Breast cancer is the most commonly occurring female cancer in developed countries but earlier diagnosis and improvements in treatment are resulting in the majority of women surviving the disease. In the United Kingdom, whilst 44,000 women are diagnosed every year, 12,000 die from their breast cancer and this number is likely to fall even further.
At present, knowledge of all the factors that result in the development and growth of breast cancer is incomplete. Factors that have been associated with an increased breast cancer risk include:
- Family history
- Benign breast disease
- Endogenous sex hormone exposure (i.e. exposure to sex hormone produced within the body)
- Exogenous hormone exposure (i.e. exposure to hormones taken in the form of medication)
- Reproductive History
It is important to realise that although these factors have been identified, their occurrence does not indicate that a woman will definitely develop breast cancer. There are almost certainly other factors that are necessary to interact for breast cancers to develop and grow but knowledge of these is incomplete.
This is the most important risk factor for breast cancer as most cases are diagnosed in women aged over 50 years. A commonly quoted statistic is that breast cancer affects 1 in every 12 women. However, it is important to understand that this figure represents risk over a woman’s whole lifetime. In women aged less than 30 years, breast cancer occurs in approximately 1 in 625 women. This increases to 1 in 13 for women by the age of 75 years.
This refers to the risk of inheriting a gene mutation that can result in the development of breast cancer. Inherited breast cancers are more likely to be diagnosed at a younger age (i.e. less than 40 years), affect both breasts and affect more than one relative within a family. In some families there is clustering of breast with ovarian, endometrial and bowel cancers. If a woman has a single first degree relative (i.e. mother or sister) diagnosed with breast cancer over the age of 50 years it is very unlikely that this places her at an increased risk of breast cancer. For any woman who has a family history of cancer, discussion with her GP should determine whether this is likely to be significant and therefore whether specialist referral to a breast unit for counselling is necessary.
Benign Breast Disease
This encompasses a diverse range of conditions of the breast, most of which are not associated with an increased risk of breast cancer. Breast cysts are not associated with any significant risk.
Endogenous hormones are produced naturally within the body. Breast cancer is a disease that predominantly affects women, being 200 times more common than in men. Female sex hormones, in particular those produced by the ovary (e.g. oestrogen, progesterone) play an important role in the development of most breast cancers. The evidence for this has largely been drawn from population studies that have revealed an increased risk of breast cancer in women who commence their menstrual periods at a younger age or who develop the menopause at an older age. The earlier a woman has her menopause, the lower her risk of developing breast cancer.
In women who have undergone the menopause, oestrogen and progesterone hormones are no longer produced by the ovary. Instead small amounts of oestrogen are produced in fat cells by the action of an enzyme called aromatase.
Postmenopausal women who are overweight are at an increased risk of breast cancer and this has been attributed to the fact that there is more fat tissue in which this synthesis of oestrogen can take place.
Exogenous hormones are those which originate outside the body. These include: the oral contraceptive pill (OCP), also known as birth control. There does appear to be a very small increase in the risk of developing breast cancer with the use of the OCP. Review of clinical studies suggests that this risk is probably restricted to younger women (i.e. aged less than 35 years) who have used the OCP for longer than 5 years. This risk is very small. It has been estimated that for every 10,000 women aged between 25 to 29 years who take the OCP for 5 years an extra 5 cases of breast cancer are diagnosed.
Hormone replacement therapy (HRT)
Recent information from clinical trials has shown that combined HRT (i.e. oestrogen plus progestogen hormone) is associated with a very small increase in the risk of developing breast cancer but only if taken long-term (i.e. for more than 5 years after the age of 50). Two years use of HRT probably results in 1 extra breast cancer per 1000 women who use it. The small increase in risk associated with combined HRT falls after it is stopped and there is no evidence that the risk of dying from breast cancer is increased in women with a history of using it. The risk of breast cancer with combined HRT is less than that associated with being overweight, over the age of 50 years or that associated with drinking 2 or more units of alcohol per day. – See our related factsheet on HRT: What you should know about the risks and benefits.
