Devita, Hellman, and Rosenberg's Cancer

LWBK1006-08 LWW-Govindan-Review December 12, 2011 18:49

Chapter 8•Principles of Medical Oncology 103

Answer 8.23. The answer is D.

Cetuximab is a chimeric antibody with promising activity in colorec-

tal cancer and other solid tumors. Currently, it is used in the second

or third-line setting, either alone or in combination with chemotherapy.

In irinotecan-resistant patients, reported overall response rates with the

cetuximab/irinotecan combination are 21% to 23%. Toxicity is usually

manageable and is mostly related to rash.

Answer 8.24. The answer is B.

Randomized discontinuation design is a novel phase 2 study design and

is useful in identifying the target population for a drug. For a drug with

an established predictive biomarker, there is no benefit to using this study

design since the target population is already defined by the biomarker.

Answer 8.25. The answer is C.

Overexpression of cyclin-dependent kinases can lead to inhibition of the

Rb gene, a key tumor suppressor. Flavopiridol acts as a cyclin-dependent

kinase inhibitor and may also have antiangiogenic properties.

Answer 8.26. The answer is B.

The RECIST criteria use evaluation of tumor size to define a response.

Limitations include the inability to measure the extent of response in sites

with unmeasurable tumor, such as pleural and ascitic fluid, bone-only

disease, and leptomeningeal disease.

Answer 8.27. The answer is B.

Computed tomography contrast perfusion has been studied in assessing

blood flow to rectal tumors treated with bevacizumab. The functionality

of vascular endothelial growth factor receptor blockers has also been

studied using dynamic-contrast magnetic resonance imaging. The utility

of these tests in assessing response to alkylating agents, tumor necrosis,

or effect on overall survival is not known.

Answer 8.28. The answer is D.

Time to tumor progression as an end point for studies involving metastatic

cancer has several advantages over using overall survival: Sample size may

be smaller, subsequent therapies do not confound the data, and the study

may be able to be completed in a shorter amount of time.