Complete run through of the MRCP Part I – Day 4 of 40

This page involves going through 8 types of cancer. I’ll try my best to cover them over the weekend.

Breast cancer

What is the breast?

The breast mostly consists of fat, lobes and ducts. The fat provided some breathing space between the lobes. The lobes are where the milk is made, under the stimulation of prolactin. The lobes drain into ducts, which meet up and drain into the nipple.

Ductal carcinoma accounts for 70% of breast cancer, and the rest is mostly lobular carcinoma.

Risk factors

Familial

Family predisposition occurs in 5-10% of breast cancers, which includes the famous BRCA 1 and 2.

BRCA1 carriers have a lifetime risk of 80% for breast cancer and 60% for ovarian cancer.
BRCA2 carriers have a lifetime risk of 80% for breast cancer and 27% for ovarian cancer.

It’s the men who get more screwed by BRCA2 though – 5% of men will get breast cancer, and 6-14% prostate cancer.

Other risk factors

Ostrogen exposure is what you don’t want. In other words, have a late menarche, an early menopause and multiple teenage pregnancies and you should be fine. The role of the COCP is controversial.

It is still the most common non skin cancer in women in the UK, but no longer the most common cause of death from cancer for British women. That distinction now goes to lung cancer.

Presentation

Increasingly, women now present from screening. Usually a mass that persists throughout the menstrual cycle. Less than 10% complain of nipple discharge, and pain in even less. Rarely, you get late neglected presentations from old ladies, or symptoms of mets and systemic features. Paget’s disease presents as eczematous change in the nipple with itching, burning, oozing or bleeding. Inflammatory lung cancer is rare in the UK (1-2%), but seems to be higher in Africa.

On examination, the malignant lump is hard, tethered with irregular margins and usually painless. There may be skin dimpling and a bloody, unilateral discharge.

The main sites for mets are BLBL: bone, lung, brain, liver.

Investigations

Younger patients (<35 years) with more dense breasts do better with ultrasound, whereas mammography is more suitable as breasts become less dense.

For the purpose of the screening programme, if there are no symptoms of breast disease then a mammography is all that is done.

For the investigation of a suspicious lump, triple assessment is usually done. This involves imaging, clinical exam and biopsy (fine needle or core biopsy).

The decision to proceed to biopsy may be determined by what the imaging showed. For example, a simple cyst may be just aspirated, but a complex cyst may need biopsy. Remember, fine needle has a smaller needle but doesn’t give you the tissue architecture or histology.

A Simplified Approach to Staging

T1 <2cm
T2 2-5cm
T3 5cm +
T4 fixed to chest wall, including peau d’orange

N1 – auxillary lymph nodes and mobile
N2 – auxillary lymph nodes and fixed OR internal mammary lymph nodes on their own
N3 – both of the N2ers (ie auxillary lymph nodes AND internal mammary lymph nodes) OR any lymph nodes around the clavicle (supra or infra)

M0 – not mets
M1 – mets

The most clinically important divide in the staging is Stage IIIA and Stage IIIB, as this determines early or late. The way I remember this is that Stage IIIB is anything with T4, IIIC is anything with N3, and IV is anything with M1. If you haven’t got any of those things, you are probably early stage.

Early treatment

Standard practice with wide local excision, with adjudvant radiotherapy. The sentinel lymph node is usually biopsied at surgery.

If the axillary nodes are clear, then opinion is divided on who gets adjuvant chemotherapy. Generally, expressing hormone receptors is a good thing; it means the cells are somewhat differentiated. Those with small, ER-positive tumours may get away without adjuvant chemotherapy in this group.

If the nodes are positive, then chemotherapy plus luteinising hormone release hormone analogue (e.g  goserelin, just like prostate cancer) or tamoxifen is given. The exception to this is premenopausal women with ER-negative tumour, who don’t get the goserelin equivalent or tamoxifen.

In addition to this, if the tumour is HER2 positive, trastuzumab is added.

Advanced breast cancer

If there are mets, then the aim is generally to palliate bony mets with bisphosphates, and maybe add on aromatase inhibitors. Aromatase inhibitors are only of benefit in post menopausal women, as they inhibit the production of estrogens from steroids, and in premenopausal wowen there’s an estrogen factory that produces volumes of estrogens that dwarf those produced by steroid conversion.

Tamoxifen

Tamoxifen is a selective ER modulator and can induce menopausal symptoms. The famous side effect is the risk of endometrial polyps and cancer. It is beneficial against osteoporosis.

DEXA scans

Breast cancer treatments induce osteoporosis by being anti estorgen. If giving aromatase inhibitors, or suppressing the ovaries, then get a baseline DEXA.

But there’s more to treatment than that…

Yup – see the NICE guidance. I’ve just tried to summarise this plus a few other sources in the least confusing way I could.

 

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