Locally advanced breast cancer: breast-conserving surgery and other factors linked to overall survival after neoadjuvant treatment.

Background: Recent data suggest that breast-conserving surgery (BCS) may positively impact overall survival (OS) in early breast cancer. However, the role of BCS in locally advanced breast cancer (LABC) following neoadjuvant therapy (NAT) remains uncertain. Methods: We conducted a retrospective cohort study involving 530 LABC patients who underwent surgery after NAT between 2010 and 2015. Outcomes examined included OS, distant recurrence rates (DRR), and loco-regional recurrence rates (LRRs). Results: Among the 927 breast cancer patients who received NAT, 530 were eligible for our study. Of these, 24.6% underwent BCS, while 75.4% underwent mastectomy (MS). The median follow-up duration was 79 months. BCS patients exhibited a higher pathological complete response (PCR) rate compared to those who underwent MS (22.3% vs. 10%, p < 0.001). The 6-year OS rates for BCS and MS were 81.5% and 62%, respectively (p < 0.000). In multivariate OS analysis, MS was associated with worse outcomes (OR 1.678; 95% CI 1.069-2.635; p = 0.024), as was body mass index (BMI) (OR 1.031; 95% CI 1.006-1.058; p = 0.017), and stage IIIB or IIIC (OR 2.450; 95% CI 1.561-3.846; p < 0.000). Conversely, PCR (OR 0.42; 95% CI 0.220-0.801; p = 0.008) was associated with improved survival. DRR was significantly lower in BCS (15.4%) compared to MS (36.8%) (OR 0.298; 95% CI 0.177-0.504). LRRs were comparable between BCS (9.2%) and MS (9.5%) (OR 0.693; 95% CI 0.347-1.383). Conclusion: Our findings suggest that BCS is oncologically safe, even for patients with large lesions, and is associated with superior OS rates compared to MS. Additionally, lower BMI, lower pretreatment stage, and achieving PCR were associated with improved survival outcomes.

Pathological macroscopic evaluation of breast density versus mammographic breast density in breast cancer conserving surgery.

Correlation between imaging and anatomopathological breast density has been superficially explored and is heterogeneous in current medical literature. It is possible that mammographic and pathological findings are divergent. The aim of this study is to evaluate the association between breast density classified by mammography and breast density of pathological macroscopic examination in specimens of breast cancer conservative surgeries. Post-hoc, exploratory analysis of a prospective randomized clinical trial of patients with breast cancer candidates for breast conservative surgery. Breast mammographic density (MD) was analyzed according to ACR BI-RADS® criteria, and pathologic macroscopic evaluation of breast density (PMBD) was estimated by visually calculating the ratio between stromal and fatty tissue. From 412 patients, MD was A in 291 (70,6%), B in 80 (19,4%) B, C in 35 (8,5%), and D in 6 (1,5%). Ninety-nine percent (201/203) of patients classified as A+B in MD were correspondently classified in PMBD. Conversely, only 18.7% (39/209) of patients with MD C+D were classified correspondently in PMBD (p < 0.001). Binary logistic regression showed age (OR 1.06, 1.01-1.12 95% CI, p 0.013) and nulliparity (OR 0.39, 0.17-0.96 95% CI, p 0.039) as predictors of A+B PMBD. Conclusion: Mammographic and pathologic macroscopic breast density showed no association in our study for breast C or D in breast image. The fatty breast was associated with older patients and the nulliparity decreases the chance of fatty breasts nearby 60%.

Characteristics and prognosis of young breast cancer patients treated in a public comprehensive cancer centre in Brazil: A retrospective cohort study.

