Tag: breast cancer

Recently, Canadian Medical Association Journal (CMAJ December 10, 2018) published new recommendations on screening for breast cancer in women aged 40-74 years who are not at increased risk for breast cancer.

These guidelines apply to women with no previous history of breast cancer, no history of the disease in a first-degree relative like a mother or sister, no known BRCA genetic mutation and no previous exposure to therapeutic radiation of the chest wall.

The recommendations come from the Canadian Task Force on Preventive Health Care. The new recommendations update guidelines first published in 2011. The guidelines are summarized below:

1. There should be no routine mammography for most women aged 40 to 49 because the risk of cancer is low in this group while the risk of false-positive results and overdiagnosis and overtreatment is higher.

2. Routine screening mammography should be done every two to three years for women aged 50 to 69.

3. For women aged 70 to 74, routine screening mammography should be done every two to three years.

4. MRI and ultrasound should not be used for screening purposes.

5. Routine clinical breast examinations or breast self-examinations to screen for breast cancer is discouraged.

Although we rely on mammography for screening the fact remains it is not a perfect screening tool. Screening may lead to overdiagnosis, resulting in unnecessary treatment of cancer that would not have caused harm in a woman’s lifetime and false-positive results that can lead to both physical and psychological consequences. Overdiagnosis and false-positives with subsequent biopsies are more common in younger women.

Other risks and limitations of mammograms include: exposure to low-dose radiation, having a mammogram may lead to additional testing in about 10 per cent of cases. Mammograms can miss one in five cancers in women.

On the other hand, mammography is the only technique proven to be safe and effective in screening for breast cancer, and mammography equipment is the only imaging technique licensed by Health Canada for breast cancer screening. It is good at finding breast cancer, especially in women ages 50 and older. Overall, the sensitivity of mammography is about 87 per cent. Screening may identify breast cancer earlier and lead to more effective and less invasive treatment.

What about women aged 40 to 49 years? Research shows balance of benefits and harms from screening is less favourable for women in this age group than for older women. If a woman in this category requests a mammogram then the guidelines suggest she should not be denied.

Death rates from female breast cancer dropped 40 per cent from 1989 to 2016. Since 2007, breast cancer death rates have been steady in women younger than 50, but have continued to decrease in older women (www.cancer.org).

You may ask, if none of the screening tests are perfect then why is there a decline in the death rate from breast cancer?

A review article in the Lancet Oncology (Why is breast-cancer mortality declining? April 2003), the authors argue that although some of the decline in breast-cancer mortality is due to a reduction in breast-cancer risk, most of it can probably be attributed to adjuvant systemic therapy and the earlier detection of palpable tumours. The authors also explain in the article why advances in the treatment of breast cancer might be outpacing the value of mammography screening.

Important thing to remember is new guidelines empower women to be in charge of their own screening protocol. The final decision on whether to be screened should fall to the patient as long as that patient understands the risks. Patients should be left ultimately to decide what is best for them.

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Is MRI test better than mammography for early detection of breast cancer?

This question applies to women who are at average risk of breast cancer. They have no personal or family history of breast cancer. The controversy over the best way to screen for breast cancer among women at average risk continues.

Regular screening for breast cancer with mammography, breast self-examinations and clinical breast examinations are widely recommended to reduce mortality due to breast cancer.

Unfortunately, the available evidence does not support the use of MRI scans, clinical breast examination or breast self-examination to screen for breast cancer among women at average risk. But we continue to use these investigations.

Recent publications have again questioned the use of MRI alone or in combination with mammography for breast screening. There are more false-positives resulting in more negative biopsies.

Some researchers (JAMA Intern Med. 2018 Apr 1) have concluded that screening with MRI is not for everyone. Women who undergo breast cancer screening with MRI are much more likely to be referred for biopsy – that will ultimately be negative – than if they have screening mammography alone.

The authors of the article warn, “This is even true of women with a personal history of breast cancer. The benefit of possible early detection of breast cancer with MRI has to be carefully weighed against unnecessary additional diagnostic manoeuvres.”

Other authors have concluded that more studies are required to identify women who will benefit from screening MRI to ensure an acceptable benefit-to-harm ratio.

The experts have to determine whether a screening test would benefit or harm the patient. There is risk of harm and cost of false-positive results, overdiagnosis and overtreatment. How many unnecessary biopsies will be done to find one cancer? How many women will have to anxiously wait for days, weeks or months to find out if they have cancer? Not easy questions to answer unless you are sailing in the same boat.

Any positive result from screening has emotional costs such as anxiety and worry for patients and their families, and financial costs to both the patient and the health care system as a result of additional and potentially unnecessary diagnostic tests.

For women with positive results on screening tests, additional diagnostic tests will usually be recommended, such as further mammography, ultrasound and/or tissue sampling with core needle biopsy.

You may ask, “Doctor, what is the best way to screen asymptomatic women with no personal or family history of breast cancer?” The answer lies in the following recommendations from the Canadian Cancer Society:

If you are 40–49: Talk to your doctor about your risk for breast cancer, along with the benefits and potential risks of mammography. The benefits of regular mammography to screen for breast cancer in women younger than 50 are still unclear.

If you are 50–69: Have a screening mammography every 2 years.

If you are 70 or older: Talk to your doctor about how often you should have a mammography.

There is some radiation involved in having mammography. The benefits of mammography and finding breast cancer early outweigh the risk of exposure to the small amount of radiation received during mammography.

