More Than a Statistic Cont.

Compliance
Related to the above is treatment compliance. Some people just "give up", refuse treatment for their cancers, or do not alter there behavior. These people are entered into the database of patients and if they die earlier than patients that agree to therapy, they are still counted in the population prediction of survival. By refusing a treatment option such a chemotherapy an individual often will often affect their prognosis. This individual is still entered into the 5 year database.

Future Research
These estimates are based on data from thousands of cases of this type of cancer in the United States each year, but the actual risk for a particular individual may differ. It is not possible to tell a person how long he or she will live with a particular cancer. Because the survival statistics are measured in five-year (or sometimes one-year) intervals, they may not represent advances made in the treatment or diagnosis of this cancer.

I hope the above postings shed some light on being an individual rather than a statistic.

Adapted from an e-mail from Dr. Robert Bayer, oncologist at Delnor Community Hospital, Geneva, IL.

More Than a Statistic Cont.

Several factors need to be considered when discussing statistical averages versus possible outcomes for an individual. These include: comparing like cancers, variability in treatment, limitations of the 5 year time frame, compliance and future research.

Comparing Apples to Apples
When comparing outcomes you must compare cancers to "like" cancers and staging is disease specific. For example a stage I lymphoma of an indolent type (grows slowly) has a far better prognosis than a stage I resected lung cancer.

Variability in Treatment
Population based survival statistics are NOT comparable to the individual because of the variability in treatment and comorbities. Example, a stage 4 breast cancer that is of an indolent type that is treated with anti-estrogen therapy has a far higher survival than a stage 4 inflammatory breast cancer that is not hormone sensitive and is generally more rapid in metastasis

5 Year Limits
The whole issue of predicting "survival" is more social than scientific, in most of the medical literature. Funding for cancer research is usually not adequate to follow patients for "life" Patients move, change phones, change names, and change doctors so frequently that research studies tend to stop after 5 years, hence 5 year data limits. Ironically the "best" data on survival comes from actuarial life insurance databases. Research studies focus on "surrogate endpoints" or measures that are quicker and easier to get than survival. Example, time from cancer resection to relapse based on serial CT scans done at pre determined intervals. This is often called "Relapse Free Survival" and is a more common research endpoint.

More Than a Statistic

Following the pathology report and diagnosis, an individual may fall into a statistical category that may have a limited bearing on the prognosis at the individual level. For example, the report may indicate that the survival rate for an individual to live for 5 years is less than 10 percent. However, such cancer survival statistics, should be interpreted with caution. The following postings will look more closely at being a statistic or an individual, and how individual choices and promising research play a role in survival statistics.

Pathology Report

Much of the foregoing information is contained in the pathology report. Reports will vary according upon one's cancer, but generally contain demographic information, tissue removed and date. The description of the tissue removed for analysis will be either a "gross or macroscopic description" of the tissue or specimen visible to the naked eye and pertains to color, weight and size of tissue. The "microscopic description" which describes features seen under a microscope and includes features of the tumor such as a carcinoma and the cell of origin within that typology, as well as the grade and stage. Often information about tumor margins will be given. This refers to the presence of the tumor in the edges of the tumor that was surgically removed. If so, the margins are said to be "positive "or "involved. " If not, they are said to be "negative" or free of tumor. The presence of markers such as PSA or hormone receptors, e.g. estrogen positive may also be referred to. Based upon the foregoing, a final diagnosis will also be present.

A site I would recommend for understanding your specific pathology report is www.mybiopsy.org. This, in turn, will allow you to ask the right questions and choose correct treatment options.

Staging

Distinct from the grading scale that estimates a cancer's aggressiveness, staging estimates how much and where the cancer is located. Several classifications exist but most common is TNM. For most cancers, the stage is based on 3 main factors called the TNM method.

1. T-refers to the original (primary) tumor's size and whether or not the tumor has grown into other nearby areas.
2. N - refers to whether or not the cancer has spread to the nearby lymph nodes.
3. M-whether or not the cancer has spread to distant areas of the body.
   

The numbers are often translated into different stages including: in situ-abnormal but not invasive, and stages I, II, III, IV with subcategories. Usually the higher the number the more advanced the disease. Not all cancers are staged by the TNM method. For e.g., leukemias, are generally not staged in this way because they are already in the blood. Also, primary brain cancers that originate in the brain (primary cancers), tend to be localized and they are graded rather than staged.

