LWBK1006-24 LWW-Govindan-Review December 12, 2011 19:15
Chapter 24•Cancer of the Breast 341ANSWERS
Answer 24.1. The answer is B.
Approximately 10% of all breast cancers are associated with germ line
mutations, while other 90% occur sporadically.Answer 24.2. The answer is A.
PARP1 is a cellular enzyme involved in the single-strand DNA repair
through the base excision repair. Since both BRCA 1 and BRCA2 are
important in DNA repair via the homologous combination repair path-
way, patients with mutations of either BRCA1 or BRCA2 may be sensitive
to PARP inhibition.Answer 24.3. The answer is B.
BRCA1-associated breast cancers usually occur in younger women, have
aggressive features, and are characterized by a “triple negative” pheno-
type (ER, PR, and HER2 negative).Answer 24.4. The answer is D.
The addition of trastuzumab to chemotherapy in the adjuvant setting
decreases recurrence rates to over 50%. Lapatinib is a dual EGFR and
HER2 receptor and HER2 activation occurs through homo- and het-
erodimer formation.Answer 24.5. The answer is A.
Li-Fraumeni syndrome is characterized by breast cancer, soft tissue
sarcoma, CNS tumors, adrenal cancer, leukemia, and prostate cancer.
Adrenal cancer, prostate cancer, and leukemia are not common in Cow-
den, Peutz-Jegher syndromes or ataxia-telangiectasia.Answer 24.6. The answer is A.
BRCA1 is the gene at locus 17q21.BRCA2, PTEN,andP53are located
on 13q12.3, 10q23.3, and 17p13.1, respectively.Answer 24.7. The answer is C.
The factors associated with an increased relative risk above 4 for the devel-
opment of breast cancer includeBRCAmutations, lobular carcinoma in
situ, atypical hyperplasia, and radiation exposure before the age of 40.
CHEK2 mutations are associated with a relative risk between 2 and 4.Answer 24.8. The answer is A.
In the Women’s Health Initiative study, combined estrogen and progestin
increased the risk of developing breast cancer with a hazard ratio of 1.24.
The increase in breast cancer was detected at 2 years, but an excess of