Now, here is the good news. The average 5-year survival rate for people with breast cancer is 90 per cent. The average 10-year survival rate is 83 per cent. If the cancer is located only in the breast, the 5-year relative survival rate is 99 per cent. Sixty-two percent of cases are diagnosed at this stage.

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“Although more than 90 per cent of patients with breast cancer have early stage disease at diagnosis, about 25 per cent will eventually die of distant metastasis,” says an article in the Canadian Medical Association Journal (CMAJ February 21, 2017) written by Julia Hamer and Ellen Warner.

In their review article Hamer and Warner say if breast cancer patients make positive lifestyle changes then they can reduce the risk of breast cancer recurrence and death. It can also be psychologically beneficial by empowering them, since the feeling of loss of control is one of the challenges of a cancer diagnosis.

The authors of the article reviewed the role of lifestyle factors, particularly weight management, exercise, diet, smoking, alcohol intake and vitamin supplementation, on the prognosis of patients with breast cancer.

Body weight influences the prognosis for breast cancer patients.

Women who gain weight during or after treatment of breast cancer have been consistently shown to be at higher risk of breast cancer–related death. Also, women who are overweight or obese at the time of diagnosis have a poorer prognosis.

Most women with breast cancer gain weight both during and after active treatment, and much of the weight is never lost. This increases the risk of recurrence and reduces survival.

There are many reasons for weight gain including stress eating, reduced activity because of fatigue or other treatment-related adverse effects, lowered metabolic rate from chemotherapy, and use of pre- and post-chemotherapy medications such as dexamethasone.

What role can exercise play in improving prognosis?

A recent review of the effect of lifestyle factors on breast cancer mortality concluded that physical activity has the most robust effect of all lifestyle factors on reducing breast cancer recurrence.

Patients should be encouraged to engage in at least 30 minutes of moderate-intensity physical activity at least five days of the week, or 75 minutes of more vigorous exercise, along with two to three weekly strength training sessions, including exercises for major muscle groups.

Both the Canadian Cancer Society and the American Cancer Society have endorsed this recommendation, says the CMAJ article.

Can a change in diet improve outcomes?

There is currently no particular style of diet that has been found to be more beneficial than another for reducing the risk of breast cancer recurrence.

Studies from the United States and China found that high consumption of soy protein or soy isoflavones after breast cancer diagnosis was associated with a 26 per cent decrease in cancer recurrence.

Is there a benefit from quitting smoking and reducing alcohol consumption?

Yes. Recent observational studies have shown women with breast cancer who have a substantial smoking history have increased breast cancer deaths compared with those who never smoked, says the article. Findings are too inconsistent to conclude alcohol consumption affects breast cancer outcomes.

There is no evidence vitamins help improve cancer prognosis.

“Of all lifestyle factors, physical activity has the most robust effect on breast cancer outcomes,” says the article.

Follow the recommended 150 minutes of moderate to vigorous exercise or 75 minutes of vigorous exercise per week, along with two to three weekly sessions of strength training.

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Longtime Newfoundland and Labrador politician, Judy Foote, has resigned as federal cabinet minister.

Foote made the move to spend more time with her family after learning she has the BRCA gene, which is hereditary and can impact her children. BRCA stands for breast cancer.

Foote said she has had two bouts with cancer, but as far as she knows, she is now cancer-free. That is good news.

BRCA testing uses DNA analysis to identify harmful changes that signal a higher risk for breast and ovarian cancer.

If a positive DNA mutation (changes in the structure of a gene) is discovered in one person, other family members can be tested to determine if they also carry a BRCA mutation. A genetic counsellor can make you understand your personal risks and prevention strategy.

About one in 200 women in North America carry a BRCA1 or BRCA2 mutation. But among certain ethnic groups the prevalence is considerably higher. The frequency in those of Ashkenazi (Eastern European) Jewish ancestry is one in 50. Other groups with high frequencies of mutations include women from Iceland and Poland.

Actor Angelina Jolie had a double mastectomy due to the presence of BRCA gene. Actor Pierce Brosnan’s daughter Charlotte Emily died of ovarian cancer at age 42. Brosnan is a former James Bond star whose first wife, Cassandra (Charlotte’s mother), also passed away due to the same disease in 1991 when she was 43.

We know if you have a family history of ovarian cancer then the risk of ovarian cancer increases amongst women in that family.

What is the difference between BRCA1 and BRCA2 genes?

The types of cancers associated with the two genes are different. Carriers of BRCA1 gene mutation have a slightly increased risk of ovarian cancer compared to those with BRCA2.

It is also known that carriers of BRCA2 genes have risks of different types of cancers, including pancreatic cancer and melanoma. For men with the BRCA2 mutation, there is an increased risk of both prostate and breast cancers.

Who is eligible for BRCA genetic testing?

A person who has:

• A strong family history of cancer
• The cancer must have occurred in young ages within the family
• If you are a member of ethnic groups known to be affected
• Based on your personal and family history a genetic counsellor can recommend BRCA genetic testing

Early detection of breast cancer has dramatically changed the prognosis of the disease. We cannot say the same thing about ovarian cancer because we do not have any tests for early detection.

More than 60 per cent of the women with ovarian cancer are in advanced stage when first diagnosed. Their five-year survival rate is less than 30 per cent. Their prognosis is poor and they have very few treatment options.

To summarise, having a BRCA gene mutation is uncommon. Inherited BRCA gene mutations are responsible for about 5 to 10 percent of breast cancers and about 15 percent of ovarian cancers. If you have a personal or family history of breast or ovarian cancer then discuss your options with your doctor. Also understand the ethical, legal, and psychosocial implications of what you find. Check if the findings will affect your insurance policy.

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