A new tumour can start to grow in the same area of the body where the cancer first started, or the cancer may have spread through the blood or lymphatic system to another part of the body, where it grows into a new tumour. This is why doctors sometimes use another treatment right after the first treatment, such as giving chemotherapy after surgery. This is called adjuvant therapy.
The goal of adjuvant therapy is to help prevent the cancer from coming back in case some cancer cells are left behind in the body.
In some cases, treatment may stop working become resistant so cancer cells are no longer being destroyed. So cancer that was shrinking or had disappeared may start to grow again and get bigger. This can happen when the genes inside cancer cells mutate. Some gene mutations make cancer cells resistant to chemotherapy and other drug treatments.
If you become resistant to a treatment, your doctor may suggest that you try another one. Many cancers can be cured with treatment.
But cancer that is thought to be cured can still come back even years later. This is why some doctors prefer to say that the cancer is in remission.
Remission means there are fewer signs and symptoms of a disease such as cancer or that they have completely gone away. Home Cancer information What is cancer? How cancer starts, grows and spreads. See topics What is cancer? Types of cancer Human body Immune system Lymphatic system Blood and bone marrow Endocrine system and hormones Female sex organs and reproductive system Male sex organs and reproductive system How cancer starts, grows and spreads Types of tumours Genes and cancer Stage and grade Prognosis and survival What causes cancer?
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A cancer diagnosis often causes a lot of anxiety and can affect a person's entire life. There are many resources for cancer patients. The outlook varies greatly for different types of tumors.
If the tumor is benign, the outlook is generally very good. But a benign tumor can sometimes cause severe problems, such as in or near the brain. If the tumor is cancerous, the outcome depends on the type and stage of the tumor at diagnosis. Some cancers can be cured. Some that are not curable can still be treated, and people can live for many years with the cancer.
Still other tumors are quickly life threatening. Burstein E. Cellular growth and neoplasia. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. Philadelphia, PA: Elsevier; chap 1. National Cancer Institute website. Symptoms of cancer. Updated May 16, Accessed July 12, Cancer genetics and genomics. But her feet hurt, too, so Elliott decided to play it safe and called her doctor, who suggested she come in for some tests.
Days later the marketing professional learned that she had developed an uncommon form of blood cancer called chronic myelogenous leukemia CML.
Normally these stem cells give rise to various blood cells in the body. The defect caused the stem cells and their progeny to produce an abnormal enzyme known as Bcr-Abl. This enzyme signals the marrow to produce too many immature white blood cells and allows them to persist longer than they should.
Once these abnormal cells enter the bloodstream, they can also cause the spleen to swell and damage other organs. CML usually starts off being fairly innocuous, especially if treated. It can, however, become aggressive and lethal if left untreated. To keep her disease in check, Elliott takes a bright yellow pill daily.
The medication, called imatinib sold under the brand name Gleevec , binds to the abnormal enzyme and shuts off the proliferation signal. Without this enzyme, the extra white blood cells mature normally and die as they should.
Indeed, a recent study suggests that CML patients who live at least two years after starting imatinib treatment can look forward to a normal life span. But the pill is not a cure. If she stops taking her medication, the cancer will return. An alternative hypothesis has recently gained traction; if it proves to be more accurate, physicians may need to adjust their therapeutic approaches, targeting their treatments to destroy particular subsets of cells within the tumor.
Two Models Oncologists have long worked under the assumption that most tumors develop from a single cell. After a series of genetic mutations, which occur as a result of exposure to radiation, cigarette smoke, dietary choices or a genetic predisposition, this single cell begins to divide uncontrollably into more cells.
Each succeeding generation of cells accumulates more genetic mistakes that make the tumor grow bigger, invade local tissues and eventually spread metastasize to other parts of the body. The alternative view proposes that only a handful of the cells in a tumor—known as cancer stem cells—have the ability to grow uncontrollably and spread.
These cells renew themselves indefinitely essentially making close duplicates of themselves and also give rise to a mix of cells having different properties and a finite life span. In this way, cancer stem cells resemble the normal stem cells sprinkled throughout the body that replace old or damaged tissues, such as skin or the lining of the intestine.
Unlike normal stem cells, however, cancer stem cells ignore any and all chemical signals that tell them to stop dividing. According to this alternative conception, most cells in the tumor will eventually die and so should be less dangerous.
The few stem cells in the tumor, however, would be particularly deadly: if even a single cancer stem cell survived the initial therapy, it could give rise to a whole new tumor weeks, months or even years later.
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