Case Study 2

For each question, choose the answer you think is correct. See the end of this page for the answers.

K.L. is a 50-year-old female with metastatic pancreatic carcinoma; her performance status is ECOG 2. She has been receiving gemcitabine with palliative intent using the GIPGEM protocol. She returns to the clinic to see her oncologist today (September 22).

Her weight on September 3 was 50 kg.

Today’s weight: 46.5 kg Height: 139 cm

Gemcitabine treatment history: Gemcitabine 1400 mg on September 3, 10, 17.

Lab results – September 22

WBC 4.7
ANC 2.7
Hgb 108
Platelets 257
Creatinine 64

1. What is the patient’s current BSA, using the Mosteller equation?

1.43 m²
1.34 m²
1.38 m²
1.31 m²

2. The physician has prescribed 1400 mg IV gemcitabine to be given on September 24. Are the dose and interval of treatment appropriate?

Yes, both the dose and interval are correct.
No, both the dose and interval are incorrect. The dose should be 1340 mg and she should be scheduled for treatment on October 1.
No, the dose is incorrect but the interval is correct. The dose should be 1340 mg.
No, the dose is correct but the interval is incorrect. She should be scheduled for treatment on October 1.

3. K.L.’s ANC = 0.9 and platelets = 180 on the day she is due to start Cycle 3, Week 1. How would these lab results affect the dose for Cycle 3?

There would be no change.
Her dose should be delayed to allow her counts to recover.
Her dose should be reduced to 1050 mg.
It is a clinical decision. The oncologist might choose to reduce her dose to 1050 mg or delay treatment.

4. Which of the following best describes the BC Cancer benefit status of gemcitabine for K.L., considering her diagnosis? Would this change if K.L. had advanced germ cell cancer?

Gemcitabine is a Class I drug when used for pancreatic cancer but funding is Restricted for use in germ cell cancer and requires case-by-case Compassionate Access Program (CAP) approval for this indication.
Gemcitabine is a Class I drug when used for germ cell cancer but requires case-by-case CAP approval for use in pancreatic cancer.
Gemcitabine is a Class I drug when used for both pancreatic cancer and germ cell cancer.
Gemcitabine is a Restricted drug when used for both pancreatic cancer and germ cell cancer if the patient does not have metastatic disease.

5. Based on the protocol, how long should K.L. continue treatment?

Continue treatment as long as there is evidence of a clinical response, usually a partial response or stable disease associated with symptom improvement (decreased pain, weight gain, improved performance status), or until there is unacceptable toxicity.
Continue treatment for 6 cycles; if there is no improvement after 6 cycles, consider an alternative protocol.
Continue treatment for 8 cycles; if there is no improvement after 8 cycles, consider an alternative protocol.
Discontinue gemcitabine, as disease progression is a sign that the tumour is unresponsive to therapy.

Answer 1

The correct answer is 2.

Rationale: Mosteller equation (round to 2 decimal places)

Answer 2

The correct answer is 4.

Rationale:

Based on the GIPGEM protocol, the dose for gemcitabine in Cycle 1 and subsequent cycles is 1000 mg/m²/week x 3 weeks, followed by 1 week rest.

Calculation of acceptable dose:

The dose based on our calculated BSA (from question 1): 1000 mg/m² x 1.34 m² is 1340 mg gemcitabine. The dose ordered by the physician is 1400 mg, which is correct because the initial BSA of 1.39 should continue to be used for subsequent cycles, as per BC Cancer Policy III-10. Dose recalculation for subsequent cycles only needs to be considered if the patient’s weight changes by greater than 10%, or results in a dose discrepancy of greater than 5%, or if the patient’s clinical status warrants a dose adjustment.

Calculation of acceptable interval:

Patient has already received Cycle 1 as 3 weeks of gemcitabine (September 3, 10 and 17). According to the protocol treatment plan, she should be scheduled for a one week rest period before resuming treatment. Therefore, the patient should not be receiving any treatment on September 24. Next scheduled treatment date should be October 1. The patient should be rebooked for the following week with updated bloodwork to be drawn within 48 hours of treatment date.

Answer 3

The correct answer is 4.

Rationale: Based on the GIPGEM protocol "Dose Modifications, Hematology" section, if the ANC is between 0.5-1.0 or the platelets are between 50-100, the dose is reduced to 75% or delayed based on clinical assessment. In this scenario, the platelets are normal, however the ANC is between 0.5-1.0 so this warrants discussion with the prescriber regarding either a decrease in dose or a delay.

Original dose = 1400 mg

75% of 1400 mg = 1050 mg

Answer 4

The correct answer is 1.

Rationale: According to the BC Cancer Benefit Drug list, gemcitabine is a Class I drug in several types of cancer. However, case-by-case approval is required for its use in germ cell cancer. Therefore, Compassionate Access Program (CAP) approval must be obtained prior to use of gemcitabine for germ cell cancer.

Answer 5

The correct answer is 1.

Rationale: Based on the GIPGEM protocol "Treatment" plan, treatment is continued as long as there is evidence of a clinical response, usually a partial response or stable disease associated with symptom improvement, or until there is unacceptable toxicity.