Risk-stratified screening approaches US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Risk-stratified screening approaches. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Risk-stratified screening approaches US Medical PG Question 1: A 57-year-old man presents to his family physician for a routine exam. He feels well and reports no new complaints since his visit last year. Last year, he had a colonoscopy which showed no polyps, a low dose chest computerized tomography (CT) scan that showed no masses, and routine labs which showed a fasting glucose of 93 mg/dL. He is relatively sedentary and has a body mass index (BMI) of 24 kg/m^2. He has a history of using methamphetamines, alcohol (4-5 drinks per day since age 30), and tobacco (1 pack per day since age 18), but he joined Alcoholics Anonymous and has been in recovery, not using any of these for the past 7 years. Which of the following is indicated at this time?
- A. Colonoscopy
- B. Chest computerized tomography (CT) scan (Correct Answer)
- C. Abdominal ultrasound
- D. Chest radiograph
- E. Fasting glucose
Risk-stratified screening approaches Explanation: ***Chest computerized tomography (CT) scan***
- This patient has a significant **smoking history** (1 pack per day since age 18 = **39 pack-years**) and is 57 years old, placing him in a high-risk group for **lung cancer**.
- Annual low-dose CT screening for lung cancer is recommended for individuals aged 50-80 with a 20 pack-year smoking history who currently smoke or have quit within the past 15 years.
- He meets all criteria: age 57, 39 pack-years, and quit only 7 years ago (within the 15-year window).
- Since he had screening **last year** with no masses, this year's visit represents the appropriate time for his **annual follow-up screening**.
*Colonoscopy*
- The patient had a colonoscopy last year with **no polyps**, suggesting he is at average risk for colorectal cancer.
- For individuals at average risk with normal findings, repeat screening colonoscopy is typically recommended every **10 years** (or every 5 years for flexible sigmoidoscopy), not annually.
*Abdominal ultrasound*
- One-time abdominal ultrasound screening for **abdominal aortic aneurysm (AAA)** is recommended for men aged 65-75 who have ever smoked.
- This patient is only 57 years old and does not yet meet the age criteria for AAA screening.
*Chest radiograph*
- While a chest radiograph can identify some lung abnormalities, a **low-dose CT scan** is far more sensitive and specific for detecting early-stage lung cancer in high-risk populations.
- Chest radiography is **not recommended** as a screening tool for lung cancer due to its lower sensitivity and lack of mortality benefit in trials.
*Fasting glucose*
- The patient had a **normal fasting glucose** of 93 mg/dL last year, and there are no new symptoms suggestive of diabetes.
- For asymptomatic adults with normal glucose, diabetes screening is typically repeated every **3 years**.
- Annual re-screening is not indicated without new risk factors or symptoms.
Risk-stratified screening approaches US Medical PG Question 2: A 25-year-old man with a genetic disorder presents for genetic counseling because he is concerned about the risk that any children he has will have the same disease as himself. Specifically, since childhood he has had difficulty breathing requiring bronchodilators, inhaled corticosteroids, and chest physiotherapy. He has also had diarrhea and malabsorption requiring enzyme replacement therapy. If his wife comes from a population where 1 in 10,000 people are affected by this same disorder, which of the following best represents the likelihood a child would be affected as well?
- A. 0.01%
- B. 2%
- C. 0.5%
- D. 1% (Correct Answer)
- E. 50%
Risk-stratified screening approaches Explanation: ***Correct Option: 1%***
- The patient's symptoms (difficulty breathing requiring bronchodilators, inhaled corticosteroids, and chest physiotherapy; diarrhea and malabsorption requiring enzyme replacement therapy) are classic for **cystic fibrosis (CF)**, an **autosomal recessive disorder**.
- For an autosomal recessive disorder with a prevalence of 1 in 10,000 in the general population, **q² = 1/10,000**, so **q = 1/100 = 0.01**. The carrier frequency **(2pq)** is approximately **2q = 2 × (1/100) = 1/50 = 0.02**.
- The affected man is **homozygous recessive (aa)** and will always pass on the recessive allele. His wife has a **1/50 chance of being a carrier (Aa)**. If she is a carrier, she has a **1/2 chance of passing on the recessive allele**.
