Malignant Pleural Mesothelioma is an aggressive form of cancer arising from the pleura. A pleura is a delicate serous membrane that lines the thorax and envelops the surface of each lung. The annual incidence of Mesothelioma is approximately 3300 in United States. Eighty percent of all malignant mesothelioma are pleural in origin.
The diagnosis of Malignant Pleural Mesothelioma can be an economic and emotional burden for anyone. Despite doctors’ guidance about life expectancy, it is a common tendency to search the internet for further resources. However, internet is flooded with tremendous amount of data and studies that neither makes conclusion easier nor silences curiosity. This post will try to address the question in its title and its variants existing all over the internet. Hopefully, it will make understanding easier for patients and their families.
Malignant Pleural Mesothelioma is the most common type of malignant mesothelioma. It occurs usually in patients above 60 years of age, typically presenting decades after an exposure to asbestos with gradually worsening clinical course. Malignant Pleural Mesothelioma (MPM) has overall survival time on the order of 9 to 17 months after diagnosis. Few patients show modest improvements in survival. Surviving MPM depends upon variety of prognostic factors among which histology and staging are the strongest ones.
Survival Based on Histology
Histology refers to the alignment, texture and form of cancer cells arranged in a tissue section obtained from the diagnostic or post surgical specimen. A clinical pathologist observes such tissues under a microscope using various stains and provides the histological subtype or variant of Malignant Pleural Mesothelioma. The widespread availability of immunohistochemistry over the past few years has greatly aided histological diagnosis and helped determine how long can a patient with Malignant Pleural Mesothelioma live with its histological subtypes.
MPM is histologically classified into 3 broad subtypes.
- Epithelioid MPM: It comprises about 60% of MPM subtypes. Typical patterns of this subtype include glandular, tubullopapillary, adenomatoid and solid epithelioid configurations. People diagnosed with Epitheliod MPM can live longer as compared to other histolgic variants as it has best prognosis. A completely resectable MPM with pure epitheliod histology holds the best outcome in terms of survival. The median survival of Epitheliod MPM is more than a year (19 months from the time of diagnosis).
- Sarcomatoid MPM: These are composed of spindle cells which may mimic malignant mesenchymal tumors. Patients diagnosed with Sarcomatoid MPM suffer worst prognosis. They live less than a year after diagnosis. The median survival is 8 months from the time of diagnosis.
- Biphasic/Mixed MPM: Biphasic or mixed mesotheliomas have both epitheliod and sarcomatoid features. The median survival is 13 months from the time of diagnosis in case of Biphasic/Mixed MPM.
|Epitheliod MPM||1 year 7 months|
|Sarcomatoid MPM*||8 months|
|Biphasic/Mixed MPM||13 months|
To summarize, you will survive the longest possible months with Epitheliod MPM and the least with Sarcomatoid MPM.
Survival Based on Staging
On the other hand, staging refers to the extent to which the cancer has invaded surrounding landmarks, distant anatomic structures and the lymph nodes of the body. The prognosis and life expectancy of MPM worsens with the advancing stage of the disease. People diagnosed in initial stages of the disease tend to live longer.
The American Joint Committee on Cancer (AJCC) stages Malignant Pleural Mesothelioma based on TNM System. TNM refers to tumor, nodes and metastasis. TNM staging is an essential tool in determination of survival as well as modality of treatment.
TNM system stages the MPM disease process mainly into four stages. Each stage has its own range of survival. The different median survivals of each stage of Malignant Pleural Mesothelioma following surgery are tabulated below:
Stage of MPM (TNM)
|I||1 year 8 months|
|II||1 year 7 months|
|III||1 year 4 months|
Survival Based on Multiple Prognostic Factors
The multifactorial prognostic grouping has been done by European Organization for Research and Treatment of Cancer (EORTC) and Cancer & Leukemia Group B ( CALGB). Both of these prognostic schemas categorize patients into different risk groups and provide median survival for each group. This will help estimate how long one can live with MPM based upon multiple risk factors.
The EORTC takes five risk factors into consideration and categorizes the MPM disease process into two groups. Based on EORTC model, a high and low risk group could be discerned, with one year survival rates of 40 and 12 percent.
It is evident from the above table that no MPM patients in high-risk group survived 2 years and 14 percent of low risk group patients survived 2 years after diagnosis. The EORTC model analyzed data from 204 patients with MPM, the prognostic significance of which was later confirmed in a multivariate analysis.
On the other hand, CALGB model takes account of different clinical characteristics affecting survival of MPM patients and validates 6 prognostic groups with different rates of survival. Patients in CALGB group I survive the longest and group VI survive the shortest number of months after diagnosis.
Malignant illnesses like MPM can be a disaster to anyone. The understanding of prognosis, staging and life expectancy is essential for patients and their families. It will help patients and their families to discuss treatment options with the doctor and plan rest of things in life accordingly.