OCN Exam Prep 2025-2026: 250+ Practice Questions & Detailed Rationales (All Domains
Covered)
1. A patient with lung cancer presents with a serum sodium of 124 mEq/L, a
serum osmolality of 250 mOsm/kg, and a urine sodium of 40 mEq/L. Which
oncologic emergency should the nurse suspect?
A. Tumor Lysis Syndrome (TLS)
B. Syndrome of Inappropriate Antidiuretic Hormone (SIADH)
C. Sepsis
D. Hypercalcemia of Malignancy
Answer: B
Rationale: SIADH is frequently associated with small cell lung cancer. Key laboratory
indicators include hyponatremia (sodium < 135 mEq/L), low serum osmolality (< 275
mOsm/kg), and inappropriately high urine sodium levels despite low serum
levels. Mometrix OCN Review notes SIADH as a critical oncologic emergency to master
for the exam.
2. Which of the following is the most appropriate initial nursing intervention for a
suspected extravasation of a vesicant chemotherapy agent?
A. Apply a warm compress immediately to the site.
B. Flush the line with 10 mL of normal saline.
C. Stop the infusion immediately.
D. Remove the IV catheter as quickly as possible.
Answer: C
Rationale: The priority action in any suspected extravasation is to stop the infusion
immediately to prevent further tissue damage. Following this, the nurse should attempt
to aspirate any residual drug from the cannula before removal, as outlined in ONCC
Sample Questions.
3. A patient diagnosed with multiple myeloma is most likely to present with which
of the following clinical findings?
A. Elevated serum potassium and phosphorus.
B. Pathologic fractures and hypercalcemia.
C. Hypouricemia and hypotension.
D. Polycythemia and thrombocytosis.
Answer: B
Rationale: Multiple myeloma is characterized by the proliferation of malignant plasma
,cells in the bone marrow, leading to osteolytic lesions. These lesions cause bone pain,
pathologic fractures, and the release of calcium into the bloodstream, resulting in
hypercalcemia. Official AOCNP® sample tests highlight bone pain and lytic lesions as
classic diagnostic signs.
4. According to the OCN® Test Content Outline, which stage of carcinogenesis
involves the initial permanent damage to cellular DNA?
A. Promotion
B. Progression
C. Initiation
D. Metastasis
Answer: C
Rationale: Carcinogenesis is a three-stage process. Initiation is the first stage, where a
carcinogen causes irreversible genetic damage to a cell's DNA. Promotion follows,
where mutated cells are stimulated to divide, and progression is the final stage where
the cells exhibit increasingly malignant behavior. This process is a core part of the OCN
Test Blueprint.
5. What is the primary clinical indicator that a patient is experiencing early sepsis
rather than late septic shock?
A. Cold, clammy skin and severe hypotension.
B. Hyperthermia, tachycardia, and flushed skin.
C. Oliguria and metabolic acidosis.
D. Multiple organ dysfunction syndrome (MODS).
Answer: B
Rationale: Early (warm) sepsis is characterized by a high cardiac output, fever
(hyperthermia), and vasodilation leading to flushed, warm skin. As the condition
progresses to late (cold) shock, the patient becomes hypothermic with cold, clammy
skin and profound hypotension. Prompt administration of IV antibiotics is the priority
treatment for early sepsis, according to ONCC practice resources.
Would you like more questions focused on a specific domain, such as Symptom
Management or Treatment Modalities?
1-50
Here is a 50-question practice set based on the
Oncology Certified Nurse (OCN®) Test Content Outline. This set is designed
for Stuvia with the answer in bold and the rationale in italics.
OCN Practice Test (Questions 1-50)
,1. A patient with lung cancer has a serum sodium of 122 mEq/L and a urine
sodium of 45 mEq/L. What is the most likely cause?
A. Tumor Lysis Syndrome
B. SIADH
C. Hypercalcemia
D. Sepsis
Answer: B
Rationale: SIADH is common in small cell lung cancer; it causes hyponatremia and high
urine sodium due to excessive ADH secretion.
2. Which stage of carcinogenesis involves the first irreversible change to DNA?
A. Promotion
B. Initiation
C. Progression
D. Metastasis
Answer: B
Rationale: Initiation is the first stage where a carcinogen causes permanent, irreversible
genetic damage to a cell.