- Therefore, the probability of an affected child = **(Probability wife is a carrier) × (Probability wife passes recessive allele) = 1/50 × 1/2 = 1/100 = 1%**.
*Incorrect Option: 0.01%*
- This percentage is too low and does not correctly account for the carrier frequency in the population and the probability of transmission from a carrier mother.
*Incorrect Option: 2%*
- This represents approximately the carrier frequency (1/50 ≈ 2%), but does not account for the additional 1/2 probability that a carrier mother would pass on the recessive allele.
*Incorrect Option: 0.5%*
- This value would be correct if the carrier frequency were 1/100 instead of 1/50, which does not match the given population prevalence.
*Incorrect Option: 50%*
- **50%** would be the risk if both parents were carriers of an autosomal recessive disorder (1/4 chance = 25% for affected, but if we know one parent passes the allele, conditional probability changes). More accurately, 50% would apply if the disorder were **autosomal dominant** with one affected parent, which is not the case here.
Risk-stratified screening approaches US Medical PG Question 3: A 49-year-old woman presents to her primary care physician for a general check up. She has not seen a primary care physician for the past 20 years but states she has been healthy during this time frame. She had breast implants placed when she was 29 years old but otherwise has not had any surgeries. She is concerned about her risk for breast cancer given her friend was recently diagnosed. Her temperature is 97.0°F (36.1°C), blood pressure is 114/64 mmHg, pulse is 70/min, respirations are 12/min, and oxygen saturation is 98% on room air. Physical exam is unremarkable. Which of the following is the most appropriate workup for breast cancer for this patient?
- A. No intervention indicated at this time
- B. Sentinel node biopsy
- C. BRCA genetic testing
- D. Mammography (Correct Answer)
- E. Ultrasound
Risk-stratified screening approaches Explanation: ***Mammography***
- The patient is 49 years old, making regular screening **mammography** the most appropriate initial workup for breast cancer, as guidelines recommend screening for women over 40.
- While breast implants can make mammograms more challenging, specialized techniques like **Eklund views** can be used to visualize breast tissue effectively.
*No intervention indicated at this time*
- This is incorrect because the patient's age (49) places her in the demographic for routine **breast cancer screening**.
- Delaying screening in this age group would increase the risk of detecting cancer at a later, less treatable stage.
*Sentinel node biopsy*
- **Sentinel node biopsy** is a procedure typically performed after a breast cancer diagnosis to stage the disease and determine lymph node involvement.
- It is not a screening tool and is therefore inappropriate as an initial workup in an asymptomatic patient without a known mass.
*BRCA genetic testing*
- **BRCA genetic testing** is indicated for individuals with a strong family history of breast or ovarian cancer, or those diagnosed with specific types of breast cancer at a young age.
- This patient has no such risk factors mentioned, making genetic testing unnecessary as a first-line screening step.
*Ultrasound*
- **Ultrasound** is often used as a follow-up to an abnormal mammogram or to evaluate specific palpable masses, especially in younger women with dense breasts.
- It is not typically recommended as a primary screening tool for breast cancer in a 49-year-old woman, especially without prior mammographic findings.
Risk-stratified screening approaches US Medical PG Question 4: An 18-year-old man presents to his primary care provider before leaving for college. He has no complaints. His past medical history is significant for asthma, acne vulgaris, and infectious mononucleosis at age 16. His home medications include doxycycline and albuterol as needed. His family history is significant for colon cancer in his father at age 50, his paternal grandfather at age 55, and an uncle at age 45. His father underwent testing for mutations in the APC gene, which were negative. There is no family history of dental abnormalities or other malignancy. The patient denies any recent weight loss, abdominal pain, hematochezia, melena, or other changes in the appearance of his stools. This patient should be screened for colorectal cancer (CRC) under which of the following protocols?