BACKGROUND: The incidence of breast cancer among women under 41 years old varies worldwide, with higher rates observed in developing countries. These young women often face later-stage diagnoses. In this study, we examine a cohort of young women who were treated for breast cancer in São Paulo, Brazil. METHODS: We conducted a retrospective cohort study involving women under 41 years old. Our objective was to describe patient and treatment characteristics, with the main outcomes being overall and disease-free survival. Our analysis explored the associations between age of menarche, history of breastfeeding, use of hormonal contraceptives, and age at diagnosis. RESULTS: Our study included 493 patients with a mean follow-up of 62.8 months. The mean age of the patients was 34.6 (SD=4.19). Of the patients, 68% presented with locally advanced disease, and 19.27% were metastatic at the time of diagnosis. We observed significant associations between age of menarche and age at diagnosis (p = 0.0096), as well as age at diagnosis and breastfeeding (p = 0.0232). Chemotherapy was administered to 92.91% of the patients as part of their treatment, while 27.2% were eligible for breast-conserving surgery. During the follow-up period, 153 patients died, with disease progression being the cause of death in 73.2% of cases. The median survival time for the entire cohort is still under review, while the metastatic patients at diagnosis had a median survival time of 28.64 months (95%CI 20.21-40.89). CONCLUSION: Our findings highlight significant associations between late-stage diagnosis and overall and disease-free survival in this patient age group. Given that the majority of patients present with locally advanced breast cancer, it is crucial to implement strategies that promote early-stage diagnosis and improve survival rates.

Measurement of extracapsular extension in sentinel lymph node as a possible predictor of residual axillary disease in breast cancer.

BACKGROUND: The presence of Extracapsular Extension (ECE) in the Sentinel Lymph Node Biopsy (SLNB) is still a doubt in the literature. Some studies suggest that the presence of ECE may be related to a greater number of positive axillary lymph nodes which could impact Disease Free Survival (DFS) and Overall Survival (OS). This study searches for the clinical significance of the ECE. METHODS: Retrospective cohort comparing the presence or absence of ECE in T1-2 invasive breast cancer with positive SLNB. All cases treated surgically at the Cancer Institute of the State of São Paulo (ICESP) between 2009 and 2013 were analyzed. All patients with axillary disease in SLNB underwent AD. OUTCOMES: Identify the association between the presence and length of ECE and additional axillary positive lymph nodes, OS and DFS between both groups. RESULTS: 128 patients with positive SLNB were included, and 65 had ECE. The mean metastasis size of 0.62 (SD = 0.59) mm at SLNB was related to the presence of ECE (p < 0.008). The presence of ECE was related to a higher mean of positive sentinel lymph nodes, 3.9 (± 4.8) vs. 2.0 (± 2.1), p = 0.001. The median length of follow-up was 115 months. The OS and DFS rates had no differences between the groups. CONCLUSION: The presence of ECE was associated with additional positive axillary lymph nodes in this study. Therefore, the OS and DFS were similar in both groups after 10 years of follow-up. It is necessary for additional studies to define the importance of AD when SLNB with ECE.

Effects of preoperative magnetic resonance image on survival rates and surgical planning in breast cancer conservative surgery: randomized controlled trial (BREAST-MRI trial).

BACKGROUND: Breast magnetic resonance imaging (MRI) has high sensitivity in detecting invasive neoplasms. Controversy remains about its impact on the preoperative staging of breast cancer surgery. This study evaluated survival and surgical outcomes of preoperative MRI in conservative breast cancer surgery. METHODS: A phase III, randomized, open-label, single-center trial including female breast cancer participants, stage 0-III disease, and eligible for breast-conserving surgery. We compared the role of including MRI in preoperative evaluation versus radiologic exam routine with mammography and ultrasound in breast cancer conservative candidates. The primary outcome was local relapse-free survival (LRFS), and secondary outcomes were overall survival (OS), mastectomy rate, and reoperation rate. RESULTS: 524 were randomized to preoperative MRI group (n = 257) or control group (n = 267). The survival analysis showed a 5.9-years LRFS of 99.2% in MRI group versus 98.9% in control group (HR = 0.72; 95% CI 0.12-4.28; p = 0.7) and an OS of 95.3% in the MRI group versus 96.3% in the control group (HR = 1.37 95% CI 0.59-3.19; p = 0.8). Surgical management changed in 21 ipsilateral breasts in the MRI group; 21 (8.3%) had mastectomies versus one in the control group. No difference was found in reoperation rates, 22 (8.7%) in the MRI group versus 23 (8.7%) in the control group (RR = 1.002; 95% CI 0.57-1.75; p = 0.85). CONCLUSION: Preoperative MRI increased the mastectomy rates by 8%. The use of preoperative MRI did not influence local relapse-free survival, overall survival, or reoperation rates.

