Cancer may affect people at all ages, even fetuses, but the risk for most varieties increases with age. Cancer causes about 13% of all human deaths. According to the American Cancer Society, 7.6 million people died from cancer in the world during 2007. Cancers can affect all animals.

Nearly all cancers are caused by abnormalities in the genetic material of the transformed cells. These abnormalities may be due to the effects of carcinogens, such as tobacco smoke, radiation, chemicals, or infectious agents. Other cancer-promoting genetic abnormalities may be randomly acquired through errors in DNA replication, or are inherited, and thus present in all cells from birth. The heritability of cancers is usually affected by complex interactions between carcinogens and the host’s genome. New aspects of the genetics of cancer pathogenesis, such as DNA methylation, and microRNAs are increasingly recognized as important.

Genetic abnormalities found in cancer typically affect two general classes of genes. Cancer-promoting oncogenes are typically activated in cancer cells, giving those cells new properties, such as hyperactive growth and division, protection against programmed cell death, loss of respect for normal tissue boundaries, and the ability to become established in diverse tissue environments. Tumor suppressor genes are then inactivated in cancer cells, resulting in the loss of normal functions in those cells, such as accurate DNA replication, control over the cell cycle, orientation and adhesion within tissues, and interaction with protective cells of the immune system.

Diagnosis usually requires the histologic examination of a tissue biopsy specimen by a pathologist, although the initial indication of malignancy can be symptoms or radiographic imaging abnormalities. Most cancers can be treated and some cured, depending on the specific type, location, and stage. Once diagnosed, cancer is usually treated with a combination of surgery, chemotherapy and radiotherapy. As research develops, treatments are becoming more specific for different varieties of cancer. There has been significant progress in the development of targeted therapy drugs that act specifically on detectable molecular abnormalities in certain tumors, and which minimize damage to normal cells. The prognosis of cancer patients is most influenced by the type of cancer, as well as the stage, or extent of the disease. In addition, histologic grading and the presence of specific molecular markers can also be useful in establishing prognosis, as well as in determining individual treatments.

Signs and symptoms

Roughly, cancer symptoms can be divided into three groups:

• Local symptoms: unusual lumps or swelling (tumor), hemorrhage (bleeding), pain and/or ulceration. Compression of surrounding tissues may cause symptoms such as jaundice (yellowing the eyes and skin).
• Symptoms of metastasis (spreading): enlarged lymph nodes, cough and hemoptysis, hepatomegaly (enlarged liver), bone pain, fracture of affected bones and neurological symptoms. Although advanced cancer may cause pain, it is often not the first symptom.
• Systemic symptoms: weight loss, poor appetite, fatigue and cachexia (wasting), excessive sweating (night sweats), anemia and specific paraneoplastic phenomena, i.e. specific conditions that are due to an active cancer, such as thrombosis or hormonal changes.

Every symptom in the above list can be caused by a variety of conditions (a list of which is referred to as the differential diagnosis). Cancer may be a common or uncommon cause of each item.

Cancer (medical term: malignant neoplasm) is a class of diseases in which a group of cells display uncontrolled growth (division beyond the normal limits), invasion (intrusion on and destruction of adjacent tissues), and sometimes metastasis (spread to other locations in the body via lymph or blood). These three malignant properties of cancers differentiate them from benign tumors, which are self-limited, and do not invade or metastasize. Most cancers form a tumor but some, like leukemia, do not. The branch of medicine concerned with the study, diagnosis, treatment, and prevention of cancer is oncology.

Cancer may affect people at all ages, even fetuses, but the risk for most varieties increases with age. Cancer causes about 13% of all human deaths. According to the American Cancer Society, 7.6 million people died from cancer in the world during 2007. Cancers can affect all animals.

Nearly all cancers are caused by abnormalities in the genetic material of the transformed cells. These abnormalities may be due to the effects of carcinogens, such as tobacco smoke, radiation, chemicals, or infectious agents. Other cancer-promoting genetic abnormalities may be randomly acquired through errors in DNA replication, or are inherited, and thus present in all cells from birth. The heritability of cancers is usually affected by complex interactions between carcinogens and the host’s genome. New aspects of the genetics of cancer pathogenesis, such as DNA methylation, and microRNAs are increasingly recognized as important.

Genetic abnormalities found in cancer typically affect two general classes of genes. Cancer-promoting oncogenes are typically activated in cancer cells, giving those cells new properties, such as hyperactive growth and division, protection against programmed cell death, loss of respect for normal tissue boundaries, and the ability to become established in diverse tissue environments. Tumor suppressor genes are then inactivated in cancer cells, resulting in the loss of normal functions in those cells, such as accurate DNA replication, control over the cell cycle, orientation and adhesion within tissues, and interaction with protective cells of the immune system.

