Breast Cancer Flashcards
Risk Factors for Breast Cancer
Female (99% of breast cancers)
Increased oestrogen exposure (earlier onset of periods and later menopause)
More dense breast tissue (more glandular tissue)
Obesity
Smoking
Family history (first-degree relatives)
The combined contraceptive pill gives a small increase in the risk of breast cancer, but the risk returns to normal ten years after stopping the pill.
Hormone replacement therapy (HRT) increases the risk of breast cancer, particularly combined HRT (containing both oestrogen and progesterone).
Genetics in Breast Cancer
BRCA refers to the BReast CAncer gene. The BRCA genes are tumour suppressor genes. Mutations in these genes lead to an increased risk of breast cancer (as well as ovarian and other cancers).
The BRCA1 gene is on chromosome 17. In patients with a faulty gene:
Around 70% will develop breast cancer by aged 80
Around 50% will develop ovarian cancer
Also increased risk of bowel and prostate cancer
The BRCA2 gene is on chromosome 13. In patients with a faulty gene:
Around 60% will develop breast cancer by aged 80
Around 20% will develop ovarian cancer
There are other rarer genetic abnormalities associated with breast cancer (e.g., TP53 and PTEN genes).
Ductal Carcinoma in Situ
Pre-cancerous or cancerous epithelial cells of the breast ducts
Localised to a single area
Often picked up by mammogram screening
Potential to spread locally over years
Potential to become an invasive breast cancer (around 30%)
Good prognosis if full excised and adjuvant treatment is used
Lobular Carcinoma in Situ
A pre-cancerous condition occurring typically in pre-menopausal women
Usually asymptomatic and undetectable on a mammogram
Usually diagnosed incidentally on a breast biopsy
Represents an increased risk of invasive breast cancer in the future (around 30%)
Often managed with close monitoring (e.g., 6 monthly examination and yearly mammograms)
Invasive Ductal Carcinoma
NST means no special/specific type, where it is not more specifically classified (e.g., medullary or mucinous)
Also known as invasive breast carcinoma of no special/specific type (NST)
Originate in cells from the breast ducts
80% of invasive breast cancers fall into this category
Can be seen on mammograms
Invasive Lobular Carcinoma
Around 10% of invasive breast cancers
Originate in cells from the breast lobules
Not always visible on mammograms
Inflammatory Breast Cancer
1-3% of breast cancers
Presents similarly to a breast abscess or mastitis
Swollen, warm, tender breast with pitting skin (peau d’orange)
Does not respond to antibiotics
Worse prognosis than other breast cancers
Paget’s Disease of Nipple
Looks like eczema of the nipple/areolar
Erythematous, scaly rash
Indicates breast cancer involving the nipple
May represent DCIS or invasive breast cancer
Requires biopsy, staging and treatment, as with any other invasive breast cancer
Screening
The NHS breast cancer screening program offers a mammogram every 3 years to women aged 50 – 70 years.
Screening aims to detect breast cancer early, which improves outcomes. Roughly 1 in 100 women are diagnosed with breast cancer after going for a mammogram.
There are some potential downsides to screening:
Anxiety and stress
Exposure to radiation, with a very small risk of causing breast cancer
Missing cancer, leading to false reassurance
Unnecessary further tests or treatment where findings would not have otherwise caused harm
Generally, the benefits far outweigh the downsides and breast cancer screening is recommended.
High-Risk Patients
There are different recommendations for screening patients with a higher risk due to a family history of breast cancer. These are in the NICE guidelines (2013, updated 2019).
There are specific criteria for a referral from primary care for patients that may be at higher risk due to their family history. For example:
A first-degree relative with breast cancer under 40 years
A first-degree male relative with breast cancer
A first-degree relative with bilateral breast cancer, first diagnosed under 50 years
Two first-degree relatives with breast cancer
Depending on their risk factors, they may be seen in a secondary care breast clinic or a specialist genetic clinic.
Patients require genetic counselling and pre-test counselling before performing genetic tests. This is to discuss the benefits and drawbacks of genetic testing, such as the implications for family members and offspring.
Annual mammogram screening is offered to women with increased risk, between specific age ranges, depending on their level of risk (potentially starting from aged 30, if high risk).
Chemoprevention may be offered for women at high risk, with:
Tamoxifen if premenopausal
Anastrozole if postmenopausal (except with severe osteoporosis)
Risk-reducing bilateral mastectomy or bilateral oophorectomy (removing the ovaries) is an option for women at high risk. This is suitable for only a small number of women and requires significant counselling and weighing up risks and benefits.