- A. Colonoscopy every 5 years beginning at age 40 (Correct Answer)
- B. Colonoscopy every 10 years beginning at age 50
- C. Colonoscopy every 1-2 years beginning at age 25
- D. Prophylactic colectomy
- E. Fecal occult blood testing annually beginning at age 40
Risk-stratified screening approaches Explanation: ***Colonoscopy every 5 years beginning at age 40***
- The patient has a strong family history of CRC, with a father diagnosed at age 50 and a paternal grandfather at age 55, placing him at increased risk.
- Current guidelines recommend that individuals with a first-degree relative diagnosed with CRC before age 60 should begin screening 10 years before the earliest diagnosis in the family, or at age 40, whichever comes first, with a colonoscopy every 5 years.
*Colonoscopy every 10 years beginning at age 50*
- This protocol is recommended for individuals with an **average risk** for colorectal cancer, which does not apply to this patient due to his strong family history.
- Starting screening at age 50 would be too late given the early onset of CRC in his family.
*Colonoscopy every 1-2 years beginning at age 25*
- This more aggressive screening schedule is typically reserved for individuals with identified **hereditary colorectal cancer syndromes**, such as **Familial Adenomatous Polyposis (FAP)** or **Lynch syndrome**.
- Though there is a strong family history, the negative APC gene testing and absence of other syndromic features (like dental abnormalities) make FAP less likely, and Lynch syndrome would typically involve other cancers.
*Prophylactic colectomy*
- **Prophylactic colectomy** is a major surgical procedure considered in rare cases of very high-risk hereditary syndromes, such as confirmed **Familial Adenomatous Polyposis (FAP)**, where the risk of CRC is almost 100%.
- This patient's family history, while significant, does not meet the criteria for such an extreme measure.
*Fecal occult blood testing annually beginning at age 40*
- While **fecal occult blood testing (FOBT)** is a valid screening method, it is typically used for individuals with average risk or in conjunction with other methods.
- Given the patient's strong family history of early-onset CRC, a **colonoscopy** is the more appropriate and comprehensive screening method.
Risk-stratified screening approaches US Medical PG Question 5: A 46-year-old woman presents to her primary care physician for her annual examination. At her prior exam one year earlier, she had a Pap smear which was within normal limits. Which of the following health screenings is recommended for this patient?
- A. Colorectal screening (Correct Answer)
- B. Blood glucose and/or HbA1c screening
- C. Blood pressure at least once every 3 years
- D. Yearly Pap smear
- E. Bone mineral density screening
Risk-stratified screening approaches Explanation: ***Colorectal screening***
- **Colorectal cancer screening** is generally recommended to start at age **45 years** for individuals at average risk.
- This patient is 46 years old, making immediate colorectal screening appropriate based on current guidelines.
*Blood glucose and/or HbA1c screening*
- **Blood glucose or HbA1c screening** for diabetes is recommended starting at age **35 for all adults** or earlier if there are risk factors such as obesity or a family history of diabetes.
- While this patient is 46, this screening should have already been initiated, and it is not the *most* uniquely recommended screening for this specific age that might have been overlooked.
*Blood pressure at least once every 3 years*
- **Blood pressure screening** should be performed **at least annually** for adults aged 40 and older, or more frequently if there are risk factors.
- Screening only every 3 years is insufficient for a 46-year-old patient.
*Yearly Pap smear*
- **Pap smear frequency** has changed; for women aged 30-65 with normal results, screening is recommended every **3 years** with cytology alone, or every 5 years with high-risk HPV testing alone or co-testing.
- A yearly Pap smear is no longer typical practice for a woman with normal prior results and no specific risk factors.
*Bone mineral density screening*
- **Bone mineral density (BMD) screening** for osteoporosis is typically recommended for women starting at age **65 years** or earlier if they have significant risk factors.
- This patient is 46 years old and has no mentioned risk factors, so BMD screening is not routinely indicated at this age.
Risk-stratified screening approaches US Medical PG Question 6: A 26-year-old primigravida woman comes to her primary care physician for the second prenatal visit. She is 10 weeks pregnant. She has no current complaint except for occasional nausea. She does not have any chronic health problems. She denies smoking or alcohol intake. Her family history is positive for paternal colon cancer at the age of 55. Vital signs include a temperature of 37.1°C (98.8°F), blood pressure of 120/60 mm Hg, and pulse of 90/min. Physical examination discloses no abnormalities. According to the United States Preventive Services Task Force (USPSTF), which of the following screening tests is recommended for this patient?
