• Uncommon <30yo.  1/3 are premenopausal, 2/3 are postmenopausal
• 1 in 11 women in Australia develop breast cancer
• Of those who present with local disease, about 50% will develop metastases. 

Risk Factors

• Increasing age (>40yo), Caucasian
• Pre-existing benign breast lumps
• Alcohol, Obesity
• HRT >5 years
• Personal history breast cancer
• Family history in a first degree relative (raises risk about 3 fold). 5% of cases are familial.
• Nulliparity, Childless until after 30yo, Late menopause (after 53yo), Early menarche
• Ionising radiation exposure

Screening

• Mammogram in women 50-69yo every 2 years
• Insufficient evidence for clinical breast exams (therefore cannot recommend them)
• Might start mammograms at 40 if first-degree relative <50years at diagnosis.

Clinical features

• Presenting symptoms of breast cancer
  • HARD irregular lump
  • Thickening or ridge
  • Breast or nipple asymmetry
  • Skin changes, skin dimpling, puckering
  • skin oedema (peau d’orange)
  • Nipple changes/distortion/eczema
  • Nipple discharge
  • Unilateral breast pain

• Relevant history
  • Previous breast issues/investigation
  • Risk factors
  • hormonal status, menstrual history, parity, recent pregnancies and breastfeeding 
  • current medications or recent changes in medication, especially exogenous hormones, complementary and alternative medicines 
  • lifestyle factors, including obesity, alcohol, physical activity and smoking 
  • most recent imaging results – screening or diagnostic 
  • previous radiation therapy or previous breast surgery, including cosmetic surgery 
  • recent breast trauma – symptoms still require investigation

Examination

• Inspection – upright
  • Arms by side, above head, pressing hips and leaning foward
  • Breast contours, skin changes, nipples
• Palpation
  • Upright – supraclavicular and axillary lymph nodes, breasts (particularly outer quadrants)
  • Lying flat – all quadrants, axillary tail, around and behind nipple
• Record details of any changes

• Nipple
• Benign nipple changes may include
  • Slit like retraction
  • Retraction that is easily everted
• Suspiscious nipple changes
  • Colour change
  • Fixed whole nipple inversion
  • Ulceration and eczematous changes
• Nipple discharge
  • Unilateral, spontaneous, bloody or serous discharge highly suspiscious
  • Positive cytology is indicative, but negative cytology is not sensitive
  • If bilateral, no blood – review, consider prolactin levels

Investigations

  Triple test

1. Medical history and breast examination
2. Imaging– mammography and/or ultrasound
3. Non-excision biopsy – core biopsy and/or fine needle aspiration (FNA) cytology.

• Mammography – Established benefit >50yo, possible benefit for women in 40s
• Breast ultrasound
  • Mainly used to elucidate an area of breast density, best method of defining benign breast disease, especially with cystic changes
  • USS more sensitive in young women
  • Most useful in women <35yo (as compared with mammography)
  • Also good for palpable masses at periphery (mammograms wont pick these up)

• Age Under 35
  • USS first line. Use mammogram if suspicious, malignant, indeterminate or USS not consistent with clinical findings
• Age 35 – 50
  • Do both mammography and USS
• Age> 50 years
  • Mammogram only, but in some cases USS may be useful, always useful if discrete breast lump
• Pregnancy/lactation
  • USS more useful
  • Mammogram if suspicious/indeterminate
• Biopsy
  • Core biopsy or FNA – image guided, Core biopsy preferred if suspicious
  • FNA if suspected cystic lesion or fibroadenoma, useful in solid lesions with an accuracy of 90 – 95%

https://cancerwa.asn.au/assets/public/2022/07/2022-03-23-investigation-of-a-new-breast-symptom-a-guide-for-general-practitioners.pdf

• Surgical referral if
  • Any component of triple test is positive or indeterminate
  • Cyst aspiration is incomplete, bloody, or lump remains post aspiration
  • Suspicious nipple discharge
  • Eczematoid changes of the nipple/areolar which persis > 1-2 and do not respond to topical treatment
  • Inflammatory breast conditions that do not resolve after 2 weeks Abx

• if stage 1 or 2: tumour excision followed by whole breast irradiation
• Total mastectomy and breast-conservation surgery had equivalent survival
• Total mastectomy preferred for larger tumour, multifocal, previous irradiation
• Radiotherapy after surgery
  • if tumours >4cm, >3 axillary nodes involved
  • positive or close tumour margins
• Chemo has an important role
• Adjuvants:
  • anti-oestrogens (tamoxifen)
  • aromatase inhibitors (eg. anastrozole)
  • monoclonal antibodies (eg Herceptin)
  • progesterone

