Breast cancer is the most common invasive cancer in females worldwide. It accounts for 16% of all female cancers and 22.9% of invasive cancers in women. 18.2% of all cancer deaths worldwide, including both males and females, are from breast cancer. Overall, you have a 1 in 8 chance of developing breast cancer in your lifetime.
Most breast lumps are not caused by cancer, but are due to fibrocystic changes in the breast tissue, related to changing hormone levels over the menstrual cycle. Breast cancer can begin in the ducts that carry breast milk to the nipple, in the lobules or glands that make the breast milk, or in other breast tissues. The most common type of breast cancer, invasive ductal carcinoma, spreads into breast tissue from a milk passage or duct. Although breast cancer is the second-leading cause of cancer death in women, earlier detection and improved treatment are helping to decrease the mortality rates from this disease.
Breast cancer rates are much higher in developed nations compared to developing ones. There are several reasons for this, with possibly life-expectancy being one of the key factor – breast cancer is more common in elderly women; women in the richest countries live much longer than those in the poorest nations. The different lifestyles and eating habits of females in rich and poor countries are also contributory factors, experts believe.
What is the difference between invasive and non-invasive breast cancer?
Invasive breast cancer – the cancer cells break out from inside the lobules or ducts and invade nearby tissue. With this type of cancer, the abnormal cells can reach the lymph nodes, and eventually make their way to other organs (metastasis), such as the bones, liver or lungs. The abnormal (cancer) cells can travel through the bloodstream or the lymphatic system to other parts of the body; either early on in the disease, or later.
Non-invasive breast cancer – this is when the cancer is still inside its place of origin and has not broken out. Lobular carcinoma in situ is when the cancer is still inside the lobules, while ductal carcinoma in situ is when they are still inside the milk ducts. “In situ” means “in its original place”. Sometimes, this type of breast cancer is called “pre-cancerous”; this means that although the abnormal cells have not spread outside their place of origin, they can eventually develop into invasive breast cancer.
Excess Pounds Raise Risk of Breast Cancer Recurrence, Death: Study
Women who are overweight or obese when diagnosed with the most common form of breast cancer have a higher risk of recurrence than slimmer patients, according to a new analysis.
“Patients who are obese are significantly more likely to have a breast cancer recurrence despite optimal therapy,” said study leader Dr. Joseph Sparano, associate chairman of oncology at Montefiore Medical Center, in New York City.
These overweight and obese women with hormone receptor-positive breast cancer – which accounts for two-thirds of all cases worldwide – are also at greater risk of dying compared to normal-weight women, he found.
The comparison found the obese women had “about a 30 percent increased risk of recurrence and 50 percent increased risk of death,” Sparano said.
Hormone receptor-positive breast cancer requires estrogen to grow, and Sparano speculated that one possibility for the link might be increased production of estrogen in heavier women.
While the new study findings, published online Aug. 27 in the journal Cancer, echo some earlier research, there are important differences, Sparano said.
Other studies have been complicated by the fact that obese patients often have additional health problems, which may have prevented them from getting appropriate therapy, Sparano said.
In the new analysis, he looked at relatively healthy patients, 6,885 women in all, enrolled in U.S. National Cancer Institute clinical trials with stage 1 to 3 breast cancer (cancers that had not spread to distant sites). They could not participate if they had serious health problems, such as liver, heart or lung disease.
The percentage considered obese (body mass index of 30 or higher) ranged from 25 to 37 percent in the three studies evaluated. Body mass index (BMI) is a calculation of fat content based on height and weight.
As BMI rose, the risk of recurrence or death increased incrementally. Being overweight but not obese also increased risk. “Obesity is clearly associated with an increased risk, and even women who were not obese but overweight tend to have a high risk,” Sparano said. However, he said he can’t pinpoint a weight threshold at which the risk begins.
It’s important to note that although a link between recurrence and excess weight was detected, the research does not show cause and effect.
Commenting on the study, Dr. Bette Caan, a senior research scientist at the Kaiser Permanente Division of Research in Oakland, Calif., said the researchers were able to address some of the shortcomings of previous studies. “To me the big news is that it is showing obesity is only related to one subtype,” Caan said. “It’s the most common subtype. Breast cancer is not one disease but several diseases,” she added.
What is not yet known, agreed Sparano and Caan, is whether reducing weight after cancer treatment might reduce the risk of recurrence or death.
