| Side Effects of Breast Cancer Treatments Not Properly Recorded LONDON, ENGLAND -- August 13, 2001 -- The side effects of breast cancer treatments are not being properly recorded, say researchers from The Cancer Research Campaign, and experts are asking how patients can make an informed decision about their treatment if they don't know the full effects it can have. Hormonal therapies, like tamoxifen and goserelin (Zoladex), tend to be viewed as a gentler option for patients. But a new study in Breast Cancer Research and Treatment (66:73-81, 2001) has exposed a wide variation in the numbers of women who experience side effects, and the kinds of symptoms they have. The team of researchers carried out an investigation as part of a wider study of tamoxifen and goserelin as adjuvant treatments for breast cancer. They interviewed 75 breast cancer patients taking one or both treatments, and compared the symptoms they reported with those recorded in their medical notes. "The results were striking," says Professor Lesley Fallowfield of the Royal Free and University College Medical School, one of the lead researchers. "We found that the symptoms in the medical notes often varied considerably from those described by the patients. Eighty-nine percent of women had some kind of side effect recorded in their medical notes. But 99 percent of women told us in interviews that they'd experienced symptoms as a result of therapy." "Clearly some side effects are being overlooked. And that could well be because our over-stretched cancer doctors simply don't have the time to spend listening to their patients about how they are feeling," added Dr. Fallowfield. There was a significant difference between the frequency of self-reported and clinician-recorded symptoms. A massive 91 percent of women believed their treatment caused hot flushes, but only 47 percent of medical records noted this. Eighty percent of women said they gained weight, but this was only listed in 21 percent of the medical notes. A literature review of published side effects backed up the group's findings. Studies tended to focus on specific and uncommon symptoms experienced by individual women, rather than detailing all the side effects for a wider group. At the same time, the severity of the symptom was often ignored completely. Dr. Fallowfield thinks that part of the problem could be attributed to terminology. "Some patients don't have a clear idea of what counts as a side effect," she says. "In at least one case the interviewee told us she hadn't had any side effects, but when we showed her a list of common symptoms she found she'd had several of them. And while a patient might say that she felt 'weepy' or 'irritable', a doctor would probably describe this as 'anxiety' or 'depression'. It can lead to confusion." "We also think that with rarer side effects, like vaginal dryness or loss of libido, there is an element of self-fulfilling prophecy. Clinicians are less likely to enquire about less common symptoms, and patients only mention them if asked. The side effects appear to be rarer than they are. We need to train our doctors in communication skills, and make sure that cancer patients aren't suffering in silence," Dr. Fallowfield concludes. According to Jean King, The Cancer Research Campaign's Director of Education Funding, "Worldwide, hundreds of thousands of women are prescribed hormone therapies for breast cancer every year. So it's extremely important that doctors and patients have a clear and comprehensive profile of the side effects. This study's findings have implications for the treatment of all cancers. It's vital that side effects of all drug therapies are accurately monitored. Otherwise, how can we compare new drugs in clinical trials with existing treatments? And how can a cancer patient make an informed choice about which treatment is best for them?" |
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| New Pink & White M&M's The maker of M&M candies has teamed up with the Susan G. Komen Breast Cancer Foundation to raise funds through the sale of their new "pink & white" M&M candies. |
| Antibiotic Use Linked to Breast Cancer Risk?
