Tag: Cancer

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Significance of BRCA genes in ovarian cancer.

International symbol of breast cancer awareness. (iStockphoto)
International symbol of breast cancer awareness. (iStockphoto)

First, it was Angelina Jolie, who had a double mastectomy because of increased genetic risk of breast cancer due to the presence of BRCA gene. The presence of BRCA gene also increases the risk of ovarian cancer. We know that if you have a family history of ovarian cancer then the risk of ovarian cancer increases amongst women in that family.

Take for example the recent announcement that 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), was also killed by the same disease in 1991 when she was 43. I am not sure if Charlotte Emily’s BRCA status is known.

There are two types of BRCA genes known as BRCA1 and BRCA2. BRCA is an abbreviation for breast cancer. These genes are tumour suppressor genes and once they undergo changes (mutation), their capacity to normally prevent cancer from developing is lost. It is now known that women found to have mutations in the genes have a very high risk of developing breast and ovarian cancers.

The genetic mutations are not common. About one in 500 to one in 1,000 individuals will carry a mutation or a gene change in one or another of these genes. It generally occurs amongst people who tend to stay together and don’t have offspring with people from other types of ethnicities. Experts say these mutations tend to stay within one group of individuals.

What distinguishes BRCA1 and BRCA2 genes is where they’re located in the chromosomes. There are also slight differences in terms of the types of cancers associated with the two genes.

The main difference in the two genes is that carriers of the 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 ovarian cancer, women with a mutated BRCA1 gene have a 25 to 65 per cent lifetime risk of developing the disease. Those with a mutated BRCA2 gene have a 15 to 20 per cent chance of developing ovarian cancer.

For men, it is little different. For men with the BRCA2 mutation, there’s an increased risk of both prostate and breast cancers.

Who can ask for BRCA genetic testing?

There has to be a strong family history of cancer. The cancer must have occurred in young ages within the family and if you are a member of ethnic groups known to be affected then you would be eligible. If you don’t meet the criteria but still want to be tested then you can go south of the border and get yourself tested for about $3,000.

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.

Each year, about 2400 Canadian women are diagnosed with ovarian cancer. Sadly, 1700 women with the disease die each year. In North America, ovarian cancer is the second most common gynecologic malignant disease and is the leading cause of death among women with gynecologic cancer.

More than 60 per cent of the women 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. Some studies have reported higher survival rates of greater than 90 per cent in women with stage one disease. Only 25 per cent of the women are diagnosed early.

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There are various surgical options for patients with breast cancer.

Doctor and patient. (iStockphoto)
Doctor and patient. (iStockphoto)

Recently, actress Angelina Jolie announced that she underwent a preventive double mastectomy after learning that she carries a mutation of the BRCA1 gene, which sharply increases her risk of developing breast cancer and ovarian cancer. This announcement again increased the discussion in the media about the choices women have when it comes to breast cancer surgery.

Not all women need a double mastectomy if they have breast cancer in one breast. About one in 200 women in North America carries a BRCA1 or BRCA2 mutation. But among certain ethnic groups the prevalence is considerably higher. Notably, the frequency in those of Ashkenazi Jewish ancestry is one in 50. Other groups with high frequencies of mutations include women from Iceland and Poland.

For the vast majority of women, who have no BRCA gene mutation, the following surgical options are available:

-Breast-conserving surgery, an operation to remove the cancer but not the breast itself, includes the following: a) Lumpectomy: Surgery to remove a tumor (lump) and a small amount of normal tissue around it. b) Partial mastectomy: Surgery to remove the part of the breast that has cancer and some normal tissue around it. The lining over the chest muscles below the cancer may also be removed. This procedure is also called a segmental mastectomy. These patients may also have some of the lymph nodes under the arm removed for biopsy. Quite often these patients require radiotherapy after surgery.

-Total mastectomy: Surgery to remove the whole breast that has cancer. This procedure is also called a simple mastectomy. Some of the lymph nodes under the arm may be removed for biopsy at the same time as the breast surgery or after. Most of the time these patients do not require radiotherapy after surgery.