- A. Colonoscopy for colorectal cancer at the age of 40
- B. HbA1C for type 2 diabetes mellitus
- C. Colonoscopy for colorectal cancer at the age of 50
- D. Glucose tolerance test for gestational diabetes mellitus
- E. Urine culture for asymptomatic bacteriuria (Correct Answer)
Risk-stratified screening approaches Explanation: ***Urine culture for asymptomatic bacteriuria***
- The **USPSTF** recommends **screening pregnant individuals for asymptomatic bacteriuria** with a urine culture at the first prenatal visit or at 12-16 weeks' gestation to prevent pyelonephritis and other adverse pregnancy outcomes.
- This patient is in her second prenatal visit at 10 weeks, making this a timely and recommended screening.
*Colonoscopy for colorectal cancer at the age of 40*
- Although the patient has a **family history of paternal colon cancer at age 55**, the general recommendation for earlier screening due to family history typically starts 10 years before the youngest affected relative's diagnosis, but not earlier than age 40, and is not a routine screening for a 26-year-old.
- This screening is not universally recommended at age 40 for everyone, and current guidelines often suggest individualized approaches based on specific family history details that are not fully met by this patient at this age.
*HbA1C for type 2 diabetes mellitus*
- The patient has **no risk factors for type 2 diabetes**, such as obesity, history of gestational diabetes, or strong family history of diabetes, that would warrant early screening with HbA1c.
- Routine screening for type 2 diabetes for an individual of her age and health status is not typically recommended by the USPSTF.
*Colonoscopy for colorectal cancer at the age of 50*
- The **USPSTF recommends screening for colorectal cancer in average-risk individuals beginning at age 45-50**.
- This patient is only 26 years old and is not in the appropriate age group for this general screening recommendation.
*Glucose tolerance test for gestational diabetes mellitus*
- Screening for **gestational diabetes mellitus (GDM)** typically occurs much later in pregnancy, usually between **24 and 28 weeks of gestation**.
- Performing a glucose tolerance test at 10 weeks pregnant is too early for GDM screening based on standard guidelines.
Risk-stratified screening approaches US Medical PG Question 7: A 28-year-old asymptomatic pregnant woman at 12 weeks gestation presents for prenatal care. She has no personal or family history of diabetes. Her BMI is 32 kg/m². She had a random glucose of 118 mg/dL at her first visit. She asks about gestational diabetes screening. Considering her risk factors and current pregnancy, what is the most appropriate screening approach?
- A. Perform 3-hour oral glucose tolerance test at 16 weeks
- B. Diagnose gestational diabetes based on random glucose and begin treatment
- C. Perform 1-hour glucose challenge test now
- D. Perform fasting glucose and hemoglobin A1c now to assess for preexisting diabetes (Correct Answer)
- E. Defer screening until 24-28 weeks gestation per routine protocol
Risk-stratified screening approaches Explanation: ***Perform fasting glucose and hemoglobin A1c now to assess for preexisting diabetes***
- A **BMI ≥ 30 kg/m²** is a major risk factor necessitating early screening at the first prenatal visit to identify **pre-existing (overture) diabetes**.
- Identifying hyperglycemia early in pregnancy allows for immediate management to reduce the risk of **congenital anomalies** associated with pre-gestational diabetes.
*Perform 1-hour glucose challenge test now*
- While the **1-hour GCT** is a valid tool for early screening, standard biomarkers like **fasting plasma glucose** or **HbA1c** are also appropriate for detecting overt diabetes at the initial visit.
- The goal in the first trimester for high-risk patients is often to rule out **Type 2 Diabetes mellitus** that existed prior to pregnancy.
*Defer screening until 24-28 weeks gestation per routine protocol*
- Routine screening at **24-28 weeks** is reserved for women without significant risk factors; this patient's **obesity** mandates earlier evaluation.
- Delayed screening in obese patients may miss a window for intensive **glycemic control** during critical fetal organogenesis.
