**2. Risk factors of breast cancer**

Being a women and getting older are the main influence to have breast cancer. It has been reported that women with age 30has a lower chance (about 1 in 1500) of developing breast cancer compared to women with age 40 (about 1 in 173) [5]. Thus, being 40 years of age or above poses significant risk for developing breast malignancy. There are several other factors that play crucial role in developing breast cancer, such as history of cancer in first-degree relatives, history of mammary gland diseases, early menarche, late menopause, Caucasian race, and late childbearing after 35 years of age. Causes of breast cancer development have also been linked to lifestyle-related factors including alcohol consumption, not being physically active, being overweight or obese and using hormone replacement therapy. Risk of having breast cancer may result from combination for these factors as reviewed by Singletary [6] as can be seen in **Table 1**.

Breast cancer classification systems have been utilized in order to organize the heterogeneity of this disease. Over many decades, these systems have been developed in order to assist in prognosis and treatment. The breast cancer classification models evolved due to advances in cancer research and understanding of the molecular heterogeneity of breast cancers. These classifications are based on histological and molecular variations in breast cancer subtypes [7]. Such classifications assist in understanding the growth and progression of breast cancer as well as in their therapeutic management.


\* There is controversy over whether pathologic hyperplasia detected in breast biopsy samples is directly equivalent to cytologic hyperplasia detected in samples obtained through FNA or nipple aspiration.

**Table 1.** Risk factors for breast cancer.

new cancer cases (23%) and 458,400 (14%) of the total cancer deaths in 2008 worldwide. Of these, about 50% of the cases of breast cancer and 60% of breast cancer deaths takes place in developing countries including Western and Northern Europe, North America, Australia and New Zealand [2]. In the United States, in 2008, the American Cancer Society (ACS) estimates that almost 182,500 women were diagnosed with breast cancer and during the year about

The breast is made up of different types of tissues including fatty, lymphatic and connective tissue. A female breast is organized into 15–20 sections called lobes. Each of these lobes contains many smaller glandular structures called lobules which responsible for milk production. The lobes and lobules are connected through a network of tubes called ducts through

Majority of breast cancers arise from the cells in the duct or from milk-producing cells in the lobules. Increase in the incidence of breast cancer observed in epidemiological studies is as a result of breast cancer risk factors. About 20–30% of diagnosed cancer cases may be associated with these factors and their activity that lead to deregulation of the normal cellular processes into neoplastic transformation of breast cells [4]. However, about 75–80% of women with breast cancer have no identifiable risk factor [4]. Therefore, different system or model is

Being a women and getting older are the main influence to have breast cancer. It has been reported that women with age 30has a lower chance (about 1 in 1500) of developing breast cancer compared to women with age 40 (about 1 in 173) [5]. Thus, being 40 years of age or above poses significant risk for developing breast malignancy. There are several other factors that play crucial role in developing breast cancer, such as history of cancer in first-degree relatives, history of mammary gland diseases, early menarche, late menopause, Caucasian race, and late childbearing after 35 years of age. Causes of breast cancer development have also been linked to lifestyle-related factors including alcohol consumption, not being physically active, being overweight or obese and using hormone replacement therapy. Risk of having breast cancer may result from combination for these factors as reviewed by Singletary [6] as

Breast cancer classification systems have been utilized in order to organize the heterogeneity of this disease. Over many decades, these systems have been developed in order to assist in prognosis and treatment. The breast cancer classification models evolved due to advances in cancer research and understanding of the molecular heterogeneity of breast cancers. These classifications are based on histological and molecular variations in breast cancer subtypes [7]. Such classifications assist in understanding the growth and progression of breast cancer

40,500 women lost their life due to breast cancer.

104 Breast Cancer and Surgery

which milk flows and reaches the nipple [3].

required to be utilized to examine this cancer.

**2. Risk factors of breast cancer**

as well as in their therapeutic management.

can be seen in **Table 1**.