-Modified radical mastectomy: Surgery to remove the whole breast that has cancer, many of the lymph nodes under the arm, the lining over the chest muscles, and sometimes, part of the chest wall muscles.

If the size of the growth in the breast is relatively big (locally advanced cancer) then the patient receives chemotherapy before surgery to shrink the tumor. Treatment given before surgery is called neoadjuvant therapy.

Treatment after surgery consists of radiation therapy, chemotherapy and hormonal therapy even if the doctor removes all the cancer that can be seen at the time of the surgery. This is to kill any cancer cells that are left behind. Treatment given after the surgery, to reduce the risk of recurrence, is called adjuvant therapy. Again, not all breast cancer patients require adjuvant therapy. Your oncologist decides on this depending on the stage of the cancer, what kind of surgery you had and what is your risk of having cancer recur.

Women who opt to have their breast completely removed can have breast reconstruction done. Breast reconstruction may be done at the time of the mastectomy or at a future time.

Some of you must have heard about sentinel lymph node biopsy in cancer surgery. The sentinel lymph node is the first lymph node to receive lymphatic drainage from a tumor. It is the first lymph node the cancer is likely to spread to from the tumor. This is biopsied. If it is negative for cancer cells then it may not be necessary to remove more lymph nodes.

This is a very simplified way to explain to you what kind of treatment options are available for women with breast cancer. In each case, your surgeon and oncologist will advise you what your options are. Because of the technology, experience and expertise of our doctors, the prognosis of breast cancer has improved a lot. So do not panic. There is plenty of help for women with breast cancer.

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Preventing Cervical Cancer – New Guidelines Published in 2013

Pap smear micrograph showing a high-grade squamous intraepithelial lesion (HSIL). (Copyright 2010 Nephron. Permission is granted to copy, distribute and/or modify this image under the terms of the GNU Free Documentation License Version 1.2 or any later version published by the Free Software Foundation.)
Pap smear micrograph showing a high-grade squamous intraepithelial lesion (HSIL). (Copyright 2010 Nephron. Permission is granted to copy, distribute and/or modify this image under the terms of the GNU Free Documentation License Version 1.2 or any later version published by the Free Software Foundation.)

Every woman should know it is important to have regular Pap smear test. Since World War II, the test has been the most widely used and successful cancer screening technique in history. It is named after the Greek doctor who invented it – Dr. George Nicholas Papanicolaou.

An article in the Canadian Medical Association Journal (CMAJ January 8, 2013) says, “The incidence of and mortality due to cervical cancer in Canada have decreased substantially in the past 50 years, and long-term survival rates after treatment are high. Lifetime incidence was 1.5 per cent in 1972, and is now 0.7 per cent; risk of death from cervical cancer is now 0.2 per cent. Most advanced cervical cancer (and associated mortality) occurs among women who have never undergone screening or who have had a long interval between Papanicolaou (Pap) tests.”

For example, in 2011, an estimated 1300 new cases of cervical cancer were diagnosed in Canada, with about 350 deaths. The risk increases after age 25 years and older, peaking during the fifth decade of life.

Pap smear test helps pick early lesions before they become cancerous. This means less invasive treatment is required and the prognosis is better. In the same issue of the CMAJ, the Canadian Task Force on Preventive Health Care has published new guidelines for Pap smear test. These guidelines, which are based on the current scientific evidence, are as follows:

-For women aged less than 20 years, no routine screening for cervical cancer. (Strong recommendation; high-quality evidence)

-For women aged 20-24 years, no routine screening for cervical cancer. (Weak recommendation; moderate-quality evidence)

-For women aged 25-29 years, routine screening for cervical cancer every three years. (Weak recommendation; moderate-quality evidence)

-For women aged 30-69 years, routine screening for cervical cancer every three years. (Strong recommendation; high-quality evidence)

-For women 70 years of age or older who have undergone adequate screening (i.e., three successive negative Pap test results in the last 10 yr), routine screening may stop. For all other women 70 years of age or older, should continue screening until three negative test results have been obtained. (Weak recommendation; low-quality evidence)

Where the recommendations are weak, the decision to undergo Pap smear test depends if the health care provider and the patient think that there is an indication to do one. If the woman is sexually active, she has multiple partners or she has sexually transmitted infection then there would be an indication to do one. One drawback with these updated recommendations is they do not address screening with tests for human papilloma virus (HPV), because there is not yet sufficient data on its effect on mortality and incidence of invasive cancer, says the article.