*Diagnose gestational diabetes based on random glucose and begin treatment*
- A **random glucose of 118 mg/dL** is within the normal range and is not diagnostic of either GDM (which requires >200 mg/dL with symptoms) or overt diabetes.
- Diagnosis requires structured testing such as an **HbA1c ≥ 6.5%**, fasting glucose ≥ 126 mg/dL, or a formal **oral glucose tolerance test (OGTT)**.
*Perform 3-hour oral glucose tolerance test at 16 weeks*
- The **3-hour OGTT** is typically the second step of a two-step screening process and is not indicated as an initial screening tool at 16 weeks.
- High-risk patients should be screened as soon as possible, often at the **first prenatal visit** (12 weeks in this case), rather than waiting until the second trimester.
Risk-stratified screening approaches US Medical PG Question 8: A 66-year-old man underwent screening colonoscopy which revealed a 1.2 cm tubular adenoma with low-grade dysplasia in the sigmoid colon that was completely removed. He has no family history of colorectal cancer. His colonoscopy 8 years ago was normal. He asks about surveillance recommendations. Considering current guidelines and competing risks, what is the most appropriate surveillance interval?
- A. Annual fecal immunochemical testing
- B. Repeat colonoscopy in 3 years
- C. Repeat colonoscopy in 10 years
- D. Repeat colonoscopy in 1 year
- E. Repeat colonoscopy in 5-10 years (Correct Answer)
Risk-stratified screening approaches Explanation: ***Repeat colonoscopy in 5-10 years***
- According to the **USMSTF 2020 guidelines**, patients with **1 to 2 small (<10 mm) tubular adenomas** should have a surveillance colonoscopy in **7-10 years**; however, for a single adenoma **≥ 10 mm** (like this 1.2 cm lesion) with low-grade dysplasia, the recommended interval is **5-10 years**.
- This recommendation balances the slightly higher risk of a **larger lesion** against the **low-grade pathology** and the patient's age and overall risk profile.
*Repeat colonoscopy in 10 years*
- A strictly **10-year interval** is reserved for patients with a **normal colonoscopy** or those with only **distal hyperplastic polyps**.
- While 10 years is the upper limit of the recommended range, the presence of a **1.2 cm adenoma** requires a surveillance designation rather than a standard screening interval.
*Repeat colonoscopy in 3 years*
- The **3-year interval** is indicated for **high-risk findings** such as **≥3 adenomas**, adenomas with **villous histology**, or those with **high-grade dysplasia**.
- This patient only had a single lesion with **low-grade dysplasia**, making 3-year surveillance an over-utilization of resources.
*Repeat colonoscopy in 1 year*
- A **1-year interval** is generally only indicated for cases of **incomplete resection**, piece-meal removal of large sessile polyps, or **inadequate bowel preparation**.
- It is not appropriate for a **completely removed** 1.2 cm tubular adenoma.
*Annual fecal immunochemical testing*
- **Fecal immunochemical testing (FIT)** is a primary **screening modality**, not a surveillance tool for patients who have already been diagnosed with adenomas via colonoscopy.
- Once an adenoma is identified, the patient enters a **colonoscopy-based surveillance** program to directly monitor for recurrent or advancing lesions.
Risk-stratified screening approaches US Medical PG Question 9: A 32-year-old woman presents for preconception counseling. She is healthy with no medical problems. Her mother and maternal aunt both had breast cancer diagnosed at ages 38 and 42, respectively. Her maternal grandmother died of ovarian cancer at age 52. The patient tested negative for BRCA1 and BRCA2 mutations 2 years ago through a commercial genetic testing panel. She asks about breast cancer screening recommendations. What is the most appropriate evaluation and management?
- A. Begin mammography at age 35 and annually thereafter
- B. Recommend clinical breast exam every 6 months only
- C. Begin annual mammography now
- D. Refer for genetic counseling and consider expanded testing with breast MRI screening (Correct Answer)
- E. Reassure that negative BRCA testing indicates average risk
Risk-stratified screening approaches Explanation: ***Refer for genetic counseling and consider expanded testing with breast MRI screening***
- Despite a negative **BRCA1/2** result, the patient's pedigree shows a **high-risk family history** (early-onset breast and ovarian cancer), which may indicate other **high-penetrance mutations** like **PALB2, TP53, or PTEN**.