Validation of the Residual Cancer Burden Index as a prognostic tool in women with locally advanced breast cancer treated with neoadjuvant chemotherapy.

AIMS: To correlate the 'Residual Cancer Burden' (RCB) index with overall survival (OS) and disease-free survival (DFS) in women undergoing neoadjuvant chemotherapy at the Cancer Institute of the State of São Paulo. METHODS: We analysed the medical records of patients with breast cancer who underwent neoadjuvant chemotherapy and breast surgery, from 2011 to December 2017. Variables analysed were age, clinical and pathological staging, molecular subtype, number of recurrences or metastases, number of deaths, value and class of the RCB index. We used the Kaplan-Meier and the log-rank statistics to evaluate the possible association between RCB and OS and DFS. A regression model was used to determine the independent association of the RCB with the outcomes controlling for confounding factors. RESULTS: 347 patients were included in the analysis with a mean age of 49.39 years. Initial clinical staging was T3 in 57.9% of patients and 43.8% of patients had N1 axillary status. Survival analysis showed a statistically significant better prognosis for the RCB 0 (pCR) subgroup compared with RCB 1, 2 and 3 (log rank p=0.01). In a multivariate analysis, only the RCB classification showed a statistically significant correlation with DFS (RCB 1, HR 6.9, CI 1.9 to 25.4, p=0.004; RCB 2, HR 4.2, CI 1.6 to 10.8, p=0.03; and RCB 3, HR 7.6, CI 2.76 to 20.8, p=0.00). CONCLUSION: We demonstrated a positive and significant relationship between the RCB index and the risk of relapse and death.

Measurement of extracapsular extension in sentinel lymph node as a possible predictor of residual axillary disease in breast cancer

Abstract Background The presence of Extracapsular Extension (ECE) in the Sentinel Lymph Node Biopsy (SLNB) is still a doubt in the literature. Some studies suggest that the presence of ECE may be related to a greater number of positive axillary lymph nodes which could impact Disease Free Survival (DFS) and Overall Survival (OS). This study searches for the clinical significance of the ECE. Methods Retrospective cohort comparing the presence or absence of ECE in T1-2 invasive breast cancer with positive SLNB. All cases treated surgically at the Cancer Institute of the State of São Paulo (ICESP) between 2009 and 2013 were analyzed. All patients with axillary disease in SLNB underwent AD. Outcomes Identify the association between the presence and length of ECE and additional axillary positive lymph nodes, OS and DFS between both groups. Results 128 patients with positive SLNB were included, and 65 had ECE. The mean metastasis size of 0.62 (SD = 0.59) mm at SLNB was related to the presence of ECE (p < 0.008). The presence of ECE was related to a higher mean of positive sentinel lymph nodes, 3.9 (± 4.8) vs. 2.0 (± 2.1), p = 0.001. The median length of follow-up was 115 months. The OS and DFS rates had no differences between the groups. Conclusion The presence of ECE was associated with additional positive axillary lymph nodes in this study. Therefore, the OS and DFS were similar in both groups after 10 years of follow-up. It is necessary for additional studies to define the importance of AD when SLNB with ECE.

The oncological safety of autologous fat grafting: a systematic review and meta-analysis.

