Cancer Flashcards
Define gastric cancer
Gastric malignancy, most commonly adenocarcinoma, more rarely lymphoma, leiomyosarcoma.
Explain the aetiology / risk factors of gastric cancer
Most cases are probably caused by environmental insults in genetically predisposed individuals that lead to mutation and subsequent unregulated cell growth.
Risk factors include: Helicobacter pylori infection; atrophic gastritis; diet high in smoked, processed foods and nitrosamines; smoking; alcohol.
Summarise the epidemiology of gastric cancer
Common cause of cancer death worldwide, with highest incidence in Asia, especially Japan. Sixth most common cancer in UK (annual incidence is 15 in 100 000).
Male:female is around 2:1. Age>50
Cancer of the antrum/body is becoming less common, while that of the cardia and gastrooesophageal junction is increasing.
Recognise the presenting symptoms of gastric cancer
In the early phases, it is often asymptomatic.
Early satiety or epigastric discomfort.
Weight loss, anorexia, nausea and vomiting.
Haematemesis, melaena, symptoms of anaemia.
Dysphagia (tumours of the cardia).
Symptoms of metastases, particularly abdominal swelling (ascites) or jaundice (liver involvement).
Recognise the signs of gastric cancer on physical examination
Physical examination may be normal.
Epigastric mass. Abdominal tenderness. Ascites. Signs of anaemia.
Many eponymous signs: Virchow’s node/Troisier’s sign: Lymphadenopathy in left supraclavicular fossa.
Sister Mary Joseph node: Metastatic nodule on umbilicus.
Krukenberg’s tumour : Ovarian metastases. (metastasis from primary site, classically in the GI tract, most commonly from gastric adenocarcinoma, particularly at the pylorus)
Identify appropriate investigations for gastric cancer and interpret the results
Upper GI endoscopy (+multiquadrant biopsy of all gastric ulcers)
Blood: FBC (anaemia) and LFTs
CT/MRI: staging of tumour and planning surgery
USS liver: staging of tumour
Bone scan: staging of tumour
Endoscopic ultrasound: Assesses depth of invasion and lymph node spread.
Laparoscopy: May be needed to determine if tumour is resectable.
Define prostate cancer
Outline the structure of the prostate gland.
Where does BPH (i.e. not prostate cancer) commonly occur
Prostate cancer, usually refers to prostate adenocarcinoma, where adeno- means gland and carcinoma refers to uncontrolled growth of cells - so prostate cancer is a tumor or growth that originates in the prostate gland.
The prostate is covered by a capsule of tough connective tissue and smooth muscle.
Beneath this layer, the prostate can be divided into a few zones.
The peripheral zone, which is the outermost posterior section, is the largest of the zone and contain about 70% of the prostate’s glandular tissue.
Moving inward, the next section is the central zone which contains about 25% of the glandular tissue as well as the ejaculatory ducts that join with the prostatic urethra.
Last, is the transitional zone, which contains around 5% of the glandular tissue as well as a portion of the prostatic urethra.
The transitional zone undergoes hyperplasia, or an increase in the number of cells, in a large percentage of older men, and that often leads to compression of the urethra.
This is called benign prostatic hyperplasia and is often considered a normal part of aging.
At microscopic level: each of glands covered by BM (mostly collagen, then a ring of cube-shaped basal cells and neuroendocrine cells, and finally an inner ring of luminal columnar cells which are within the lumen or centre of the gland.
Luminal cells secrete substances into prostatic fluid including PSA.
Explain the aetiology / risk factors of prostate cancer
Prostate adenocarcinoma most often results from a genetic mutation in a luminal cell, but can also be a basal cell, and it results in that cell dividing uncontrollably.
Some risk factors for a genetic mutation include old age, obesity, and a high fat-low fiber diet.
Mutations in two genes that have been linked specifically to prostate cancer are breast cancer gene 1 and breast cancer gene 2, also known as BRCA1 and BRCA2 - both of which also cause breast cancer.
Early on, prostate cancer cells depend heavily on androgens for survival, but eventually, the cancer cells mutate and find a way to keep multiplying without relying on androgens.
Summarise the epidemiology of prostate cancer
…
Recognise the presenting symptoms of prostate cancer
Early on, prostate cancer typically causes no symptoms.
That’s because the majority of prostate cancers arise in the posterior peripheral zone, which is far away from the urethra.
As a result, these tumors can grow quite large before they cause problems with urination.
Over time, if the cancer does compress or invade the urethra or bladder, it can cause difficulty urinating, bleeding, and pain with urination and ejaculation.
If the cancer becomes metastatic, it most commonly spreads to the bones, like the vertebrae or pelvis, resulting in hip or lower back pain.
Recognise the signs of prostate cancer on physical examination
Prostate cancer can be detected by a digital rectal examination, which is where a finger, is inserted into the rectum to feel against the anterior wall of the rectum which lies along the posterior part of the prostate.
A tumor located here would feel like an irregularly hard lump.
But if the tumor arises elsewhere, like in the anterior peripheral zone, then the tumor would be out of reach during the digital rectal exam.
Identify appropriate investigations for prostate cancer and interpret the results
Another approach is to use a transrectal ultrasound or MRI to image the prostate.
Prostate cancer can also cause an elevation in the prostate specific antigen.
But ultimately, the diagnosis of prostate cancer requires a biopsy, so that the cells can be scored using the Gleason grading system.