Diagnosis usually requires the histologic examination of a tissue biopsy specimen by a pathologist, although the initial indication of malignancy can be symptoms or radiographic imaging abnormalities. Most cancers can be treated and some cured, depending on the specific type, location, and stage. Once diagnosed, cancer is usually treated with a combination of surgery, chemotherapy and radiotherapy. As research develops, treatments are becoming more specific for different varieties of cancer. There has been significant progress in the development of targeted therapy drugs that act specifically on detectable molecular abnormalities in certain tumors, and which minimize damage to normal cells. The prognosis of cancer patients is most influenced by the type of cancer, as well as the stage, or extent of the disease. In addition, histologic grading and the presence of specific molecular markers can also be useful in establishing prognosis, as well as in determining individual treatments.

Signs and symptoms

Roughly, cancer symptoms can be divided into three groups:

• Local symptoms: unusual lumps or swelling (tumor), hemorrhage (bleeding), pain and/or ulceration. Compression of surrounding tissues may cause symptoms such as jaundice (yellowing the eyes and skin).
• Symptoms of metastasis (spreading): enlarged lymph nodes, cough and hemoptysis, hepatomegaly (enlarged liver), bone pain, fracture of affected bones and neurological symptoms. Although advanced cancer may cause pain, it is often not the first symptom.
• Systemic symptoms: weight loss, poor appetite, fatigue and cachexia (wasting), excessive sweating (night sweats), anemia and specific paraneoplastic phenomena, i.e. specific conditions that are due to an active cancer, such as thrombosis or hormonal changes.

Every symptom in the above list can be caused by a variety of conditions (a list of which is referred to as the differential diagnosis). Cancer may be a common or uncommon cause of each item.

It has long been recognized that the female hormone oestrogen can stimulate the growth of breast cancer. Most oestrogen is produced by the ovaries until they cease to function at the menopause. Even after the menopause, some oestrogen is still produced by the adrenal glands.
The most common hormone treatment is tamoxifen, which is usually given as tablets, and which blocks the action of oestrogen on breast cancer cells and thus prevents them growing. It will act against any malignant cells which may have spread to other parts of the body before the breast cancer was removed surgically.
The many trials which have been carried out to assess the use of tamoxifen have shown it to be of benefit to almost all women with breast cancer.
Hormone therapy with tamoxifen cannot guarantee a cure, but it does significantly reduce the risk of the cancer recurring. Tamoxifen has to be taken for at least 2 years, and some doctors recommend it is continued for 5 years or more.

Side-effects of tamoxifen
Tamoxifen causes few side-effects. Some women suffer from nausea or tiredness, and frequent hot flushes similar to those experienced at the time of the menopause are quite common. Pre-menopausal women may develop irregular periods, and older women may have vaginal spotting of blood. However, as other causes of vaginal discharge need to be ruled out, you should tell your doctor immediately if you experience this.
A recent study indicated that tamoxifen may be associated with a slight increase in the incidence of cancer of the lining of the womb (endometrial cancer). Vaginal discharge or bleeding may be an early sign of this type of cancer. As in 80 per cent of cases endometrial cancer is curable, and the increase in risk for women taking tamoxifen is small, its benefits for those with breast cancer still outweigh its risks.

The ovaries
If there is a high risk that the breast cancer has spread to other parts of the body in pre-menopausal women, it may be advisable to stop their ovaries producing oestrogen. The ovaries can be removed surgically, in an operation called bilateral oophorectomy, or they can be treated by radiotherapy, which is usually given over a period of a week and which will gradually stop the ovaries working over the next few months. Alternatively, a drug called goserelin (Zoladex) can be given by injection once a month, usually for 2 years.

    *53/39/5*

It has long been recognized that the female hormone oestrogen can stimulate the growth of breast cancer. Most oestrogen is produced by the ovaries until they cease to function at the menopause. Even after the menopause, some oestrogen is still produced by the adrenal glands.
The most common hormone treatment is tamoxifen, which is usually given as tablets, and which blocks the action of oestrogen on breast cancer cells and thus prevents them growing. It will act against any malignant cells which may have spread to other parts of the body before the breast cancer was removed surgically.
The many trials which have been carried out to assess the use of tamoxifen have shown it to be of benefit to almost all women with breast cancer.
Hormone therapy with tamoxifen cannot guarantee a cure, but it does significantly reduce the risk of the cancer recurring. Tamoxifen has to be taken for at least 2 years, and some doctors recommend it is continued for 5 years or more.

