By Ted Gansler, MD, MPH
Like other contributors to the Expert Voices blogs, I am occasionally asked to reply to questions from journalists about various cancer-related topics. The most recent question I received is whether it is true that women who carry a cell phone in their bras are at increased risk for developing breast cancer.
This kind of question is surprisingly difficult to answer. It’s relatively easy to write about things that are known to cause cancer. It’s more difficult to be confident that something does not cause cancer, but one can still provide some guidance if there have been at least a few carefully-conducted epidemiologic studies with negative results. The most challenging requests we receive are often about questions that researchers have not addressed by scientific studies of humans populations. This is one such question.
Cause or Coincidence?
There are a few known instances of breast cancer in young women who have kept cell phones in their bras. (Even when cell phones are not being used for conversation or texting, if they are on then they still periodically emit low energy electromagnetic signals to stay in touch with nearby cell towers.) Because breast cancer is an uncommon and tragic occurrence among young women, these cases have received significant attention on television and on the Internet.… Continue reading →
By Ambassador Sally G. Cowal
We celebrate International Women’s Day March 8. Originally, it was an event to promote equal political rights, including the right to vote, for women. As a Chicagoan I’m proud to say that one of the earliest Women’s Day observances was held in that city in 1908!
Today, although women have the right to vote almost everywhere, health inequalities and disparities between women in the developed and developing worlds — and between men and women in many countries and regions of the world — continue to exist.
Women’s health is important, not only for women, but for men and for families. Women are the caregivers in most places in the world, and when a woman is ill or dies prematurely, her family -particularly her children – carry the burden. That is one of the reasons why it is so important to prevent premature illness and death in women from cancer. Although we think of cancer as a disease that affects people in high income countries, the reality is that 57% of cancer cases and 65% of cancer deaths are in low and middle income countries – that is 5.3 million deaths a year. And the trends point to a continuing shift of the burden to lower income countries.… Continue reading →
By James C. Salwitz, MD
Breast cancer will kill more than 450,000 women worldwide this year, and in the United States alone, 232,000 will be newly diagnosed. Two important recent events shift the conversation from disease treatment to prevention. The most public was the stunning statement of actress Angelina Jolie that she had both her breasts removed because she carried a breast cancer gene (BRCA1). This announcement served to greatly increase awareness and discussion of choice in preventing the disease.
Second, was the decision by the U.S. Preventative Services Task Force (USPSTF) to recommend the use of medications for prevention of breast cancer in women who are at increased risk.
Many factors influence breast cancer risk
In order to prevent breast cancer, we must first understand its causes. While we do not know all, we do understand that certain factors increase the chance of getting breast cancer. Some of these risk factors can be reduced through improved lifestyle, but not all.
Most breast cancer occurs not because of known genetic mutations, but because of a combination of risk factors. One important risk factor is increasing age, with most breast cancers occurring in women 55 years of age and older.
Some risk factors include an early age for a first period (start of menses), a late first pregnancy, and no pregnancy at all.… Continue reading →
By Debbie Saslow, PhD
There are a limited number of things that women can do to lower their risk of breast cancer, including getting regular physical activity, limiting alcohol, and maintaining a healthy weight. Breastfeeding has often been included in the protective behaviors against breast cancer, but the research has been inconsistent.
Looking at the research on breastfeeding and breast cancer risk, it is clear that this has been a difficult area to study. If breastfeeding does lower risk, the level of protection is small and depends on women breastfeeding for a long time. In countries such as the U.S., most women who breastfeed their babies stop after several months, or they breastfeed less frequently as they start to supplement with formula and baby food. Women who have many children and breastfeed each baby for a long time seem to be at somewhat lower risk of breast cancer than women who have smaller families and breastfeed for a shorter time. Studies that have found that breastfeeding does lower breast cancer risk have also found that protection builds up over time (that is, duration of breastfeeding) and number of children that are breastfed.
The major study (Collaborative Group on Hormonal Factors in Breast Cancer; Lancet, 2002 Jul 20; 360 (9328): 187-95) that supports breastfeeding as protective against breast cancer was published in 2002.… Continue reading →
The Relationship between Weight and Breast Cancer
By Lauren Teras, PhD
Breast cancer is the most common cancer among women today. More than 1 million women world-wide are diagnosed with this cancer each year, mostly in the 50 and older age group. Breast Cancer Awareness Month highlights this international public health problem, and it is a good time to consider ways in which we can reduce our risk of this cancer. While many factors beyond our control contribute to risk, like age and family history, we do know of a few ways we can lower the risk of breast cancer.
