A 37-year-old woman presents to the triple assessment breast clinic following a GP referral regarding a new breast lump. She denies itching, bleeding, or abnormal nipple discharge. On examination, she has a 1.5cm breast lump in the 7 o'clock position in the left breast. There are no palpable axillary lymph nodes. An axillary ultrasound scan shows no evidence of axillary lymphadenopathy. Tissue biopsy shows evidence of an invasive ductal carcinoma and the breast cancer is triple-negative for oestrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. A subsequent staging CT scan of the chest, abdomen, and pelvis confirms no distant metastases.

Which of the following is the next best step in the management of this patient?

Options:
explanation: This is incorrect because this patient's breast cancer is 1.5cm which is small. This means that she can have a wide local excision without the need for a mastectomy. However, patients can have a mastectomy depending on their preference as breast-conserving surgery such as a wide local excision can give an unacceptable cosmetic result to some females, for example if the breast is small and a wide local excision would actually represent a significant proportion of the breast tissue being removed. Another indication for mastectomy is if the patient is unsuitable for radiotherapy, since radiotherapy is usually required to the whole breast after having breast conserving surgery (i.e. a wide local excision.)
name: Mastectomy
label: e
answer: no
explanation: This patient has a malignant breast mass isolated to the breast with no distant spread, and as such has a potentially curable cancer. These patients undergo wide local excision with sentinel lymph node biopsy. A sentinel lymph node biopsy is carried out when there are no palpable lymph nodes on examination or on ultrasound imaging. This helps to identify whether any cancer cells are present within these lymph nodes, which are not yet detectable using imaging/examination; if positive, the patient will subsequently have axillary lymph node clearance. If there were palpable lymph nodes/ultrasound identified any lymphadenopathy, these would be biopsied directly. If the biopsy subsequently confirms the cancer has spread to involve the lymph nodes, then an axillary clearance will be performed without need for a sentinel lymph node biopsy.
name: Wide local excision with sentinel lymph node biopsy
label: a
answer: yes
explanation: Letrozole is an aromatise inhibitor used for post-menopausal women in the management of oestrogen receptor breast cancer, either neo-adjuvantly or adjuvantly. It works by reducing peripheral aromatisation of androgens to estrogens in fat, and so is only effective in post menopausal women, since in pre-menopausal women the ovaries (rather than fat) produce the bulk of the oestrogen. This patient is oestrogen receptor negative, and as such would not benefit from tamoxifen. Furthermore, due to the reasonably small size of the lump, she likely does not require neo-adjuvant treatment prior to surgery. Aromatase inhibitors may cause osteoporosis, so careful monitoring of the bone mineral density is required.
name: Letrozole
label: c
answer: no
explanation: Trastuzumab, also known as Herceptin, is used in HER2+ (human epidermal growth factor receptor) breast cancer, either as neo-adjuvant or adjuvant therapy. This patient has triple-negative breast cancer so it is not indicated in this case. Furthermore, due to the reasonably small size of the lump, she likely does not require neo-adjuvant treatment prior to surgery. Serious side effects of trastuzumab involve cardiac dysfunction and teratogenicity.
name: Trastuzumab
label: d
answer: no
explanation: Tamoxifen is a selective oestrogen receptor modulator which is used in pre or post menopausal women with eostrogen receptor positive malignancy, either as neo-adjuvant (to shrink tumours prior to surgery if particularly large) or adjuvant (post operatively) therapy. This patient is oestrogen receptor negative, and as such would not benefit from tamoxifen. Furthermore, due to the reasonably small size of the lump, she likely does not require neo-adjuvant treatment prior to surgery. Tamoxifen has an anti-oestrogenic effect on breast tissue but a positive effect on the uterus, so increases the risk of endometrial cancer. It is also associated with VTE.
name: Tamoxifen
label: b
answer: no

Correct answer: a


Learning point: Triple-negative breast cancer without lymphadenopathy requires wide local excision and sentinel lymph node biopsy.