Mesothelioma Prognosis

Medical statistics can be valuable snapshots, but they only tell part of the story.  The statistics discussed in this article are addressed to pleural mesothelioma and peritoneal mesothelioma, which develop in the outer lung lining and the abdominal cavity respectively.  Over ninety percent of all mesothelioma cases are of these varieties.  Currently, the average survival period for a patient diagnosed with mesothelioma is about one year.  That is an average, however, that is impacted by three other important statistics. 

• The latency period for mesothelioma can be anywhere from twenty to fifty years.  Most of the individuals diagnosed with mesothelioma are in their fifties or older and have other, mitigating health factors.  Many are or have been cigarette smokers; some have heart problems or general health that is somewhat delicate due to age.

• A mesothelioma diagnosis is often not made until the disease has been present for some time and has developed into a mature, invasive form of cancer.  One of the reasons for this fact is that mesothelioma symptoms often don’t manifest while the cancer is in its developmental stage. 

• The other is that mesothelioma symptoms – shortness of breath, chest pain, pleural effusion, a persistent cough – are also symptoms associated with much more common health problems, particularly for smokers and people over fifty.  Those can include heart disease, COPD symptoms, pneumonia, even influenza.  Mesothelioma is a relatively rare disease and thus is often not considered in the initial diagnostic considerations.

Prognosis Factors

One of the critical issues with a mesothelioma diagnosis is the question of whether or not the disease has been caught early enough that surgery is an option.  Most mesothelioma diagnoses don’t meet this standard but for those that do there is the possibility of slowing the disease substantially. 

Early Treatment

Usually when physicians opt for surgery with this it means that the cancer is still localized and has not metastasized into the lymph system or into other areas of the body.  In the case of pleural mesothelioma, surgery usually includes removal of one or more of the lung lobes on the side of the body where the disease has developed.

Other mesothelioma treatment options include chemotherapy and radiotherapy.  At this point, medical science has not developed a set of chemotherapy drugs that are effective beyond extending survival time a few months.  The fact is that all mesothelioma patients who are receiving chemotherapy and radiation treatment are receiving palliative therapy, designed to extend the life for a short period and to ease some of the symptoms.

Types of Mesothelioma

Cell type plays a role in a mesothelioma prognosis analysis.  The two types of cells that develop into mesothelioma cancers are epithelioid cells and sarcomatoid cells.  Some patients have biphasic mesothelioma, wherein both types of cells are present.  Epithelioid cells respond to treatment more readily and the chemotherapy drugs currently available are more effective with epithelioid calls than sarcoma cells.

Prognosis Statistics

The figure given for average survival beyond diagnosis is just one perspective on the figures that are available.  There are not a lot of mesothelioma case studies that have large populations.  Looking past the average, accepted norms are that generally ten percent of all mesothelioma patients will be alive three years after diagnosis and five percent will be alive five years after diagnosis. 

Case Studies

There are fewer case studies of patients who were diagnosed early enough for surgical intervention.  One that is often cited, however, is an analysis conducted at the Dana Farber Cancer Institute that followed 120 patients diagnosed from 1980 to 1995, all pleural mesothelioma patients who were initially treated with surgery.  Of those 45% were alive two years later and 22% were alive five years later.

In the Dana Farber study, patients with epithelioid mesothelioma fared much better than those with biphasic or sarcomatoid cases.  74% of epithelioid cases were alive after two years and 39% were alive after five years.  Of those patients with sarcomatoid or biphasic mesothelioma 20% were alive two years after diagnosis and at the five year mark all had died.

An oft-cited analysis done in Northern Italy looked at every mesothelioma case within a population area that included 4.5 million people.  In this study, 24% of pleural mesothelioma patients were alive after one year and 34% of peritoneal mesothelioma patients had survived one year after diagnosis. 

There are other, small case studies with more optimistic statistics than the national averages quoted here and there are unattributed statistics on several web sites that are extremely optimistic, one of which cites the five year survival rate as 9% of all cases, with correspondingly high figures for years one through four.  That statistic dates from 2002; in 2009 the American Cancer Society estimates that the five year survival rate for mesothelioma patients is 10%

Prognosis: the Limits to Statistical Value

Every patient who contracts mesothelioma is still a name rather than a number.  The factors that enter into survival rates are myriad and complex: age, relative health, stage of the disease at diagnosis; there is evidence now developing that genetics has something to do with both risk of developing the disease and the likelihood of positive response to treatment.

There is no question that mesothelioma is a lethal and aggressive form of cancer, but even for a disease once considered a death sentence there is no one set of statistics that tell the entire story.  Despite its rarity there is significant research being done on diagnostic techniques and non-surgical treatment options: at the moment progress for survival rates is being measured in months.  However for each patient, the ultimate result will be dictated by a mixture of factors known and unknown.