1.2.1 Breast Clinical Manifestation
Early breast cancer often has no obvious symptoms，manifests only as mild breast pain，mostly dull pain，a few stabbing pain，and pain does not change with the menstrual cycle.Advanced cancer invade nerve to cause intense pain that will radiate to the ipsilateral shoulders and arms.The main symptoms of breast cancer are breast lump，pain，nipple discharge，nipple changes，local skin changes and axillary fossa lymphadenectasis.
Breast lumps
Breast lumps are the most common symptom of breast cancer，and about 90%of patients who come to the hospital with this symptom.
1.Sites：Most of lumps are located in the upper outer quadrant，followed by the upper inner quadrant，upper and central areas，and less other parts.［18］
2.Number：Single lump of unilateral breast cancer is common，while multiple lumps of unilateral breast cancer and primary bilateral breast cancer are less.
3.Size：Lumps vary in size.The lump in early breast cancer are usually small.If the visit is late，the breast mass is usually large.
4.Shape，surface and boundary：The shape of lump is varied，generally irregular，such as round，oval，flat.The surface of lump is not smooth and there is a nodular feeling.
5.Hardness：The texture of lump is not identical completely，more hard mostly，someone like medullary carcinoma rich in cells can be slightly soft，cystic papillary carcinoma may be cystic.
6.Range of motion：When the lump is small，the range of motion is large，and the mass often moves with the surrounding soft tissues.
Breast pain(https://www.daowen.com)
Breast pain can be seen in a variety of breast diseases，but pain is not a common symptom of breast cancer.Benign or malignant breast tumors usually appear painless，and be found by physical examination or touched.Breast cancer accompanied by inflammation presents as distending pain or tenderness，and terminal cancer may have shoulder swelling if the lump invades nerve or axillary fossa lymphadenectasis oppresses or invades brachial plexus.
Nipple discharge
Nipple discharge in breast cancer is second only to breast lump and breast pain，and it is common in ductal or intraductal cancers.Nipple discharge is bloody，serous or watery.The early clinical manifestation of intraductal carcinoma may be only effusion but not obvious mass.Malignant change of intraductal papilloma and papillary paget disease can also be accompanied by nipple discharge.
Nipple changes
When the cancer invades the nipple or areola，the fibrous tissue and ductal of the breast occur contracture，resulting in the nipple flattening，retraction and depression.Breast cancer patients with abnormal changes in the nipple，usually manifested as nipple erosion or nipple retracted.Sometimes the affected breast is raised，leading to nipples that are not on the same level.
Local skin changes
The change of skin is related to the location，depth and extent of the cancer invades，usually as skin adhesion，superficial varicose veins，skin redness and skin edema.In addition，advanced breast cancer can encroach on the skin to cause ulcer and lump break，which look like cauliflower and does not heal.If the cancer cells infiltrate into the skin and continue to grow，they may occur scattered distribution of hard nodules in the skin around the main lesion，namely satellite nodules of the skin.
Axillary fossa lymphadenectasis
As breast cancer progresses，it can invade lymphatic vessels and metastasize to its local lymphatic drainage area.Early metastasis generally can not touch the axilla and supraclavicular fossa lymph nodes.If the axillary and supraclavicular lymph nodes are swollen，hard and less active，or fused，the possibility of metastasis is high.If axillary lymph node metastasis is positive，and immunohistochemistry indicates that the source of breast，and imaging examination has not found the primary breast lesions，so it is necessary to be vigilant against insidious breast cancer.