A 2004 study found that smoking does in fact increase ones risk of breast cancer. Woman who began smoking before the age of 20 and those who started at least five years before their first pregnancy seem to be most at risk. Heavy smoking or smoking over a long period of time also increases the risk. There is no evidence that passive smoking increases ones risk. Also, on a positive note, researchers found no evidence of a significantly higher risk in former smokers.
One study showed that for women with a close blood relative with the disease, daily alcohol consumption appeared to more than double the risk of breast cancer. A more recent study found that 60 percent of breast cancer cases in women worldwide were attributable to alcohol consumption. But the mechanism(s) of alcohol-induced breast cancer are poorly understood.
Research shows that 10%-70% of cases may be prevented by changing diet. Although it is difficult to determine what foods put you at risk for breast cancer a diet high in fat has been implicated in increasing risk but more research needs to be done. The best course of action is to eat plenty of fruits and vegetable and stay away from foods high in fat or cholesterol, sugar and processed foods. On the bright side, healthy eating is beneficial no matter what.
Age at Menarche
Early age of menarche (onset of period) is associated with an increased risk of breast cancer. Nutrition in early life will strongly influence of the age of menarche.
Birth and breast feeding
Part of the reason that women in developing countries have a higher risk of breast cancer than women in developing countries may be because women in developed countries have fewer children and a limited duration of breast feeding. The younger a woman is when she first gives birth the lower her risk of breast cancer. Also, women who do not breast feed are at greater risk for breast cancer and the longer a woman breast feeds the greater the protection.
Parity or having more than one child, is also recognized as reducing the risk of breast cancer. The higher the number of full-term pregnancies the greater the protection a woman has against breast cancer.
Age at Menopause
The later a woman goes through menopause the higher her risk. Postmenopausal women have a lower risk of breast cancer than premenopausal women of the same age. This holds true for both natural menopause and surgically induced menopause.
Bodyweight and Physical Activity
About 8% of breast cancer in the UK may be because of obesity or being overweight. Being overweight and obesity are measured using the BMI (body mass index). A high BMI may even increase the risk of postmenopausal breast cancer. Similarly, physical activity has a preventative effect on breast cancer. This may indirectly affect risk by lowering a women’s BMI or it may have a direct effect on hormonal and growth factor levels. Either way, physical activity is a good way of lowering your risk of breast cancer.
|Increase in breast cancer risk
|Age at onset of periods less than 11 years
|1.50 x increase
|Age at natural menopause greater than 55 years2.00 x increase Postmenopausal obesity
|1.60 x increase
|Alcohol (more than 2-3 units per day)
|1.50 x increase
|HRT for more than 5 years
|1.26 x increase
Treatment of Breast Cancer
If you go to a breast screening and are diagnosed with breast cancer there are five main treatments of cancer: surgery, radiotherapy, hormone therapy, chemotherapy and biological treatment. One or a combination of these therapies may be used. There are no set treatments for a specific type of breast cancer, all treatments are chosen on an individual basis and it is important to speak to your doctor about all treatments types and come to an agreement. Some of the factors that are considered when deciding on a treatment are:
- Whether you have had your menopause
- The type of breast cancer you have
- The size of your breast tumour
- The stage of your breast cancer
- The grade of your cancer cell
- The results of test on your cancer cells
- Your general health
If there is a specific treatment you are interested in and your doctor does not mention it, make sure to speak up. Similarly, if your doctor suggests a treatment that you are not comfortable with, make your concern known. Your physician probably has good reasons for choosing the treatment s/he did and should be able to explain it to you.
Each year nearly 7,000 cases of ovarian cancer are diagnosed in the UK. It is the 4th most common cancer in women after breast, bowel and lung cancer.
The ovaries are part of a woman’s reproductive system. They are located on each side of the uterus. Cancer develops when the cells in the ovary get out of control. There are two types of growth that can occur in the ovaries. The first is benign, (non-cancerous) and the tumour can be surgically removed. The second is malignant (cancerous) and is treated according to the stage or type of ovarian cancer of the woman.
