Mesothelioma is recognized as a rare disease, with only about 3,000 new diagnoses each year. Malignant pleural mesothelioma, which develops in the lining of the lungs, is the most commonly diagnosed. This type accounts for about 80% or more of all mesothelioma diagnoses. Malignant peritoneal mesothelioma, which develops in the lining of the abdominal cavity, is the second-most diagnosed. Both types are considered difficult to treat and have an average prognosis of about one year.
Doctors have found rare cases where patients have developed both pleural and peritoneal mesothelioma. A new study from Columbia University investigated how co-occurring mesothelioma diagnoses impact treatment options and survival in 50 patients.
Receiving a Co-Occurring Mesothelioma Diagnosis
Research has shown co-occurring diagnoses among cancer patients is becoming more frequent. Patients may develop a secondary form of cancer or other health conditions some time after their initial diagnosis. These associated conditions may be related to factors like genetics, histology of the initial diagnosis or the treatments the patient underwent.
Studies have shown mesothelioma patients may first develop other asbestos diseases or later develop other types of cancers and health conditions. For instance, many pleural mesothelioma patients may first be diagnosed with asbestosis or pleural thickening.
Developing both pleural and peritoneal mesothelioma, however, is rare and has only been recorded in a small number of cases. For the 50 patients in this latest study, researchers noted that 52% of participants were diagnosed with a second type of mesothelioma one year after their original diagnosis. For the patients who received their second diagnosis after the one-year mark, the study found it occurred on average about 30 months after the initial diagnosis.
Based on this data, the researchers concluded that patients have the highest risk of being diagnosed with both types of mesothelioma within the first year after diagnosis.
Patients Still Eligible for Multimodal Treatment
Research has found a multimodal treatment approach is typically the most effective option to improve survival for mesothelioma patients. Studies have shown that a combination of therapies typically has better results than one treatment applied on its own.
For instance, chemotherapy applied individually has shown varied success. Some studies have found about 19% of pleural mesothelioma patients survived two years following chemotherapy treatment. Despite limited success on its own, research shows chemotherapy before surgery can extend survival to three years or more in some cases.
Although multimodal treatment is preferred, it might not be an option for patients with more advanced disease. As mesothelioma metastasizes (spreads), treatment options can become more limited. Surgery, for instance, typically becomes unsafe once tumors spread beyond the original tumor location. In some cases, doctors may opt for a treatment plan focused on palliative therapies for patients with late-stage mesothelioma to relieve symptoms and improve quality of life.
A co-occurring diagnosis of pleural and peritoneal mesothelioma appears comparable to diagnosis at a more advanced stage, since the cancer is present in more organs and could metastasize more quickly. However, researchers found most of these patients can still receive multimodal treatment and prolong survival.
Treatment varied among the study participants based on their individual case, with many patients undergoing surgery and/or chemotherapy. Some participants were eligible to undergo hyperthermic intraperitoneal chemotherapy (HIPEC), a heated chemotherapy wash applied directly to the abdomen. For patients solely diagnosed with peritoneal mesothelioma, the combination treatment of HIPEC with surgery has shown a 5-year survival rate of more than 50%.
Survival in Patients with Pleural and Peritoneal Mesothelioma
A number of factors impact mesothelioma prognosis, such as mesothelioma type and cell type, stage at diagnosis and patient age and overall health. In addition to the usual factors that impact prognosis, survival in patients diagnosed with both types of mesothelioma may also be influenced by:
- The type of mesothelioma diagnosed first
- Treatments underwent before the secondary diagnosis
Researchers found patients with co-occurring mesothelioma diagnoses experienced a survival benefit after treatment comparable to those diagnosed with either pleural or peritoneal mesothelioma. Overall survival was determined based on the time from the patient’s initial diagnosis.
On average, the study found patients survived 33.9 months. Patients diagnosed with pleural mesothelioma or peritoneal mesothelioma have an average life expectancy of about six months to one year after diagnosis.
As the secondary mesothelioma diagnosis occurred 12 – 30 months after the initial diagnosis, more research is required to fully understand how co-occurring mesothelioma diagnoses influence treatment and survival.