Breast cancer incidence has been substantially increasing in developing countries
in the last decades.[1 ] In Brazil, the total number of new diagnosed cases reaches 60,000 a year, resulting
in an incidence rate of 60/100,000 women per year.[2 ] Despite the high incidence, breast cancer is described as a relatively good prognosis
cancer. The worldwide incidence/mortality rate is 3.3.[3 ] However, this ratio varies within different populations with an evident decrease
in developing countries when comparing to developed ones. The impact in prognosis
in this scenario may be attributed to late diagnosis and discrepant technological
improvement on cancer therapies.[4 ]
Mammographic screening has been described as an effective method for early breast
cancer detection with substantial impact on breast cancer specific survival. A Norwegian
study showed the implementation of a breast cancer screening program was able to detect
an increased number of ductal carcinomas in situ (DCISs), and substantially reduced
the number of locally advanced and metastatic tumors, resulting in a significant improvement
in the breast cancer specific prognosis.[5 ] They observed the fact of inviting women to mammography screening was the most significant
factor impacting survival. This result has demonstrated that breast cancer awareness
is a crucial piece of a breast cancer screening program.[6 ]
The National Institute of Cancer in Brazil has issued an official recommendation for
breast cancer screening in 2004, which was updated in 2015. It recommends mammography
biennially for women aged 50 to 69 years old among the general population.[7 ] However, it did not establish a standardized screening program, configuring an opportunistic
one. Analyzing publicly available data from the Fundação Oncocentro de São Paulo (FOSP,
in the Portuguese acronym), the organization responsible for compiling cancer data
registry from the public health system across the State of São Paulo,[8 ] it is possible to figure out how catastrophic is the result of the current breast
cancer screening program in Brazil. [Fig. 1 ] demonstrates the distribution of breast cancer stages from 2000 to 2018 in the group
of women eligible for mammography screening (from 50 to 69 years old). Note that ∼
40% of the women are diagnosed with locally advanced or metastatic breast cancer.
This scenario is strikingly distinct from the data in the Norwegian population before
the implementation of the breast cancer screening program ([Table 1 ]).
Table 1
The prevalence of invasive breast cancer according to stage in the state of São Paulo,
Brazil from 2000 to 2017 and in the Norwegian population before the implementation
of the national breast cancer screening program
Stage
Brazil (n = 22,527)
Norwegian (n = 26,883)
I
21.3%
48.5%
II
35.2%
38.5%
III
25.2%
5.3%
IV
8.9%
6.5%
X
1.6%
−
Fig. 1 Breast cancer distribution according to stage in the state of São Paulo, Brazil.
Source: FOSP - Fundação Oncocentro de São Paulo.[8 ]
Combining data from the Brazilian Geography and Statistics Institute (IBGE, in the
Portuguese acronym) and FOSP, we observed that from 2003 to 2013, the biennial mammography
coverage increased by 10.5%. From 2000 to 2016, the proportions of in situ and localized
tumors increased 6.9% and 3.9%, respectively. During the same period, the proportions
of regional and distant tumors decreased by 7.1% and 4%, respectively.[9 ] However, this scenario is far away from an acceptable level in a R$ 2.2 trillion
GDP federated state.[10 ]
The impact of late diagnosis in breast cancer is remarkable. Analyzing data from a
public reference hospital in Ribeirão Preto, state of São Paulo, Brazil, including
all breast cancer patients from 2000 to 2013 (n = 1,955), we observed a similar scenario. A total of 1,025 patients were diagnosed
with locally advanced or metastatic disease, and 34.5% of them presented with a tumor > 5 cm
(T3) in diameter or as T4 stage (skin/chest wall involvement or inflammatory breast
cancer). [Fig. 2 ] shows the 10-year disease specific survival according to the T stage among this
population. Note how worse is the disease specific survival among T3 and T4 stage
patients (non-published data). Cancer is a progressive disease, thus late stage diagnosis
is usually due to the lack of patient awareness or the delay on patient referral and
diagnosis/treatment. It's not clear how each of these factors contributes to the current
scenario. What is clear is that effective measures should be implemented as soon as
possible.[11 ] The implementation of a structured breast cancer screening program, including a
routine invitation to eligible women to participate and the offer of a fast track
access for patients with suspicious clinical or subclinical breast lesions, is crucial
for early stage breast cancer diagnosis.
Fig. 2 10-year breast cancer specific survival among 1,752 invasive non-metastatic breast
carcinoma patients according to T stage. *Data from an unpublished study approved
by the local Committee in Ethics number 2.638.453/2018.