Side-effects of tamoxifen
Tamoxifen causes few side-effects. Some women suffer from nausea or tiredness, and frequent hot flushes similar to those experienced at the time of the menopause are quite common. Pre-menopausal women may develop irregular periods, and older women may have vaginal spotting of blood. However, as other causes of vaginal discharge need to be ruled out, you should tell your doctor immediately if you experience this.
A recent study indicated that tamoxifen may be associated with a slight increase in the incidence of cancer of the lining of the womb (endometrial cancer). Vaginal discharge or bleeding may be an early sign of this type of cancer. As in 80 per cent of cases endometrial cancer is curable, and the increase in risk for women taking tamoxifen is small, its benefits for those with breast cancer still outweigh its risks.

The ovaries
If there is a high risk that the breast cancer has spread to other parts of the body in pre-menopausal women, it may be advisable to stop their ovaries producing oestrogen. The ovaries can be removed surgically, in an operation called bilateral oophorectomy, or they can be treated by radiotherapy, which is usually given over a period of a week and which will gradually stop the ovaries working over the next few months. Alternatively, a drug called goserelin (Zoladex) can be given by injection once a month, usually for 2 years.

    *53/39/5*

Although in most cases lumps and pain in the breasts are due to benign conditions, it is advisable to see your doctor as soon as possible if you notice any change in your breasts. The early detection and treatment of breast cancer could mean having an operation to remove a small lump, which leaves a small scar, rather than losing your breast altogether. Even more importantly, it could save your life.

Signs of disease
There are various signs of disease that a doctor will look for, some of which you may be able to detect yourself by regularly examining your breasts. These signs include a newly apparent lump which is persistent rather than cyclical, inflammation of the skin, obvious veins which are more visible on one side of the breast, a change in the general shape of the breast, or a retracted or weeping nipple. Although nipple discharge can be associated with various diseases, it may be an early sign of a cancer, particularly if bloody, and can occur before any lump is large enough to be felt. A malignant tumour which is close to the surface of the breast may pull at the overlying skin, causing it to dimple slightly. This is an important sign of malignancy. Another serious sign is a condition known as peau d’orange, in which the skin of the breast becomes pitted like that of an orange. It occurs because the lymph vessels which drain fluid away from the breast become blocked, and the breast swells as the fluid accumulates. The tiny pits are due to tethering of small areas of the skin between the lymphatic swellings.
Ulceration of a cancer through the skin is a late sign of advanced disease.

Visible changes
Most of the signs of disease mentioned above can only be detected by looking at the breasts, and it is now generally accepted that being aware of their normal appearance and regularly inspecting them for any apparent changes may be more important than breast self-examination by feeling them – known as palpation.
If you feel happy and confident about examining your breasts by touch, you should continue to do so. But it is important that you also look at them and are aware of any visible abnormal changes that occur. If you do not like feeling your breasts yourself, simply being aware of their appearance is a reasonable alternative, although you can ask your GP or practice nurse to check them for you.
Practicing breast awareness from the time the breasts develop may be beneficial, and can be done, for example, while applying deodorant with your arm raised, in the bath or shower. If you get used to looking at your breasts and become familiar with their normal appearance, you are more likely to detect any visible changes which may occur and thus be able to seek treatment early when necessary.     *3/39/5*

Although in most cases lumps and pain in the breasts are due to benign conditions, it is advisable to see your doctor as soon as possible if you notice any change in your breasts. The early detection and treatment of breast cancer could mean having an operation to remove a small lump, which leaves a small scar, rather than losing your breast altogether. Even more importantly, it could save your life.

Signs of disease
There are various signs of disease that a doctor will look for, some of which you may be able to detect yourself by regularly examining your breasts. These signs include a newly apparent lump which is persistent rather than cyclical, inflammation of the skin, obvious veins which are more visible on one side of the breast, a change in the general shape of the breast, or a retracted or weeping nipple. Although nipple discharge can be associated with various diseases, it may be an early sign of a cancer, particularly if bloody, and can occur before any lump is large enough to be felt. A malignant tumour which is close to the surface of the breast may pull at the overlying skin, causing it to dimple slightly. This is an important sign of malignancy. Another serious sign is a condition known as peau d’orange, in which the skin of the breast becomes pitted like that of an orange. It occurs because the lymph vessels which drain fluid away from the breast become blocked, and the breast swells as the fluid accumulates. The tiny pits are due to tethering of small areas of the skin between the lymphatic swellings.
Ulceration of a cancer through the skin is a late sign of advanced disease.

