Oncology Flashcards
What happens when there is a loss of heterozygosity at vHL locus on Chromosome 3?
Overproduction of VEGF.
Compare and contrast sunitinib and sorafenib
Essentially they are both TKIs, however sorafenib is a ‘dirtier’ drug in a sense that it acts upon multiple TKs such as VEGF, PDGF, FGF, C/B-raf.
Used as a second line agent.
Similar side effect profile as sunitinib.
How is tamoxifen metabolized?
CYP2D6 is necessary to form its two most important active metabolites.
Therefore strong inhibitors such as fluoxetine, paroxetine and bupropion should be avoided.
In early breast cancer pre-menopausal patients, who benefits from addition of ovarian suppression?
Ovarian suppression can be achieved via oophorectomy, GnRH agonist or pelvic radiation.
Addition of ovarian suppression to either AI and tamoxifen improves disease free survival ONLY in women <35 and those who received chemotherapy (ie, high risk disease)
Role of prophylactic salpingo-oophorectomy in high risk (ie, BRCA1/2) and average risk patients
In high risk groups, prophylactic BSO reduces ovarian and breast cancer risk.
In average risk group however, long term complications from BSO outweighs benefits - significantly increased risk of CVD, osteoporosis (as ovary continues to produces androstenedione and testosterone in significant amounts after menopause. These are converted to estrogen in local tissues)
Therefore ovarian conservation until at least age 65 improves long term survival in women at average risk of ovarian cancer when undergoing hysterectomy for benign disease.
What constitutes moderately increased CRC risk (category 2)?
What is the recommended screening?
Represents 1-2% of population.
1st degree relative with CRC diagnosed <55, or
2x 1st/2nd degree relatives with CRC at any age
Colonoscopy every 5 years from age 50, or
10 years younger than age of first diagnosis of bowel cancer in the family, whichever comes first.
What proportion of breast cancers are directly attributable to BRCA1/2?
5-10% cases only.
Chemotherapy option in metastatic cholangiocarcinoma/gall bladder cancer
First line therapy is low dose cisplatin and gemcitabine.
Also sensitive to 5FU and derivatives, oxaliplatin and irinotecan.
Combination with radiotherapy can be considerd especially in R1 or N+ disease.
4 features of carcinoid syndrome
Diarrhoea
Bronchospasm
Triscuspid stenosis
Pellagra
Carcinoid syndrome is mainly related to metastatic tumours originating in the midgut (distal small intestine, proximal colon)
Other sites such as foregut/hindgut rarely produces carcinoid syndrome as they lack DOPA decarboxylase
General chemotherapy regime in SCLC?
Platinum based chemotherapy with etoposide.
Causes of hand-foot syndrome
- Capecitabine/5-FU
- Vemurafenib/dabrafenib
- Pegylated doxorubicin
- Cytarabine
4 major risk factors for RCC
- Smoking
- Obesity
- Hypertension
- vHL - 2-3% of cancers are familial
Mechanism of HPV causing cervical cancer?
HPV 16/18 produces oncogenes E6 and E7 respectively.
E6 - inhibits the p53 tumour suppressor gene
E7 - inhibits RB suppressor gene
Main toxicity related to trastuzumab
Cardiac toxicity with reversible reduction in EF, improves after cessation of treatment. Needs 3 monthly measurements of EF whilst on treatment.
Which targeted therapy may be beneficial in gastric cancer?
Trastuzumab.
15% of gastric cancers are HER2 positive.
Follow up schedule for non-metastatic CRC stage II to III
High recurrence rates - 50% by 2 years, 80% by 3 years.
Most powerful way of determining the future recurrence risk is to examine the resected tumour after resection.
Therefore patients are usually followed up for 5 years with following schedules:
Follow up with:
- Initial perioperative colonoscopy to exclude synchronous lesion, then repeat colonoscopy at 12-18 months to identify new lesions, then 3-5 yearly
- CT chest/abdo/pelvis yearly for 3 years
- CEA - 3 monthly for 2 years, then 6 monthly
What constitutes high volume metastatic prostate cancer?
Management?
Visceral metastases OR greater than 4 bone metastases.
Metastatic prostate cancer is now managed with upfront chemohormonal therapy consisting of ADT with docetaxel based on CHAARTED and STAMPEDE trial.
Side effects of vemurafenib?
BRAF inhibitor used in V600E mutation positive melanoma patients.
25% develop cutaneous SCCs Arthralgia Rash Fatigue Photosensitivity Alopecia
What constitutes high CRC risk? (category 3)
What is the recommended screening?
Represents <1% of population.
> 3 1st/2nd degree relatives with CRC and multiple CRCs in 1 person, or
CRC <50 and at least 1 relative with endometrial or ovarian cancer
Suspected FAP in a relative with CRC.