Worldwide obesity has more than doubled since 1980. Once considered a problem only in high income countries, being overweight and obese is now dramatically on the rise all over the world, particularly in urban areas. As of 2008, the World Health Organization estimated that 1.4 billion adults were overweight, including 300 million obese individuals. In the year 2000, for the first time in human history, the number of adults worldwide who were overweight was greater than the number of adults who were underweight. In fact, approximately 65% of the world’s population lives in countries where being overweight and obese kills more people than being underweight.… Continue reading →
By Marji McCullough, ScD, RD
EDITOR’S NOTE: Dr. McCullough added the following statement 4/8/14 in response to questions related to sources of isoflavones:
Research on soy and cancer is highly complex, controversial, and evolving.
When concerns about soy are raised, they generally focus on findings from rodent models of cancer which tend to use isolated soy compounds like soy protein isolate or high doses of isoflavones (compounds found in soy). However, soy is metabolized differently in humans than it is in mice and rats, so findings in rodents may not apply to people. (See: http://www.ncbi.nlm.nih.gov/pubmed/16614407 for more on this.)(Setchell, AJCN, 2011). There is no evidence in the medical literature that soy protein isolate is bad for humans, compared to other forms of soy. Soy protein isolate is often used as a supplement in randomized studies of the effects of soy on health and none of these studies have shown harm.
Most of the studies suggesting benefits of soy consumption in people have measured how much soy foods people are eating, including tofu, soybeans, and soy milk. These foods are more commonly eaten in Asian countries. In the U.S., purified forms of soy are used in the food supply, including in energy bars and soy hot dogs. The few US studies that have measured these forms of soy do not suggest harm.… Continue reading →
By Mia M. Gaudet, PhD
Certain types of cancer often seem to run in families. Sometimes, it’s because families share certain risk factors (like smoking) that can cause cancer. Other times, though, there is an inherited link – a slight difference in the genetic code that is passed down from generation to generation.
Only about 5% – 10% of all cancers are inherited. It’s an important area of research because identifying genetic causes of cancer could help us understand who might need to be screened for a certain type of cancer more often, or take other steps to protect themselves from this disease. This is the first blog in a series where we’ll explore what researchers have learned about some of the cancers that have a strong genetic link, and who might be candidates for genetic counseling and testing. Today we’ll focus on breast cancer. [more]
Who has increased risk?
Women with 1 or more first-degree relatives (mother, sister, daughter) previously diagnosed with breast cancer have at least double the risk of breast cancer than the general population. A woman with a family history of breast cancer has a much higher risk of being diagnosed with breast cancer if she has 2 or more first-degree relatives who had it, or the first-degree relative had her cancer before age 50, or in both breasts. Having a family history of other cancers, such as ovarian cancer, might also lead to an increased risk of breast cancer.… Continue reading →
By Ted Gansler, MD, MBA, MPH
You have probably seen and heard a lot about breast cancer during the past few weeks, but as we approach the end of this year’s breast cancer awareness month this is a good time to ask how much of the information you encountered is actually true. See if you know which of the following statements are true and which are false… [more]
TRUE OR FALSE: Most breast cancer is hereditary. You don’t need to worry if you don’t have a family history of breast cancer.
FALSE. Only about 5% to 10% of breast cancer cases are thought to be the result of gene defects (called mutations) inherited from a parent. The lifetime risk for breast cancer can be as high as 80% for members of some families who inherit certain mutations of BRCA genes. The risk is not nearly as high for most women with a family history of breast cancer. On average, having 1 first-degree relative (mother, sister, or daughter) with breast cancer approximately doubles a woman’s risk, and having 2 first-degree relatives triples her risk. About 20% to 30% of women with breast cancer have a family member with this disease (although most of these families do not have abnormal BRCA genes).… Continue reading →
By Debbie Saslow, PhD
A recent study has shown that for some women diagnosed with breast cancer, extensive lymph node surgery isn’t needed. This is great news because removal of lymph nodes in the armpit area can have debilitating and life-long side effects.
Here is a little background: In the United States, about 210,000 new cases of invasive breast cancer will be diagnosed this year. Of the invasive cancers, about 30% of cases, or 63,000 cancers, will be diagnosed at the “regional stage,” which means the cancer has spread to nearby lymph nodes. The findings of this study are important for women in this group.
The women who participated in the study:
- had breast cancer that had spread to the first 1 or 2 nearby lymph nodes,
- had received treatment including lumpectomy and radiation therapy,
- had tumors that were less than 5 cm-about 2 inches-across, and
- did not have any lymph nodes in the armpit that could be felt during examination.
While not a requirement of the study, almost all of the women participating also had received chemotherapy after, but not before, their lumpectomy.
Nine hundred women participated in the study. Half had just 1 or 2 lymph nodes removed using a procedure called sentinel lymph node dissection.… Continue reading →