Q: I am 48 and was diagnosed with breast cancer in 2006. I had a mastectomy and chemotherapy. I’ve always had canker sores, but after my cancer treatment I had a mouthful of them and continue to get many at a time. Most of them are on my tongue and the roof of my mouth. What causes them? Is there a test to see what I am lacking in my body that keeps them coming back? Is there treatment?
A: Canker sores (aphthous ulcers) are very common, particularly in women. Many factors can cause canker sores, including chemotherapy and vitamin deficiencies, as well as the hormonal changes of menstrual cycles. There are some self-care steps you can take that may help decrease the frequency of canker sores. But, I’d also recommend you get a dental check-up and see your doctor to investigate the cause of your canker sores.
Canker sores are small, shallow lesions that develop on the soft tissues in your mouth — usually under your tongue, inside your cheeks or lips, and at the base of your gums. Chemotherapy attacks cells that grow rapidly, mainly cancer cells. Because the tissue lining of your mouth also has a high cell turnover rate, chemotherapy can affect it, too, making that area prone to sores during cancer treatment.
To decrease the likelihood that they will develop mouth sores when undergoing chemotherapy, I advise patients to stay away from substances that can injure the mouth’s sensitive lining. These substances include alcohol and tobacco products, as well as food and beverages that are extremely hot, cold or high in acidity. They also need to be careful not to put anything rough or sharp into their mouth. Even though you’re finished with your cancer treatment, these guidelines may also be helpful in your situation.
Practicing good oral hygiene may reduce canker sores, too. It would be a good idea to see your dentist for a thorough dental exam. In some cases, mouth sores may be a sign of a dental infection or another mouth abnormality.
In addition, talk to your doctor about testing your body’s level of vitamin B12. Some research has shown that people who are vitamin B12 deficient are more likely to have more frequent and larger numbers of canker sores. If your B12 level is low, taking a vitamin supplement or increasing B12 in your diet by eating more fish, shellfish, meat and dairy products may reduce canker sores.
Studies have shown that garlic and zinc can also be helpful for people who have frequent canker sores. Both are available in over-the- counter tablets. Ask your doctor if these may be right for you.
Although canker sores are bothersome, the good news is that they aren’t serious, and rarely are they a sign of an underlying medical condition. Some people who have frequent canker sores worry that there may be something wrong with their immune system. The immune system changes that can lead to an increase in canker sores are often relatively mild and typically don’t affect a person’s overall health.
To decrease the number and frequency of canker sores you have, try the self-care steps outlined above, go to the dentist, have your B12 level checked and, in conjunction with your doctor, consider over-the- counter remedies that may be helpful.
Dr. Judith Kaur is an oncologist at Mayo Clinic, Rochester, Minn. Write to: medicaledge@mayo.edu.
