Mesothelioma prognosis

 

A malignant mesothelioma is a form of cancer that affects mesothelium- a thin lining of internal organs. It is rare cancer, caused by long-term exposure to asbestos. The benign form is even rarer and we know almost nothing about it- its causes are unknown. Just like in case of other malignancies- the timely established diagnosis improves patient’s life expectancy and chances for recovery. Mesothelioma, in general, has a poor prognosis. The reason for such a poor prognosis lies in a fact that mesothelioma remains „silent“ for a long time (long latency period) and often, at the time the first symptoms emerge, the disease has already advanced to its terminal stage.

By the end of this article, you will find out about mesothelioma prognosis depending on the relevant factors.

Factors that affect the life expectancy of malignant mesothelioma

Staging and life expectancy

Prognosis depends almost entirely on the stage of the disease at time of diagnosis. Essentially, staging is based on the categorization of mesothelioma according to how much it spread. Staging is a common step in diagnosing all malignancies and staging systems differ depending on the type and location of cancer.

For malignant mesothelioma, the system of four stages (stage 1-4) is used to describe the extent of cancer within the body. Stage 1 has the best prognosis, while stage 4 is used for terminal disease (palliative care).

Once determined, the stage of cancer does not change as the disease progresses or recedes. The classification is performed only once, at the time of diagnosis. Stages help doctors choose the treatment program to begin with, but later on, progression or regression of a disease determines the actual treatment.

Staging is done after numerous diagnostic tests have been performed (imaging techniques, laboratory findings, and physical examination).

Having in mind how rare the mesothelioma is, only pleural mesothelioma has detailed guidelines for staging, while other types (peritoneal and pericardial) are classified based on the American Joint Committee on Cancer (AJCC) general guidelines.

Stage 1

The cancer is in one location, there is no detectable spreading to lymph nodes, other organs or tissues. Surgery is the treatment method of choice in such cases.

Stage 2

Cancer has spread on the surrounding organs and tissues, lymph nodes may be involved as well. In such cases, surgical resection is the treatment method of choice, but the success depends on the extent of the growth.

Stage 3

Cancer has invaded surrounding tissues and entire anatomical region, infiltrates structures like chest wall, regional lymph nodes, esophagus, etc. In cases like this surgery is not an option (in terms of curative treatment, palliative interventions may be an option, depending on the symptoms). Other treatment modalities may be tried.

Stage 4

Cancer has spread to distant organs and regions across the body. The treatment goal in this stage is to reduce discomfort and pain. Rarely, palliative surgical intervention may be carried out.

Pleural Mesothelioma Staging

Since the Pleural mesothelioma is the most common type, different systems for its staging has been developed over years. The most important are:

–    Butchart Staging System

–    TNM Classification

–    Brigham Staging System

Each of these has its advantages and disadvantages. Each patient diagnosed with Pleural mesothelioma goes through all of these classifications.

Staging systems provide guidance about prognosis. Each patient reacts differently to the treatment, so sometimes those classified as stage 2 outlive patients with stage 1 mesothelioma. The point is- no matter the stage, there’s always hope!

The lower the stage, the longer the life expectancy is. Here are the numbers:

–    Stage 1 malignant mesothelioma life expectancy is (on average) 21+ months.

–    Stage 2 malignant mesothelioma life expectancy is (on average) 19 months.

–    Stage 3 malignant mesothelioma life expectancy is (on average) 16 months.

–    Stage 4 malignant mesothelioma life expectancy is (on average) 12 months.

Location and life expectancy

Pleural mesothelioma has a better prognosis than peritoneal mesothelioma, while pericardial mesothelioma is quite often diagnosed not before an autopsy. Over the past 10 years, the treatment and prognosis for peritoneal mesothelioma have improved.

Age and life expectancy

In general, older patients have a shorter life expectancy. The explanation lies in the fact that older population often has comorbidities that interfere with the treatment.

–    If the age at the diagnosis is <65 yo, the life expectancy is (on average) 12 months

–    If the age at the diagnosis is 65+ yo, the life expectancy is (on average) 8 months

–    If the age at the diagnosis is 75+ yo, the life expectancy is (on average) 4 months

Cell Type and life expectancy

The mesothelioma can be divided into three categories based on the cell type: epithelioid, sarcomatoid, and biphasic (a mixture of epithelioid and sarcomatoid cancer). In general, epitheloid carcinoma has the longest life expectancy (19 months for pleural and 54 months for peritoneal mesothelioma), biphasic has the poorer prognosis (13 months for pleural and 4.6 months for peritoneal mesothelioma), while the sarcomatoid type has the shortest life expectancy (8 months for pleural mesothelioma, there is not enough statistical data for the estimation of the life expectancy in case of peritoneal mesothelioma).

Sex and life expectancy

Women diagnosed with malignant mesothelioma live, on average, 5.5 months longer than men. The incidence of malignant mesothelioma is lower in women, due to occupational differences.

Other factors and life expectancy

Factors that correlate with a better prognosis are non-smokers (and no history of smoking), normal white blood cell count at the time of diagnosis, low platelet count, low hemoglobin level, asymptomatic.

On the other hand, the prognosis is poorer in those who are smokers (or have been smokers at some point of their lives), have elevated white blood cell count, have high platelet and/or hemoglobin count and report symptoms.

Survival Rates

While the life expectancy is period of time a person is expected to live, the survival rate is a median percentage of patients who live a certain amount of time. Typically, the 5-year survival rate is a standard statistic category in cancer treatment and prognosis research, but having in mind how aggressive and deadly malignant mesothelioma is, shorter periods of time are used as statistical categories as well.

Just like in case of life expectancy, different factors affect survival rates.

Survival rates depending on the mesothelioma type

Peritoneal mesothelioma has the highest survival rates. The first year survive 92% of the patients, and at 10 years mark 39% of patients are still alive.

Pleural mesothelioma 1-year survival rate is 73% and after 10 years less than 5% of patients are still alive.

Pericardial mesothelioma 1-year survival rate is 51%, while there is no available data for 10 year survival period (it’s close to 0%).

Survival rates depending on the age and sex at the time of diagnosis

Depending on the age and sex, 5-years survival rate varies from 54% for women and 35% for men younger than 45 years at the time of diagnosis to %5 for women and 3% for men older than 75 years at the time of diagnosis.

Is there such a thing as accurate prognosis?

Apparently, the question of mesothelioma prognosis is not straight forward. A number of factors affect it. All the data stated above is just a guide to a rough approximation.