With COVID-19 affecting the respiratory system, pulmonary precaution is vital for pleural mesothelioma patients who are now at an increased risk for more severe side effects and complications. Patients develop tumors on internal organs as a result of asbestos exposure.
Pleural mesothelioma accounts for 80-90 percent of all diagnosed cases, and between 1999 and 2017 there were almost 50,000 mesothelioma-related deaths. Due to the aggressive nature of this cancer, patients with stage I mesothelioma have an average life expectancy of just under 2 years and 1 year for stage IV.
The prognosis for mesothelioma patients is not comparable to more curable cancers like thyroid and prostate. However, refined treatments and clinical trials are giving patients improved survival.
Mesothelioma Studies
Combined treatments have proven successful; a study in India on peritoneal type mesothelioma patients tested two distinct methods of peritonectomy combined with chemotherapy (Pleura Peritoneum 2019; doi: 10.1515/pp-2019-0015). This surgery has often determined the most successful in addition to heated chemotherapy.
The two methods allowed researchers to measure effectiveness. Their key findings indicated three points: 1) patients treated with complete peritonectomy rather than partial had an average of 5 months longer recurrence-free; 2) there was an average 3-year survival rate of 80 percent for complete peritonectomy patients and a 3-year survival rate of 60 percent for partial; 3) along with these numbers, 80 percent of complete peritonectomy patients survived 4 years or longer, with only half that for partial peritonectomy survival rates.
Another study for testicular mesothelioma noted the benefits of intensive surgery to obstruct tumor development to the lymph nodes (Ann Med Surg 2019; https://doi.org/10.1016/j.amsu.2019.10.012). Mesothelioma has the potential to metastasize in new stages, and especially in this region, a radical orchidectomy is a first-line option.
During the study, researchers noted that the common radical orchidectomy treatment yields a 2-year survival rate. In addition, nearly 60 percent of patients relapse within 24 months post-surgery, and the survival rate after the relapse is 1 year. As recurrence rates are still high even after surgery, researchers propose lymph node resection, supplementary with orchidectomy.
Most recently, a study analyzed immunohistochemistry as a diagnostic tool (Iran J Pathol 2019;14(2):122-126). Doing this, researchers identified various cell surface proteins that are specific to malignant pleural mesothelioma cells. Mesothelioma is a challenging type of cancer, as it shares many symptoms of similar respiratory cancers and diseases, oftentimes resulting in misdiagnosis. In order to make more accurate diagnoses, novel techniques are required to differentiate cancerous cells.
This study, published by Tabriz University of Medical Sciences, contrasted pleural mesothelioma cells to metastatic lung carcinoma cells. The primary focus was the proteins which determined the exact cell type, utilizing immunohistochemistry stain-dying to expose the cells. If the methods from this study become widely acknowledged and further evaluated to ensure accuracy, it could lead to early treatment, a crucial step to cancer remission.
Immunotherapy
Immunotherapy is continuing to prove viable for mesothelioma patients, and a clinical trial in Italy examined the results of ramucirumab combined with gemcitabine (J Clin Oncol 2020; doi: 10.1200/JCO.2020.38.15_suppl.9004). Ramucirumab is "a monoclonal antibody that binds to antigens on cancer cells. This stops the cells from signaling new blood vessel growth and slows cancer cell growth." Gemcitabine is a certain chemotherapy drug that imitates the body's DNA. Once doing so, it prevents DNA production, eventually killing cancerous cells. As a second-line treatment for patients, 81 received ramucirumab and gemcitabine, and 80 patients were given gemcitabine alone. There was promise after initial survival statistics for patients who underwent the multimodal therapy with nearly twice the median survival time.
Radiation Therapy
In Switzerland, a retrospective radiotherapy study was conducted with 21 pleural mesothelioma patients for 8 years, concluding in 2018 (Front Oncol 2019; doi: 10.3389/fonc.2019.00961). The patients already had previous treatment including pleurectomy and/or decortication, chemotherapy and then surgery, or systemic chemotherapy only. When the cancer recurred, researchers treated them with stereotactic body radiotherapy. By applying this method, it avoids damage to any healthy tissue. Patients returned after 1 year, and 73.5 percent of the affected tumors did not develop further, indicating a positive outcome.
Going Forward
These treatments are still advancing, and some of this critical research has been stalled during COVID-19. Mesothelioma Awareness Day on September 26 is an important reminder that patients affected by this disease deserve continued support. It is pertinent to note that studies are still ongoing, providing promise for mesothelioma patients and other cancer patients who can similarly participate in clinical trials and studies. While mesothelioma is taxing on a patient's body, treatment is continuing to progress and offer an extended life expectancy and enhanced patient care.
For more information on mesothelioma cancer, visit https://www.mesothelioma.com/