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Changes in mastectomy rates at a Brazilian public hospital over 20 years (1989 to 2008)

CONTEXT AND OBJECTIVE: Recently, breast-conserving surgery (BCS) has been replacing mastectomy for breast cancer treatment. The aim of this study was to evaluate the changes in mastectomy and BCS rates and the factors relating to these shifts. DESIGN AND SETTING: A retrospective study in a Brazilian public hospital. METHODS: Pathological records from female patients who underwent surgery for breast cancer at Hospital das Clínicas, Universidade Federal de Minas Gerais (HC-UFMG), between 1989 and 2008 were reviewed. The mastectomy and BCS rates were calculated. The chi-square test was used to assess factors associated with type of surgical treatment and to compare trends in treatment type over the years. Logistic regression was used for multivariate analysis. RESULTS: From 1989 to 2008, 2050 breast cancer surgical specimens were received in our service, corresponding to 1973 patients; 1324 (64.6%) of them were from mastectomy and 726 (35.4%) from BCS. A shift from mastectomy towards BCS was observed (P < 0.001). In multivariate analysis, earlier year of surgery (P < 0.001), larger tumor size (P < 0.001), having at least one positive axillary lymph node (P < 0.001) and patients’ age greater than 68 years (P = 0.007) were predictors of mastectomy. CONCLUSIONS: There was a shift from mastectomy towards BCS in our institution over the years. This may reflect consolidation of BCS (plus radiotherapy) as an equivalent treatment to mastectomy in terms of survival and a shift to earlier diagnosis for the disease. RESUMO CONTEXTO E OBJETIVO: Recentemente, a cirurgia conservadora tem substituído a mastectomia para tratamento cirúrgico do câncer de mama. O objetivo deste estudo é avaliar as mudanças nas taxas de mastectomia e cirurgia conservadora e os fatores relacionados a essas mudanças. TIPO DE ESTUDO E LOCAL: Estudo retrospectivo em hospital público brasileiro. MÉTODOS: Dados patológicos das pacientes submetidas a cirurgia para câncer de mama no Hospital das Clínicas, Universidade Federal de Minas Gerais (HC-UFMG), de 1989 a 2008, foram revistos. As taxas de mastectomia e cirurgia conservadora foram calculadas. O teste qui-quadrado foi usado para avaliar fatores relacionados ao tipo de tratamento cirúrgico empregado e comparar tendências de tipo de tratamento ao longo dos anos. Regressão logística foi usada para análise multivariada. RESULTADOS: De 1989 a 2008, 2.050 espécimes cirúrgicos de câncer de mama foram recebidos em nosso serviço, correspondentes a 1.973 pacientes; 1.324 (64,6%) correspondentes a mastectomia e 726 (35,4%) correspondentes a cirurgia conservadora. A cirurgia conservadora se tornou mais frequente ao longo dos anos (P < 0,001). Em análise multivariada, ano mais precoce da cirurgia (P < 0,001), maior tamanho tumoral (P < 0,001), ter ao menos um linfonodo axilar positivo (P < 0,001) e idade maior de 68 anos (P = 0,007) foram preditores de mastectomia. CONCLUSÕES: As cirurgias conservadoras se tornaram mais frequentes em relação às mastectomias ao longo dos anos. Isso pode refletir a consolidação da cirurgia conservadora (associada a radioterapia) como equivalente à mastectomia em termos de sobrevida, bem como diagnóstico mais precoce da doença. IMD, PhD Student. General Surgeon, Department of Anatomical Pathology, Faculdade de Medicina da Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil. IIMedical Student, Department of Anatomical Pathology, Faculdade de Medicina da Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil. IIIStatistics Student, Department of Statistics, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil. IVPhD. Associate Professor, Department of Statistics, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil. VMD, PhD. Associate Professor, Department of Anatomical Pathology, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil.


INTRODUCTION
Breast cancer is the most common cancer in women worldwide, and also the most common cause of cancer deaths in this group. 1 It was estimated that Brazil would have 49,240 new cases of the disease in 2011. 2 Mortality from breast cancer is still high in Brazil, mostly due to a delay in diagnosis. [1][2][3][4] During the first half of the 20 th century, Halsted's radical mastectomy and some variations of the procedure were used to treat the disease. [5][6][7][8] In the 1970s, Fisher's group in the United States and Veronesi's group in Italy started comparing the prognoses of patients who had undergone breast-conserving surgery (BCS; wide local excision known as lumpectomy in the United States and quadrantectomy in Italy) and mastectomy for early-stage breast cancer. They showed that, when associated with radiotherapy, BCS equaled mastectomy regarding long-term survival. [9][10][11][12][13][14] This led the United States National Institutes of Health to publish a consensus in 1991 stating that BCS could be used when possible. 15 After this consensus had been published, mastectomy rates decreased to less than 50% in some countries. [16][17][18][19][20][21][22] Recently, some American hospitals have reported an increase in mastectomy rates, although American and European statistics in general do not show this increase. 16 Table 1 shows the distribution of frequencies according to the type of surgical procedure, history of contralateral breast cancer, laterality, pathological tumor size (pT), status of regional lymph nodes (pN), histopathology and age range.
The total number of surgeries increased over the years, from 45 cases in 1989 to 160 in 2008 (   year of treatment, larger tumor size (pT) and positive regional lymph node status (pN). Histopathology was not significant in the model. The results from the Hosmer and Lemeshow test showed that the model fit was good (P = 0.251).