3. What is the priority intervention for a suspected vesicant extravasation?
A. Apply a cold compress
B. Remove the IV
C. Stop the infusion
D. Aspirate the drug
Answer: C
Rationale: Immediate cessation of the infusion is the first step to minimize tissue
exposure.
4. A patient with multiple myeloma reports new-onset back pain and leg
weakness. What is the priority concern?
A. Pathologic fracture
B. Spinal cord compression
C. Hypercalcemia
D. Osteolytic lesions
Answer: B
Rationale: Leg weakness combined with back pain in myeloma patients is a hallmark
sign of spinal cord compression, an oncologic emergency.
5. Which lab value is an unfavorable prognostic factor in Hodgkin Lymphoma?
A. Hemoglobin 12 g/dL
, B. Albumin 4.0 g/dL
C. Lymphocyte count < 600/mm³
D. WBC 8,000/mm³
Answer: C
Rationale: An absolute lymphocyte count of less than 600/mm³ is associated with a
poorer prognosis in advanced Hodgkin Lymphoma.
6. What is the primary cause of palmar-plantar erythrodysesthesia (Hand-Foot
Syndrome)?
A. Allergic reaction
B. Capillary rupture from pressure/friction
C. Bacterial infection
D. Peripheral neuropathy
Answer: B
Rationale: Certain drugs leak out of capillaries in the palms and soles due to high
pressure and friction, causing redness and pain.
7. A patient on Tamoxifen for metastatic breast cancer reports increased bone
pain shortly after starting. This is likely:
A. Disease progression
B. A "flare" reaction
C. Drug resistance
D. Inadequate dosing
Answer: B
Rationale: A "tumor flare" is a temporary increase in bone pain or tumor size often seen
when initiating hormone therapy; it usually indicates a good response.
8. Which medication is most appropriate for a patient with lymphomatous
meningitis?
A. Docetaxel
B. Cytarabine
C. Tamoxifen
D. Cisplatin
Answer: B
Rationale: Intrathecal cytarabine or methotrexate is standard for treating leptomeningeal
involvement.
9. What is the most common mechanism of metastasis?
A. Direct extension
B. Angiogenesis
Covered)
1. A patient with lung cancer presents with a serum sodium of 124 mEq/L, a
serum osmolality of 250 mOsm/kg, and a urine sodium of 40 mEq/L. Which
oncologic emergency should the nurse suspect?
A. Tumor Lysis Syndrome (TLS)
B. Syndrome of Inappropriate Antidiuretic Hormone (SIADH)
C. Sepsis
D. Hypercalcemia of Malignancy
Answer: B
Rationale: SIADH is frequently associated with small cell lung cancer. Key laboratory
indicators include hyponatremia (sodium < 135 mEq/L), low serum osmolality (< 275
mOsm/kg), and inappropriately high urine sodium levels despite low serum
levels. Mometrix OCN Review notes SIADH as a critical oncologic emergency to master
for the exam.
2. Which of the following is the most appropriate initial nursing intervention for a
suspected extravasation of a vesicant chemotherapy agent?
A. Apply a warm compress immediately to the site.
B. Flush the line with 10 mL of normal saline.
C. Stop the infusion immediately.
D. Remove the IV catheter as quickly as possible.
Answer: C
Rationale: The priority action in any suspected extravasation is to stop the infusion
immediately to prevent further tissue damage. Following this, the nurse should attempt
to aspirate any residual drug from the cannula before removal, as outlined in ONCC
Sample Questions.
3. A patient diagnosed with multiple myeloma is most likely to present with which
of the following clinical findings?
A. Elevated serum potassium and phosphorus.
B. Pathologic fractures and hypercalcemia.
C. Hypouricemia and hypotension.
D. Polycythemia and thrombocytosis.
Answer: B
Rationale: Multiple myeloma is characterized by the proliferation of malignant plasma
,cells in the bone marrow, leading to osteolytic lesions. These lesions cause bone pain,
pathologic fractures, and the release of calcium into the bloodstream, resulting in
hypercalcemia. Official AOCNP® sample tests highlight bone pain and lytic lesions as
classic diagnostic signs.
4. According to the OCN® Test Content Outline, which stage of carcinogenesis
involves the initial permanent damage to cellular DNA?
