Precancerous cells are cells with an abnormal appearance suggestive of an increased cancer risk. These cells are not cancerous themselves, but can precede the development of cancer. When a patient has precancerous cells, they are an indicator that the patient should be monitored carefully in the future. Consistent screening and monitoring will help a doctor identify cancer early, if it shows up, allowing for prompt provision of treatment. Precancerous cells can also indicate the need for prophylactic treatment to prevent the appearance of cancer.
Such cells are identified in the laboratory by analyzing a sample of cells from the patient's body. A doctor may take a cell biopsy if physical changes have been observed and there is a concern about cancer, or a biopsy may be taken as part of a routine medical screening like a Pap test for women. A lab technician will look at the cells under a microscope, examining them for signs of abnormalities.
Precancerous cells are not normal in appearance, but they are also not invasive. The cells have arisen from cells naturally present in the area where the biopsy was taken, and are usually older cells that are not dying or are dividing in unexpected ways. The abnormal cell growth is not spreading, and does not carry a risk of appearing in other parts of the body. A cell abnormality is often seen when people have infections, inflammation, or irritation, and precancerous cells are often linked with chronic irritation.
If abnormal cells are identified in a biopsy sample, a doctor may request a repeat test to confirm or follow up. In addition, the patient will be interviewed to see if there is an explanation. For example, if a patient recently had a yeast infection, some abnormal cells might be expected on a Pap because of the associated inflammation and irritation, and the cells might not be a cause for concern. If there is no clear reason for abnormal cells to be present, the cells will be treated as precancerous.
Recommendations for patients with precancerous cells can include a wait and see approach to check for changes, along with recommendations for increased frequency of screenings and tests. If the patient's future tests come up clean repeatedly, screenings can be stepped back to a more normal frequency. Another option can be prophylactic treatment to kill cancer cells before they have a chance to spread, like a prescription for tamoxifen offered to a woman with precancerous cells in her breast.