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Breast cancer: news in diagnosis and treatment
Rev Assoc Med B ras 2015; 61(6):543-552 543
REVIEW ARTICLE
Breast cancer: news in diagnosis and treatment
Afonso Celso P into Nazário1, Gil Facina2, José Roberto F ilassi3
1Associate Professor, Habilitation (BR: Livre Docência), Head of the Division of Mastology at Escola Paulista de Medicina, Universidade Federal de São Paulo (EPM-UNIFESP), São Paulo, SP, Brazil
2Adjunct Professor, Habilitation (BR: Livre Docência), Division of Mastology at EPM-UNIFESP, São Paulo, SP, Brazil
3Associate Professor, Habilitation (BR: Livre Docência), Head of the Mastology Sector, Division of Gynecology, Department of Obstetrics and Gynecology, Hospital das Clínicas, Faculdade de Medicina,
Universidade de São Paulo, São Paulo, SP, Brazil
Summary
Study conducted at Discipline of Mastology
of the Departament of Gynecology at
Escola Paulista de Medicina, Universidade
Federal de São Paulo (EPM-UNIFESP) and
at Sector of Mastology of the Discipline of
Gynecology at Faculdade de Medicina
da Universidade de São Paulo (FMUSP),
São Paulo, SP, Brazil
Article received: 10/14/2015
Accepted for publication: 10/19/2015
*Correspondence:
Address: Rua Nova York, 609 – apt. 73-L
Postal code: 04560001
São Paulo, SP – Brazil
Conflict of interest: none
The authors discuss the main innovations in the diagnosis and treatment of
breast cancer, particularly in diagnostic imaging and screening, and in locore-
gional and systemic therapies.
Keywords: breast cancer, diagnosis, treatment.
Introduction
Breast cancer is currently the most common malignancy
among women in developed countries, except for non-
melanoma skin tumors. In the United States (US), 231,840
new cases were estimated in 2015, which corresponded
to 29% of cases of female cancer in the country. Brazil fol-
lows this trend, with an estimate in 2014 of 57,120 new
cases, which makes it the most common malignancy
among Brazilian women. In terms of incidence, the US
saw an increase, between 1980 and 1987, of 4% per year
probably due to the intensification of mammographic
screening programs. Between 1987 and 2002, this figure
continued to grow, but at a lower rate (0.3% annually).
Between 2002 and 2003, breast cancer incidence fell by
7.5%, probably due to a decline of 50% in the prescription
of hormone therapy for postmenopausal women in that
country, after the release of the Women’s Health Initia-
tive (WHI) study, remaining stable after 2007. In addition
to a high incidence, breast cancer also has a high mortal-
ity rate. It is the second leading cause of death due to ma-
lignancy among American women, second only to lung/
bronchial cancer. In 2015, it was responsible for 40,920
deaths in the US. However, the mortality rate, which grew
between the years 1975 and 1990 at an annual rate of 0.4%,
declined between 1990 and 2002, presenting an annual
drop of 2.3%, possibly due to early detection and better
treatment. In Brazil, it is responsible for the largest num-
ber of deaths caused by malignant cancers among wom-
en and, unfortunately, the mortality rate remains high
and growing, because the disease is still diagnosed in ad-
vanced stages. When the diagnosis is delayed, treatment
is mutilating and aggressive. Thus, every effort should be
made in order to detect the disease as soon as possible.
Breast cancer is the result of failure in the normal ca-
pacity of cells to proliferate and differentiate, which is
caused by various genetic changes, culminating in malig-
nant transformation. Mammary carcinogenesis is an ex-
tremely complex process and can be didactically divided
into three stages: initiation, promotion and progression.
At initiation, a phenotypically normal cell becomes ma-
lignant, usually presenting an intermediate stage of cel-
lular atypia. Genetic mechanisms are involved in this stage
and can be inherited (familial breast cancer) or acquired
throughout life (sporadic breast cancer).
The familial form accounts for only 10% of cases of
breast cancer and the leading genetic alteration found is in-
activation of tumor suppressor genes. The genetic disorder
is present right from the beginning of life, transmitted
through germ line cells (autosomal dominant inheritance)
and, therefore, tends to occur at an earlier age, i.e., premeno-
pausal and often bilaterally. The main genes involved are
BRCA1 and BRCA2. BRCA1 is located on chromosome 17
and the carriers of this mutation have a high susceptibili-
ty to breast (65% up to throughout life) and ovary (39%)