OBJECTIVE: To present a systematic review of the literature and a meta-analysis evaluating the oncological safety of autologous fat grafting (AFG). SUMMARY BACKGROUND DATA: AFG for breast reconstruction presents difficulties during follow-up radiological exams, and the oncological potential of grafted fat is uncertain. Previous studies confirmed that the fatty tissue could be transferred under a good condition suitable would not interfere with mammographic follow-up, although the issue of oncological safety remains. METHODS: We reviewed the literature published until 01/18/2021. The outcomes were overall survival (OS), disease-free survival (DFS), and local recurrence (LR). We included studies that evaluated women with breast cancer who undergone surgery followed by reconstruction with AFG. We synthesized data using the inverse variance method on the log-HR (log of the hazard ratio) scale for time-to-event outcomes using RevMan. We assessed heterogeneity using the Chi2 and I2 statistics. RESULTS: Fifteen studies evaluating 8541 participants were included. The hazard ratios (HR) could be extracted from four studies, and there was no difference in OS between the AFG group and control (HR 0.9, 95% CI 0.53 to 1.54, p = 0.71, I2 = 58%, moderate certainty evidence), and publication bias was not detected. The HR for DFS could be extracted from six studies, and there was no difference between the AFG group and control (HR 1.01, 95% CI 0.73 to 1.38, p = 0.96, I2 = 0%, moderate certainty evidence). The HR for LR could be extracted from ten studies, and there was no difference between the AFG group and control (HR 0.86, 95% CI 0.66 to 1.12, p = 0.43, I2 = 1%, moderate certainty evidence). CONCLUSION: According to the current evidence, AFG is a safe technique of breast reconstruction for patients that have undergone BC surgery and did not affect OS, DFS, or LR.

Accuracy of frozen section in intraoperative margin assessment for breast-conserving surgery: A systematic review and meta-analysis.

BACKGROUND AND OBJECTIVES: It is well established that tumor-free margin is an important factor for reducing local recurrence and reoperation rates. This systematic review with meta-analysis of frozen section intraoperative margin assessment aims to evaluate the accuracy, and reoperation and survival rates, and to establish its importance in breast-conserving surgery. METHODS: A thorough review was conducted in all online publication-databases for the related literature up to March 2020. MeSH terms used: "Breast Cancer", "Segmental Mastectomy" and "Frozen Section". We included the studies that evaluated accuracy of frozen section, reoperation and survival rates. To ensure quality of the included articles, the QUADAS-2 tool (adapted) was employed. The assessment of publication bias by graphical and statistical methods was performed using the funnel plot and the Egger's test. The review protocol was registered in PROSPERO (CRD42019125682). RESULTS: Nineteen studies were deemed suitable, with a total of 6,769 cases. The reoperation rate on average was 5.9%. Sensitivity was 0.81, with a Confidence Interval of 0.79-0.83, p = 0.0000, I2 = 95.1%, and specificity was 0.97, with a Confidence Interval of 0.97-0.98, p = 0.0000, I-2 = 90.8%, for 17 studies and 5,615 cases. Accuracy was 0.98. Twelve studies described local recurrence and the highest cumulative recurrence rate in 3 years was 7.5%. The quality of the included studies based on the QUADAS-2 tool showed a low risk of bias. There is no publication bias (p = 0.32) and the funnel plot showed symmetry. CONCLUSION: Frozen section is a reliable procedure with high accuracy, sensitivity and specificity in intraoperative margin assessment of breast-conserving surgery. Therefore, this modality of margin assessment could be useful in reducing reoperation rates.

Levonorgestrel-releasing intrauterine system and breast cancer risk: A systematic review and meta-analysis.

