14. Breast Cancer Therapy May Cause Cavities

by H. W. Moss

Rampant tooth decay is a potential side effect of breast cancer therapy that is preventable with proper dental treatment during chemotherapy. However, few oncologists discuss this aspect of care with their patients and it is common to discourage dental work during chemotherapy.

Increased tooth decay is probably due to dry mouth which is a direct result of chemotherapy, although radiation caries are well known in medicine. Whatever the cause, the condition can be treated with fluoride, but because the patients themselves do not see a cause and effect, they rarely report the problem back to their doctors.

Dentists are familiar with the problem and a publication put out by the Dental Oncology Education Program in Austin, Texas, titled “Oral Health in Cancer Therapy” discusses the subject. But the booklet is meant primarily for health care professionals and deals with the effect all types of cancer therapy may have on the patient’s mouth.

Meanwhile, few oncologists believe a link between breast cancer therapy and tooth decay even exists.

Dr. Ernest Rosenbaum, a clinical professor at the University of California San Francisco and author of “Everyone’s Guide to Cancer Therapy,” said that in 40 years of practice he never heard of dental problems as a result of breast cancer therapy.

“I have not seen rampant tooth decay from chemo,” said Dr. Rosenbaum. “That does not mean it does not exist, I just have not seen it.”

Others say there is an obvious connection and it can be prevented.

“Patients are not aware of the relationship between their breast cancer therapy and tooth decay,” said Dr. Jeffrey Katz, a San Francisco dentist who frequently sees the problem. Dr. Katz believes the cancer support team should explain the problem and the prevention which is direct, frequent fluoride irrigation, fluoride pills or both. Dr. Katz said he believes there is a failure in the feedback loop.

“There’s a big barrier between oncological medicine and dentistry,” he said.

Dr. Richard Jordan, a specialist in oral pathology and oral medicine also at UCSF, said he could find no literature or studies on the subject, but said that chemotherapeutic drugs will cause dry mouth and may attack the saliva producing cells.

“The simple question is, do you have a dry mouth? Your teeth are still part of your body and teeth are often something people don’t worry about when they have more pressing issues they have to deal with,” Dr. Jordan said. “Patients need to be aware that their teeth are at risk. All of these side effects are completely preventable.”

Meanwhile, patients say they are not being told their teeth may rot.

“That was not one of the things they talked about,” said one breast cancer survivor who wished to remain anonymous. “They told me while you’re in the middle of chemo, you may not see the dentist. So if you have any time, try and get it done now.”

This patient knew she had a single cavity but could not have it repaired prior to beginning cancer treatment. Six weeks after chemotherapy, with radiation under way and surgery looming, she finally saw a dentist. She was alarmed to learn she now had six cavities, known as caries in the dental profession, and the one she was worried about could no longer be saved. It required a root canal. Worse news: her dentist did not want to work on her teeth while she underwent radiation therapy.

“It is entirely poor medical judgment to prevent a patient from seeing a dentist during chemo,” Dr. Katz said. “That is totally common and did not have to happen. It is absolutely unnecessary. That could have been monitored, treated and minimized with proper counseling and treatment.” Going one step further, Dr. Katz believes the dentist should be part of any breast cancer medical team from the beginning.

It is well known that left untreated, teeth will melt away in weeks after radiation therapy to the head and neck. Less well known is a link between chemotherapy and tooth decay, if there is one, but anecdotal evidence is mounting.

Janis Hoobler, library coordinator with the Health and Healing Library in San Francisco is a Hodgkin’s Disease cancer survivor who went through ten months of chemotherapy. She attributes her gum disease to that medication.

“I didn’t have a problem before chemo, I had the problem after chemo,” Hoobler said.

Alexandra Andrews, webmaster for cancerlynx.com and a cancer survivor who lives in Berkeley, said she had a considerable amount of tooth decay after surviving inflammatory breast cancer. She believes the link between tooth decay and cancer treatment is real, but the question is not being asked in follow up interviews with survivors.

“Nobody studied this,” said Andrews who was involved in two research projects, one on post breast therapy pain syndrome and one on lymphedema. “Do oncologists ask their patients about their teeth? Do patients tell them?” she pondered.

The down side of tooth decay can be deadly. Untreated dental caries lead to abscesses, root canals, loss of crowns, bridges, teeth and fillings. A variety of periodontal diseases including bone loss around the teeth may occur. Left untreated, people have died from dental abscesses.

“They never talk about tooth decay with cancer patients,” said Dr. Katz. He believes the subject should be right up there with a discussion of nausea and hair loss. “It is a known side effect of radiation therapy along with chemotherapy.”

Dr. Deborah Greenspan, an oral surgeon at UCSF School of Dentistry, said tooth decay can be due to diet changes as patients consume more sugar – perhaps without being aware they are doing so. However, she places the majority of the problem squarely on a condition known as xerostomia or dry mouth.

“There are over 100 drugs that can cause dry mouth and when that happens you can get a devastating type of dental decay,” said Dr. Greenspan. “Chemotherapeutic drugs are one group of drugs that cause this condition.”

If a patient has a cavity to begin with, it can easily spread to other teeth, she noted.

“Cavities are caused by bacteria which is passed from tooth to tooth,” said Dr. Greenspan. “So that first tooth infects all the others. Saliva is the way the mouth washes itself. Make sure you get fluoride.”

Dr. Katz recommends the proper use of oral or systemic fluoridation along with dietary considerations for cancer patients. “Fluoride,” he said. “Rinse with it, put it directly on the teeth with a tooth brush and/or take pills.”