Understanding the Cancer Process

Cancer is a group of many related diseases. These diseases begin in cells, the body’s basic unit of life. Cells have many important functions throughout the body.

Normally, cells grow and divide to form new cells in an orderly way. They perform their functions for a while, and then they die. This process helps keep the body healthy.

Sometimes, however, cells do not die. Instead, they keep dividing and creating new cells that the body does not need. They form a mass of tissue, called a growth or tumor.

Tumors can be benign or malignant:

• Benign tumors are not cancer. They can usually be removed, and in most cases, they do not come back. Cells from benign tumors do not spread to other parts of the body. Most important, benign tumors of the prostate are not a threat to life.
  

  >Benign prostatic hyperplasia (BPH) is the abnormal growth of benign prostate cells. In BPH, the prostate grows larger and presses against the urethra and bladder, interfering with the normal flow of urine. More than half of the men in the United States between the ages of 60 and 70 and as many as 90 percent between the ages of 70 and 90 have symptoms of BPH. For some men, the symptoms may be severe enough to require treatment.

• Malignant tumors are cancer. Cells in these tumors are abnormal. They divide without control or order, and they do not die. They can invade and damage nearby tissues and organs. Also, cancer cells can break away from a malignant tumor and enter the bloodstream and lymphatic system. This is how cancer spreads from the original (primary) cancer site to form new (secondary) tumors in other organs. The spread of cancer is called metastasis.

When prostate cancer spreads (metastasizes) outside the prostate, cancer cells are often found in nearby lymph nodes. If the cancer has reached these nodes, it means that cancer cells may have spread to other parts of the body — other lymph nodes and other organs, such as the bones, bladder, or rectum. When cancer spreads from its original location to another part of the body, the new tumor has the same kind of abnormal cells and the same name as the primary tumor. For example, if prostate cancer spreads to the bones, the cancer cells in the new tumor are prostate cancer cells. The disease is metastatic prostate cancer; it is not bone cancer.

brain cancer

Brain cancer is a disease of the brain where cancer cells (malignant) grow in the brain tissue. Cancer cells grow to form a mass of cancer tissue (,tumor) that interferes with brain tissue functions such as muscle control, sensation, memory, and other normal body functions. Tumors composed of cancer cells are called malignant tumors, and those composed of noncancerous cells are called benign tumors. Cancer cells that develop from brain tissue are called primary brain tumors. Statistics suggest that brain cancer is not rare and is likely to develop in about 20,000 people per year.

What is metastatic brain cancer?

Cancer cells that develop in a body organ such as the lung (primary cancer tissue type) can go to other body organs such as the brain. Tumors formed by such cancer cells that spread (metastasize) to other organs are called metastatic tumors. Metastatic brain cancer is a mass of cells (tumor) that originated in another body organ and has spread into the brain tissue. Metastatic tumors in the brain are more common than primary brain tumors.

What causes brain cancer?

Primary brain tumors arise from many types of brain tissue (for example, glial cells, astrocytes, and other brain cell types). Metastatic brain cancer is caused by the spread of cancer cells from a body organ to the brain. However, the causes for the change from normal cells to cancer cells in both metastatic and primary brain tumors are not fully understood. Data gathered by research scientists show that people with certain risk factors (situations or things associated with people that increase the probability of developing problems) are more likely to develop brain cancer. Individuals with risk factors such as having a job in an oil refinery, as a chemist, embalmer, or rubber-industry worker show higher rates of brain cancer. Some families have several members with brain cancer, but heredity as a cause for brain tumors has not been proven. Other risk factors such as smoking, radiation exposure, and viral infection (HIV) have been suggested but not proven to cause brain cancer. There is no good evidence that brain cancer is contagious, caused by head trauma, or caused by cell phone use.

What are the symptoms of brain cancer?

The most common symptoms of brain cancer are weakness, difficulty walking, seizures, and headaches. Other common symptoms are nausea, vomiting, blurry vision, or a change in a person’s alertness, mental capacity, memory, speech, or personality. These symptoms can also occur in people that do not have brain cancer, and none of these symptoms alone or in combination can predict that a person has brain cancer. A few brain cancers produce few or no symptoms.

What tests are used to diagnose brain cancer?

The initial test is an interview and physical examination of the person by a competent health-care provider. The results of this interaction will determine if other specific tests need to be done.

