What is breast cancer?

Breast cancer is a phenomenon in which mammary epithelial cells proliferate uncontrollably under the action of multiple carcinogenic factors. In the early stages of the disease, symptoms such as breast lumps, nipple discharge, and enlarged axillary lymph nodes often occur. In the late stages, cancer cells may metastasize to distant sites, leading to multi-organ lesions and directly threatening the patient's life.

Breast cancer is often called the "pink killer". Its incidence rate ranks first among female malignant tumors, while male breast cancer is relatively rare. With the improvement of medical level, breast cancer has become one of the solid tumors with the best treatment effect.

Incidence of Breast Cancer

Breast cancer is one of the most common cancers in women worldwide. According to WHO, 2.3 million women were diagnosed with breast cancer in 2022, resulting in 670,000 deaths. The incidence of breast cancer is on the rise worldwide. In 2020, the number of new cases of breast cancer reached 2.26 million, surpassing lung cancer (2.2 million cases) for the first time and becoming the number one cancer in the world. The number of cases of breast cancer is expected to rise from 2.3 million in 2020 to more than 3 million in 2040, and 1 million people will die from breast cancer each year.

Risk factors for breast cancer include increasing age, obesity, harmful use of alcohol, family history of breast cancer, history of radiation exposure, reproductive history (such as age at menarche and first pregnancy), tobacco use, and postmenopausal hormone therapy. About half of breast cancers occur in women who have no other identifiable risk factors for breast cancer other than gender (female) and age (over 40). Treatment of breast cancer depends on its subtype and how far it has spread, and the treatment measures include surgery, radiotherapy, and medication.

The global burden of breast cancer is growing, which has disproportionately affected underserved populations, so there is an urgent need to address global cancer inequities.

Types of Disease

Non-invasive cancer

Also known as carcinoma in situ, it refers to the lesion confined to the primary site and not metastasizing. It can be divided into lobular carcinoma in situ, ductal carcinoma in situ, and nipple eczematoid breast cancer, with a good prognosis.

Invasive cancer

It refers to the infiltration of cancer cells and extensive invasion of surrounding tissues, which is prone to cancer metastasis. It is divided into invasive non-special cancer and invasive special cancer. Other factors need to be combined to judge the prognosis.

Invasive non-special cancer

Including invasive ductal carcinoma, invasive lobular carcinoma, scirrhous carcinoma, simple carcinoma, etc. These types are the most common, accounting for about 80%.

Invasive special cancer

Including papillary carcinoma, apocrine carcinoma, squamous cell carcinoma, medullary carcinoma, adenoid cystadenocarcinoma, mucinous adenocarcinoma, etc.

Other rare cancers

In addition to the above common pathological tissue typing, there are some rare breast cancers. The pathological tissue typing is mostly derived from the microscopic characteristics of the tumor rather than its biological behavior, such as spindle cell carcinoma, signet ring cell carcinoma, etc.