Oncology

Question 1

Cytotoxic agents: side-effects

Answer 1

1. Alkylating agents
   - Haemorrhagic cystitis, myelosuppression, transitional cell carcinoma: Cyclophosphamide
2. Cytotoxic antibiotics
   - Lung fibrosis: Bleomycin
   - Cardiomyopathy: Anthracyclines (e.g doxorubicin)
3. Antimetabolites
   - Myelosuppression, mucositis, liver fibrosis, lung fibrosis: Methotrexate
   - Myelosuppression, mucositis, dermatitis: Fluorouracil (5-FU)
   - Myelosuppression: 6-mercaptopurine
   - Myelosuppression, ataxia: Cytarabine
4. Acts on microtubules
   - Vincristine: Peripheral neuropathy (reversible) , paralytic ileus
   Vinblastine: myelosuppression: Vincristine, vinblastine
   - Neutropaenia: Docetaxel
5. Topoisomerase Inhibitors
   - Myelosuppression: Irinotecan
6. Other cytotoxic drugs
   - Ototoxicity, peripheral neuropathy, hypomagnesaemia: Cisplatin
   - Myelosuppression: Hydroxyurea (hydroxycarbamide)

Question 2

On examination patient has a third heart sound and the apex beat is displaced to the 6th intercostal space, anterior axillary line. Which one of the following chemotherapeutic agents is most likely to be responsible?

Answer 2

Doxorubicin
Anthracyclines (e.g. doxorubicin) may cause cardiomyopathy

Question 3

Paclitaxel and Docetaxel

Answer 3

are taxane chemotherapeutic agents. their main side effects include peripheral neuropathy, myelosuppression (bone marrow suppression), and hypersensitivity reactions.

Question 4

Bleomycin

Answer 4

is a glycopeptide antibiotic used in chemotherapy. Its primary toxicity is pulmonary fibrosis, which can lead to shortness of breath but would not typically cause a third heart sound or displaced apex beat. The pulmonary fibrosis caused by bleomycin is dose-dependent and irreversible.

Question 5

Dactinomycin

Answer 5

also known as actinomycin D, is an antineoplastic antibiotic used in chemotherapy. Its main side effects are myelosuppression (bone marrow suppression) and gastrointestinal toxicity.

Question 6

BRCA2-positive, what other form of cancer would he most likely to be at increased risk for men?

Answer 6

BRCA2 mutation is associated with prostate cancer in men

BRCA2 mutations substantially increase the risk of developing breast cancer in both men and women. It is also associated with ovarian cancer in women and prostate cancer in men. Although BRCA1 mutation is thought to be associated with young-onset colorectal cancer, no association has been observed in BRCA2 carriers.

Question 7

Tumour markers

Answer 7

Monoclonal antibodies
CA 125 Ovarian cancer
CA 19-9 Pancreatic cancer
CA 15-3 Breast cancer

Tumour antigens
Prostate specific antigen (PSA) Prostatic carcinoma

Alpha-feto protein (AFP) Hepatocellular carcinoma, teratoma

Carcinoembryonic antigen (CEA) Colorectal cancer

S-100 Melanoma, schwannomas

Bombesin Small cell lung carcinoma, gastric cancer, neuroblastoma

Question 8

Which one of the following cancers is least likely to be inherited?

Answer 8

Gastric cancer

Between 5 and 10% of all breast cancers are thought to be hereditary. Mutation in the BRCA1 and BRCA2 genes also increase the risk of ovarian cancer. For colorectal cancer around 5% of cases are caused by hereditary non-polyposis colorectal carcinoma (HNPCC) and 1% are due to familial adenomatous polyposis. Women who have HNPCC also have a markedly increased risk for developing endometrial cancer - around 5% of endometrial cancers occur in women with this risk factor.

Question 9

A 69-year-old man is admitted with lower back pain. He has a past medical history of prostate cancer, asthma, diabetes and hypertension. The pain radiates down the right leg and he has reduced power in that leg. He also has a reduced anal tone. The lumbar spine x-ray shows no obvious fracture.

What should the next investigation of choice be?

Answer 9

MRI lumbosacral spine

Red flags for lower back pain include associated lower limb pain, limb weakness, paraesthesia/numbness, and reduced perianal tone (rule out spinal cord compression via urgent MRI) the results discussed with the on-call neurosurgical team.

Question 10

Which of the following cancers is calcitonin a tumour marker for?

Answer 10

Medullary thyroid cancer

Question 11

Which one of the following is most associated with raised levels of CA 19-9?

Answer 11

Pancreatic cancer

Question 12

Which of the following cytotoxic agents is most associated with lung fibrosis?

Answer 12

Bleomycin

Question 13

completed a course of chemotherapy complains of difficulty using her hands associated with ‘pins and needles’. She has also experienced urinary hesitancy. Which cytotoxic drug is most likely to be responsible?

Answer 13

Vincristine - peripheral neuropathy

Urinary hesitancy may develop secondary to bladder atony.