Risk Factors

• Sex: Being a woman is the strongest risk factor for breast cancer. Women are 100 times more likely to develop breast cancer than men
• Age
  • woman in her 30s the risk is approximately 1 in 250
  • woman in her 70s, it is approximately 1 in 30
  • Most breast cancers are diagnosed after the menopause
  • about 75% of breast cancer cases occur after 50 years of age. 
• Family history
  • Women with a mother, sister or daughter with breast cancer are, on average, at twice the risk of those with no affected first-degree relative (ie RR 2).
  • The risk increases with the number of first-degree relatives affected and, when three or more first-degree relatives are affected, the risk becomes more than three times that for women with no affected first-degree relatives (ie RR >3). 
  • The risk associated with family history increases also when relatives with breast cancer are diagnosed at a young age and when the family is of Jewish descent Ashkenazi or Eastern European Jewish ancestry
  • rare deleterious mutations in genes such as BRCA1 and BRCA2 that are associated with a high risk of the disease. 
  • A family history of ovarian cancer increases the risk of breast cancer because the risk of ovarian cancer is also associated with these genes. 
• Breast conditions
  • Women diagnosed with invasive breast cancer are at two to six times the population risk of developing cancer in the contralateral breast (other breast). 
  • preinvasive breast conditions
    • lobular carcinoma in situ
    • ductal carcinoma in situ
    • atypical ductal hyperplasia.
  • Mammographic breast density
    • Women having the highest degree of breast density are at four to six times greater risk than women with little or no breast density.
• Endogenous oestrogens
  • Postmenopausal women with high levels of circulating oestrogens (women with levels in the top 20%) have a two-fold increased risk of breast cancer compared with women with low levels of circulating oestrogens (women with levels in the bottom 20%)
• Hormonal factors
  • Factors associated with a modestly increased risk (RR 1.25–1.99) include:
    • older age at menopause (over 55 years vs 55 years or less)
    • use of combined hormone replacement therapy (current users vs never)
    • use of oral contraceptive pill (vs never, risk decreases to normal 10 years after ceasing use)
    • younger age at menarche (commencement of menstruation younger than 12 years vs 12 years or more)
    • high circulating levels of androgens (women with levels in the top 20% vs women with levels in the bottom 20% for postmenopausal women and possibly for premenopausal women)
    • high circulating levels of insulin-like growth factors (IGF-1 and IGFBP-3, women with levels in the top 25% vs women with levels in the bottom 25%, possibly only for postmenopausal women)
    • use of diethyl stilbestrol(DESPLEX)  during pregnancy and exposure to diethylstilbestrol in utero

• Factors associated with a decreased risk (RR <0.8) include:
  • parity (giving birth to at least one child vs never having carried a pregnancy; ie nulliparity)
  • earlier age at first birth (<25 years vs >29 years)
  • breastfeeding (at least 12 months’ total duration vs no breastfeeding) 
  • number of births (≥4 vs 1).
• Personal and lifestyle factors
  • Factors associated with a modestly increased risk (RR 1.25–1.99) include:
    • taller height (≥175 cm vs <160 cm)
    • overweight and obesity for postmenopausal women (body mass index >25 kg/m2  vs <21 kg/m2)
    • alcohol consumption (three or more standard drinks per day compared with none)
    • a previous personal history of some types of cancer other than breast cancer including melanoma, colorectal, ovarian, endometrial and thyroid cancer
    • high-dose ionising irradiation, especially before age 20.
  • Factors associated with a decreased risk (RR <0.8) include:
    • physical activity (two or more hours of brisk walking or equivalent per week vs no activity).

• Factors that have not been shown to impact on risk for breast cancer
  • pregnancy termination or abortion
  • tobacco smoking (study findings are inconsistent)
  • exposure to environmental tobacco smoke (study findings are inconsistent)
  • environmental pollutants
  • wearing a bra or different types of bra
  • silicone implants
  • use of underarm deodorant or antiperspirant
  • stress.

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Screening

🔹 Clinical Breast Examination (CBE)

• ❌ Not recommended for breast cancer screening in average-risk women
• ❌ No age group has shown benefit from routine clinical breast exams
• ✅ Women should still:
  • Be familiar with the normal look and feel of their breasts
  • Promptly report any changes to their GP:
    • Lump
    • Nipple discharge or changes
    • Skin colour/texture change
    • Pain in a breast
• No specific method of breast self-checking is recommended over another

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🔹 Mammography – Age Recommendations

• ✅ 50–74 years: Biennial mammographic screening (BreastScreen Australia) is recommended
• ⚠️ 40–49 years:
  • May consider starting earlier (especially if:
    • First-degree relative diagnosed <50 years)
  • May self-refer for biennial screening from age 40
• ❌ ≥75 years:
  • Insufficient evidence to recommend for or against screening
  • No routine recall

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🔹 Family History Definitions