The most frequently used test to detect brain cancer is a CAT scan (computed automated tomography or CT). This test resembles a series of x-rays and is not painful, although sometimes a dye needs to be injected into the vein for better pictures of some internal brain structures. Another test that is gaining popularity because of its high sensitivity for detecting anatomic changes in the brain is MRI (magnetic resonance imaging). This test also resembles a series of x-rays and shows the brain structures in detail better than CT. MRI is not as widely available as CT scanning. If the tests show evidence (tumors or abnormalities in the brain tissue) of brain cancer, then other doctors such as neurosurgeons and neurologists that specialize in treating brain ailments will be consulted to help determine what should be done to treat the patient. Other tests (white blood cell counts, electrolytes, etc.) are likely to be ordered by the health-care giver to help determine the patient’s state of health or to detect other health problems.

treatment.

What is the treatment for brain cancer?

A treatment plan is individualized for each brain cancer patient. The treatment plan is constructed by the doctors who specialize in brain cancer, and treatments vary widely depending on the cancer type, brain location, tumor size, patient age, and patient’s general health status. A major part of the plan is also determined by the patient’s wishes. Patients should discuss treatment options with their health-care providers.

Surgery, radiation therapy, and chemotherapy are the major treatment categories for most brain cancers. Individual treatment plans often include a combination of these treatments. Surgical therapy attempts to remove the tumor by cutting it away from normal brain tissue. Radiation therapy attempts to destroy tumor cells by using high energy radiation focused onto the tumor. Chemotherapy attempts to destroy tumor cells using chemicals (drugs) that are designed to destroy specific types of cancer cells. All treatments attempt to spare normal brain cells.

Other treatments that may be part of some treatment plans may include hyperthermia (heat treatments), immunotherapy (immune cells directed to kill certain cancer cell types), or steroids to reduce inflammation and brain swelling. Clinical trials (treatment plans designed by scientists to try new chemicals or methods on patients) can be another way for patients to obtain treatment specifically for their cancer cell type.

The best treatment for brain cancer is designed by the team of cancer specialists in conjunction with the wishes of the patient.

What are the side effects of brain cancer treatment?

Side effects of brain cancer treatment vary with the treatment plan and the patient. Most treatment plans try to keep all side effects to a minimum. For some patients, the side effects of brain cancer treatment can be severe. Treatment plans should include a discussion of potential side effects and the likelihood of them developing, so the patient and their caregivers (family, friends) can make appropriate treatment decisions in conjunction with their medical team. Also, if side effects develop, the patient has some knowledge of what to do about them such as when to take certain medicines or when to call their doctor to report health changes.

Surgical side effects include an increase in current symptoms, damage to normal brain tissue, brain swelling, and seizures. Other changes in brain functions such as muscle weakness, mental changes, and decreases in any brain-controlled function can occur. Combinations of these side effects may happen. The side effects are most noticeable shortly after surgery but frequently decline with time. Occasionally, the side effects do not decline.

Chemotherapy usually affects (kills) rapidly growing cancer cells but also can affect normal tissue. Chemotherapy is usually given intravenously so the drugs can reach most body organs. Common side effects of chemotherapy are nausea, vomiting, hair loss, and loss of energy. The immune system is often is depressed by chemotherapy, which results in a high susceptibility to infections. Other systems, such as the kidneys and the reproductive organs, may also be damaged by chemotherapy. Most of the side effects decline over time, but some may not.

Radiation therapy has most of the same side effects as chemotherapy. Most radiation therapy is focused onto the brain cancer tissue, so some systems do not receive direct radiation (immune system, kidneys, and others). The effects on systems not receiving the direct radiation are usually not as severe as those seen with chemotherapy. However, hair and skin are usually affected, resulting in hair loss (sometimes permanently) and reddish and darkened skin that needs protection from the sun.
What is the prognosis (outcome) of treated brain cancer?

Survival of treated brain cancer varies with the cancer type, location, and overall age and general health of the patient. In general, most treatment plans seldom result in a cure. Survival greater that five years, which is considered to be long-term survival, is less than 10% no matter what treatment plan is used.

So, why use any treatment plan? Without treatment, brain cancers are usually aggressive and result in death within a short time span. Treatment plans can prolong survival and can improve the patient’s quality of life for some time. Again, the patient and caregivers should discuss their prognosis when deciding on treatment plans.