INTRODUCTION: Epidemiological studies have shown that some hormonal contraceptive methods are associated with increased breast cancer risk, especially if used over long periods. Our objective was to conduct a systematic review and meta-analysis of the literature on the risk of breast cancer development in women using the 52-mg levonorgestrel-releasing intrauterine system (LNG-IUS). MATERIAL AND METHODS: We performed a thorough review of peer-reviewed publications from 10 January 1999, through 31 July 2019, using combinations of search terms for breast cancer risk and LNG-IUS in the Medline, EMBASE, LILACS (Latin American and Caribbean Health Sciences Literature), and Scielo databases. This review was registered in PROSPERO (CRD42017059076). Studies reporting breast cancer risk estimates among healthy users of LNG-IUS were included according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analysis) criteria. Two authors performed data extraction, and a third author resolved disagreements. The quality of evidence was evaluated using the Downs and Black instrument. A funnel plot was generated, and a linear regression test of funnel plot asymmetry was used to assess publication bias. Finally, we performed a random-effects model (owing to high study heterogeneity) meta-analysis of seven suitable studies, stratified by the age distribution of patients (<50 years, ≥50 years, and mixed). RESULTS: We identified 96 studies and manually cross-referenced and excluded duplicate articles. Seventy articles were excluded on the basis of the inclusion and exclusion criteria, resulting in the assessment of 26 full-text articles. Eight articles were considered adequate for inclusion in this systematic review, and seven studies were included in the meta-analysis. Three publications were case-control studies and five were cohort studies. According to the Downs and Black instrument, 5 studies were rated as "good" and 3 studies were deemed "fair". Our meta-analysis results indicated increased breast cancer risk in LNG-IUS users: for all women, odds ratio (OR) = 1.16 (95% CI 1.06-1.28, I2  = 78%, P < .01); for women aged <50 years, OR = 1.12 (95% CI 1.02-1.22, I2  = 66%, P = .02); and for women aged ≥50 years, OR = 1.52 (95% CI 1.34-1.72, I2  = 0%, P = .84). CONCLUSIONS: Current evidence suggests that LNG-IUS users have an increased breast cancer risk regardless of age and indication. The effect of LNG-IUS on breast cancer risk seems to be larger in older users. However, our systematic review detected methodological issues across the available studies, and confounding factors may be responsible for at least a fraction of the risk effects associated with LNG-IUS use. Nevertheless, users of LNG-IUS should be aware of these trends. We believe that caution is needed, and risks should be balanced against proven health benefits (eg effective treatment of heavy menstrual bleeding and avoidance of surgical interventions), when prescribing LNG-IUS for long periods of use, especially in women with other known breast cancer risk factors such as old age, obesity, and familial predisposition.

CHEST WALL RESECTION FOR LOCOREGIONAL RECURRENCE OF BREAST CANCER: A FEASIBLE AND EFFECTIVE / Ressecção da parede torácica para recidiva locorregional de câncer de mama: um método efetivo e reprodutível

Objective: The aim of this study was to evaluate survival after chest wall resection for breast cancer locoregional recurrence. Secondary endpoints were symptomatic control and safety of the procedure. Method: This was a retrospective review including all patients who underwent chest wall resection for breast cancer local recurrence at the Division of Thoracic Surgery of the School of Medicine of São Paulo University, from January 1998 to November 2011. Full thickness chest wall resection involving bones and/or soft tissues was performed to achieve macroscopical free margins. Results: Eighteen patients were included in this study with a mean followup of 83.5 months. The interval between mastectomy and chest wall recurrence (CWR) was 4.2 years (0.5 to 9 years). The resection was complete in 12 patients (66%) and incomplete in 6 (33%), in whose resection would involve amputation of an upper limb. Mean tumor size was 8.25 cm and resection of the costal arch was necessary in 10 patients. There was no operation death and after two years, 66% of patients were alive. Six patients died due to distant recurrence of breast cancer on patients who died to inflammatory acute abdomen. The mean survival among patients who died was 25.2 months (12 to 42 months). At the last follow up visit, eleven patients were alive. Conclusion: CWR for locally recurrent breast cancer is feasible and safe in selected patients, who did not develop metastatic disease, allowing good quality of life for a considerable period. Larger and prospective series are needed to endorse our findings.

