Peritoneal mesothelioma is a rare and aggressive cancer that arises from the peritoneum, the membrane lining the abdominal cavity. It is caused by exposure to asbestos, and its symptoms include abdominal pain, swelling, and weight loss. Peritoneal mesothelioma is difficult to treat, and conventional therapies such as surgery, chemotherapy, and radiation have limited effectiveness. However, in recent years, immunotherapy has emerged as a promising treatment option for peritoneal mesothelioma.
Immunotherapy is a type of cancer treatment that harnesses the power of the immune system to fight cancer. It works by stimulating the immune system to recognize and attack cancer cells. There are several types of immunotherapy, including checkpoint inhibitors, CAR-T cell therapy, and cancer vaccines. In the case of peritoneal mesothelioma, the most promising form of immunotherapy is checkpoint inhibitors.
Checkpoint inhibitors are a type of immunotherapy that targets proteins called checkpoints on the surface of immune cells. These checkpoints normally prevent immune cells from attacking healthy cells in the body. However, cancer cells can use these checkpoints to evade the immune system. Checkpoint inhibitors block these checkpoints, allowing the immune system to recognize and attack cancer cells.
Several clinical trials have investigated the use of checkpoint inhibitors for the treatment of peritoneal mesothelioma. One of the most promising studies was a phase II trial of the checkpoint inhibitor pembrolizumab, which was published in The Lancet Oncology in 2018. The trial included 25 patients with advanced peritoneal mesothelioma who had previously received chemotherapy. The patients received pembrolizumab every three weeks for up to two years.
The results of the trial were encouraging. Overall, 20% of patients had a partial response to pembrolizumab, meaning that their tumors shrank by at least 30%. Another 40% of patients had stable disease, meaning that their tumors did not grow or shrink significantly. The median progression-free survival (the length of time during which patients did not experience disease progression) was 4.1 months, and the median overall survival (the length of time patients survived without disease progression) was 11.4 months.
Another study, published in JAMA Oncology in 2020, investigated the use of the checkpoint inhibitor nivolumab in combination with chemotherapy for the treatment of peritoneal mesothelioma. The study included 38 patients with peritoneal mesothelioma who had not received prior chemotherapy. The patients received nivolumab in combination with cisplatin and pemetrexed, which are commonly used chemotherapy drugs for mesothelioma.
The results of the study were also promising. The overall response rate (the percentage of patients who had a partial or complete response to treatment) was 58%, and the disease control rate (the percentage of patients who had a partial or complete response or stable disease) was 68%. The median progression-free survival was 7.2 months, and the median overall survival had not yet been reached at the time of publication.
While these studies suggest that immunotherapy may be effective for the treatment of peritoneal mesothelioma, it is important to note that immunotherapy is not a silver bullet. Not all patients respond to immunotherapy, and some patients may experience severe side effects such as immune-related adverse events. Additionally, immunotherapy is often expensive and may not be covered by insurance.
In conclusion, immunotherapy is a promising treatment option for peritoneal mesothelioma. Checkpoint inhibitors such as pembrolizumab and nivolumab have shown encouraging results in clinical trials, and ongoing research is investigating the use of other types of immunotherapy such as CAR-T cell therapy and cancer vaccines. However, given the complexity of peritoneal mesothelioma and the limitations of immunotherapy, it is important for patients to discuss their treatment options with a qualified healthcare professional.
