LWBK1006-09 LWW-Govindan-Review December 12, 2011 18:51
110 DeVita, Hellman, and Rosenberg’s CANCER: Principles and Practice of Oncology ReviewANSWERS
Answer 9.1. The answer is C.
Initially, it was thought that the action of antibodies or humoral immunity
was mainly responsible for the response to malignant cell development.
However, it has been discovered that malignant cell development is closely
related to the cellular arm of the immune response, specifically a response
to T cells. B cells do not play a major role in the immune response to
tumor cells.Answer 9.2. The answer is B.
For existing malignancies, the main mechanism for immunotherapy is
to try to increase the level of immune lymphocytes. These immune lym-
phocytes would be responsible for recognizing the cancer antigens and
destroying the cancer cells. Although the development of antibodies that
target growth factors on cancer cells may help in reducing the overall
tumor burden, this does not work by directly destroying the cancer cells.Answer 9.3. The answer is A.
There are three methodologies for identifying tumor antigens that are
present on the surface of the cancer cells. The first approach is using T cells
that have a known ability to recognize intact cancer cells and assessing
this by cytokine release or lysis in culture. The second approach is using
a “reverse immunology” technique where T cells are generated by sensi-
tization with peptides from proteins previously described. These T cells
are then used to test the ability to detect intact cancer cells and to deter-
mine if the peptides are found on the surface of the cancer cell. The final
approach is to use antisera from patients with known cancer and compare
them with cancer DNA libraries already constructed. The development
of antibodies has not been used to detect antigens on the cell surface.Answer 9.4. The answer is A.
Melanocyte differentiation antigens include MART-1, gp100, and tyro-
sinase. CDK4 and HLA-A*1101 are both mutated antigens associated
with melanoma. NY-ESO-1 is a cancer testis antigen expressed in breast
cancer, prostate cancer, and melanoma.Answer 9.5. The answer is D.
Reverse immunology has been used to develop reactive T cells to com-
monly overexpressed gene products found in certain types of cancer. Tar-
gets of this technique have been CEA, PSA, and Her-2/neu. p53 is often
overexpressed in many cancer types. One of the difficulties in using p53
is the common mutations that are found and the wide expression of p53
in normal cellular tissues. Although epidermal growth factor receptor has
been used in the development of some tyrosine kinase inhibitors, it has
not been used in the development of reactive T cells.