Panorama do câncer de mama em mulheres no norte do Tocantins – Brasil Overview of female breast cancer in northern Tocantins – Brazil

Objective: to evaluate the temporal variation of the percentages of female breast cancer in early and late stages and analyze socio-demographic variables associated with these stages. Methods: study of secondary data performed between the years of 2000 and 2015 in the Araguaína Regional Hospital Araguaína TO – Brasil. Results: breast cancer in advanced stages were diagnosed in 51.1% of the cases and at an early stage in 48.9%. There was no difference between the percentages of patients with early and late stages over the years. Women of race/black, illiterate and origin of the southeast of Pará presented a higher percentage of late staging at diagnosis. Conclusions: most women was diagnosed with advanced disease; the time evolution of the proportion of cases (advanced/early) did not demonstrate variational changes over the years; association of the disease has been identified in advanced stage in women of race/black, illiterate and from the southeast of Pará state.

to those casellas.Comparison of media between both groups were made by t Student test for independent samples.For comparison of more than two groups, it was used the non-parametric Kruskal-Wallis test in view of the violation of the assumption of normality of data necessary for ANOVA (analysis of variance).When media differences were identified, their analysis was performed by Dunn-Bonferroni multiple comparison.For all statistical tests, it was used a significant level of 5%.This study was registered at Plataforma Brasil and was analyzed by the Research Ethical Committee # 639460.

RESULTS
In the studied period (2000 to 2015), 1409 analytical and non-analytical women with breast cancer were registered at Sis-RHC/HRA.At first consultation, the most frequent stages were: IIA, IIB, IIIB and IV (Figure 1).In consequence, the more frequent stage group of women with breast cancer at HRA was stage III, followed by stage II, 35.2% and 33.7%, respectively (Figure 2).When stages 0,I and II were grouped as early stages, and II and IV as late stages, it was observed that 51.8% of patients were diagnosed with late disease, while 48. 25 with early tumor at diagnosis over the studied years (Figure 3).Evolutionary analysis of breast cancer stages did not show any significant difference of percentage proportions (p=0.757) between early and late stages at diagnosis over the studied years (Figure 4).
Of the total of 1409 women, only 2.2% (28 patients) had no information about stage at the register, and the same was observed among some demographic and social variables.Thus, the analysis of correlation of socio-demographic variables and stage (early or late) shows distinct quantity of registers.Women with race/black color (p=0.012),illiterate (p=0.003) and from southeast of Para state showed higher percentage of late stage.On the other hand, white women, with higher education, from other regions, showed higher percentage of early diagnosis.Other variables such as age range, referral center, marital status, family history, alcohol abuse and smoking did not show any association with early or late stage of the disease (Table 1).

