Cancer is a family affair. Protection against this disease is also a family affair. A new idea for protection is not equal in impact as any other. What do you do when there is conflict within and between the available recommendations?

I wrote in The team that switched off that cancer about one gene found in fruit flies and mammals, mice and humans in this case, as a trigger. The scientists were able to switch off/on the cancer. This finding promises new simple strategies in the treatment of at least some cancers such as the colon's. Here I will review answers to what to do to mitigate the breast cancer risk.

Four specialists have reported in November 2008 for the American Cancer Society: "A 3.9% decrease in breast cancer incidence has been observed between 2001 to 2004, along with a 2.2% decrease in breast cancer mortality between 1990 to 2004."[1] Furthermore, "This review will summarize information on potential pharmacologic, nutritional, surgical, and behavioral approaches to reducing breast cancer risk," offerred Mahoney et al.

One hundred and sixty three references were reviewed by the authors. I recommend the article for details behind my words. All factors that influence risk of breast cancer are described in Figure 1 taken from the article. Basically, risks fall into two classes depending on whether modifiable or not modifiable. Some factors such as age at first child birth, age at menopause, and breast feeding are listed as potentially modifiable.





Figure 5

Figure 1. Factors Influencing Risk of Breast Cancer

The authors recommend: "Patients should be encouraged to maintain a healthy lifestyle for their overall well-being and to remain up to date with recommendations for screening and surveillance." The following  conclusions are culled from the article:



1. There is no clear evidence that specific dietary components can effectively reduce breast cancer risk.

2. Some studies suggest that about 4% of all breast cancers in developed countries might be attributable to alcohol consumption.

3. Current evidence suggests that the use of combination postmenopausal hormone therapy (HT)  consisting of estrogen plus progestin increases breast cancer risk even if used for short intervals (eg, 5 years). However, the use of estrogen alone increases breast cancer risk more modestly, without an increase in breast cancer risk until 10 to 15 years of therapy. Also, breast cancer risk declines rapidly after discontinuing use of estrogen-only HT.

4.  Gaining over 20 pounds in weight during adulthood has been reported to result in an increased risk of breast cancer. Data from the WHI Observational Study revealed that among never users of HT, baseline body mass index (BMI)  in excess of 31 resulted in a doubling of the risk for postmenopausal breast cancer. The impact of weight gain is more apparent for hormone receptor-positive breast cancers.


5. Physical activity and obesity are closely related through many factors that may independently or jointly influence breast cancer risk (eg, estrogen levels, body-fat distribution, insulin levels, insulin-like growth hormone, and mammographic density). Although observational studies provide evidence that higher levels of physical activity result in lower rates of breast cancer, some researchers have argued that intervention trials are needed to better define this relationship, even though the feasibility of maintaining compliance for a sufficiently long time is doubtful. Moreover, regular physical activity is an important weight-control strategy. All persons, regardless of gender, should be encouraged to engage in at least 30 minutes of moderate-to-vigorous intensity physical activity on at least 5 days per week.


6. Use of pharmacotherapy for breast cancer risk reduction should be individualized to each patient based on their medical history, family history, quantified estimate of developing breast cancer, and patient preferences. While serotonin reuptake inhibitors are known to decrease the formation of the active metabolite of tamoxifen (endoxien), the clinical impact of this is unclear.

Finally, one major area pertains to race and ethnicity. The authors maintain: "While racial/ethnic factors impact screening, from a practical perspective, the issue of limited minority enrollment is relatively minor since breast cancer risk factors are generally similar across racial/ethnic groups, with biologic differences in breast cancer more related to differences in hormone-receptor status among racial/ethnic groups." Consider, however, Figure 2 for "Age-adjusted Breast Cancer Incidence and Mortality Rates, 2000 to 2004, by Race/Ethnicity" taken from the article.

Figure 1
Figure 2. Age-adjusted Breast Cancer Incidence and Mortality Rates, 2000 to 2004, by Race/Ethnicity. Abbreviations: PI, Pacific Islander; AI/AN, American Indian/Alaska Native.3 SEER, NCI, DCCPS, Surveillance Research Program, Cancer Statistics Branch, retrieved March 22, 2008, from http://seer.cancer.gov./

Observe much higher incidence and mortality with White and Black, respectively in comparison with the lowest incidence and mortality seen within the American Indian/ Alaska Native. It is no wonder the authors mention elsewhere: "Qualitative and quantitative approaches to risk assessment should be used to identify women at increased risk of breast cancer for whom genetics consultation, individualized surveillance, and/or chemoprevention may be appropriate."

Mahoney and colleagues urge women interested in breast cancer chemoprevention to consider participation in clinical trials.

What do you think?

Article:
[1] Martin C. Mahoney, MD, PhD, Therese Bevers, MD, Eleni Linos, MD, MPH and Walter C. Willett, MD, DrPH, Opportunities and Strategies for Breast Cancer Prevention Through Risk , Reduction, CA Cancer J Clin 2008; 58:347-371.
DOI: 10.3322/CA.2008.0016