• 👪 First-degree relatives:
  • Parents
  • Siblings (brothers/sisters)
  • Children
• 👪 Second-degree relatives:
  • Grandparents
  • Grandchildren
  • Aunts and uncles
  • Nieces and nephews

redbook v 10

🔹 Breast Cancer Risk Categories

Risk Level	Average or Slightly Increased	Moderately Increased	Potentially High Risk / Mutation Carriers
Population Proportion	Majority of population	<4%	<1%
Risk Compared to Average	~1.5×	~1.5–3×	>3×
Lifetime Risk by Age 75	9–12.5%	12–25%	25–50%
Example Histories	No family history 1st-degree relative ≥50y 2nd-degree relative any age Two 2nd-degree relatives ≥50y on same side Relatives on both sides ≥50y	1st-degree <50y (no high-risk features) Two 1st-degree relatives on same side ≥50y Two 2nd-degree on same side, ≥1 <50y	Family with: breast/ovarian cancer +: • additional affected relative(s) • diagnosis <40y • bilateral BC • breast + ovarian in same woman • male BC • Ashkenazi Jewish ancestry • BRCA1/2 mutation Or: BC <45y + sarcoma in another <45y
Age 40–49	✔️ Optional self-referral to BreastScreen ⚠️ Less mortality benefit, more false positives	✔️ Annual mammograms 📌 Especially if strong FHx or early-onset case	✔️ Annual imaging may include MRI + mammogram 📌 MRI Medicare rebate for asymptomatic women <60y
Age 50–74	✔️ Biennial mammograms recommended (via BreastScreen) 📌 Active recall system in place	✔️ Continue annual or biennial screening based on individual risk profile	✔️ Ongoing enhanced surveillance (MRI and/or mammography)

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🔹 Preventive Advice (All Risk Levels)

• Counsel women on lifestyle measures that reduce breast cancer risk:
  • Regular physical activity
  • Normal BMI maintenance (esp. postmenopausal)
  • Minimising alcohol
  • Childbearing and breastfeeding
• Encourage breast self-awareness (not formal BSE):
  • Prompt reporting of new/unusual symptoms: lump, nipple changes/discharge, skin texture/color changes, pain

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🔹 Clinical Role

• GPs play a vital role in:
  • Identifying strong family histories
  • Referring to familial cancer services when indicated (e.g., BRCA1/2)
  • Using family history tools (see Genetics chapter of guidelines)

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🔹 Screening Harms and Limitations

• Overdiagnosis rates from RCTs: ~11–19%
• Modelling estimates (US):
  • Biennial screening (ages 40–74): ~14 overdiagnosed cases/1000 women (range 4–37)
• Screening in women aged 40–49:
  • Does reduce mortality
  • But has smaller benefit than older women
  • Higher risk of false positives and unnecessary biopsies

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🔹 Dense Breasts

• Insufficient evidence to recommend routine supplemental ultrasound or MRI in women with dense breasts
• Management remains controversial

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🔹 Non-recommended Screening Modalities

• Thermography: Not recommended
  ‣ High false positive and false negative rates
• Polygenic risk scores (PRS):
  ‣ Not currently recommended in general practice

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🔹 Genetic Risk Assessment

• Single nucleotide polymorphism (SNP)-based breast cancer risk assessment:
  • Only after comprehensive genetic counselling
  • Discuss insurance implications and limitations
• Genetic testing only offered with pre- and post-test counselling
• Refer high-risk women to familial cancer clinics for:
  • Risk stratification
  • Genetic testing
  • Personalised risk-reduction plans

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🔹 Evidence-Based Risk Factors

• 2018 Cancer Australia review (Table 5.2):
  • Summarises convincing/probable risk factors for breast cancer
  • Includes genetic, hormonal, lifestyle, and environmental factors

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🔹 Aboriginal and Torres Strait Islander Considerations

• See: National Guide to a Preventive Health Assessment (ATSI-specific recommendations)
• Tailored screening and early detection strategies should be considered

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🔹 Management of High-Risk Individuals

• Surveillance and risk reduction may include:
  • Annual imaging: mammogram ± MRI or ultrasound
  • Regular clinical breast exams
  • Chemoprevention:
    • SERMs: e.g., tamoxifen, raloxifene
    • Aromatase inhibitors: e.g., exemestane, anastrozole
  • Risk-reducing surgery:
    • Mastectomy
    • Salpingo-oophorectomy (if ovarian cancer risk also elevated)

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Hereditary conditions predisposing to breast cancer

			%
Disease	Other tumour susceptibility	Inheritance	BC	HPBC	Location
Familial breast BRCA1	Ovary, prostate	AD	1.7	50	17q21
Familial breast BRCA2	Ovary, prostate, male breast cancer	AD	1.2	35	13q12
Li-Fraumeni TP53	Sarcoma, brain, adrenocortical	AD	0.1	1	17p13.1
Ataxia-telangectasia ATM	Homozygotes (leukaemias)	AR	0	0	11q22.3
	Heterozygotes (gastric)		2	4–8
Cowden PTEN	Skin, thyroid, bowel	AD	<1	<1	10q23.3
Reifenstein	?	XLR	<1	0	Xq11
Hras variant		AD	?8	0	11p15.5
hCHK2	Breast	AD	4	0	22q12.

AD, Autosomal dominant

AR, autosomal recessive

XLR, X linked recessive

HPBC, highly penetrant hereditary breast cancer (eg >3 affected relatives).

Ductal Carcinoma in situ

• Precursor to invasive breast cancer
• Non-invasive abnormal proliferation of milk duct epithelial cells
• Readily detected on mammography
• Now comprises 20% of breast cancer
• May present clinically with a palpable mass or nipple discharge
• Management is challenging decision – total mastectomy vs breast-conserving therapy with or without radiotherapy
• Excellent outcomes, with low local recurrence rates and survival of at last 98%