Condensed Overview of cancer
Cancer develops from genomic lesions (mutations) to cells that lead to abnormal growth and persistence of cells (malignant behavior).
Mutations can lead to épigénomiques changes that activate or deactivate specialized genes that would protect the cell from becoming a cancer or being detected by the immune system.
* Lymphomas are highly susceptible to chemotherapy and classical radiation therapy, which work by damaging the DNA of cells in rapid division causing cells to initiate programmed cell death.
Targeted approaches to cancer treatment include:
1) by inhibiting the pathways of the cell that are activated by mutations that lead to malignant behavior
2) by activating genes that have been silenced, or by disabling hyperactive genes – called epigenetic treatments
4) by targeting cell surface antigens that are expressed only on lymphocytes, such as CD20 (Rituxan), CD19, CD22, CD30.
5) by inhibition of how corrupted cancer cells or hack the host system, such as the immune system or the blood supply.
Why lymphoma is generally more sensitive than the treatment of other cancers
Lymphoma comes from immune cells that fight the infection called lymphocytes. Normal lymphocytes reproduce and increase in number, in response to an infection. We feel bad during infections because of this activity and the inflammation that arises. When the work is done, the infection stunned, the lymphocytes die so as not to interfere with the function of the organs and we begin to feel better too.
Lymphoma is similar to a normal reaction to an infection, but a reaction that is not extinguished. Defective immune cells continue to persist and divide, even if no infection led. (with some notable exceptions, like H-pylori positive MALT)
A reason lymphoma is very susceptible to chemotherapy and radiation therapy is that normal cells of this type have a fundamentally short life span that they are built for rapid replication, but also to die quickly.
The immune cells of this type are intrinsically chemo-and radiation-sensitive as evidence by how our normal lymphocytes figures pricked the nose during chemotherapy unlike most other cell types in our Body. Importantly, these important cells emerge again from stem cells that rarely divide and are not affected by the types and doses of chemotherapy or standard radiotherapy. In a few weeks or more, the normal lymphocytes needed to protect us from infection by rebound to normal levels.
In the news:
In normal tissues, the rates of new cell growth and old cell death are maintained in equilibrium.
In cancer, this balance is broken. This disturbance may result from uncontrolled cell growth or loss of a cell's ability to undergo "apoptosis."
Apoptosis, or "Cell suicide," is the mechanism by which old or damaged cells normally self-destruct. "
Lymphomas are often very sensitive and susceptible to different treatments.
Aggressive lymphomas are often cured and indolent lymphomas are often well managed when treatment is indicated.
Importantly, recent advances in the understanding of lymphoma have led to new effective therapies.
Classification Organization of neoplastic Diseases World Health
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Simplified lymphoma-how it starts
Our body is made of many cells of several types. Cells have specialized jobs and names, such as skin, nerves, heart, lungs, blood, immune cells, and so on. For the human body to function normally, each organ must have a certain number of cells.
By design, the cells in most organs have a short life span. Therefore, to continue to operate the body needs to replace these cells lost by the process of cell division.
cell division and cell death are controlled by genes found in the cell nucleus. The genes work as an instruction manual indicating the cell what proteins to do. These proteins, in turn, control the behavior of the cell.
Some proteins direct the cell to divide; Others how long it will live; and others begin cell death – a normal process by which the body gets rid of old, useless, or damaged cells.
Under normal conditions there is a balance in which the new cells replace old, and each cell performs specific tasks of its kind: cardiac cells pump, stomach cells produce acids, cells Immunes recognize the invaders and kill them, and so on. The scale ensures that the organs and systems work properly and meet the needs of the body.
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The onset of cancer
In any cell state, the genetic code can be damaged so that the instructions contained in the "manual " are modified to produce types and amounts of abnormal proteins that can lead to abnormal cell behavior.
Instead of resting, the cells may continue to divide; Instead of dying the cells stay alive. Mutations can also disable genes that can repair damaged DNA, or that can induce cell death when mutations in the cell are detected. See also tumor suppressor genes
Lymphocytes are very active cells, which undergo many normal transformations in their life cycle and many more cell divisions than most other cell types. They are designed to divide quickly to treat infections, but also die quickly when the infection is under control.
Cell division, being a very complex process, is prone to errors. Errors may not be "picked up " or can often be inconsequential. The defective or atypical cell will not necessarily lead to cancer, however. Additional errors must occur. Before it becomes a cancer the parent cell divides repeatedly, passing on defects that have a malignant potential to the children's cells. Additional "Strokes" on atypical cells may result from exposure to chemicals, viral infections, oxidation, random errors.
For example: an atypical (slightly defective) lymphocyte can remain active longer because of chronic stimulation by a bug or virus (chronic infection being associated with an increased risk of contracting lymphoma) – making errors in Additional random copy more likely to occur.