Objetivo: O objetivo deste estudo foi avaliar a sobrevida após ressecção da parede torácica para recidiva locorregional de c âncer de mama. Desfechos secundários foram controle dos sintomas e a segurança do procedimento. Métodos: Estudo retrospectivo de todos os pacientes submetidos à ressecção da parede torácica para recidiva local do câncer de mama na Divisão de Cirurgia Torácica da Faculdade de Medicina da Universidade de São Paulo, de janeiro de 1998 a novembro de 2011. A ressecção da parede torácica foi realizada com espessura total podendo envolver ossos e/ou tecidos moles, a fim de atingir margens livres macroscópicas. Resultados: Dezoito pacientes foram incluídos neste estudo, com seguimento médio de 83,5 meses. O intervalo entre a mastectomia e a recidiva da parede torácica (RPT) foi de 4,2 anos (0,5 a 9 anos). A ressecção foi completa em 12 pacientes (66%) e incompleta em 6 (33%), cuja ressecção envolveria a amputação do membro superior. O tamanho médio do tumor foi de 8,25cm e a ressecção do arco costal foi necessária em 10 pacientes. Não houve óbito devido à operação e, após dois anos, 66% dos pacientes estavam vivos. Seis pacientes morreram devido à recorrência sistêmica do câncer de mama e uma paciente morreu devido a um abdome agudo inflamatório. A sobrevida média entre os pacientes que morreram foi de 25,2 meses (12 a 42 meses). Na última consulta de acompanhamento, onze pacientes estavam vivos. Conclusões: A RPT para a recidiva locorregional do câncer de mama é factível e segura em pacientes selecionados, que não desenvolveram doença metastática, permitindo boa qualidade de vida por um período considerável. São necessárias séries maiores e prospectivas para endossar nossas achados

Variations in the body mass index in Brazilian women undergoing adjuvant chemotherapy for breast cancer.

PURPOSE: To evaluate variations in the body mass index in patients undergoing adjuvant chemotherapy for breast cancer, and to associate these changes with patient's age and adjuvant chemotherapy regimen. METHODS: We performed a retrospective cohort study in order to correlate any variation in the body mass index before and after adjuvant chemotherapy with patient's age and adjuvant chemotherapy regimen. Patients who received any form of prior hormone therapy, such as tamoxifen or aromatase inhibitors, were excluded. We selected data for 196 patients with stage I to III breast cancer who were treated by radical or conservative surgery and received adjuvant chemotherapy at the Cancer Institute of the State of São Paulo, Brazil. RESULTS: Before adjuvant chemotherapy, 67.8% of patients were classified as overweight or obese according to their body mass indices. Around 66.3% (95% CI 59.7-73.0) of the patients exhibited an increase in the body mass index after adjuvant chemotherapy. The average age of all patients was 56.3±11.3 years. Participants whose body mass index increased were younger than those with no increase (54.7±11.1 versus 59.3±11.2 years; p=0.007). Patients were treated with the following adjuvant chemotherapy regimens: doxorubicin, cyclophosphamide, and paclitaxel (AC-T, 129 patients, 65.8%); 5-fluoracil, doxorubicin, and cyclophosphamide (36 patients, 18.4%); cyclophosphamide, methotrexate, and 5-fluoracil (16 patients, 8.2%); docetaxel and cyclophosphamide (7 patients, 3.6%); and other regimen (8 patients, 4.1%). The AC-T regimen showed a statistically significant association with increase in the body mass index (p<0.001 by ANOVA). CONCLUSIONS: Most patients with breast cancer showed an increase in the body mass index after adjuvant chemotherapy, especially after the AC-T chemotherapy regimen.

