Breast Cancer: Risk Factors and Prevention

Breast Cancer: Risk Factors and Prevention

Anything that increases the chances of a person to develop cancer is called risk factor. These risk factors are not directly cancer causing but can influence the development of cancer. Different people have different risk factors to develop cancer. Some people having several risk factors do not develop cancer whereas others may develop cancer having no known risk factor.

Most breast cancers are sporadic which is due the damaging of genes of a person after they born or by chance. These genes have no risk of passing from one generation to other.

There is only 5% to 10% chances of developing inherited breast cancer. Inherited breast cancer develops when mutations which are gene changes are transferred from parents to children. Most of such mutations are in tumer suppression genes such as BRCA1 or BRCA2. These genes generally keep the cells to grow out of control and turn into cancer. But when these cells contain a mutation, it can give rise out of control growth.

Most women that develop breast cancer do not have any obvious risk factor and also do not have inherited genes that cause breast cancer. The development of breast cancer is influenced by multiple risk factors. So all women should have awareness of changes in their breasts. Women should have mammograms on regular basis that is X-ray of the breasts and detect a tumor that is often too small to be felt.

The following risk factors may influence the development of breast cancer in a woman:

Age

The risk of development of breast cancer increases with the age of a woman. Most of the breast cancer develops in women having age over than 50.

Personal history of breast cancer

A woman having breast cancer in one breast have higher risks of cancer development in either breast.

Family history of breast cancer 

Breast cancer may invade in the family having any of these situations:

·         0ne or more women having age less than 45 are diagnosed.

·         Diagnosis of one or more women having breast cancer before age 50 and having additional family history of cancer such as melanoma, prostate cancer and pancreatic cancer.

·         Both mother and father’s family are diagnosed with ovarian and breast cancer in multiple generations.

·         A woman having diagnosed with a second breast cancer in the other breast or in the same breast or having breast cancer in both breasts and ovarian cancer.

·         Diagnosis of breast cancer in male relative.

·         Having a history of breast cancer, prostate cancer, pancreatic cancer and ovarian cancer on same side of the family.

·         Possessing Ashkenazi Jewish ancestry

All of the above mentioned situations are signs of carrying inherited breast cancer genetic mutation such as BRCA1 or BRCA2.

Inherited risk/genetic predisposition

Breast cancer as well as other type of cancer are associated with genes that increases the risk of developing cancer. The most common mutations of cancer are BRCA1 or BRCA2. Mutations in these genes are associated with an increased risk of developing ovarian and breast cancer as well as other types of cancer. There is also a risk of developing breast cancer as well as prostate cancer having mutations in these genes.

Other hereditary conditions or gene mutations that can icrease risks of breast cancer are far less common than BRCA1 or BRCA2.

·         Lynch syndrome: It is associated with the MLH1, MSH2, MSH6, and PMS2 genes

·         Cowden syndrome: It is associated with the PTEN gene

·         Li-Fraumeni syndrome: It is associated with the TP53 gene

·         Peutz-Jeghers syndrome: It is associated with the STK11 gene

·         Ataxia telangiectasia: It is associated with the ATM gene

·         Hereditary diffuse gastric cancer: It is associated with the CDH1 gene

·         PALB2 gene

·         CHEK2 gene

There are also other genes that may cause an increased risk of There are also other genes that are responsible for increasing risks of developing breast cancer. Research is also continue to identify the other genes that can influence the risks of breast cancer.

Known Mutations in BRCA1 and BRCA2 genes and other genes associated with hereditary syndromes can be now tested through genetic testing. This can be done through “panel test”. A panel test can identify mutations in several genes at the same time. These tests are not for everyone and only recommended after proper genetic counselling.

Personal history of ovarian cancer

Mutations in BRCA1 and BRCA2 genes greatly increase the risks of breast cancer and ovarian cancer. Therefore a women having hereditary ovarian cancer due to mutations in BRCA gene have also increased risks of developing breast cancer. Women having breast risk without inherit BRCA1 or BRCA2 genetic mutation have lower risks of developing ovarian cancer.

Early menstruation and late menopause 

Women in which menstruation began before ages of 11 or 12 or having menopause after age of 55 have generally higher risks of developing breast cancer. This is due to the longer time exposure of breast cells to estrogen and progesterone. Estrogen and progesterone are hormones in females that regulate the development of secondary sex characteristics such as pregnancy and breast development. These production of these hormones decreases with age of woman having steep decrease around menopause. The risk of developing breast cancer increases having long time exposure to these hormones.