Presentation of Breast Cancer
Clinical features that may suggest breast cancer are:
Lumps that are hard, irregular, painless or fixed in place
Lumps may be tethered to the skin or the chest wall
Nipple retraction
Skin dimpling or oedema (peau d’orange)
Lymphadenopathy, particularly in the axilla
Referral in Breast Cancer
The NICE guidelines (updated January 2021) recommend a two week wait referral for suspected breast cancer for:
An unexplained breast lump in patients aged 30 or above
Unilateral nipple changes in patients aged 50 or above (discharge, retraction or other changes)
The NICE guidelines recommend also considering a two week wait referral for:
An unexplained lump in the axilla in patients aged 30 or above
Skin changes suggestive of breast cancer
The NICE guidelines suggest considering non-urgent referral for unexplained breast lumps in patients under 30 years.
Triple Assessment
Imaging
Younger women generally have more dense breasts with more glandular tissue.
Ultrasound scans are typically used to assess lumps in younger women (e.g., under 30 years). They are helpful in distinguishing solid lumps (e.g., fibroadenoma or cancer) from cystic (fluid-filled) lumps.
Mammograms are generally more effective in older women. They can pick up calcifications missed by ultrasound.
MRI scans may be used:
For screening in women at higher risk of developing breast cancer (e.g., strong family history)
To further assess the size and features of a tumour
Lymph Node Assessment
Women diagnosed with breast cancer require an assessment to see if cancer has spread to the lymph nodes. All women are offered an ultrasound of the axilla (armpit) and ultrasound-guided biopsy of any abnormal nodes.
A sentinel lymph node biopsy may be used during breast cancer surgery where the initial ultrasound does not show any abnormal nodes.
Sentinel Lymph Node Biopsy
Sentinel node biopsy is performed during breast surgery for cancer. An isotope contrast and a blue dye are injected into the tumour area. The contrast and dye travel through the lymphatics to the first lymph node (the sentinel node). The first node in the drainage of the tumour area shows up blue and on the isotope scanner. A biopsy can be performed on this node, and if cancer cells are found, the lymph nodes can be removed.
Breast Cancer Receptors
Breast cancer cells may have receptors that can be targeted with breast cancer treatments. These receptors are tested for on samples of the tumour and help guide treatment. There are three types of receptors:
Oestrogen receptors (ER)
Progesterone receptors (PR)
Human epidermal growth factor (HER2)
Triple-negative breast cancer is where the breast cancer cells do not express any of these three receptors. This carries a worse prognosis, as it limits the treatment options for targeting the cancer.
Gene Expression Profiling
Gene expression profiling involves assessing which genes are present within the breast cancer on a histology sample. This helps predict the probability that the breast cancer will reoccur as a distal metastasis (away from the original cancer site) within 10 years.
The NICE guidelines (2018) [DG34] recommend this for women with early breast cancers that are ER positive but HER2 and lymph node negative. It helps guide whether to give additional chemotherapy.
Breast cancer metastasies to
L – Lungs
L – Liver
B – Bones
B – Brain
Treatment of Breast Cancer
Tumour Removal
The objective is to remove the cancer tissue along with a clear margin of normal breast tissue. The options are:
Breast-conserving surgery (e.g., wide local excision), usually coupled with radiotherapy
Mastectomy (removal of the whole breast), potentially with immediate or delayed breast reconstruction
Axillary Clearance
Removal of the axillary lymph nodes is offered to patients where cancer cells are found in the nodes. Usually, the majority or all lymph nodes are removed from the axilla. This increases the risk of chronic lymphoedema in that arm.
Chronic Lymphoedema
Lymphoedema is a chronic condition caused by impaired lymphatic drainage of an area. Lymphoedema can occur in an entire arm after breast cancer surgery on that side, with removal of the axillary lymph nodes in the armpit.
The lymphatic system is responsible for draining excess fluid from the tissues. The tissues in areas affected by an impaired lymphatic system become swollen with excess, protein-rich fluid (lymphoedema).
The lymphatic system also plays an important role in the immune system. Areas of lymphoedema are prone to infection.
There are specialist lymphoedema services that can help manage patients. Non-surgical treatment options include:
Massage techniques to manually drain the lymphatic system (manual lymphatic drainage)
Compression bandages
Specific lymphoedema exercises to improve lymph drainage
Weight loss if overweight
Good skin care