DISCUSSION
Our study evaluated a series of women who were treated for breast cancer at a Brazilian public general hospital in the state of Minas Gerais that is also a reference center for breast cancer    In summary, the final regression model showed that use of mastectomy was associated with older age (> 68 years), earlier 0% 1 9 8 9 1 9 9 0 1 9 9 1 1 9 9 2 1 9 9 3 1 9 9 4 1 9 9 5 1 9 9 6 1 9 9 7 1 9 9 8 1 9 sus stating that BCS could be used for tumors smaller than three centimeters. 40 However, by the 2000s, developed countries had lower mastectomy rates, ranging from 35% to 46%. [16][17][18] In a significant percentage of cases, we were unable to estimate the tumor size (20.8%) because multiple specimens were derived from the same tumor (incisional biopsies) or because some procedures had been performed in other institutions. We were also unable to estimate lymph node status in 16.4% of the patients, because they had not undergone surgical axillary staging or had undergone this procedure in another institution. Even though this could have affected our results, tumor size and lymph node status were strong independent predictors of the type of surgical treatment.
Other than tumor size and lymph node status, many other factors are known to affect the use of BCS or mastectomy. 17,18,20,23,[31][32][33][34][35]41 In our study, as in many other studies, older age was found to be a predictor of mastectomy. This differs from other studies, like those by Katipamula et al. 20 (younger age was found to be a risk factor for mastectomy), McGuire et al. 23 and Adkinsson et al. 25 On the other hand, Reitsamer et al. 32 showed that there was no correlation between age and type of surgery, and Zorzi et al. 18 and Chagpar et al. 42 showed higher mastectomy rates in older women. This may be explainable by different perception of breast importance in different cultural settings. It may also be attributable to our methodology, which selected only the last procedure performed on the patient. Therefore, the older woman may in fact have undergone BCS but might have had a recurrence later on and needed a mastectomy. Sixty-seven patients (5.1% of the mastectomies) first underwent breast conserving surgery and then mastectomy in a second intervention. Some authors have also reported that adjuvant therapy (such as chemotherapy) is less prescribed to older women, especially with a poor health status, 43,44 and thus a more aggressive local therapy may have been chosen. It has been noticed that younger women have higher recurrence rates after BCS. 45,46 Since the source of our study was pathological records, patients' choices were not addressed although they could have influenced mastectomy rates. 22,28,35,47 Some authors have concluded that, even though the public health system pays for mammograms, the adherence of women to screening mammograms is still low in Brazil, especially among less privileged women. Lima-Costa and Matos 3 showed that, in 2003, only 43% of women between the ages of 50 and 69 years (the age recommended for screening mammograms according to the Brazilian National Cancer Institute 40 ) had had a mammogram within the previous two years. Marchi and Gurgel 4 showed that a higher percentage had had a first mammogram (68%), but that less than 50% of the patients were adherent to biannual screening. Moreover, women within the public system were less likely to comply with subsequent screening. 4 This could be responsible for our high percentage of patients with locally advanced tumors (11.9% infiltrating the skin or chest wall). This differs from developed countries, such as the United States, Italy and the United Kingdom, in which most women undergo screening mammograms as recommended. [17][18][19] It may be possible that women with more advanced tumors are more frequently referred to our hospital, and therefore we have a higher than expected percentage of large tumors. On the other hand, even though still low, we are experiencing an increase in breast cancer screening, which has now become a focus of public health policies. SISMAMA (Information System for Breast Cancer Control), implemented by the Brazilian National Cancer Institute in 2009, 48 is a tool for following up patients with abnormal breast examinations (imaging or pathology), and is also being used to direct funding for breast cancer screening.
In our study, IDC was associated with higher chances of mastectomy in univariate analyses than were DCIS, LCIS and special-type carcinomas. In multivariate analyses, the association was not significant. This differs from some studies, like those of   Katipamula et al., 20 Chagpar et al. 42 and Lee et al., 30 which showed higher mastectomy rates among patients with ILC.
Since the late 1980s, 15 many developed countries have reported decreasing mastectomies rates for early breast cancer. [19][20][21] However, no Brazilian data from either public or private hospitals concerning the type of surgery performed is available in the indexed literature. Through the present study, we have been able to conclude that in our hospital, which provides public care for breast cancer, this shift did not occur until recently. Moreover, we observed higher mastectomy rates for the same period than in developed countries such as the United States, Italy and the United Kingdom. [16][17][18] Even though total mastectomy rates alone are not an accurate measurement for breast cancer care, they bring an insight into the complex issues involved in surgical management of the disease. 16,22,24,25,[28][29][30][31][32][33][34][35]47 In our study, one of these issues is the increasing frequency of early breast cancer at the time of surgery, which is a necessary condition for performing BCS, and is associated with better patient outcomes. 36

CONCLUSIONS
There was a clear shift from mastectomies towards BCS for breast cancer treatment at HC-UFMG over the 20 years of this study. This may reflect not only consolidation of BCS plus radiotherapy as an equivalent treatment to mastectomy in terms of overall survival, but also a shift to less locally advanced tumors at diagnosis, due to a higher percentage of women undergoing screening mammograms.