PLAB 1 Oncology Questions: 10 Free Practice MCQs

Ten PLAB 1-style oncology questions with the answer and the reasoning behind it. They come from the UK.med bank, which has 16 oncology questions and many more across every topic.

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1. 1 / 10

   A 54-year-old woman has persistent bloating and early satiety. Transvaginal ultrasound shows a 6 cm multilocular ovarian mass with solid areas and ascites; CA125 is 96 IU/mL.

   What is the most appropriate next management step in primary care?

   • A. Arrange repeat ultrasound in 6 months before referral
   • B. Arrange a percutaneous biopsy in primary care before discussing the case with the gynaecological cancer team
   • C. Refer urgently to a gynaecological cancer service using the suspected cancer pathway
   • D. Proceed directly to ovarian removal without specialist assessment
   Show answer

   Answer: C. Refer urgently to a gynaecological cancer service using the suspected cancer pathway

   Why: The ultrasound findings suggest ovarian cancer, so NICE recommends referral to a gynaecological cancer service through the suspected cancer pathway. Specialist assessment then guides imaging, tissue diagnosis when indicated, and treatment planning; primary care should not arrange biopsy or proceed directly to surgery.

   • A. A complex mass with solid areas and ascites is suspicious and should not be monitored for months in primary care.
   • B. Primary care biopsy is not the recommended route; specialist assessment should determine appropriate imaging and tissue sampling.
   • D. The decision about surgery, staging and any tissue diagnosis belongs with the specialist gynaecological cancer team after assessment.

   Sources: NICE NG12, recommendation 1.5.10, amended 2026; NICE CG122, recommendations 1.2.2 to 1.2.3

2. 2 / 10

   A 56-year-old post-menopausal woman presents to her GP with a 2-month history of persistent abdominal bloating, early satiety, and pelvic discomfort. She has no change in bowel habit. The GP suspects ovarian cancer.

   What is the correct initial investigation pathway in primary care according to NICE guidelines?

   • A. Refer immediately on a 2-week wait (2WW) Suspected Cancer pathway
   • B. Order a pelvic ultrasound scan first; check CA125 only if the scan is abnormal
   • C. Measure serum CA125; if elevated (>= 35 U/mL), arrange an urgent pelvic ultrasound scan
   • D. Order a serum CEA and CA19-9; refer to general surgery if elevated
   Show answer

   Answer: C. Measure serum CA125; if elevated (>= 35 U/mL), arrange an urgent pelvic ultrasound scan

   Why: NICE guideline CG122 outlines that if a woman presents with persistent abdominal distension, bloating, early satiety, pelvic pain, or urinary urgency, the GP should measure serum CA125. If CA125 is >= 35 U/mL, an ultrasound of the abdomen and pelvis should be performed. If ultrasound shows a mass or ascites, the Risk of Malignancy Index (RMI) is calculated to guide 2WW referral.

   • A. A direct 2WW referral is only indicated if there is a palpable abdominal/pelvic mass. In the absence of a mass, the GP must check CA125 and perform ultrasound first to calculate the RMI.
   • B. NICE guidelines state that CA125 is the initial test in primary care, and if >= 35 U/mL, it triggers the ultrasound, not the other way around.
   • D. CEA and CA19-9 are not the recommended screening biomarkers for ovarian cancer in primary care. CA125 is the specific marker of choice.

   Sources: NICE CG122

3. 3 / 10

   A 56-year-old post-menopausal woman presents with a 3-month history of abdominal bloating, early satiety, and pelvic pain. An ultrasound scan of the pelvis reveals a 7 cm multilocular right ovarian cyst with solid components and a small volume of ascites. Her serum CA125 is 180 U/mL.

   What is the recommended tool to calculate her risk of malignancy and guide referral, and what is its components?

   • A. Risk of Malignancy Index (RMI); based on CA125 level, menopausal status, and ultrasound features
   • B. FIGO Staging System; based on CT scan findings, surgical biopsy and peritoneal washings
   • C. ROMA score; based on HE4, CA125, and age
   • D. IOTA simple rules; based on magnetic resonance imaging (MRI) findings
   Show answer

   Answer: A. Risk of Malignancy Index (RMI); based on CA125 level, menopausal status, and ultrasound features

   Why: NICE guideline CG122 recommends the Risk of Malignancy Index (RMI) for triage of suspected ovarian cancer. RMI is calculated as: RMI = U (ultrasound score: 0, 1, or 3 based on features like multilocular cysts, solid areas, metastases, ascites, bilateral lesions) x M (menopausal status: 1 if pre-menopausal, 3 if post-menopausal) x CA125 (absolute value). A score >= 200 indicates high risk and requires specialist multidisciplinary team management.

   • B. FIGO is used for staging cancer post-operatively/histologically, not for initial risk assessment and referral triage of a pelvic mass.
   • C. The ROMA score is an alternative biomarker algorithm but is not the primary tool recommended in standard UK/NICE guidelines.
   • D. IOTA rules use ultrasound descriptors, not MRI, and RMI remains the standard score used for referral criteria in the NHS.

