chloride was intraperitoneally administrated daily for 10 times. One month after operation, all the patients underwent regular intravenous chemotherapy. Before and after the IL-2 immunotherapy, some Th1 type cytokines in the peripheral blood of the patients in the two groups were detected by ELISA, and the intraperitoneal recurrence and liver metastasis rates and the 3-year survival rate were statistically evaluated after intensive follow-up.

RESULTS: IL-2 intraperitoneal immunotherapy significantly elevated the level of some Th1 type cytokines (P < 0.01 compared with that of control group), and the 3-year survival rate of group II was 18.1% higher and the rates of intraperitoneal recurrence and liver metastasis were 16.9% and 6.0% lower than those of group I significantly (P < 0.05-0.01).

CONCLUSION: The combination of intraperitoneal IL-2 immunotherapy and thermochemotherapy could promote Th1 immune paradigm and enforce anti-tumor activity of bodies, which plays a positive role in preventing gastric and colorectal cancer from intraperitoneal recurrence and development.