Types of Ovarian cancer:
There are three main cell types in which ovarian cancers can start:
- Germ cell tumours which start from the cells that are responsible for producing the ova (eggs).
- Stromal tumours which are connected to the tissue cells that hold the ovary together and produce the female hormones estrogen and progesterone.
- Epithelial cells which cover the outer surface of the ovary. This is the most common type, making up 90% of ovarian cancer cases.
The causes of ovarian cancer:
Although the exact causes are not known, there are high risk factors which may increase the chances of developing ovarian cancer. The following are some of them:
- Family history of cancer: if another woman in the family has ovarian cancer, or cancer of the breast, uterus, colon or rectum, there may be an increased chance.
- Personal history of cancer: if a woman has previously been diagnosed with any of the above cancers.
- Age: ovarian cancer is more likely to develop after the menopause. It is most common in women aged over 50. Also, if a woman began to menstruate early and entered menopause late, there is a high risk.
- Previous pregnancies: if women have had children, they have a lower risk of developing ovarian cancer.
- Use of infertility drugs: the use of the oral contraceptive pill decreases the chances of developing ovarian cancer. A woman is more at risk if she has not used any birth control methods but this varies with each individual.
- Childhood obesity: women who are obese at the age of 18 are at a higher risk of developing ovarian cancer before menopause.
Ovarian cancer used to be called ‘the silent killer’ as most women will not be diagnosed until the cancer has spread. However, there is now growing scientific evidence that repeated symptoms could alert women to the possibility of ovarian cancer. These could include:
Early stage ovarian cancer
- Pain in the lower abdomen or side
- A bloated, full feeling in the abdomen.
Later stage ovarian cancer
- Back pain
- Irregular periods
- Abdominal pain
- Increased passing of urine
- Pain during sex
- Swollen abdomen
Advanced ovarian cancer
- Loss of appetite
- Shortness of breath
With any of these symptoms a woman should contact her GP. However, less serious diseases, such as ovarian cysts, can produce similar symptoms.
Diagnosing ovarian cancer
In most cases, once the GP is contacted and general health tests are done, a specialist may be recommended for further tests, such as an ultrasound scan and a CT scan (often referred to as a CAT scan) to view the pelvis. One of the tests done as a standard practice while investigating potential malignancy of an ovary is a blood test to measure a tumour- marker, known as CA125.
A laparoscopy might be recommended, which involves inserting a telescope into the abdomen via a small cut just below the belly button. This would allow the ovaries and surrounding organs to be thoroughly checked. If tests suggest a non-cancerous cyst, then women may be asked to return for regular examinations. If ovarian cancer is suspected then abdominal surgery would most likely be recommended.
Treating ovarian cancer depends very much on individual circumstances. It is usually determined by the type of ovarian cancer, how far the cancer has spread, how the cells appear under the microscope and a woman’s general health. Her doctor will advise as to the kind of surgery that best suits. The three main types are surgery, radiotherapy or chemotherapy.
Most ovarian cancers are treated firstly through surgery. Omental biopsy is usually undertaken when ovarian cancer is suspected. This is to remove a sample from the “fatty apron” which hangs from the large bowel and is where cancer would spread to if the ovary were to be malignant. Surgery can range from the removal of the affected ovary and its fallopian tube, to a total hysterectomy – the removal of the ovaries, fallopian tubes and the uterus. After surgery, the remaining cancer cells can be removed by chemotherapy and/or radiotherapy.
Chemotherapy is the use of drugs to kill cancer cells. They are usually given by mouth or injected into a vein. There is usually a cycle for this kind of treatment, which takes place in monthly stages. As the drugs enter the bloodstream, they kill cancer cells which have moved away from the ovary. The typical course for ovarian cancer would involve up to 3 to 6 cycles, with regular examinations.
Radiotherapy uses radiation such as high energy x-rays to kill cancer cells and shrink tumours.
In both cases, side effects would occur, such as:
- Hand and foot rashes
- Loss of appetite
- Mouth sores
- Skin irritation
Recovery prospects are far greater if the cancer is diagnosed early. Coping with cancer can be a difficult time, for the patient, but also for family and friends.