   Sources: NICE CG122

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5. 4 / 10

   A 61-year-old post-menopausal woman presents to the clinic with a 2-week history of light vaginal bleeding. She has not used hormone replacement therapy. Physical examination is unremarkable.

   What is the most appropriate first-line investigation to assess her risk of endometrial cancer?

   • A. Outpatient endometrial biopsy (Pipelle) as the first test
   • B. Transvaginal ultrasound (TVUS) to measure endometrial thickness
   • C. Hysteroscopy and dilatation and curettage (D&C)
   • D. Serum CA125 and pelvic MRI
   Show answer

   Answer: B. Transvaginal ultrasound (TVUS) to measure endometrial thickness

   Why: Post-menopausal bleeding (PMB) accounts for 95% of endometrial cancer presentations. Under NICE guidelines, women >55 with PMB must be referred on a 2-week wait pathway. Transvaginal ultrasound is the primary investigation. An endometrial thickness <4 mm essentially rules out endometrial cancer (risk <1%), whereas thickness >=4 mm requires endometrial biopsy (Pipelle or hysteroscopy-guided).

   • A. Endometrial biopsy is indicated if the endometrial thickness on TVUS is >= 4 mm, or if the ultrasound is inconclusive, but is not the initial test of choice before ultrasound.
   • C. Hysteroscopy is an invasive procedure reserved for cases where biopsy is unsuccessful, atypical, or endometrial thickness is significantly elevated, not first-line.
   • D. CA125 and MRI are used for staging of ovarian and endometrial cancer respectively, not for initial screening of post-menopausal bleeding.

   Sources: NICE NG12

6. 5 / 10

   A 56-year-old man, who has smoked 20 cigarettes a day for 35 years, presents to his GP with a 4-week history of a persistent dry cough and some unexplained fatigue. He has not had any weight loss, fever, or haemoptysis.

   What is the most appropriate next step in management under NICE cancer referral guidelines (NG12)?

   • A. Refer the patient immediately to the respiratory clinic on a 2-week wait (2WW) suspected cancer pathway
   • B. Request an urgent chest X-ray (to be performed within 48 hours)
   • C. Prescribe a 5-day course of Amoxicillin and review in 2 weeks
   • D. Reassure the patient and advise him to return if the cough persists for another 4 weeks
   Show answer

   Answer: B. Request an urgent chest X-ray (to be performed within 48 hours)

   Why: NICE guideline NG12 recommends offering an urgent chest X-ray (to be performed within 48 hours) to assess for lung cancer in people aged 40 and over if they have two or more unexplained symptoms, or if they have ever smoked and have one or more unexplained symptoms (such as cough, fatigue, shortness of breath, chest pain, weight loss, or appetite loss). Haemoptysis in a patient aged 40 and over warrants direct 2WW referral.

   • A. A 2WW referral for lung cancer is indicated if the chest X-ray is suggestive of cancer, or if the patient has unexplained haemoptysis. In the absence of haemoptysis or abnormal imaging, a chest X-ray is performed first.
   • C. The patient is stable with no signs of acute bacterial infection (fever, purulent sputum). Delaying investigation for a heavy smoker with a persistent cough is unsafe.
   • D. Reassurance without investigation is incorrect given the patient's high-risk profile (age and smoking history) and persistent symptoms.

   Sources: NICE NG12

7. 6 / 10

   A 35-year-old woman presents to general practice with a 3-month history of post-coital bleeding. Speculum examination reveals an abnormal, ulcerated cervical lesion.

   What is the most important risk factor for Cervical Cancer?

   • A. Human Papillomavirus (HPV) infection
   • B. Combined Oral Contraceptive Pill
   • C. Smoking
   • D. Nulliparity
   Show answer

   Answer: A. Human Papillomavirus (HPV) infection

   Why: Persistent infection with high-risk Human Papillomavirus (specifically types 16 and 18) causes over 70% of cervical dysplasias and carcinomas worldwide. Combined oral contraceptive pill use and cigarette smoking act as secondary cofactors for disease progression. Nulliparity increases the risk of endometrial and ovarian cancers, whereas multiparity is associated with cervical carcinoma.

   • B. Small risk.
   • C. Cofactor.
   • D. Risk for endometrial/ovarian cancer.

   Sources: Jo's Trust

8. 7 / 10

   A 52-year-old female undergoing chemotherapy for breast cancer presents to the oncology assessment unit with a temperature of 38.8°C and rigors. She is tachycardic (105 bpm) and normotensive. Her absolute neutrophil count is 0.3 x 10^9/L.

   Within what timeframe should empiric intravenous antibiotics be administered?

   • A. Within 1 hour of presentation
   • B. Immediately after blood culture results are finalized
   • C. Within 4 hours of presentation
   • D. Only if the patient's blood pressure drops below 90 mmHg systolic
   Show answer

   Answer: A. Within 1 hour of presentation

   Why: Neutropenic sepsis is defined as a temperature of >38°C (or symptoms of sepsis) in a patient with a neutrophil count <0.5 x 10^9/L. It is a medical emergency. NICE CG151 mandates starting empiric IV antibiotics (typically Piperacillin/Tazobactam) within 1 hour of arrival (the 'golden hour'), without waiting for blood culture or detailed lab results.