In a commentary related to the guidelines, Dr. Janet Dollin says, “When Dr. Georgios Papanicolaou developed his famous test in the 1940s, we did not know that cervical cancer is a preventable sexually transmitted infection.” The role of cancer causing virus like HPV was not known. We now know infection with specific strains of HPV is a necessary precursor to cervical cancer. Some of these viruses cause genital warts – another sexually transmitted infection.

Dr. Dollin says, “Indeed, improving uptake and access to HPV vaccination and cervical screening would do more to lower the rates of cervical cancer than deciding at what age to start Pap testing and how frequently it should be done.” The National Advisory Committee on Immunization (NACI) recommends the vaccination of boys and girls to prevent the burden of HPV disease.

Dr. Dollin says that the US Preventive Services Task Force recommends screening for women aged 21-65 years with a Pap every three years or, for women aged 30-65 years who want to lengthen the screening interval, a combination of Pap and HPV testing every five years.

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Indoor Tanning Beds are Not Safer than Natural Sunlight

A woman lying in a tanning bed. (Stockbyte/Thinkstock)
A woman lying in a tanning bed. (Stockbyte/Thinkstock)

Many snowbirds are getting ready to move down south for winter. Some are also booking holidays to get away for a couple weeks to warmer places. The idea is to get away from cooler temperatures, spend time on a beach and soak in the natural sunlight. Before they go away, some travellers visit indoor tanning salons to get a mild tan thinking that this would protect them from sunburn and skin cancer.

There are people who like to look tanned year round and visit indoor tanning salons on a regular basis ignoring the fact that indoor tanning is as bad as basking in the natural sunlight. Some parents encourage their children to visit indoor tanning salons. Studies have shown indoor tanning bed use and childhood sunburns increase skin cancer in young adults.

There is no doubt, exposure to ultraviolet (UV) radiation damages your skin, whether the exposure comes from tanning beds or natural sunlight. The damage eventually leads to premature aging of the skin and skin cancer.

A recent Mayo Clinic study, published in the April 2012 issue of Mayo Clinic Proceedings, found dramatic rise in skin cancer in young adults, especially among people under 40. Researchers speculate indoor tanning bed use and childhood sunburns are key culprits. The study found the incidence of melanoma has escalated, and young women are the hardest hit.

“We anticipated we’d find rising rates, as other studies are suggesting, but we found an even higher incidence than the National Cancer Institute had reported using the Surveillance, Epidemiology and End Result database, and in particular, a dramatic rise in women in their 20s and 30s,” says lead investigator Jerry Brewer, M.D., a Mayo Clinic dermatologist, who was quoted in one of the reports.

The study found the incidence of melanoma increased eightfold among young women and fourfold among young men. The lifetime risk of melanoma is higher in males than females, but the opposite is true in young adults and adolescents. The good news is mortality rates from the disease have improved over the years, likely due to early detection of skin cancer and prompt medical care.

If you are a frequent user of indoor tanning beds then you are 74 per cent more likely to develop melanoma. Young women frequent indoor tanning salons more often than young men even though many of them know indoor tanning has carcinogenic effects that increase the risk of melanoma.

A study from New Brunswick showed that by Grade 12, one-third of girls were using tanning salons, and one-third of them were going with their mothers, says a report in the Medical Post. It is unacceptable that mothers should encourage their daughters to expose themselves to well recognized carcinogens. There are seven other studies involving nearly 7,400 cases showing that first exposure to sunbeds before age 35 increase melanoma risk by 75 per cent.

The message is clear, exposure to ultraviolet rays ultimately lead to premature aging of the skin and skin cancer. So, understand the risk and take care of yourself. There are many ways to enjoy winter months. Be safe and have fun.

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