This dissertation is focused on the evaluation of cancer spectrum related to
hereditary and familial breast cancer. In BRCA1 mutation carriers, mean
cumulative risk at age 70 years is 57% (95% CI, 47% to 66%) for breast cancer
and 40% (95% CI, 35% to 46%) for ovarian cancer. Moreover, in BRCA2
mutation carriers mean cumulative risk at age 70 years is 49% (95% CI, 40%
to 57%) for breast cancer and 18% (95% CI, 13% to 23%) for ovarian cancer.
Various studies reported contradictory data concerning risk of cancer at sites
different than breast and ovary in both of carriers of mutations in BRCA1 and
BRCA2 genes.
We selected families referred to “Screening and follow-up for hereditary
and familial cancers” Unit of University “Federico II” in Naples for
oncogenetic counseling. Families were analyzed in order to evaluate the cancer
spectrum related with inherited and familial breast and ovarian cancer. We
examined 104 pedigrees for a total of 4100 individuals (2117 females, 1983
males), all of Caucasian ethnicity. Based on family history of breast cancer
and/or ovarian cancer and on clinical characteristics at diagnosis, pedigrees
were classified according to Modena model in: hereditary with clustering (41
families; 39%), hereditary without clustering (27 families; 26%) and familial
(36 families; 35%).
A total of 587 independent events of cancer have been detected in the 104
families on study. In particular among the three major categories in which
individuals have been grouped, 294 cases (17.6%) of tumors were registered in
the category of hereditary with clustering constituted of a cohort of 1670
individuals, 103 cases (9.8%) of tumors in the category of hereditary without
clustering constituted of a cohort of 1053 individuals and 190 cases (13.8%) of
tumors in the familial category constituted of a cohort of 1377 individuals.
In the hereditary with clustering group a high frequency emerges for cancer
of ovary (2%), uterus (1,4%), prostate (1,4%) and lung (0,9%). A moderate
frequency emerges for colon-rectum (0,8%) and stomach (0,7%) cancers. In
the hereditary without clustering group a similar association has not been
revealed except for colon-rectum cancer ((0,8%). In the familial group a high
frequency has been registered for cancers of ovary (1,3%), uterus (2%), and
colon-rectum (1,3%). A moderate frequency has been registered for prostate
cancer (0,9%).
We also determined frequency of tumors in families with mutations of
BRCA1/2 genes. In the 10 families with BRCA1 mutations, 76 events of
cancers have been detected in a total of 486 individuals. It emerges a clustering
with ovarian (4.9%), uterine (1.2%) and bladder cancer (0.8%). In the 6
families with BRCA2 genotype, 33 events of cancers have been registered in a
total of 185 individuals. It emerges a clustering with ovarian (2.8%), uterine
(2,8%), colon-rectum (1%) and prostate cancers (2,6%).
At least, the statistical analysis have not revealed a typical cancer spectrum,
because differences of statistical value have not been gained for any specific
site other than breast in our series among risk categories and sex
