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What does the beginning of breast cancer look like?

Breast cancer is one of the most common cancers among women worldwide. It starts when cells in the breast begin to grow out of control and can then invade nearby tissues or spread to other areas of the body. The earliest changes that signify breast cancer is starting to develop are not always noticeable without medical tests, but some early signs can appear before a lump becomes noticeable. Being aware of the early signs of breast cancer is important for early detection and treatment.

What are the earliest signs of breast cancer?

Some of the earliest signs of breast cancer include:

Changes in the look and feel of the breast

– Swelling, thickening, or lumpiness in part of the breast or underarm area. Lumps are often the first noticeable symptom of breast cancer, but not all lumps are cancerous. Non-cancerous breast lumps are usually painful, whereas cancerous lumps are typically not painful.

– Changes in the size or shape of the breast. Subtle changes may occur before a lump is large enough to be felt. One breast looking larger or lower than the other breast.

– Nipple tenderness, inversion, or spontaneous discharge (fluid leaking from the nipple). These changes are often not cancerous but should be evaluated by a doctor.

– Changes to the skin over the breast such as dimpling, puckering, scaliness, or new creases and pitting resembling the skin of an orange. This occurs when cancer cells are spreading and pulling at the skin tissue.

Nipple discharge

Nipple discharge refers to any fluid coming from the nipple that is not breast milk. Discharge may be:

– Clear, milky, yellow, green, or dark in color
– Thick and sticky or thin and watery
– Occurring in one or both breasts

Nipple discharge is common and benign in many cases, especially during or after pregnancy. However, persistent unilateral discharge (affecting only one breast) that is bloody, spontaneous, or occurs without squeezing the nipple, could indicate an underlying breast problem. It should be examined by a doctor to identify the cause.

Skin changes

Some women notice changes to the skin overlying the breast or nipple well before a lump is detected. Signs can include:

– Redness, pitting, thickening, or scaling of the skin
– Rash or sores resembling eczema
– Swollen or distended pores

Inflammatory breast cancer is a rare but fast-growing type of breast cancer that often causes redness and swelling of the breast. Although it may not always form a distinct lump, it warrants immediate medical attention.

Breast pain

Breast pain (mastalgia) is very common and is not usually a sign of cancer. But new, persistent breast pain should not be ignored, especially when it occurs in only one breast. Pain associated with breast cancer is not always a sore lump. It can also feel like:

– A burning sensation
– Tenderness or discomfort
– Tightness or aching
– Stabbing pains

Severe and unexplained breast pain should be evaluated by an oncologist to determine the cause.

What causes early signs of breast cancer?

The early changes that occur in a developing breast cancer are related to how cancer cells form and grow within breast tissue:

Atypical cell growth

Cancer begins when healthy cells acquire mutations in their DNA that allow them to divide and multiply uncontrollably. As more abnormal cells amass, they form a tumor that can be too small to see or feel. Before cancer spreads elsewhere, it is called ductal carcinoma in situ (DCIS) or lobular carcinoma in situ (LCIS).

Tissue changes

With continued growth, small tumors begin pressing on nearby breast tissue, blood vessels, and ducts. This causes architectural changes visible in a mammogram, such as:

– Microcalcifications (tiny deposits of calcium)
– Changes to breast thickness or texture
– Abnormal duct patterns

Later, enlarging cancers may cause fluid to build up, thickening of the skin, or nipple changes.

Local invasion

Left untreated, cancer cells invade the matrix surrounding breast tissue and can penetrate blood and lymph vessels. This enables cancer to metastasize (spread) throughout the body. Locally advanced breast cancers have substantial growth but have not yet metastasized.

Who is at risk of developing early stage breast cancer?

Certain factors can increase a woman’s risk of developing breast cancer and influence how early it may appear:


The risk of breast cancer increases with age, with most diagnoses occurring after age 50. However, young women can also develop breast cancer, so all women should be vigilant about changes.


Having close relatives who developed breast cancer may increase risk. Inherited mutations in BRCA1 and BRCA2 genes increase the lifetime risk of breast cancer to 55-65%.

Reproductive history

Women who began menstruating before age 12 or reached menopause after age 55 have a higher risk. Nulliparity (never giving birth) also increases risk.

Previous breast cancer

A personal history of breast cancer, precancerous lesions, or radiation therapy to the chest heightens the risk of developing subsequent breast cancers.


Obesity, smoking, excessive alcohol use, and limited physical exercise are linked to increased breast cancer risk.

Hormone therapy

Taking combined estrogen-progesterone hormone replacement therapy (HRT) during menopause can increase risk, especially with prolonged use.

How can I check for early signs of breast cancer?

Some techniques women can use to detect subtle breast changes include:


Performing regular breast self-examinations helps women become familiar with the typical look and feel of their breasts. Reporting any new lumps, swelling, or skin changes to a doctor is essential.

Clinical breast exam

During an annual well-woman exam, a doctor manually palpates the breasts for abnormalities in texture, shape, or suspicious masses. Doctors can often detect cancers smaller than what is palpable by a woman doing self-exams.

Imaging tests

– Mammograms – Low-dose x-rays that can detect tumors too small to feel. Annual mammograms are recommended starting at age 40.

– Ultrasound – Sound waves produce images of internal breast tissues, sometimes distinguishing solid masses from fluid-filled cysts.

– MRI – Magnetic resonance imaging provides detailed three-dimensional imaging of the breast and can detect early growths. It is used in conjunction with mammograms in some women at high risk.

What are the stages of early breast cancer?

The stage of breast cancer describes how far it has progressed anatomically within the breast tissue and lymph nodes:

Stage 0

Refers to non-invasive breast cancers confined to the ducts (DCIS) or lobules (LCIS). The abnormal cells have not spread into surrounding tissues.

Stage I

The tumor is 2 cm (about 3/4 inch) or smaller and has not spread outside the breast. Small clusters of cancer cells in lymph nodes are sometimes present.

Stage II

Divided into IIA and IIB depending on tumor size and lymph node involvement:

– Stage IIA – No tumor in the lymph nodes, but one of the following:
– The tumor is larger than 2 cm but not larger than 5 cm
– Microscopic clusters of cells in the lymph nodes
– Two or more areas of cancer in the same breast

– Stage IIB – One of the following:
– The tumor is larger than 5 cm but has not spread to lymph nodes
– Cancer has spread to 1-3 lymph nodes in the armpit or breastbone

What is the outlook for early stage breast cancer?

Breast cancer is highly treatable in the early stages. The 5-year survival rates for localized breast cancers are:

– Stage 0 – Almost 100%
– Stage I – 100%
– Stage IIA – 93%
– Stage IIB – 91%

Early diagnosis dramatically improves the prognosis. It allows for breast-conserving surgery and less aggressive therapies with fewer complications compared to more advanced disease.


Many early breast tumors begin with subtle changes that are imperceptible on imaging and not yet palpable. As breast cancer progresses, signs like lumpiness, nipple discharge, skin changes, or breast pain may arise. Following recommended screening guidelines and being vigilant about new breast changes can lead to detection at the earliest stages when breast cancer is most treatable. Women should discuss any concerning symptoms with their doctor as soon as they appear. With proactive monitoring and early intervention, most women diagnosed with early stage breast cancer go on to live long, healthy lives.