Active immunotherapy for gastric cancer
Gastric cancer is one of the most common and deadly cancers worldwide. Surgical resection of early-stage localized disease is the only curative treatment, as advanced gastric cancer is often resistant to standard cytotoxic therapy including chemotherapy and radiotherapy. On the other hand, evidence is accumulating that immune-based approaches could significantly ameliorate the course of this disease.
A primary course of xenogeneic vaccine-based immunotherapy for gastric cancer developed at our Centre comprises 10 subcutaneous vaccinations and takes about 3 months. The particular supporting vaccination schedule is determined by disease stage and an overall health state of the patient. The entire vaccine treatment regimen is conducted on an outpatient basis. Minor self-limiting injection-site reactions can develop, including influenza-like syndrome with body temperature rising up to 38ºC and musculoskeletal discomfort. Vaccine-induced immune reactivity is specifically directed to destroy tumor cells and suppress the development of residual disease.
Our own experience in XPV-based immunotherapy of patients with gastric cancers shows that significant clinical effects of various grades (complete or partial response, disease stabilization) and ≥ 6 months duration can be achieved in a significant proportion of stage IV patients. Therefore, we suggest that xenogeneic vaccine therapy could prove to be one of the most effective modalities if initiated as early as before or immediately after surgical resection of the primary tumor and its metastases.
Case 1. A 44-year-old female patient I was diagnosed with signet ring cell gastric carcinoma. Combined gastrectomy was carried out and one course of polychemotherapy was conducted. Two months later, signs of disease progression were noted: UI revealed enlarged lymph nodes within both the gate of the liver and the retroperitoneal space. Vaccinotherapy was started at that time, and 3 months after vaccinotherapy initiation, UI revealed no signs of the disease. The reduction of ESR to normal and the elevation of Hb level were noted in blood tests. Final examination revealed that the patient was in good condition, and no evidence of disease was observed at 2-year follow-up after immunotherapy.
Case 2. A 54-year-old male patient I was diagnosed with low-grade differentiated gastric adenocarcinoma. Multiple lesions were noted in the left lung (the condition after radiochemotherapy). Vaccinotherapy was started, at which time patient had complains of general weakness, periodic vomiting, and low grade fever. The state of patient’s health worsened at 3 months after immunotherapy initiation, i.e. patient experienced daily vomiting, lack of appetite, significant loss of weight and intense paint in the epigastric region. Nevertheless, vaccinotherapy was not stopped. Two months later, patient’s health slightly improved in that vomiting attacks became less frequent, blood parameters returned to normal. However, UI revealed a lesion of 15 mm diameter in the bottom pole of the right kidney. The patient’s state was stable for 4 months, after which gastric obstruction developed and surgery (Bilrot 2 operation) was performed. UI revealed no additional pathological symptoms. A chest x-ray examination did not detect any tumor signs in lungs. Final examination revealed no evidence for disease progression at 2-year follow-up after vaccinotherapy.