It details some possible causes for precancerous cells and how they may be treated. Precancerous cells are also called premalignant cells. They are defined as abnormal cells that could turn into cancerous cells, but which, by themselves, are not invasive or spreading. The concept of precancerous cells, and whether they progress or not, may sometimes be confusing. Sometimes precancerous cells progress to cancer, but more often they don't. They may stay the same—that is, remain abnormal but not invasive—or they may even become normal again.
This means that left alone, they will not spread to other regions of the body. They are simply abnormal cells that could, in time, undergo changes that would transform them into cancer cells. That said, not all precancerous cells need to be removed right away. Another point of confusion is that cancer cells and precancerous cells can co-exist. As an example, consider some people who are diagnosed with breast cancer. They have cancer cells present, but there may be other regions in the breasts and even in the tumor itself in which precancerous cells are found as well.
In many tumors, both malignant and premalignant cells are found. These cells are found in the skin and the lining tissue of many organs. This is in contrast to cancers, such as sarcomas, which begin in mesothelial cells. Some precancerous states include:. Precancerous cells are abnormal cells that may arise in the colon, the skin, and many other parts of the body.
They are not cancer cells, but neither are they normal cells. Most of these cells will not progress into a cancer. They have changed in ways that suggest it is possible, though, for a cancer to develop. The word "dysplasia" is often used to mean the same thing as "precancerous cells," yet there are a few differences. In many cases, when healthcare providers speak of dysplasia, they are indeed talking about these abnormal cells that could turn into cancer cells.
But in some cases, the term "severe dysplasia" is used to describe cells that are already cancerous. They are still contained within the tissues in which they began and have not spread. This is known as carcinoma in situ. Precancerous changes are usually described in degrees or levels of abnormality.
Severity and grade are the two main ways that are used to describe them. Dysplasia can range from mild to severe:. An example that might make this more clear is the cervical dysplasia found on some Pap smears. Cells that show a mild dysplasia rarely become cancer cells. There is a bit of confusion on where exactly to draw the line between severe dysplasia and carcinoma in situ. They have not spread.
Another way to describe how severe any precancerous changes in cells have become is by using a grading system. With cervical cells, these grades are usually used when a biopsy is done after finding dysplasia on a pap smear. An example of this would be low-grade dysplasia seen on a biopsy of the cervix. The likelihood of these changes progressing to cancer is fairly low. In contrast, high-grade colon dysplasia associated with colon polyps has a high risk of continuing on to become colon cancer.
Dysplasia describes physical changes in cells that are identified when they're seen under a microscope. These changes may be mild, moderate or severe. The changes also may be called low- or high-grade. The risk that these cells may become cancer cells is greater when they are found to be severe or show high-grade dysplasia.
There are quite a few factors that can cause cells to become precancerous. They vary depending upon the particular type of cells involved. In the past, researchers believed that the damage was done by carcinogens , or cancer-causing agents in the environment, that transform healthy cells into abnormal ones. Scientists who work in a field called epigenetics are now learning that the cells in our body are more resilient than that.
A host of factors, whether carcinogens or hormones or perhaps even stress, work together. The combination is what determines how abnormal changes in a cell may progress. One way of understanding causes is to look at the possible reasons for why damage may happen to healthy cells, leading to the genetic changes that in turn drive abnormal growth and development.
This figure is lower in the U. For example, a human papillomavirus HPV infection can cause inflammation, leading to precancerous cells in the cervix. HPV is also an important cause of dysplasia that may progress into head and neck cancers, such as tongue cancer and throat cancer.
Most HPV infections clear before any abnormal cell changes take place. If dysplasia does begin, it may go away on its own or with treatment. On the other hand, it also may progress to cervical cancer if it is not treated.
Another example is Helicobacter pylori H. This bacteria causes inflammation and can result in a condition called chronic atrophic gastritis. It may lead to precancerous changes in the lining of the stomach, which in turn may progress into stomach cancer. Chronic inflammation in tissue can lead to precancerous changes. An example is in people who have gastroesophageal reflux disease GERD for a prolonged period of time.
One important area of research is to learn whether or not removing areas of high-grade dysplasia caused by the condition will lower the risk of it turning into esophageal cancer. Another example is inflammation of the colon in people with inflammatory bowel disease IBD.
IBD can lead to polyps with colon dysplasia, which in turn can eventually lead to colon cancer. Chronic irritation from tobacco smoke , air pollution , and some industrial chemicals can result in dysplasia of the bronchi , the main airways into the lungs. If this is found early—during a bronchoscopy and a biopsy, for example—the precancerous cells may sometimes be treated with cryosurgery. It is a procedure for freezing these cells, meant to halt their growth before they have a chance to become lung cancer.
There are quite a few factors that may contribute to changes in precancerous cells. They include bacterial infection and chronic inflammation of tissues in the body. Irritation caused by environmental factors, such as smoking or chemical exposure, also may lead to abnormal cell changes.
A discussion of precancerous cell changes offers a good opportunity to talk about another concept that can be hard to grasp. This is called latency, and its role in the development of cancer. The latency period is defined as the period of time between exposure to a cancer-causing substance a carcinogen and the later development of cancer.
People are often surprised when they develop cancer many years after exposure to a carcinogen. For example, some people are diagnosed with lung cancer even when they quit smoking three decades earlier. Genetic damage is done when cells are first exposed to a cancer-causing agent. But it's usually an accumulation of this damage, and the genetic mutations involved over time, that causes a cell to become precancerous. The cell may then progress through stages of mild to moderate—and on to severe—dysplasia before finally becoming a cancer cell.
This progress toward cancer also may be limited by other factors in its environment, or it may even revert back into a normal cell. The process is much more complex than once thought, but understanding the basics does help to explain the latency period seen with many cancers.
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An abnormal Pap smear test does not mean you have cancer, but it could mean that you have precancerous cells or HPV. Laser therapies are medical treatments. Laser light is tuned to very specific wavelengths, allowing it to be focused into powerful beams.
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What causes cervical dysplasia? Are there risk factors for cervical dysplasia? Diagnosing cervical dysplasia. Treatment of cervical dysplasia. Can cervical dysplasia be prevented? Cervical Cancer Risk Factors. Read this next.
Although doctors have been able to screen for cervical cancer for more than half a century, it is the second leading cause of cancer deaths among women. Cervical cancer, or invasive cervical cancer, occurs when abnormal cells on the surface of the cervix spread deeper into the cervix, or to other tissues or organs. Cervical cancer occurs most often in women over the age of It is different from cancer that begins in other parts of the uterus and requires different treatment.
Most cervical cancers are squamous cell carcinomas and adenocarcinomas. Having multiple sexual partners, especially those who have had multiple partners themselves, can increase the risk, though sometimes people can develop the condition from exposure to just one partner. People with compromised immune systems, such as those with HIV, transplant recipients or those taking immunosuppression drugs, also are at higher risk. HPV infection and cervical dysplasia generally cause no symptoms.
Regular gynecological visits including a pelvic exam and Pap test can identify the conditions. Then your physician can help manage them before they turn cancerous.
In some cases, the body clears HPV infection on its own. Symptoms of cervical cancer usually do not appear until abnormal cervical cells become cancerous and invade nearby tissue. The most common symptom is abnormal bleeding that starts and stops between regular menstrual periods, or that occurs after sexual intercourse, douching, or a pelvic exam. Other symptoms may include:.
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