C. Velicer et al. Journal of the American Medical Association, February 18, 2004 Other Articles in this Edition March 2004 Research News Antibiotic Use Linked to Breast Cancer Risk? Negative Hormone Receptor Status Linked to Good Response to Chemo Before Surgery Abortion Does Not Increase Breast Cancer Risk Background and importance of the study: Antibiotics are among the most common medications prescribed by doctors for the past 50 years. These drugs treat infections caused by bacteria and other microorganisms—living things so small you need a microscope to see them. Antibiotics are regularly prescribed for acne and infections of the ears, throat, and sinuses. They are also very effective in treating serious conditions like pneumonia (lung infection) and meningitis (infection in the lining of the brain). Since they were discovered in 1929, antibiotics have saved countless lives. But in recent years there has been increasing concern about over-use of antibiotics. For example, in many cases these drugs are prescribed for conditions that they can't help, like flu, which is caused by a virus. If you've been miserable with a bad cold or flu, you can easily understand why antibiotics might be given frequently—even before it's clear that your condition is due to a bacterial infection. You're feeling sick, but you drag yourself out to the doctor's office. You want to leave there with something to do or take that could make you feel better. Some patients ask for—and even demand—antibiotic medicine. And if pushed, many doctors will go along with the patient's wishes. You might be thinking, "Well, there's no harm done if I get an antibiotic 'just in case.' " But when antibiotics are used a lot for conditions they can't treat (or when people don't complete the full course of their antibiotic treatment), the bacteria that the medicine is supposed to kill develop a resistance. This means that the next time you get antibiotics for a bacterial infection, the treatment might not be as effective. And in the overall population, this means that there are more types of bacteria that do not respond to many common types of antibiotics. As a result of these concerns, many doctors are now trying to prescribe antibiotics more carefully. Still, for certain conditions, some people do need to take antibiotics for long periods of time. In recent years there has also been concern about whether antibiotics, while curing numerous conditions, might also increase people's risk for other diseases. Specifically, researchers have wondered whether there might be a link between antibiotic use and cancer risk. Here's why: Some antibiotics interfere with the body's ability to absorb cancer-protective substances from the food we eat. Tetracycline and some other antibiotics increase the body's production of substances called prostaglandins. These substances increase the body's immune response. And this leads to the production of chemicals that are THOUGHT (not proven) to increase cancer risk. (One study found that when women suppressed these chemicals regularly with drugs such as ibuprofen, their breast cancer risk decreased.) A Finnish study published in 2000 found that women who took antibiotics for urinary tract infections had a greater risk of breast cancer than women who did not have infections and did not take antibiotics. But the study had many drawbacks. It looked at only a few antibiotics, and it included no information on how long the women took the drugs. The researchers in this study set out to look more closely at the possible link between antibiotic use and breast cancer risk. Study design: Researchers from Seattle, Wash., and from the National Cancer Institute in Washington, D.C., looked at medical and pharmacy records of women enrolled in a large health plan in Washington State. The records showed all the prescriptions the women had filled over a 20-year period. They also showed what diseases the women had been treated for, including breast cancer. Using these records, the researchers were able to compare the antibiotic use of two groups of women: 2,266 who had been diagnosed with invasive breast cancer, and 7,953 who had never had the disease. As much as possible, the researchers made sure that the women in the two groups were similar in: age, level of education, race, number of children, and how long they had been enrolled in the health plan. When the researchers compared the two groups, they tried to adjust their findings to account for differences in other factors that can also influence breast cancer risk, including: age of first menstruation (when the women first got their period), obesity, family history of breast cancer, use of hormones (birth control and hormone replacement therapy after menopause), age when the women first gave birth, menopausal status, and age at menopause. They used the medical records to try to find this information for as many of the women as possible. But what if breast cancer risk was linked to the specific diseases the antibiotics were treating, and not to the drugs themselves? To account for this possibility, the researchers looked at two groups of women who took the same antibiotics for the same amount of time—but to treat different conditions: acne and respiratory infections. The researchers then compared the breast cancer rates in these two groups. Study results: The researchers got fairly complete records on the amount of antibiotics women used, on whether women got breast cancer and the stage of their disease, and on how long they were enrolled in the health plan. Then they went to work putting all of the calculations together to see if there was any possible connection between using antibiotics and getting breast cancer. It's important to note that the researchers couldn't get complete records on a number of proven (not just possible) risk factors for breast cancer. About 20% of the women's medical charts did not have full information on the following proven risk factors: family history of breast cancer, age of first menstruation, obesity, and age at first birth. For about 13% of the women, the researchers could not find complete information about use of hormone replacement therapy. The researchers also did not have complete information about race or educational background for over 50% of the women. Although these factors may not be directly linked to breast cancer risk, they might affect the results of this study. For example, they might affect how often the women got sick and needed antibiotics, how regularly they got screened for breast cancer, and other health-related