Can Exercise Reduce Breast Cancer Risk?

We know you’ve heard about the many benefits of exercise to your overall physical and cardiovascular health. But do you know the relationship between exercise and your immune system, and its’ role in minimizing risk of getting certain types of cancer? Today we’ll explore how exercise can help minimize your breast cancer risk.

Exercise increases the body’s ability to provide adequate oxygen to your cells, which is essential for cell metabolism.  Increased oxygenation boosts the immune system, elevates  mood, and helps control obesity.  Evidence continues to mount that exercise later in life may become a factor for reducing breast cancer incidence.

A recent study recruited women with breast cancer from 31 hospitals in or near New York City. These cases were aged from 20 to 98 years old, and were diagnosed with breast cancer between 1996 and 1997. The controls were women who had never been diagnosed with breast cancer, and were matched to cases based on age. This is important, as age is a significant risk factor for breast cancer. The study included 1,508 cases and 1,556 controls to collect data for impact of exercise on breast cancer occurrence.

Study Outcomes:

When adjusting for age, the researchers found that:

  • Regular physical activity during adolescence was not associated with a difference in risk of developing breast cancer.
  • Women who reported engaging in 10 to 19 hours of physical activity during their reproductive (pre-menopausal) years had a 33% reduction in the odds of developing breast cancer after menopause, compared with women who reported no regular activity during these years (odds ratio 0.67, 95% confidence interval 0.48 to 0.94). No significant differences were seen at other activity levels.
  • Women who reported engaging in approximately 9 to 17 hours of physical activity during post-menopausal years had a 30% reduction in the odds of developing breast cancer after the menopause, compared with women who reported no regular physical activity during these years (odds ratio 0.70, 95% confidence interval 0.52 to 0.95).

How did the researchers interpret the results?

The researchers concluded that women can “reduce their breast cancer risk later in life by maintaining their weight and engaging in moderate amounts of physical activity”.

Back to the Basics

With all the vast number of treatments for breast cancer, most having numerous debilitating side effects, it may be time that we go back to the basics of good health and include exercise as a treatment recommendation to reduce breast cancer incidence. Exercise in moderation, based on the individual’s health, comes with many benefits and usually has no cost associated, unless one decides to join a gym or exercise class. Exercise may be the best value in reducing breast cancer incidence.  One thing is certain: Participating in regular exercise later in life will increase one’s overall health, improve mood, and control obesity.

Do you, as a Nurse Navigator, recommend exercise for your breast cancer patients? Does your Breast Center offer any programs to help facilitate patients’ exercise during treatment?

Study Results: Can Metformin Reduce Breast Cancer Incidence?

The diabetes drug, Metformin, commonly prescribed for management of adult onset of diabetes shows promising results in a clinical comparison of postmenopausal women for prevention of breast cancer development.

Study:  68,019 postmenopausal women, including 3,40l with diabetes at entry point, were observed for a mean of 11.8 years. During this time 3,237 invasive breast cancers were diagnosed and were confirmed by pathology reports.

Results Compared with that in women without diabetes, breast cancer incidence in women with diabetes differed by diabetes medication type (P = .04). Women with diabetes receiving medications other than Metformin had a slightly higher incidence of breast cancer (hazard ratio [HR], 1.16; 95% CI, 0.93 to 1.45), and women with diabetes who were given Metformin had lower breast cancer incidence (HR, 0.75; 95% CI, 0.57 to 0.99). The association was observed for cancers positive for both estrogen receptor and progesterone receptor and those that were negative for human epidermal growth factor receptor 2.

This one study presents evidence that Metformin may reduce breast cancer incidence.  Metformin has been used successfully for many years to control blood sugar. Additional studies are needed to confirm this finding in search for a drug that can be used for prevention and management of breast cancer.

Source:  American Society of Clinical Oncology, June 2012

Vast Differences Found Between BRCA1 ER Positive and ER Negative Breast Cancers

We recently came across this data that we want to share with each of you:

BRCA1 germline mutations are one of the main causes of hereditary early-onset breast and ovarian cancer. Recent analysis of BRCA1 mutations conducted by researchers from the Institute of Cancer Research in London, provide additional insight regarding estrogen receptor status of the breast tumor. When a woman has a genetic confirmation of a positive BRCA1 mutation there is a difference between a diagnosis of an ER positive or an ER negative tumor. In more than 80% of cases, tumors arising in BRCA1 germline mutation carriers are estrogen receptor ER negative; however, up to 15% are ER positive.

Researchers reported a summary of the following characteristics found in the study:

Characteristic BRCA1/ER Negative BRCA1/ER Positive
 
Age  participants 54 52
Sex Female Female
Histological grade 3 2
Mitoses/10 HPF 81 15
ER Negative Positive
PR Negative Negative
HER2 Negative Negative
BRCA1 mutation c.124delA/p.Ile42TyrfsX8 c.4485-?_4986 + ?del/p.Ser1496CysfsX14
Somatic BRCA1 wild-type allele* Loss Loss
TP53 mutation c.927_928delTA c.951C > T
Molecular subtype Basal-like Luminal B
Tumor cell content GAP* (H&E) 71% (70%) 42% (60%)

This study confirms for Breast Health Navigators that a diagnosis of breast cancer, even when we have a confirmation that the tumor is BRCA1 positive, may vary in characteristics of the tumor.

The Journal of Pathology (2012); Pathological Society of Great Britain and Ireland