Studies looking at the effect of reducing dietary fat on the risk of recurrence in obese women have come up with conflicting results. In one study, reduced fat didn’t lead to weight loss or reduced recurrence. More study is needed, these experts say.
It might turn out that weight loss only plays a role in reducing recurrence risk for some women, Caan said.
When Should Screening Mammograms Begin?
New guidelines have created confusion about when to begin receiving this important breast cancer screening exam.
Early breast cancer detection is the key to a good prognosis and the most successful treatment possible. One important tool in the fight against breast cancer is an imaging procedure called mammography.
The standard approach has been to start regular mammography screenings at age 40. But in November 2009, the United States Preventive Services Task Force created shock waves when they released new guidelines recommending routine screening mammograms for women to begin a decade later, at age 50.
This decision was based on the fact that, in younger women, the “harms” from getting a mammogram may outweigh the benefits — those harms being the frequent false-positive findings on the mammograms of women in their 40s, which can cause needless anxiety and result in additional imaging studies and biopsies. The “benefit” this group refers to is the number of deaths prevented by getting regular mammograms — they estimate that it would take about 1,900 screening mammograms in women under 50 to save one life, as opposed to about 1,300 screening mammograms in women over 50.
For women 50 and older, the task force also recommends a change in frequency: a mammogram every one to two years instead of the previous recommendation of every year, and then annually after age 59.
The task force is a government-appointed group of experts in the field of breast cancer, but its recommendations are not binding for women or their physicians. In fact, the guidelines suggest that some women who are at higher risk of breast cancer may want to talk with their physicians about starting — or continuing — to get mammograms between ages 40 and 50. The guidelines may, however, may make getting your insurance company to pay for these mammograms a little harder, since insurance companies often use these guidelines to make coverage decisions.
However, not all experts and organizations agree with the task force. For instance, the American Cancer Society (ACS) stands by its recommendation to begin getting regular mammograms at age 40. The National Cancer Institute has said it will begin a review of its own recommendations, which are currently similar to those of the ACS.
What is a 40-something woman to do? For now, the best advice may be to set aside a few minutes during your next physical exam, and talk it over with your own doctor to determine the right schedule for you in view of your needs and your family medical history.
Keep in mind that the new task force guidelines are only recommendations for screening mammograms; anyone with symptoms of possible breast cancer, such as a breast lump, should be tested, which usually includes a mammogram, right away. Everydayhealth.com
In 2012, it is estimated that among U.S. women there will be:
- 226,870 new cases of invasive breast cancer (includes new cases of primary breast cancer among survivors, but not recurrence of original breast cancer among survivors).
- 63,300 new cases of in situ breast cancer (includes ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS), of those, about 85 percent will be DCIS). DCIS is a non-invasive breast cancer and LCIS is a condition that increases the risk of invasive breast cancer.
- 39,510 breast cancer deaths.
American Cancer Society. Cancer Facts and Figures 2012. Atlanta, GA: American Cancer Society, 2012.
Healthy Lifestyle Choices
Healthy lifestyle choices may help lower your risk of breast cancer as well as your risk of heart disease, diabetes, colon cancer and osteoporosis. To promote overall health and possibly reduce your risk of breast cancer, everyone should try to:
- Be physically active.
- Maintain a healthy weight.
- Choose 100 percent whole grain foods (like 100 percent whole grain breads and cereals, brown rice, popcorn and quinoa) more often.
- Limit red meat and processed meat (choose chicken, fish or beans instead).
- Cut down on “bad” fats (saturated and trans fats), and eat more “good” fats (polyunsaturated and monounsaturated fats, like olive and canola oil).
- Get enough vitamin D and calcium every day. For women and men ages 51 to 70, this means 10 mcg600 IU of vitamin D and 1,200 mg of calcium. For men ages 51 to 70, this means 600 IU of vitamin D and 1,000 mg of calcium.
- Take a daily multivitamin with 400 mcg of folic acid (often called folate on nutrition labels).
- If you drink alcohol, limit to drink less than one drink of alcohol a day (for women and fewer than two drinks
- a day for men). Those who drink alcohol should try to get enough folic acid, either through a multivitamin or foods like oranges, orange juice, leafy green vegetables and fortified breakfast cereals.
Adapted from the American Cancer Society’s Nutrition and Physical Activity Guidelines, Washington University School of Medicine’s Siteman Cancer Center’s Your Disease Risk and Institute of Medicine’s Dietary Reference Intakes for Calcium and Vitamin D