Tumor Grading

Tumor grading, together with the stage of the tumor, assists doctors in planning treatment strategies. Tumor grading is an estimate of the tumor's malignancy and aggressiveness based on how the tumor cells appear under a microscope and the number of malignant characteristics they possess. Cancer cells are often undifferentiated and are termed primitive or anaplastic as they do not appear specialized like normal cells. There nuclei are also larger and irregular and there is also exhibit a large volume of dividing cells. While more than one scale is used depending upon the type of cancer, the following scale is commonly used:

• G1 Well-differentiated (Low-grade and less aggressive)

• G2 Moderately well-differentiated (Intermediate-grade and moderately aggressive)

• G3 Poorly differentiated (High-grade and moderately aggressive)

• G4 Undifferentiated (High-grade and aggressive)

Multiple Myeloma

Multiple myeloma is a cancer of the plasma cells. In multiple myeloma, abnormal myeloma cells divide repeatedly making more and more abnormal cells. These cells collect in multiple sites in the bone marrow and outer parts of the bones crowding out normal blood cells. This causes extensive destruction within the skeleton involving bones in the spine with consequent bone pain and fractures. Compressed vertebrae may put pressure on nerves causing more pain. The overproduction of plasma cells may crowd out the production of  red blood cells (RBC) thereby causing anemia.

Sarcomas

Sarcomas are a rare group of cancers that occur more commonly in children and rarely in adults. It is a cancer of the connective tissue or cells whose primary function is to hold or connect the body together. These sarcomas can be broken down into soft tissue sarcomas or tissues that connect, surround or support tissues or organs of the body including the nerves, fat, muscles tendons and blood tissues, and hard tissue sarcomas that affect the bone and cartilage. Primary bone cancer is rare with the most common type of bone cancer being osteosarcoma, which develops in new tissue in growing bones. Others include chondrosarcoma of cartilage tissue and Ewing's sarcoma in immature nerve tissue in bone marrow. Bone sarcomas occur more frequently in the extremities such as the arms and legs. 

Leukemia/lymphoma

Leukemia is a cancer of the organs that make blood: the bone marrow and the lymph system. The overabundance of white blood cells crowd the bone marrow and prevent it from producing enough red, white blood cells and clotting platelets. The body then loses its ability to fight infection, as well as increased possibility of anemia, easy bruising and bone pain. Leukemia may be acute which involves immature cells and half chronic with cells more advanced in development and tends to progress slowly. Leukemia represents approximately 5% of cancers and is generally associated with an older population. However, until recently childhood leukemia was the most common cancer of children. 

Lymphoma is a general term for cancers that develop in the lymphatic system affecting the body's immune system. There are two basic kinds of lymphoma, Hodgkin's which is a  unique kind of lymphoma and Non-Hodgkin's. The distinction between leukemia and lymphomas is somewhat arbitrary. If bone marrow involvement and circulating cells predominate or if they constitute the first recognized manifestation of the disease, the process is termed leukemia. Lymphomas originate in lymphoid tissues and rarely go into the blood stream.

Categories of Cancer, Carcinomas

As stated in previous post, cancer is not a monolithic disease but rather several hundred (albeit with often common pathways.) For our purposes they can be generally broken down into three major categories and further into hundreds of subtypes. The first two categories, carcinomas and sarcomas are solid tumors and leukemias and lymphomas are dispersed cells that may form a solid tumor.  The most common, carcinomas (from the Greek word crab due to often clawlike extensions) account for approximately 80-90 percent of all cases. Most carcinomas affect organs that secrete something such as the breast, the lungs (mucus) or pancreas. Most originate in the epithelium or sheets of cells that cover the surface area of affected tissue. The application of cancer rehabilitation to several specific cancers will be discussed in future entries.

Age

It is said that age is the single biggest risk factor for cancer and while one can get cancer at any age, the highest rate occurs in decades 6-8. This fits with the view that cancer is a multistep process  with genetic mutations or alterations in our DNA which involves going from a less malignant to a more malignant and invasive disease. The longer our exposure to carcinogens the longer we live, genetic mutations and tumors taking years to develop, and the ability of our immune systems to combat cancer as we age are thought to create these changes.

What is Cancer?

Cancer is not a single or monolithic disease but rather a group of 200 plus diseases characterized by uncontrolled growth of abnormal cells resulting in malignant tumors. Distinct from a benign or encapsulated tumor, malignant tumors possess the ability to penetrate tissues or organs, and move or metastasize to other sites. Depending on its stage, grade and site of origin, cancers have the ability to seed to an adjacent area called seeding or to metastasize from a primary to secondary or distant sites by the vascular or lymphatic systems. Later stage cancers may effect the functioning of vital organs, upset the body's metabolic process, or create obstructions.