Recommendations:
- Genetic counselling and testing
- If FAP - total colectomy and ileorectal anastomosis, sigmoidoscopy from age 12-15, duodenal screening froma ge 25 or at time of colectomy.
- If HNPCC - colonoscopy 1-2 yearly from age of 25 or 5 years younger than familial case.
Indications for adjuvant chemotherapy in breast cancer
- Axillary node involvement
- Node negative tumour with size >1cm
- Other adverse prognostic markers (age <35, negative ER/PR status, high grade tumour)
What are the treatment options in RCC refractory/not amenable to surgical therapy?
First line - sunitinib
Second line - sorafenib/axitinib
Third line - Bevacizumab
Fouth line - mTOR inhibitors such as everolimus in patients with progressive disease on VEGFR-TKI
Bowel cancer screening in Australia
FOBT every 2 years from 50-70 age
FOBT detects human Hb
Proven to decrease mortality by 20% in 3 large clinical trials.
Duke’s classification of CRC.
A - limited to mucosa/submucosa
B - through muscularis propria and into or through serosa
C - involvement of regional LN
D - distant metastasis
Pre-operative management of rectal cancer
MRI to assess local extent of the cancer
If surgical margins are threatened, neoadjuvant chemoradiotherapy.
No strong evidence for post operative adjuvant chemotherapy currently.
How is BRCA 1/2 transmitted?
Autosomal dominant.
In adult intussusception, what diagnosis would you consider?
Metastatic melanoma until proven otherwise.
What options do you have as an adjuvant therapy in Stage 3 melanoma after surgery and lymphadenectomy +/- radiation?
At present, NONE.
No trials have shown evidence that adjuvant therapy in melanoma improves survival.
Therefore current option in adjuvant setting is observation only or enrolling in a clinical trial.
What constitutes average CRC risk (category 1)?
What is the recommended screening?
Asymptomatic, no history of CRC/UC, no family history.
FOBT every 2 years from age of 50
Can consider sigmoidoscopy every 5 years from 50 age
Describe 4 side effects of 5FU/capecitabine used in colon cancer.
- Diarrhoea and mucositis
- Hand foot syndrome (plantar-palmar erythema)
- Cardiac toxicity secondary to coronary vasospasm
- Myelosuppression
capecitabine has more PPE
Match the following skin manifestations with the associated cancers:
Erythroderma Sweet Syndrome Migratory thrombophlebitis Acanthosis nigricans Dermatomyositis
Erythroderma - lymphoma
Sweet’s syndrome - MDS, other haematological disorder
Migratory thrombophlebitis - pancreatic cancer
Acanthosis nigricans - gastric cancer
Dermatomyositis - ovarian, lung ca
What does terrestrial UV radiation consist of?
5% - UVB which is mostly absorbed by epidermis
95% are UVA which can penetrate below the dermis.
UVA may be more damaging tot he skin by free radical generation, photoageing, immunosuppression and photocarcinosis.
What other cancers are associated with HNPCC?
Especially endometrial Ca and second CRC primary
Others include ovarian, stomach, small bowel, hepatobiliary, and renal cancers.
When would you consider post-mastectomy chest wall radiotherapy?
- > 5cm breast cancer
2. Lymph node involvement
How are breast cancers divided into 4 groups according to tumour biology and how do the treatments differ?
Luminal A - strongly ER/PR positive, HER2 negative with low proliferation. Endocrine treatment only.
Luminal B - ER/PR positive, HER2 negative, high proliferation. Chemotherapy and endocrine treatment
HER2+ - ER/PR negative, HER2 positive. Chemotherapy with Herceptin +/- endocrine therapy
Basal like - triple negative with high proliferation. Only treatment option is chemotherapy.
What is the significance of ulceration in melanoma?
Heralds high risk for metastatic disease.
Upstages the prognosis of all such patients compared to patients with melanoma of equivalent thickness without ulceration.
How does PARP inhibitors work in relation to BRCA1/2 mutations?
BRCA1/2 genes produce critical co factors in repair of dsDNA breaks.
Single strand DNA repair processes are mediated by PARP.
Therefore in tumour cells deficient in BRCA, inhibition of PARP results in inability to repair DNA as they have no other methods of DNA repair (unlike normal cells which will still have dsDNA repair mechanisms intact)
When would you consider axillary node dissection?
- If clinically node positive pre-op
2. SNB positive
Cancers associated with PTEN mutation (Cowden Syndrome)
- Breast
- Thyroid
- Endometrial
- GU
What is the role of everolimus in metastatic breast cancer?
Can be used to overcome endocrine resistance.
BOLERO-2 study showed that when everolimus was added to exemestane (AI), improvement in progression free survival was seen. However due to high dose of everolimus used, side effects were common, which were mucositis, diarrhoea, hyperglycaemia/hyperlipidaemia, pneumonitis.
Colonoscopy in HNPCC
Lifelong colonoscopy 1-2 yearly.
What characterizes limited stage SCLC?