Visible changes
Most of the signs of disease mentioned above can only be detected by looking at the breasts, and it is now generally accepted that being aware of their normal appearance and regularly inspecting them for any apparent changes may be more important than breast self-examination by feeling them – known as palpation.
If you feel happy and confident about examining your breasts by touch, you should continue to do so. But it is important that you also look at them and are aware of any visible abnormal changes that occur. If you do not like feeling your breasts yourself, simply being aware of their appearance is a reasonable alternative, although you can ask your GP or practice nurse to check them for you.
Practicing breast awareness from the time the breasts develop may be beneficial, and can be done, for example, while applying deodorant with your arm raised, in the bath or shower. If you get used to looking at your breasts and become familiar with their normal appearance, you are more likely to detect any visible changes which may occur and thus be able to seek treatment early when necessary.     *3/39/5*

A cancer is a collection of cells which are growing and multiplying uncontrollably. Cancer of the breast is the most common type of cancer affecting women, followed by cancer of the uterus, lung and bowel.
Breast cancer is not a single entity; there are various cancers which can develop in the breast, many of which respond well to treatment and are not immediately life threatening. Early detection and diagnosis are important, as treatment of a small breast tumour at an early stage of development may have a better outcome than for most other types of cancer.
Some 75 per cent of breast cancers occur in women over the age of 40; only 2 per cent develop in those younger than 30. The vast majority form in the upper outer quadrant of the breast, and are relatively slow-growing tumours. The life expectancy of a woman receiving no treatment is about 3 years, although many women live with untreated tumours for 10 years or more.
Approximately 1 in 12 women in the UK will develop a breast cancer at some time during their lives. Although this figure may seem high, it is less surprising when compared with the figure of 1 in 3 or 4 people developing some form of cancer. However, this statistic needs to be put in context: the most common form of cancer in the UK is cancer of the skin, which in the majority of cases can be treated successfully.
Most of the risk factors associated with the development of breast cancer have been identified by large epidemiological studies, and the actual added risk these pose is usually very small. Many factors are not accepted by all experts as genuine risks. It has also to be borne in mind that women with all the risk factors may not develop breast cancer; and those with none may do so.
The two biggest risk factors are being a woman, and increasing age. Others may include a family history of breast cancer, having children at a late age, not breast-feeding children, or not having children at all. The most convincing evidence points towards a genetic predisposition in some women, especially those who develop breast cancer at an early age, some factors in the environment, possibly diet related, and the female hormone oestrogen. Different factors may play a part in different women, and some women are more prone to developing breast cancer than others.
Although mammography of young breasts is unreliable, breast screening should ideally begin at the age of 35 for women with substantial risk factors, rather than at 50 as is currently normal in the UK. Some large centers run special clinics for women in the higher risk categories. It is also very important that women in these categories learn the techniques of breast self-examination and of breast awareness.
Although there is controversy about the role of the various possible risk factors, the one thing that does seem clear is that the cause of breast cancer (and of many other cancers) is multi-factorial – various different factors combining together in an individual to result in its development. Environmental factors probably act through specific genes in those at risk.     *17/39/5*

A cancer is a collection of cells which are growing and multiplying uncontrollably. Cancer of the breast is the most common type of cancer affecting women, followed by cancer of the uterus, lung and bowel.
Breast cancer is not a single entity; there are various cancers which can develop in the breast, many of which respond well to treatment and are not immediately life threatening. Early detection and diagnosis are important, as treatment of a small breast tumour at an early stage of development may have a better outcome than for most other types of cancer.
Some 75 per cent of breast cancers occur in women over the age of 40; only 2 per cent develop in those younger than 30. The vast majority form in the upper outer quadrant of the breast, and are relatively slow-growing tumours. The life expectancy of a woman receiving no treatment is about 3 years, although many women live with untreated tumours for 10 years or more.
Approximately 1 in 12 women in the UK will develop a breast cancer at some time during their lives. Although this figure may seem high, it is less surprising when compared with the figure of 1 in 3 or 4 people developing some form of cancer. However, this statistic needs to be put in context: the most common form of cancer in the UK is cancer of the skin, which in the majority of cases can be treated successfully.
Most of the risk factors associated with the development of breast cancer have been identified by large epidemiological studies, and the actual added risk these pose is usually very small. Many factors are not accepted by all experts as genuine risks. It has also to be borne in mind that women with all the risk factors may not develop breast cancer; and those with none may do so.
The two biggest risk factors are being a woman, and increasing age. Others may include a family history of breast cancer, having children at a late age, not breast-feeding children, or not having children at all. The most convincing evidence points towards a genetic predisposition in some women, especially those who develop breast cancer at an early age, some factors in the environment, possibly diet related, and the female hormone oestrogen. Different factors may play a part in different women, and some women are more prone to developing breast cancer than others.
Although mammography of young breasts is unreliable, breast screening should ideally begin at the age of 35 for women with substantial risk factors, rather than at 50 as is currently normal in the UK. Some large centers run special clinics for women in the higher risk categories. It is also very important that women in these categories learn the techniques of breast self-examination and of breast awareness.
Although there is controversy about the role of the various possible risk factors, the one thing that does seem clear is that the cause of breast cancer (and of many other cancers) is multi-factorial – various different factors combining together in an individual to result in its development. Environmental factors probably act through specific genes in those at risk.     *17/39/5*