- Women with a **lifetime risk >20%** based on models (e.g., **Tyrer-Cuzick**) or those with hereditary risk require **supplemental screening with Breast MRI** in addition to mammography.
*Begin annual mammography now*
- **Annual mammography alone** is insufficient for patients with a significant hereditary risk profile; **Breast MRI** is required to improve sensitivity in high-risk populations.
- Screening usually begins at age 30 or **10 years earlier** than the youngest diagnosis in the family, but current guidelines prioritize comprehensive **risk assessment** first.
*Reassure that negative BRCA testing indicates average risk*
- A negative test in the patient (without a known familial mutation) is **uninformative**; it does not rule out other genetic drivers or a strong **polygenic risk**.
- Reassuring her as "average risk" ignores the significant **familial clustering** of cancer, potentially delaying lifesaving early detection measures.
*Recommend clinical breast exam every 6 months only*
- **Clinical breast exams** lack the sensitivity to serve as a standalone management strategy for women with high **familial risk**.
- Evidence suggests that clinical exams do not significantly reduce **mortality** compared to advanced imaging protocols in hereditary cancer syndromes.
*Begin mammography at age 35 and annually thereafter*
- This delay is inappropriate; for high-risk families, screening often starts at **age 25 to 30** depending on the specific history and risk models.
- Starting at age 35 without incorporating **MRI screening** or updated **multi-gene panel testing** fails to address her specific hereditary risk profile.
Risk-stratified screening approaches US Medical PG Question 10: A 45-year-old woman presents requesting colorectal cancer screening after her sister was recently diagnosed with colon cancer at age 48. Further history reveals her sister's cancer was found to have microsatellite instability-high (MSI-H) features. The patient has no personal history of polyps or cancer and no gastrointestinal symptoms. Her sister is undergoing genetic testing for Lynch syndrome. What is the most appropriate next step in screening for this patient?
- A. Begin colonoscopy screening at age 50 per routine guidelines
- B. Defer screening until sister's genetic testing results are available
- C. Begin colonoscopy screening now and repeat in 10 years if normal
- D. Refer for genetic counseling and consider colonoscopy (Correct Answer)
- E. Begin annual FIT testing
Risk-stratified screening approaches Explanation: ***Refer for genetic counseling and consider colonoscopy***
- The sister's diagnosis at age 48 and **MSI-H** status strongly suggest **Lynch syndrome** (Hereditary Nonpolyposis Colorectal Cancer), necessitating specialized **genetic counseling** to evaluate family risk.
- While awaiting genetic results, guidelines for a **first-degree relative** diagnosed before age 60 require **colonoscopy** starting at age 40 or 10 years earlier than the relative's diagnosis (here, age 38).
*Begin colonoscopy screening now and repeat in 10 years if normal*
- For a patient with a **first-degree relative** diagnosed before age 60, the screening interval must be every **5 years**, not 10 years.
- A **10-year interval** is only appropriate for average-risk individuals or those with a single second-degree relative with cancer.
*Begin annual FIT testing*
- **Stool-based tests** like FIT or guaiac-based FOBT are not recommended as the primary screening modality for high-risk individuals with significant **family history**.
- **Colonoscopy** is the gold standard for these patients as it allows for the detection and removal of lesions in the **proximal colon**, which is often involved in Lynch syndrome.
*Defer screening until sister's genetic testing results are available*
- Screening should not be delayed while awaiting genetic testing; since the patient is already 45 and her sister was diagnosed at 48, she is already **past the recommended start date** (age 38).
- Immediate action is required based on the known **family history** regardless of whether a specific mutation is identified.
*Begin colonoscopy screening at age 50 per routine guidelines*
- Routine guidelines for **average-risk** individuals have been lowered to age 45, but this patient is **high-risk** due to her sister's early-onset cancer.
- Waiting until age 50 ignores the **10-year rule** (screening 10 years prior to a relative's diagnosis), which would have mandated screening to begin at age 38 for this patient.
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