Variations in the body mass index in Brazilian women undergoing adjuvant chemotherapy for breast cancer / Variações no índice de massa corpórea em mulheres brasileiras submetidas à quimioterapia adjuvante por câncer de mama

PURPOSE: To evaluate variations in the body mass index in patients undergoing adjuvant chemotherapy for breast cancer, and to associate these changes with patient's age and adjuvant chemotherapy regimen. METHODS: We performed a retrospective cohort study in order to correlate any variation in the body mass index before and after adjuvant chemotherapy with patient's age and adjuvant chemotherapy regimen. Patients who received any form of prior hormone therapy, such as tamoxifen or aromatase inhibitors, were excluded. We selected data for 196 patients with stage I to III breast cancer who were treated by radical or conservative surgery and received adjuvant chemotherapy at the Cancer Institute of the State of São Paulo, Brazil. RESULTS: Before adjuvant chemotherapy, 67.8% of patients were classified as overweight or obese according to their body mass indices. Around 66.3% (95% CI 59.7–73.0) of the patients exhibited an increase in the body mass index after adjuvant chemotherapy. The average age of all patients was 56.3±11.3 years. Participants whose body mass index increased were younger than those with no increase (54.7±11.1 versus 59.3±11.2 years; p=0.007). Patients were treated with the following adjuvant chemotherapy regimens: doxorubicin, cyclophosphamide, and paclitaxel (AC-T, 129 patients, 65.8%); 5-fluoracil, doxorubicin, and cyclophosphamide (36 patients, 18.4%); cyclophosphamide, methotrexate, and 5-fluoracil (16 patients, 8.2%); docetaxel and cyclophosphamide (7 patients, 3.6%); and other regimen (8 patients, 4.1%). The AC-T regimen showed a statistically significant association with increase in the body mass index (p<0.001 by ANOVA). CONCLUSIONS: Most patients with breast cancer showed an increase in the body mass index after adjuvant chemotherapy, especially after the AC-T chemotherapy regimen. .

OBJETIVO: Avaliar variações no índice de massa corpórea em pacientes que estão passando por quimioterapia devido ao câncer de mama, e relacionar tais alterações com a idade da paciente e o regime de quimioterapia. MÉTODOS: Estudo de coorte retrospectivo que correlacionou variações no índice de massa corpórea pré- e pós-quimioterapia com a idade da paciente e o regime de quimioterapia. Foram excluídas as pacientes que receberam terapia hormonal prévia, seja como tamoxifeno ou inibidores da aromatase. Os dados de 196 pacientes com estágio I a III de câncer de mama foram selecionados, e elas foram tratadas por cirurgia radical ou conservadora que receberam quimioterapia adjuvante no Instituto do Câncer do Estado de São Paulo, Brasil. RESULTADOS: Antes da quimioterapia adjuvante, 67,8% das pacientes foram classificadas com sobrepeso ou obesas de acordo com seus índices de massa corpórea. Aproximadamente 66,3% (IC95% 59,7–73,0) das pacientes exibiram aumento no índice de massa corpórea após a quimioterapia adjuvante. A média de idade das pacientes foi de 56,3± 11,3 anos. Pacientes que apresentaram aumento no índice de massa corpórea eram mais jovens do que aquelas que não apresentaram aumento algum (54,7±11,1 versus 59,3±11,2 anos; p=0,007). As pacientes foram tratadas com os seguintes regimes de quimioterapia: doxorrubicina, ciclofosfamida e paclitaxel (AC-T, 129 pacientes, 65,8%); 5-fluoracil, doxorrubicina e ciclofosfamida (36 pacientes, 18,4%); ciclofosfamida, metotrexato e 5-fluoracil (16 pacientes, 8,2%); docetaxel e ciclofosfamida (7 pacientes, 3,6%) e outros regimes (8 pacientes, 4,1%). O regime AC-T mostrou uma relação significativa com o aumento do índice de massa corpórea (p<0,001 por ANOVA). CONCLUSÕES: A maioria das pacientes ...