Editing Breast cancer (section)

== '''Other scenarios''' ==

=== '''Male breast cancer''' ===

** Epidemiology
*** Comprises 0.8% of all breast cancers
** Risk factors
*** Factors that increase effect of oestrogen - cirrhosis, obesity, exogenous oestrogen
*** Factors that decrease effect of testosterone - testicular non-descent, infection, trauma, 5alpha reductase inhibitors, Klinefelter's syndrome)
*** Genetics - BRCA2
*** Increasing age
*** Radiation exposure
*** ''Gynaecomastia is not a risk factor''
** Pathophysiology
*** 90% invasive ductal carcinoma
*** >90% hormone receptor positive
** Presentation
*** Local pain
*** Axillary lymphadenopathy
*** Nipple retraction
*** Ulceration
*** Bleeding
*** Discharge 
** Differential diagnosis
*** Primary breast cancer
*** Metastatic cancer
*** Gynaecomastia
*** Sarcoma
*** Breast abscess
** Staged and treated nearly the same
** Total mastectomy usually required because most of the tumours are subareolar, and it's also harder to give radiotherapy
** Chest wall resection required much more commonly since there is less breast tissue (modified radical mastectomy)
** SLNB is reliable. Axillary management is alike to in females.
** Since nearly 90% of cancers are hormone positive, and tamoxifen can be used (aromatase inhibitors raise testosterone levels)
** ALL patients with male breast cancer should be referred to genetics
** Contralateral breast cancer is almost unheard of in men, no need to perform routine screening mammography

=== '''Breast cancer in pregnancy''' ===

** Important to mention to respect wishes of patient with respect to fetus and discuss at MDM. 
*** Early termination of pregnancy does not improve breast cancer outcomes.
*** Delaying oncological treatment until birth is not usually a good option
*** Breastfeeding is safe and feasible from both breasts afterwards
*** Customary to recommend delaying conception for 2 years after initial treatment
** More likely to be ER/PR negative and HER2 + or -; more commonly high-grade; more commonly locally advanced
** Any breast lump discovered during pregnancy/lactation should be evaluated with mammogram (shielded), USS and biopsy
*** Usually start off with USS, especially if presenting complaint was lump
*** MRI is difficult to interpret without gadolinium due to pregnancy-related changes, but gadolinium is probably harmful to fetus, especially in first trimester
** Staging
*** Common approach for node-positive disease: 
**** CXR with shielding
**** USS abdo/liver
**** MRI liver/chest/brain/other area as required - without gadolinium
**** Low-dose bone scan only if there are symptoms of bony metastases
** Local treatment options:
*** Mastectomy usually the safest option, especially early on in pregnancy - radiation can't be given during pregnancy
*** BCS may be an option later in pregnancy when RTX can be given post-partum without too much delay
** Regional treatment:
*** SLNB can be done safely with 99mTc sulfur colloid like normal, but not blue dye
*** ALND is usually performed for the positive axilla
** Systemic treatment
*** Start chemotherapy once the first trimester is over
**** Neoadjuvant anthracycline is safe starting the second trimester - doesn't cross the placenta - series of 197 women with no increased risk of complications of birth or development
**** Taxanes appear safe - growing evidence base
*** Don't recommend delaying systemic therapy until after delivery
** Contraindicated:
*** Trastuzumab is not given - causes oligohidramnios in 50%
*** Tamoxifen is not safe for fetus
*** Immunotherapy
*** Blue dye
*** Radiotherapy
** Most common approaches:
*** First trimester: 
**** Early: mastectomy + SLNB, followed by CTX in second trimester if required and hormonal/HER2 therapy post-partum
**** Advanced: mastectomy + ALND + CTX in second trimester and hormonal/HER2 therapy +/- RTx post-partum
*** Second or third trimester
**** Early cancer: BCS with post-partum RTx vs mastectomy. SLNB. Endocrine/HER2 therapy post-partum.
**** Advanced: neoadjuvant + mastectomy + ALND + adjuvant trastuzumab/endocrine post-partum

=== '''Metastatic breast cancer of unknown primary''' ===

** Biopsy of involved node - might not be malignant, benign conditions can also cause lymphadenopathy
** Staging workup, CT CAP +/- PET
** Bilateral breast MRI will find a primary breast cancer in 75% of these patients
*** Then need MRI-guided USS
** Treatment will ALND +/- neoadjuvant CTX
** Management of ipsilateral breast is controversial
*** Best survival with mastectomy
*** Whole-breast RTX may give comparable survival, although only small retrospective reports to back it up