All disease within one radiation field: ie ipsilateral lung and hilar/mediastinal lymph nodes. Curable in 20-30% with concurrent chemoradiotherapy.
Breast screening - when does it start and what is its impact?
2 yearly breast mammogram from age of 50 to 74.
Impact of survival mainly in younger women - 40% reduction in mortality in women between ages of 39-49. Non significant 18% survival in women aged 50-59.
Adjuvant treatment options for resected pancreatic cancer
Current recommendation is gemcitabine plus capecitabine (5FU derivative)
Combination therapy is better than single agent.
Radiotherapy increases toxicity, not useful in pancreatic cancer when combined with chemotherapy
5 factors in determining a ‘high risk’ breast cancer
- Multiple relatives with breast or ovarian cancer
- Early onset of disease in Pt/family
- > 1 primary cancer (contralateral breast or ovarian cancer)
- Vertical transmission including men
- Rare malignancies in family history: eg sarcomas and breast cancer in Li-Fraumeni syndrome
All women <70 with ovarian cancer should be screened for BRCA. (15%)
Risk factors for ovarian cancer
- Age
- Nulliparity
- Carrier of BRCA1/2
Risk is reduced by OCP use
When would you consider pneumonectomy over lobectomy in surgically resectable lung cancer?
Pneumonectomy if proximal cancer - ie <2cm to the carina
BRCA1/2 mutations as it relates to breast cancer:
- Histology
- Grade
- Steroid receptors
- HER2 expression
- Histology - medullary carcinomas are more common in BRCA1, but majorities are ductal ca of no special type
- Grade - generally higher grade than general population
- Steroid receptors - BRCA1 more likely to be ER/PR negative. BRCA 2 has no difference to gen pop
- HER2 expression - BRCA1/2 generally negative to HER2 expression
What are the risk reduction strategies available for BRCA carriers?
- Bilateral BSO once childbearing is complete (preferably before age 40) - reduces risk of brast cancer by 50% and ovarian cancer by 90%
- Bilateral mastectomy - reduces risk of breast cancer by 90%
If the patient does not want bilateral mastectomy, screening is available from age of 25 in forms of:
- Breast self examination
- Annual mammogram from age of 40 (or 5 years younger than the relative with breast cancer)
- MRI breast from age of 25
- Chemoprevention with Tamoxifen in pre/post menopausal, or aromatase inhibitors in post menopausal women
- OCP can also be considered to reduce ovarian ca risk but may increase breast cancer risk
Side effects of cetuximab
Side effects of bevacizumab
Hypersensitivity reaction
Skin toxicity
Magnesium wasting
Bevacizumab SE: Hyptertension, haemorrhage and perforation due to tumour necrosis, 2x VTE risk
Significance of dihydropyrimidien dehydrogenase deficiency
Predicts intolerance to 5FU and its pro drug capecitabine.
What does BRCA mutation in ovarian cancer predict?
> 90% of the tumours will be high grade serous ovarian cancer.
Predict response to platinum based therapy’o
What is the function of BRCA 1/2?
DNA repair gene.
What should all patients with breast conserving surgery have?
Adjuvant radiotherapy. Long term follow up of breast-conservation trials confirm significantly increased rates of local relapse when radiotherapy is omitted approaching 30%
Main side effect of EGFR antibodies such as cetuximab
Facial rash - however development of facial rash is predictive of eventual treatment response.
What is the role of bevacizumab in stage 4 NSCLC?
Results from the ECOG 4599 phase III trial demonstrated that in non-SCC NSCLC patients, median survival was significantly longer for those who received chemotherapy plus bevacizumab 15 mg/kg every 3 weeks than for those who received chemotherapy alone (12.3 months vs 10.3 months).[6] Patients with SCC are not eligible for bevacizumab, because of the risk of pulmonary hemorrhage.
Causes of false negative PET CT
- Hyperglycaemia - FDG and glucose compete for some receptor
- Small tumours <7mm in diameter
- Tumours with slow growth or metabolism
How do you grade neuroendocrine tumours?
How does grade of the tumour influence staging?
Depends on Ki67 and mitotic count.
Staging scans depend on the grade of the tumour.
Grade 1/2 - DOTATATE PET/CT with assessment of somatostatin receptor density - checks suitability for somatostatin analogue treatment and potentially for peptide radionucleotide receptor therapy (PRRT).
Grade 3 - FDG PET used
Match the class to the following drugs:
Leuprolide/Goserelin Flutamide Cyproterone acetate Abiraterone acetate Enzalutamide
Leuprolide/Goserelin - GnRH agonist
Flutamide - steroidal anti-androgen
Cyproterone acetate - antiandrogen
Abiraterone acetate - blocks biosynthesis of androgens at ALL sites including testes, adrenal glands and prostate tumour cells.
Enzalutamide - androgen receptor antagonist (extremely high affinity). Crosses blood brain barrier.