Timing of pregnancy 

Women having their first pregnancy after age of 35 or never having a full-term pregnancy have higher risks of developing breast cancer.

Hormone replacement therapy after menopause 

Postmenopausal hormone therapy or hormone replacement with estrogen and progestin between the past 5 years or for several years increases the risks of developing breast cancer in woman. However women taking only estrogen with receiving progestin for up to 5 years due to removal of uterus have lower risks of developing breast cancer.

Oral contraceptives or birth control pills

Some studies have shown that oral contraceptives also have little influence on the risks of developing breast cancer but other research have shown no link between the use of oral contraceptives and developing the breast cancer. However the research on this topic is under process.

Race and ethnicity

The most common cancer diagnosis in women is breast cancer other than skin cancer, regardless of the race. The risks of developing breast cancer are high in white women than in black women, but among women younger than 45, breast cancer is more common in black women than in white women. There is also chances of death from disease in black women. Reasons may include socioeconomic factors affecting access to medical care, difference in biology, and other health conditions.
Women of Ashkenazi or Eastern European Jewish heritage have higher risks of developing breast cancer because they have more chances of inherited BRCA gene mutation. Breast cancer is least commonly diagnosed in Asian/Pacific islander, Hispanic and American Indian/Alaska Native women. Both Hispanic and black women have higher chances of cancer diagnosis than white women. However, survival rates are higher in Hispanic women than white women. The reasons behind increasing rate of breast cancer diagnosis in second generation Asian/Pacific Islander and Hispanic women are unclear. However, the increased rate is preferentionally related to diet changes and living lifestyles in United States.

Atypical hyperplasia of the breast

The diagnosis of atypical hyperplasia have increased the rate of breast cancer development in future. It is associated with abnormal but not cancerous cells that have been found in the biopsy of the breast.

LCIS

LCIS refers to the abnormal cells present in glands or lobules of the breast. It is not categorized as cancer. However, LCIS in 1 breast causes an increase in the risk of development of invasive breast cancer in either breast in the future. LCIS can be removed during biopsy for checking other changes. There is also recommendation of additional treatment.

Breast density 

Standard imaging tests such as mammography finds it difficult to find tumor in dense breast tissue. Dense breast tissues means having more milk ducts, milk glands and supportive tissue the breast than fatty acid. Higher levels of estrogen may be the cause of breast density and normally decreases with age. Mammogram results contain information breast density and showing the results with a woman having dense breast tissue. Researches are ongoing of decreased risk factors of breast cancer associated with lowering breast density.

Lifestyle factors

Different lifestyle factors may also contribute to the risk factors of developing breast cancer.

·         Weight

It has been shown by recent studies that postmenopausal women that are overweight or obese have an increased risk factor of developing breast cancer. These women also have high chances of developing breast cancer after treatment.

·         Physical activity 

The risks of developing breast cancer is also associated with decreased physical activity and have higher chances of cancer come back after treatment. By regular physical activity, the risks of developing breast cancer can be minimized. This can be done by maintaining a healthy body weight, causing changes in a women’s immune factors or metabolism.

·         Alcohol

Recent research have shown that having more than one alcoholic drinks including wine, beer and spirits per day increases the risks of developing breast cancer as chances of cancer come back after treatment.

·         Food

There are no reliable evidences that confirms that avoiding or eating specific foods decreases the risks of breast cancer or cancer come back after treatment. However eating vegetables and more fruits and fewer animal fats is associated with many health benefits.

Socioeconomic factors

More affluent women in all ethnic and racial groups have higher risks of developing breast cancer than less affluent women. It is due to unknown reasons. But these differences may be due to difference in environmental exposure, diet and other factors such as breast density. Women living in poverty have higher risks of cancer diagnosis at an early stage and less chances to survive the disease than more affluent women. This may be due to multiple factors including health conditions such as obesity, lifestyle factors and tumor biology. Availability of treatment and access to health care also play additional roles.

Exposure to radiation at a young age

Women’s risk of breast cancer may increases due to exposure to ionizing radiations at a young age. For example risks of developing breast cancer increase due to therapeutic radiation to the chest for Hodgkin lymphoma.

The little amount of radiation a woman receiving during mammogram may not associated with increased risks of developing breast cancer.