Devita, Hellman, and Rosenberg's Cancer

LWBK1006-20 LWW-Govindan-Review December 12, 2011 19:4

262 DeVita, Hellman, and Rosenberg’s CANCER: Principles and Practice of Oncology Review

Question 20.4.3. A 62-year-old patient with diabetes, hypertension, and chronic moder-

ate renal insufficiency developed abdominal discomfort and early sati-

ety. An esophagogastroduodenoscopy revealed a gastric mass measuring

6 cm, and biopsy confirmed GIST with three mitoses per hpf. A CT scan

revealed at least three hepatic metastases and multiple omental lesions.

His current creatinine clearance is 36 mL/min. You recommend:

A. No dose adjustment is necessary for moderate renal insufficiency, and

start imatinib 400 mg PO daily.

B. A 25% dose reduction and give 300 mg PO daily

C. A 50% dose reduction and give 200 mg PO daily

D. Give sunitinib because imatinib is contraindicated for patients with

moderate renal insufficiency.

Question 20.4.4. A 52-year-old woman with metastatic gastric GIST had an initial com-

plete response to daily imatinib 400 mg with resolution of her hepatic and

peritoneal metastases after 6 months of therapy. Imatinib was continued

for 18 months when her CT scan showed recurrent hepatic lesions. Ima-

tinib was increased to 800 mg daily. However, subsequent scans revealed

progressive disease. You recommend starting sunitinib for this patient.

Which of the following statements is NOT true?

A. Secondary resistance to imatinib therapy may be associated with the

development of secondary KIT or PDGFRA mutations.

B. Sunitinib therapy for patients with imatinib-resistant GIST improved

progression-free survival compared with placebo.

C. Patients with GIST harboring exon 9 mutation have a higher response

to sunitinib than those with exon 11 mutation.

D. Patients with the wild-type GIST are resistant to both imatinib and

sunitinib therapy.

Question 20.4.5. The patient in Question 20.4.4 started sunitinib 50 mg daily for 28 days

followed by a 2-week break. After two cycles, repeat CT scans showed

a decrease in her measurable lesions. In addition to hypopigmentation of

her hair, she also noted progressive generalized fatigue. She denies any dys-

pnea on exertion, diarrhea, or pedal edema. Physical examination reveals

an erythematous rash in her hands, clear lungs, no cardiac gallops or rubs,

and no focal neurologic deficits. Pertinent laboratory tests are as follows:

White blood cell 5.6×103 cells/L

Hemoglobin 11.8 g/dL

Sodium 145 mmol/L

Potassium 4.5 mmol/L

Creatinine 0.8 mg/dL

Total bilirubin 0.5 mg/dL

Alkaline phosphatase 118/L

What would you order next?

A. Magnesium level

B. Magnetic resonance imaging of the brain

C. Thyroid function tests

D. 25-Hydroxycholecalciferol level