The Gleason scale identifies the two most common cell patterns within the prostate tissue and assigns a score between one and five to both of them:
SCORES:
1- normal, well differentiated cells
5- highly abnormal cells barely resembling normal prostate tissue
Once the primary and secondary patterns have each received a score from one to five, these two numbers are added together, resulting in a total Gleason score between two and 10 with two representing low-grade tumors and 10 representing high-grade, dangerous tumors.
Treatment:
In terms of treatment, when the tumor is confined to the prostate, and hasn’t metastasized, active surveillance is usually done.
This includes routine tumor marker measurement as well as imaging, to ensure that the prostate cancer remains confined to the prostate.
If the tumor spreads beyond that point, treatment options include surgery, radiation therapy, chemotherapy, and hormonal therapy.
Treatment may include chemotherapy, radiation therapy, surgery, and hormonal therapy, but active surveillance is also an option in many cases where it’s localized to the prostate.
Define tumour lysis syndrome
Rapid cell death with initiation of chemotherapy resulting in:
- hyperkalaemia,
- hyperphosphataemia,
- hyperuricaemia (–> gout)
- secondary hypocalcaemia,
- acute renal failure.
It damages the kindeys and may cause potentially life-threatening renal failure.
Note, it’s called secondary hypocalcaemia because it occurs SECONDARY to hyperphosphataemia.
Explain the aetiology / risk factors of tumour lysis syndrome
How to prevent?
Risk factors
How does it cause damage to the kidneys?
High levels of potassium, phosphate, and urate, and low levels of calcium can lead to clinical manifestations of:
Kidney injury and failure
Abnormal heart rhythms
Muscle cramps and weakness
Seizures
See high risk tumours below.
Risk factors:
- Dehydrated patients
- Those with existing kidney dysfunction
Renal dysfunction:
Calcium phosphate crystals obstruct renal tubules –> AKI
Nucleic acid –> uric acid –> hyperuricaemia –> urate nephropathy and risk of AKI
Summarise the epidemiology of tumour lysis syndrome
Who is most likely to develop TLS
Not all cancer patients are at equal risk of developing TLS
High risk tumours following chemo include those that have rapidly dividing cells:
- Acute leukaemia (myeloid OR lymphoid)
- High grade lymphoma
Can occur spontaneously before cancer treatment, but is more common within a week of starting treatment.
Not just in patients with traditional chemo, also in patients receiving steroids, hormonal therapy targeted therapy, or radiation therapy.
Recognise the presenting signs and symptoms of tumour lysis syndrome
Nausea +/- vomiting
Haematuria
Lack of appetite/fatigue
Dark urine, reduced urine output
(LOW CALCIUM:) Numbness, seizures, hallucinations
(LOW CALCIUM:) Muscle cramps and spasm
(HIGH POTASSIUM:) Heart palpitation and muscle weakness
Identify appropriate investigations for tumour lysis syndrome and interpret the results
TLS is diagnosed based on blood tests, along with signs and symptoms. Its onset may be subtle, with only a few abnormal laboratory values, but it can also present with frank kidney and organ failure.
What are the B symptoms of lymphoma
Weight loss, fever and night sweats
What are the types of bladder cancer, which is most common of these
Bladder cancer can either be a
transitional cell carcinoma (most common) or a squamous cell carcinoma.
How would you differentiate haematuria between bladder cancer and glomerulonephritis
What about ureteric stone
Bladder cancer causes macroscopic haematuria.
Glomerulonephritis causes micrcoscopy usually.
Ureteric stone usually microscopic
Define thyroid cancer, what are the subtypes
GOOD (90%):
Papillary(80%),
follicular, (10%)
These originate from thyroxine producing stroma and commonly present as solitary lump in a euthyroid patient. Infiltrative symptoms like hoarseness/dysphagia may be seen
Papillary tumours are slow growing and have excellent survical rates.
BAD:
Medullary and anaplastic tumours
Aetiology and RFs for thyroid cancer
CHILDHOOD EXPOSURE TO RADIATION (for papillary tumours)
MEN syndrome IIa and IIb associated with medullary thyroid cancers.
Lymphoma associated with hashimoto’s thyroiditis
Hx for thyroid cancer
Slow growing thyroid neck lump/nodule
Discomfort on swallowing or hoarse voice
Examination for thyroid cancer
Palpable nodule or diffuse enlargement of thyroid gland
If cervical nodes enlarged, suspect malignancy
Usually patient is euthyroid
Are thyroid cancers usually hyper/hyp/eu thyroid?
Euthyroid
Investigations for thyroid cancer
BLOOD:
TFTs. If hyperthyroid, less likely to be malignant. Bone profile. See tumour markers.
FNA cytology/US guided core needle biopsy:
Histological diagnosis.
Imaging: USS, isotope scanning, CT/MRI, bone scan
1st investigations: TSH, USS neck, FNA, laryngoscopy (paralysed vocal cord highly suggestive of malignancy)
see for histological diagnosis
What is the tumour marker for papillary and follucular vs medullar cancers
Serum thyroglobulin (only for papillary and follicular tumours)
Serum calcitonin (for medullar thyroid cancer)
What thyroid cancer type does this describe:
-Well differentiated, derived from parafollicular calcitonin secreting C cells
Medullary adenocarcinomas
