Oncologists in Japan have found a way to determine which patients would best benefit from second-line chemotherapy. Second-line treatment is a second treatment that doctors perform after trying another treatment first. When the first treatment doesn’t work or stops working, a second-line treatment is tried to see if it will benefit patients. Patients between the years 2007 and 2019 were studied at the National Cancer Center Hospital in Tokyo.
Peritoneal mesothelioma and pleural mesothelioma occur in different parts of the body. Peritoneal mesothelioma occurs in the peritoneum, which lines the abdomen while pleural mesothelioma occurs in the mesothelium that surrounds the lungs called the pleura. Most people with mesothelioma were exposed to asbestos at work many years earlier. It typically takes many years for workers exposed to asbestos to develop the cancer. Mesothelioma is also dose dependent, meaning that the more asbestos someone is exposed to, the higher the chance that the person will develop mesothelioma. This does not mean that small amounts of asbestos were not dangerous. Even one exposure can lead to mesothelioma later in life. Peritoneal mesothelioma is typically treated with Alimta (pemetrexed) combined with platinum-based drugs cisplatin or carboplatin. Second-line treatments for mesothelioma are not approved as standard treatments, but if the cancer comes back, it is an option for patients.
When second-line chemotherapy is used, it is not always beneficial to all patients. The researchers wanted to know if there could be a way to detect what patients will benefit from second-line chemotherapy before treating patients. The doctors looked at 54 mesothelioma patients who underwent first-line chemotherapy and 26 who had second-line therapy. Some patients also received drugs like gemcitabine, nivolumab, or taxane to help make the chemotherapy more effective. The patients who had second-line chemotherapy had a median overall survival of 16.9 months and it took 3.2 months for the cancer to start growing again. Patients with the longest survival had six or more rounds of first-line chemotherapy.
Researchers have concluded that second-line chemotherapy could be an option for refractory malignant peritoneal mesothelioma, which is mesothelioma that does not respond to treatment. It could be very beneficial in patients who have undergone six cycles of the platinum-based chemotherapy pemetrexed used as a first-line treatment. Approximately 2,500 Americans are diagnosed with mesothelioma every year and first-line chemotherapy is only slightly effective for these patients. If a second-line treatment is found, more patients could live longer and better lives after diagnosis.