factors that could be related to both antibiotic use and breast cancer risk. When they analyzed all the information they were able to gather, the researchers found that the more antibiotics women used, the greater their breast cancer risk was. Over an average 17-year period, women who took antibiotics for more than 500 days, or had more than 25 antibiotic prescriptions, had more than twice the risk of breast cancer as women who had not taken any antibiotics. The risk increase was smaller for women who took antibiotics for fewer days. Women who had between 1 and 25 prescriptions during the same 17-year average period were, on average, 1.5 times more likely to be diagnosed with breast cancer than women who took no antibiotics. If, for example, the average risk of getting breast cancer over the study period was 5%, then increasing it by 1.5 times means a risk of 7.5%. The researchers consistently found this increased risk for all types of antibiotics used. Women who took the same antibiotics for the same amount of time had about the same risk of breast cancer, even when they took these drugs to treat different conditions. Conclusion: This study found that using antibiotics more was linked to an increased risk of breast cancer. But the researchers emphasized that their study did not show that antibiotics CAUSE breast cancer. It's possible that women who take more antibiotics have weakened immune systems that puts them at a higher risk for different diseases, including infections and breast cancer. If that were the case, it could be weakened immune systems that are connected to increased breast cancer risk, NOT taking antibiotics. The researchers also noted that the medical records they used did not have complete information on different breast cancer risk factors for many of the women. They couldn't completely rule out that differences in risk factors, and not differences in antibiotic use, might explain the results. For example, maybe women who are more likely to take medicine for infection (antibiotics) are also more likely to take medication for menopausal symptoms (hormone therapy with estrogen and progesterone). Reliable research has shown that women who take hormone therapy for an extended period have an increased risk for breast cancer. If women who take hormone therapy are also more likely to use antibiotics, and if you only have complete information on the antibiotic use, then you might jump to the conclusion that antibiotics increase the risk of breast cancer. But the more correct conclusion is that the increased breast cancer risk is connected to the use of hormone therapy. It's also important to remember that this was a "retrospective" study. This means that the study looked at women who already had breast cancer and tried to find connections between the cancer and other factors in the women's lives. This type of study is much less reliable than a "prospective" study, in which two or more groups are followed BEFORE developing the disease to see how a particular factor affects how many women in each group will get it. Take-home message: At first glance, this study's findings can seem very scary. After all, so many of us have taken antibiotics over the course of our lives, and we give them to our children and other family members. But it's important to remember that this study did NOT show that antibiotics cause breast cancer. As the researchers pointed out, the women who took a lot of antibiotics may have had weaker immune systems or other factors that made them more prone to breast cancer than the women who did not take antibiotics. So far, no research has shown that antibiotics directly cause cancers to grow. The researchers also noted that they were not able to get complete information on many proven breast cancer risk factors. This means that they could not rule out the possibility that risk factors other than antibiotic use may have caused the differences in breast cancer risk between the two groups of women. In addition, it's very important to remember that antibiotics are one of the most effective types of medication available for treating infection. This is particularly true for women who get an infection when their immune system is weakened by chemotherapy. So as far as we know now, the benefits of antibiotics far outweigh their possible risks. Still, if your doctor has prescribed an antibiotic for you, especially for a long period of time, make sure you understand: what the antibiotic is treating, how much you should take, and how long you should take it. Whenever possible, before an antibiotic is given, find out if you really have a bacterial infection. And if you do, find out which is the best antibiotic to use. Doctors find out if you have a bacterial infection by ordering a "culture." Secretions (body fluids) associated with the infection are collected and tested to see if bacteria or other microorganisms are present. The fluids tested might be: urine, if you think you might have a bladder infection; mucus or fluid from the throat, if you think you have "strep throat"; or a blood sample, if your temperature is a little bit elevated and you're feeling lousy during chemotherapy. If the culture shows a bacterial infection, then a second test is done. This is called a "sensitivity" test. It looks at the ability of various types of antibiotics to kill off the bacteria. Your doctor uses the results of the sensitivity test to pick the best antibiotic to fight the specific infection you have. If you have a significant fever and your blood counts are low from chemotherapy, your doctor will probably start you on antibiotics right after a blood culture is taken. This way, antibiotic protection starts as soon as possible. The choice of therapy can be modified as soon as the test results become available. It's a good idea to avoid taking antibiotics for a viral disease (like the flu) or other conditions that antibiotics have no ability to treat. As long as you're careful about taking antibiotics—and your doctor is careful about prescribing them—you'll get the greatest benefit from them and the least amount of possible risk. Many more studies are needed before we can know whether there is a true link between antibiotic use and increased breast cancer risk. Stay tuned to breastcancer.org for future studies on this important topic. |
| Lymph Node Areas Adjacent to Breast Area
A Pectoralis major muscle B Axillary lymph nodes: levels I C Axillary lymph nodes: levels II D Axillary lymph nodes: levels III E Supraclavicular lymph nodes F Internal mammary lymph nodes |
| LYMPHLAND |