DISCUSSION
This analysis highlighted some epidemiologic characteristics of women with breast cancer at the High Complexity Oncology Unit at Araguaína -TO, Brazil, over 16 years (2000 to 2015).It is important to stress that the Araguaina Regional Hospital is a referral center for oncology at the state of Tocantins, southeast of Para state and south of Maranhão state.Also, HRA had available only one public service of radiotherapy in the state until 2015.
Considering possible limitations of this work, during the studied period, the percentage of women with breast cancer in late stages in this region of the country is elevated (around 50% of patients).Similar results or even worse were found in Indian women and from Sub-Saharan Africa.In those countries, 70 to 90% of patients are diagnosed with stages III and IV 8,9 .In many parts of the planet, high percentages of breast cancer  patients diagnosed with late stage are usually observed in underdeveloped areas [8][9][10] .
In particular, the state of Tocantins in Brazil (former north part of Goias state) is a underdeveloped region and has been considered one of the most vulnerable health areas in Brazil for decades.However, after the creation of the Tocantins state in 1988, a gradual growth of several economic sectors such as commerce, civil construction, and improvement of health care and education, was observed, in special at the city of Araguaína 11 .Due to this apparent development of the region, it would be expected that the number of advanced breast cancer over the years would slow down, but this did not happen.Detailed analysis of staging showed that high percentages of advanced cases persisted over the years, with little variation (more or less) of 50% over the 16 years studied.These results showed that local and regional health actions to control cancer were inefficient over the years.Some Brazilian researches verified that, even in most developed regions of the country, it may be found high percentages of advanced breast cancer 12 .And others had showed significant improvement in the reduction of late stage diagnosis and mortality rates 12,13 .In general, the percentage of patients with late stage cancer and the mortality rate due to breast tumor are lowering in south, southeast and centralwest Brazilian regions.However, it is important to stress that in many of those studies, it was discussed the reality of single Health Centers and with better qualification for oncologic attention 15,16 .When broader studies involving public institutions with regional representativeness are analyzed, it is verified that the percentage of patients diagnosed with late stage of the disease is considerably higher than that observed in health centers dedicated to oncologic treatment 16 .
Several factors may contribute to late diagnosis of women with breast cancer.For example, difficult access to medical care, low number of specialized centers, and scarce knowledge of breast cancer among health care professionals 9,14,17,18 .For improvement, it is necessary a well-structured health system, with proactive professionals, that can anticipate the occurrence of the disease in a participative society with active citizens.
In developed countries, with good health system, mortality rate due to breast cancer is lowering over the last years and is closely related to early diagnosis.The development of efficient programs to treat breast cancer includes screening with mammography of target population, exams with good quality and adequate treatment of the disease 19,20 .There should be equivalent attention from promotion to palliative care in late stages.In those countries, less than 10% of tumors are detected in late stages 21 .
In Brazil, actions against breast cancer have been inefficient and without correct comprehensiveness, leading to higher rate of diagnosis in late stages, and high mortality of Brazilian women due to breast cancer 17 .In northern region of Brazil, it is observed the lowest coverage of mammography screening of target women 22 .
It was also observed in this study that there is a strong association between late stage and race/ black color (p=0,012).Similar results were also found by other authors, that verified that black women   delayed more to diagnose and treat the disease, compared to white race 23 .In the USA, where racial miscegenation is less evident, white women present higher incidence of breast cancer in comparison to other races and ethnicity.However, African-American women are more prone to die due to the disease.These differences are caused by difference of access to health care and treatment 21,23 .However, data collection about trace/color of patients with breast cancer is still faulty, since it is recommended self-classification.It must be pointed out that the high grade of miscegenation in Brazil, as well as the subjectivity to determine the color of the skin, may cause bias in the interpretation of collected data 13 .Also, another aspect of the more aggressiveness of breast cancer in black women may be related to the phenotype triple-negative that seems to occur with higher frequency in young African-American women, particularly during pre-menopause 24 .
In relation to schooling, in this study, we observed a significant association with clinical stage (p=0.003):illiterate women showed higher percentage of late stage disease, while patients with complete higher education showed more early stage disease.These findings are in accordance to others in literature, including studies that showed a direct relation of schooling and mortality rate due to breast cancer.Most deaths in women with low schooling are associated with diagnosis of breast cancer in late stage 25 .
In the poorest regions of the planet and with very low schooling rates, stigma associated with cancer slows down the search for medical care.Survival rate in 5 years is less than 50% in Gambia, Uganda and Algeria, compared to almost 99% in the USA 4 .On the other hand, women with higher grade of schooling look for more early diagnosis of breast cancer, attending medical offices and performing mammography 26 .
In this analysis, it is also possible to observe that patients from the southeast region of Para State showed higher percentage of late stage cancer (p=0.009),maybe due to some particularities of this regions.Southeast region of Para State has no medical care, low social development and poor economics and schooling 11 .Data from IPEA (Instituto de Pesquisa Econômica Aplicada-Applied Economics Research Institute) shows that Para State has in absolute number a percentage above national media of illiterate people (13.8%), reaching 23% in rural areas and 7% in urban areas.There is also a difference between white illiterates (5.9%) and black illiterate people (13.4%).Another aspect that reinforces disparity is per capita income that, in that population, is less than half of national media 11 .Therefore, such aspects associated to the low quality of health care, difficult access to specialized health oncologic centers and referral inefficacy, justify the results here described.Similar results were presented by other authors, that stated that the difficulty to access the public health care is higher in low socio-economic and lower schooling patients, making also difficult health actions for early diagnosis 27 .In regions with low human development index, such as Western Africa, more than 70% of patients with breast cancer were diagnosed at stages III or IV 27,28 .Similar results were verified in Libya and Nigeria 28 .However, in more developed regions such as Europe and USA, women are more frequently diagnosed with early stage disease 28 .
The importance of early diagnosis of breast cancer in public health services is been highlighted, by promotion of discussion about access and inclusion of those patients.In order to face these challenges, it is important to involve society, researchers, medical professionals and health managers.
We can conclude that our study showed that actions to fight breast cancer in the region are inefficient, since most women in northern Tocantins were diagnosed with late stage disease, and temporal evolution of the proportion of cases with late or early diagnosis has not changed over the years 2000 to 2015.Late stage breast cancer in women from Tocantins was associated with race/black color, low level of schooling, and origin from southeast Para.Finally, due to the situation of breast cancer in northern Tocantins, it is possible to assume that health care and prevention of the diseases are inadequate, with chronic health deficiency.Future epidemiologic research information will improve the understanding of breast cancer and other chronic diseases in the region and will guide the necessary actions to be taken to improve health care of affected population or at greater risk.

Figure 1 .
Figure 1.Breast cancer stage in HRA from 2000 to 2015.Figure 2. Grouping of breast cancer at HRA from 2000 to 2015.

Figure 2 .
Figure 1.Breast cancer stage in HRA from 2000 to 2015.Figure 2. Grouping of breast cancer at HRA from 2000 to 2015.

Figure 3 .
Figure 3. Breast cancer status at HRA from 2000 to 2015.Figure 4. Temporal status of breast at HRA from 2000 to 2015.

Figure 4 .
Figure 3. Breast cancer status at HRA from 2000 to 2015.Figure 4. Temporal status of breast at HRA from 2000 to 2015.

Table 1 .
Socio-demographic data and breast cancer status.
¤ -Descriptive level of Chi-square test or Exact Fisher (*)