New research shows adjuvant radiotherapy is most likely to help pleural mesothelioma patients in the early stages of the disease. By the time mesothelioma is at Stage III or Stage IV, adjuvant radiotherapy is unlikely to improve survival.
Researchers at MD Anderson Cancer Center in Texas conducted the study on more than 2,500 pleural mesothelioma patients. Their results appear in the most recent issue of the Journal of Thoracic Disease.
The study could help mesothelioma patients and doctors make more informed choices about their care.
Defining the Stages of Pleural Mesothelioma
The four stages of mesothelioma relate to the severity of the cancer and how far it has spread.
In Stage I mesothelioma, the tumor is confined to the pleural membrane and has not spread. Stage I mesothelioma is the most responsive to treatments like surgery, adjuvant radiotherapy, and chemotherapy. Patients with Stage I mesothelioma have the longest life expectancy.
Mesothelioma patients with Stage II disease may have some mesothelioma in nearby organs but no mesothelioma cells in their lymph nodes.
In Stage III and IV, tumors are larger and have spread to other organs and lymph nodes. At this stage, treatment options are more limited and survival is often much shorter.
Doctors use the staging system to help determine mesothelioma prognosis. Knowing the patient’s stage can help them decide whether or not to perform surgery or offer additional treatments like adjuvant radiotherapy.
Adjuvant Radiotherapy and Mesothelioma Survival
The new study uses information from the National Cancer Database. Doctors reviewed the cases of 2,846 pleural mesothelioma patients. The patients all had mesothelioma surgery between 2004 and 2013.
Two hundred and thirteen of the patients (7%) had adjuvant radiotherapy after surgery. Adjuvant therapy is treatment delivered after the primary treatment is complete.
The researchers compared the outcomes of the patients who had surgery and radiation with the stage of their cancer when they started.
“Adjuvant radiation was associated with improved survival among those who were stage I-II (P=0.024), but not stage III or IV,” writes study author David B. Nelson. Patients in the later stages of mesothelioma lived for about the same amount of time as those who did not have any adjuvant radiotherapy.
The shortest survival times were in people with Stage IV sarcomatoid mesothelioma.
The research team is calling for more study on the usefulness of adjuvant radiotherapy in people with pleural mesothelioma.
Nelson, DB, et al, “Defining the role of adjuvant radiotherapy for malignant pleural mesothelioma: a propensity-matched landmark analysis of the National Cancer Database”, April 2019, Journal of Thoracic Disease, pp. 1269-1278, http://jtd.amegroups.com/article/view/28310/20869