   • B. Blood culture results take 24-48 hours. Delaying antibiotics for cultures would lead to overwhelming sepsis and death.
   • C. A 4-hour window is too slow for neutropenic sepsis, where the 'door-to-needle' time target for antibiotics is strictly 1 hour.
   • D. Antibiotics must not be held for shock; the presence of fever and neutropenia is sufficient to diagnose neutropenic sepsis and initiate therapy.

   Sources: NICE CG151

9. 8 / 10

   A 64-year-old postmenopausal woman has a complex 8 cm adnexal mass with solid components and moderate ascites on ultrasound. She reports new early satiety and abdominal bloating.

   What is the most appropriate management?

   • A. Arrange follow-up ultrasound in six months because the mass is asymptomatic.
   • B. Perform an ovarian cyst biopsy before referral.
   • C. Refer urgently to a gynaecological cancer service using the suspected cancer pathway.
   • D. Start empirical chemotherapy based on the ultrasound appearance.
   Show answer

   Answer: C. Refer urgently to a gynaecological cancer service using the suspected cancer pathway.

   Why: The complex mass, ascites and persistent symptoms make ovarian cancer a concern. NICE recommends urgent referral to a gynaecological cancer service when there is ascites or a pelvic mass, and when ultrasound suggests ovarian cancer. Chemotherapy should not be started without specialist assessment and usually tissue confirmation.

   • A. The patient has symptoms and suspicious imaging, so routine surveillance is unsafe.
   • B. Biopsy is not the primary care step before specialist assessment of a suspicious mass.
   • D. Chemotherapy requires specialist assessment and generally confirmed tissue diagnosis before treatment.

   Sources: NICE NG12, Suspected cancer: recognition and referral, recommendations 1.5.1 and 1.5.10, updated 2026; NICE CG122, recommendation 1.2.4.1

10. 9 / 10

    A 62-year-old woman presents with a 6-week history of unexplained weight loss and loose stools. She has no rectal bleeding and no abdominal mass. A Faecal Immunochemical Test (FIT) is requested, and the result is 85 mcg Hb/g (abnormal is >= 10 mcg Hb/g).

    What is the correct next step in her management under NICE cancer referral guidelines (NG12)?

    • A. Repeat the FIT test in 2 weeks to confirm the result before deciding on referral
    • B. Initiate a trial of a low-FODMAP diet and review in 1 month
    • C. Refer the patient to gastroenterology on a 2-week wait (2WW) suspected colorectal cancer pathway
    • D. Refer for a routine outpatient colonoscopy, as she has no rectal bleeding or mass
    Show answer

    Answer: C. Refer the patient to gastroenterology on a 2-week wait (2WW) suspected colorectal cancer pathway

    Why: NICE guideline NG12 recommends offering a Faecal Immunochemical Test (FIT) to check for occult blood in patients without rectal bleeding who have symptoms such as unexplained weight loss, abdominal pain, or change in bowel habit. A result of >= 10 mcg Hb/g requires referral on a 2-week wait pathway for suspected colorectal cancer. Direct 2WW referral (without FIT) is indicated if there is a palpable rectal/abdominal mass, or unexplained rectal bleeding in older adults.

    • A. Repeating the test delays diagnosis. Any result >= 10 mcg Hb/g is a trigger for colonic investigation.
    • B. Dietary changes are for irritable bowel syndrome, not for an older patient with unexplained weight loss and a highly abnormal FIT result suggesting malignancy.
    • D. The patient meets the criteria for suspected cancer (FIT >= 10); a routine referral is inappropriate as it causes dangerous delays.

    Sources: NICE NG12

11. 10 / 10

    A 67-year-old postmenopausal woman has persistent bloating, increasing abdominal girth and early satiety. Examination detects ascites and a pelvic mass. Ultrasound shows a complex adnexal lesion with solid components.

    What is the most appropriate management?

    • A. Refer urgently to a gynaecological cancer service through the suspected cancer pathway.
    • B. Repeat CA125 in three months and refer only if it continues to rise.
    • C. Arrange a transvaginal needle biopsy before contacting secondary care.
    • D. Reassure her because complex ovarian cysts are usually benign after menopause.
    Show answer

    Answer: A. Refer urgently to a gynaecological cancer service through the suspected cancer pathway.

    Why: Ascites, a pelvic mass and suspicious ultrasound findings raise concern for ovarian cancer. NICE recommends a suspected cancer pathway referral to a gynaecological cancer service in this setting. Specialist teams decide staging and whether tissue diagnosis is needed before treatment.

    • B. Surveillance would delay specialist assessment of a mass with ascites.
    • C. Primary care needle biopsy is not the initial step for a potentially malignant adnexal mass.
    • D. A complex mass with ascites in a postmenopausal patient needs prompt assessment rather than reassurance.

    Sources: NICE NG12, Suspected cancer: recognition and referral, recommendations 1.5.1 and 1.5.10, updated 2026

Exam-style questions written by MedHub for practice. They are not official exam questions.