The first cell to lose control of normal growth is called the original cell. When the original cell divides, the new cells inherit the genetic defects of the parent cell. Thus, in cancer, the descendants of the original cell are clones of this cell.
One characteristic of cancer cells is that they show benefits of growth and survival on normal cells. Cell division is not balanced by cell death. Abnormal cells can eventually form lumps called tumors.
The word tumor simply means a mass of cells. Tumors can be either benign or malignant. Benign tumors are not a threat to life or long-term health, while malignant tumors are. The word means "malignant" showing great malignancy and being willing to do evil. A way that pathologists identify a tumor as malignant is if the cells inside, there is clonal – all identical to the original cell. On the other hand, benign tumors are composed of related but different cells.
The characteristics of cancer cells include:
Limitless potential to divide and develop
The recruitment of normal cells that contribute to the acquisition of traits by creating the stamp "tumor microenvironment. " *
Note: lymphomas are considered systemic cancers, because both normal and abnormal lymphocytes (the original cell) have the ability to migrate throughout the body to fight infection. So finding lymphoma cells in the bone marrow or spleen is not uncommon, and not considered a metastasis.
This report added emerging features: 1) reprogramming of energy metabolism and 2) evade immune destruction.
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Lymphoma is a type of blood cancer
Blood is a liquid made up of plasma and many types of blood cells, such as red cells (erythrocytes), white blood cells (leukocytes) and platelets. Blood flows through the heart, arteries and veins. It carries "food, hormones, vitamins, antibodies, heat and oxygen to the body tissues."
Cancers B-cell per cell maturation Stage – click to enlarge
Lymphoma is a cancer that affects a type of white blood cells, the lymphocytes of the immune cells that normally protect against the disease. About 85% of the lymphomas are of the origin of B cells and 15% of the origin of T cells.
B cells originating and mature (differentiate) in bone marrow.
T cells also begin in the bone marrow, but they differ and mature in the thymus gland.
Natural killer cells are a third type of lymphocytes. They specialize in destroying foreign cells and perhaps signaling to alert other invading immune cells.
leukocytes – click to enlarge
The different types of lymphoma are determined depending on what type of lymphocyte became cancerous and the stage of development. Click on cell cancers B by developing cells to enlarge the above illustration.
As with other cancers, the root cause of lymphomas is damage to genes that lead to abnormal (deregulated) growth controls in the cell.
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Lymphomas are a family of related cancers.
The original cell determines the lymphoma subtype, and influences its clinical behaviour – growth rate and treatment sensitivity.
The original cell. such as T lymphocytes, B cells and NK cells, and stage of maturation of this cell determines the type of lymphoma. This is often referred to as the cell type or diagnosis. such as small cleaved follicular lymphoma.
When a lymphocyte becomes malignant, its biological behavior is stopped at this stage. This stage of development of its influence location trends and growth rates and other cellular behaviors.
Analogy: Consider that just as children grow faster than adults, cells at early stages of development tend to grow faster than they do at mature stages.
Malignant cells can then accumulate to form tumors that increase the lymph nodes or spread to other areas of the lymphatic system, such as the spleen or bone marrow, or outside the lymphatic system to the skin, Mucous membranes or linings of the stomach.
What is the extent of the lymphoma is, is summarized by the step. Staging is the process of determining where lymphoma is located by imaging and other methods.
NOTE: It is common for lymphoma to be at stage IV at the time of diagnosis. But, the advanced stage of the disease does not mean that the treatments will not be effective.
About growth rate. The original cell will also influence the speed or slow down the lymphoma cells tend to grow. The trend of growth lymphoma is also called quality.
Aggressive grade lymphomas ivide and grow rapidly, and therefore fast and aggressive treatment is indicated.
Indolent grade lymphomas may not divide faster than normal lymphocytes. Here, the malignant behavior can be cell death resistance – a default of "clear " itself after it's normal functions have been accomplished. The result is a slow accumulation of excess cancer cells causing tumors to form, but more slowly.
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Mutations also influence clinical behaviour
Damage to specific DNA – and gene expression – is likely to be variable for patients with the same diagnosis.
These differences may explain, in part, why patients with the same diagnosis may have lymphomas that develop at different rates and respond differently to the same treatments.
Remember that the expression of genes determine which proteins the cells express and that determines the behavior. The response to treatment is also cellular behavior. For example, treatment-induced DNA damage detection cells will initiate cell death, but only if the genes that can activate the cell death program are functioning or activated by treatment.
"Ultimately, it may well be that the optimal treatment will be determined by the clinical and biological characteristics of the patients."
Dr. Bruce Cheson – Progress in the treatment of non-Hodgkin's lymphoma – Medscape (free connection)
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Your lymphoma is unique
Factors that can explain clinical differences in lymphomas:
Cell type: T cells, B cells, NK cells, and subtypes of each;
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