Breast cancer: symptoms, treatment and survival

Breast cancer is a disease in which cells in the breast grow uncontrollably, forming a malignant tumour. Most breast cancers begin in the milk ducts (ductal carcinoma) or milk-producing lobules (lobular carcinoma). It is the most commonly diagnosed cancer in the UK, accounting for around 15% of all new cancer cases each year.

According to the NHS, symptoms to report to your GP include: a new lump or thickening in the breast or armpit; a change in breast size or shape; dimpling, puckering or redness of the skin; a rash on or around the nipple; nipple discharge outside pregnancy or breastfeeding; a nipple that has become inverted; or persistent unexplained pain in the breast or armpit. Most lumps are not cancer, but all should be assessed promptly.

Breast cancer is the most commonly diagnosed cancer in the UK. Around 55,000 people are diagnosed every year — approximately 55,000 women and 370 men. About 1 in 7 women in the UK will develop breast cancer at some point in their lifetime. Around 80% of diagnoses are in women aged 50 and over.

Breast cancer arises from genetic mutations in breast cells that allow uncontrolled growth. These mutations may be inherited (as with BRCA1 or BRCA2 gene variants), arise spontaneously with age, or be triggered by hormonal and lifestyle factors. Most breast cancers are not caused by an inherited gene fault — around 5–10% are linked to inherited mutations. The exact cause in any individual case is rarely identifiable.

Main risk factors include: being female; increasing age (most diagnoses are in women over 50); a family history of breast or ovarian cancer; inherited BRCA1 or BRCA2 mutations; dense breast tissue; previous breast cancer; prolonged oestrogen exposure; combined HRT use; being overweight after the menopause; drinking alcohol; and not breastfeeding. Having risk factors does not mean breast cancer will develop, and many women without any known risk factors are diagnosed.

Breast cancer is diagnosed through triple assessment: a clinical examination by a specialist; mammography or ultrasound imaging; and a core needle biopsy of any suspicious area. Additional tests such as MRI, CT or bone scans may be used to stage the disease. Biopsy results confirm whether cancer is present and provide information on type, grade and receptor status to guide treatment planning.

Breast cancer is staged from 0 to IV. Stage 0 (DCIS) means cancer cells are confined within a duct. Stage I means a small tumour (up to 2 cm) with no lymph node spread. Stages II and III involve larger tumours or spread to nearby lymph nodes. Stage IV (metastatic) means the cancer has spread to other organs such as the bones, liver, lungs or brain. Stage determines treatment options and prognosis.

Treatment is planned by a multidisciplinary team and depends on tumour type, stage and receptor status. Main options include surgery (lumpectomy or mastectomy); radiotherapy; chemotherapy; hormone therapy (tamoxifen or aromatase inhibitors for oestrogen-receptor-positive cancers); targeted therapy such as trastuzumab (Herceptin) for HER2-positive disease; CDK4/6 inhibitors; and immunotherapy for triple-negative breast cancer. Most patients receive a combination of treatments.

The five-year survival rate for breast cancer in England is approximately 85%. For Stage I disease, five-year survival exceeds 98%. For Stage IV (metastatic) breast cancer, five-year survival is approximately 28%, though outcomes have improved significantly with modern treatments. More than three-quarters of women diagnosed today will survive for ten or more years.

The NHS recommends becoming familiar with how your breasts normally look and feel, and reporting any new or unexplained change to your GP promptly. Check the entire breast area, including the armpits and up to the collarbone, looking and feeling for lumps, changes in shape, skin changes, nipple changes or new pain. Do not wait for a scheduled screening appointment if you notice something different.

Breast cancer can occur at any age, but risk increases significantly with age. Around 80% of UK breast cancers are diagnosed in women aged 50 and over, with peak incidence in the 65–69 age group. Breast cancer in women under 40 is uncommon but does occur — younger women are not invited for routine NHS screening but should see a GP with any concerns.

Yes. Around 370 men are diagnosed with breast cancer each year in the UK — less than 1% of all breast cancer cases. Symptoms are similar to those in women: a lump or swelling in the chest area, nipple discharge, or skin changes. Men with a family history of breast cancer or who carry a BRCA2 gene variant are at higher risk. Male breast cancer is often diagnosed later because awareness is lower.

Some breast cancers are linked to inherited gene faults, but the majority are not. Approximately 5–10% of breast cancers are associated with inherited mutations in genes including BRCA1, BRCA2, TP53 and PALB2. Women with a strong family history can be referred for genetic counselling and testing via their GP. A positive BRCA test carries significant implications and options including enhanced surveillance and preventive surgery.

BRCA1 and BRCA2 are tumour suppressor genes. Inherited mutations in these genes significantly increase the risk of breast and ovarian cancer. Women with a BRCA1 mutation have approximately a 65–72% lifetime risk of breast cancer; those with BRCA2 have approximately a 45–69% lifetime risk. Both genes also raise ovarian cancer risk. BRCA2 mutations are the most common inherited cause of male breast cancer. NHS genetic testing is available for those who meet clinical criteria.

Triple negative breast cancer (TNBC) is a subtype that tests negative for oestrogen receptors, progesterone receptors and HER2 — accounting for about 15% of breast cancers. Because it does not respond to hormone therapy or anti-HER2 treatments, treatment relies on chemotherapy and, increasingly, immunotherapy (pembrolizumab). TNBC tends to grow faster and recur more often than receptor-positive cancers, and is more common in younger women.

Secondary or metastatic breast cancer — Stage IV — is breast cancer that has spread from the breast to other parts of the body, most commonly the bones, liver, lungs or brain. It is not a new cancer but an extension of the original. It is not currently curable, but is treatable: many patients live for several years with good quality of life on modern treatments including hormone therapy, CDK4/6 inhibitors, targeted therapy and immunotherapy.

The NHS Breast Screening Programme invites all women registered with a GP in England, aged 50–71, for a mammogram every three years. A mammogram is a low-dose X-ray that can detect tumours too small to feel. Women outside this age range can self-refer by contacting their local breast screening unit. Women with a family history of breast cancer may be offered earlier or more frequent screening via their GP.

Combined HRT (oestrogen plus progestogen) is associated with a moderately increased risk of breast cancer, rising with longer duration of use. Oestrogen-only HRT (used by women who have had a hysterectomy) carries a lower risk. The NHS states that for most women, the benefits of HRT for menopausal symptoms outweigh the risks, but decisions should be made individually with a GP. The increased risk from combined HRT is broadly comparable to drinking one to two units of alcohol per day.

While no measure eliminates risk entirely, the NHS advises: maintaining a healthy weight, especially after the menopause; limiting alcohol; being physically active regularly; breastfeeding where possible; and discussing HRT risks with a doctor. Women with high genetic risk may be offered chemoprevention (tamoxifen or anastrozole) or preventive surgery (mastectomy or oophorectomy) after specialist genetic counselling.

The World Health Organization notes that over 70% of breast cancer deaths occur in low- and middle-income countries. Five-year survival in these settings is often below 50%, compared with 85% in England — primarily because of late diagnosis and unaffordable treatment. World Aid Network funds cancer treatment for poor patients through locally-licensed oncologists, working to close this survival gap.