A. Promotion
B. Progression
C. Initiation
D. Metastasis
Answer: C
Rationale: Carcinogenesis is a three-stage process. Initiation is the first stage, where a
carcinogen causes irreversible genetic damage to a cell's DNA. Promotion follows,
where mutated cells are stimulated to divide, and progression is the final stage where
the cells exhibit increasingly malignant behavior. This process is a core part of the OCN
Test Blueprint.
5. What is the primary clinical indicator that a patient is experiencing early sepsis
rather than late septic shock?
A. Cold, clammy skin and severe hypotension.
B. Hyperthermia, tachycardia, and flushed skin.
C. Oliguria and metabolic acidosis.
D. Multiple organ dysfunction syndrome (MODS).
Answer: B
Rationale: Early (warm) sepsis is characterized by a high cardiac output, fever
(hyperthermia), and vasodilation leading to flushed, warm skin. As the condition
progresses to late (cold) shock, the patient becomes hypothermic with cold, clammy
skin and profound hypotension. Prompt administration of IV antibiotics is the priority
treatment for early sepsis, according to ONCC practice resources.
Would you like more questions focused on a specific domain, such as Symptom
Management or Treatment Modalities?
1-50
Here is a 50-question practice set based on the
Oncology Certified Nurse (OCN®) Test Content Outline. This set is designed
for Stuvia with the answer in bold and the rationale in italics.
OCN Practice Test (Questions 1-50)
,1. A patient with lung cancer has a serum sodium of 122 mEq/L and a urine
sodium of 45 mEq/L. What is the most likely cause?
A. Tumor Lysis Syndrome
B. SIADH
C. Hypercalcemia
D. Sepsis
Answer: B
Rationale: SIADH is common in small cell lung cancer; it causes hyponatremia and high
urine sodium due to excessive ADH secretion.
2. Which stage of carcinogenesis involves the first irreversible change to DNA?
A. Promotion
B. Initiation
C. Progression
D. Metastasis
Answer: B
Rationale: Initiation is the first stage where a carcinogen causes permanent, irreversible
genetic damage to a cell.
3. What is the priority intervention for a suspected vesicant extravasation?
A. Apply a cold compress
B. Remove the IV
C. Stop the infusion
D. Aspirate the drug
Answer: C
Rationale: Immediate cessation of the infusion is the first step to minimize tissue
exposure.
4. A patient with multiple myeloma reports new-onset back pain and leg
weakness. What is the priority concern?
A. Pathologic fracture
B. Spinal cord compression
C. Hypercalcemia
D. Osteolytic lesions
Answer: B
Rationale: Leg weakness combined with back pain in myeloma patients is a hallmark
sign of spinal cord compression, an oncologic emergency.
5. Which lab value is an unfavorable prognostic factor in Hodgkin Lymphoma?
A. Hemoglobin 12 g/dL
, B. Albumin 4.0 g/dL
C. Lymphocyte count < 600/mm³
D. WBC 8,000/mm³
Answer: C
Rationale: An absolute lymphocyte count of less than 600/mm³ is associated with a
poorer prognosis in advanced Hodgkin Lymphoma.
6. What is the primary cause of palmar-plantar erythrodysesthesia (Hand-Foot
Syndrome)?
A. Allergic reaction
B. Capillary rupture from pressure/friction
C. Bacterial infection
D. Peripheral neuropathy
Answer: B
Rationale: Certain drugs leak out of capillaries in the palms and soles due to high
pressure and friction, causing redness and pain.
7. A patient on Tamoxifen for metastatic breast cancer reports increased bone
pain shortly after starting. This is likely:
A. Disease progression
B. A "flare" reaction
C. Drug resistance
D. Inadequate dosing
Answer: B
Rationale: A "tumor flare" is a temporary increase in bone pain or tumor size often seen
when initiating hormone therapy; it usually indicates a good response.
8. Which medication is most appropriate for a patient with lymphomatous
meningitis?
A. Docetaxel
B. Cytarabine
C. Tamoxifen
D. Cisplatin
Answer: B
Rationale: Intrathecal cytarabine or methotrexate is standard for treating leptomeningeal
involvement.
9. What is the most common mechanism of metastasis?
A. Direct extension
B. Angiogenesis
