Abstract P4-10-09: Delay in diagnosis of breast cancer in Mexican young women: Report of the “Joven y Fuerte” prospective cohort pilot phase

Background: Delay in diagnosis and treatment initiation of breast cancer (BC) has been associated with advanced stages and poor outcome. In developed countries, age has not been solely reported as an independent predictor of diagnosis delay. In Mexico, median time since tumor detection to treatment initiation is about 7 months, but young women are underrepresented in these studies. We aim to describe time intervals related to diagnosis in Mexican young women with BC (YWBC).

Methods: Newly diagnosed YWBC were invited to participate as part of this prospective cohort. Patient accrual began in November 2014 at two public cancer centers in Mexico. Patients completed self-report surveys including questions regarding mode of detection, time from first symptom to medical appointment (patient interval) and time from first symptom to diagnosis (total interval). Pearson chi-square tests were used to examine the effects of patient and clinical characteristics on patient interval and clinical stage.

Results: 96 YWBC with median age at diagnosis of 35 y (range 21-40) were enrolled in our pilot phase. 82.3% had tumor detected by self or partner. 62.5% of YWBC were diagnosed as locally advanced disease (IIB-IIIC). Median tumor size was 3.5 cm (0.5-12.0), with node involvement in 66.7%. 53.1% of YWBC had a patient interval of <6 months, but roughly 27.1% had a total interval <6 months. While only 13.5% had a patient interval >12 months, 39.6% reached a total interval >12 months. Patient interval and clinical stage were not significantly associated with occupation, education, marital status, current partner or method of detection.

 N(%)TimePatient intervalTotal interval<1 month29 (30.2)7 (7.3)1-3 months18 (18.8)9 (9.4)4-6 months4 (4.2)10 (10.4)7-12 months10 (10.4)24 (25.0)>12 months13 (13.5)38 (39.6)No symptoms0 (0.0)3 (3.1)NA22 (22.9)5 (5.2)Method of Detection Patient/Partner detected tumor79 (82.3)Clinical detection0 (0.0)Image detected9 (94)NA8 (8.3)Clinical stage 02 (2.1)IA13 (13.5)IB1 (1.0)IIA14 (14.6)IIB17 (17.7)IIIA28 (29.2)IIIB8 (8.3)IIIC7 (7.3)IV6 (6.2)

Conclusions: In this cohort, most patients had a greater total delay than previously reported in Mexico, possibly attributed to long health-system intervals, which could contribute to worse outcomes in YWBC. The prospective nature of this study allows the recollection of biologic characteristics, treatment scheme and adherence to treatment, to determine their impact on clinical outcome besides diagnosis delay. “Joven & Fuerte”, the first dedicated program for the care of young breast cancer patients in Latin America, aims to develop YWBC-tailored interventions to early diagnose or “downstage” BC among young women by endorsing patient navigation, increasing general population awareness and improving providers' knowledge in low-middle income countries, such as Mexico.

Citation Format: Castro-Sanchez A, Barragan-Carrillo R, Miaja M, Platas A, Martinez Cannon BA, Fonseca A, Vega Y, Bukowski A, Chapman J-A, Goss P, St. Louis J, Bargallo-Rocha JE, Mohar A, Peña-Curiel O, Villarreal-Garza CM. Delay in diagnosis of breast cancer in Mexican young women: Report of the “Joven y Fuerte” prospective cohort pilot phase [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-10-09.

Abstract P6-11-09: Physician knowledge and attitudes towards fertility preservation in Mexican young breast cancer patients

Background: In Mexico, approximately 30% of young women with breast cancer (YWBC) are childless and >40% express concern about infertility risk secondary to cytotoxic treatment. However, only 30% of patients recall being disclosed by their physician of such risk. The aim of this study was to characterize and analyze the caregivers' behavior, attitudes and knowledge towards fertility preservation in YWBC in a limited resource setting, such as Mexico.

Materials and Methods: A 20-item survey was designed and validated by an expert panel, which was answered by participants of the annual meeting of the Mexican Society of Oncology 2016, as well as by physicians affiliated to the same association via web. Pearson chi-square tests were used to assess factors associated with the likelihood of disclosure of infertility risk, discussion about methods of fertility preservation and referral to a reproductive health specialist.

Results: The participants' demographic characteristics are displayed in Table 1 and are associated with the main areas of interest in Table 2.

Characteristics%Age ≤40y56>40y44Gender Male69Female31Specialty Medical36Surgical53Other12Clinical Practice Public26Private9Both65Knowledge safety subsequent pregnancy Fair64Not fair36Knowledge safety ovulation inductors Fair38Not fair62Knowledge safety GnRH analogues Fair37Not fair63

 Inform about infertility riskInform about preservation strategiesRefer to a specialist %p%p%pAge      ≤40y56.5 46.2 54.9 >40y44.5.8653.8.00845.1.72Gender      Male67.6 73.1 65.4 Female32.4.7226.9.14934.5.24Specialty      Medical30.2 31.1 28.4 Surgical57.7 57.7 60.5 Other12.1.579.2.4211.1.18Clinical practice      Public19.8 12.6 19.8 Private19.8 21.0 15.4 Both60.4.0266.4.00264.8.51Sense of responsibility      Low-Middle8.8 5.0 8.0 High91.2<.00195.5<.00192.0<.001Inform about infertility risk      Always--94.1 64.8 Not always--5.9<.00135.2.013

The caregivers' most influential factor in all areas was their self-reported sense of responsibility on disclosing patients about infertility risk. Those physicians that inform patients about infertility risk are statistically more likely to discuss fertility preservation strategies and to refer to a reproductive health specialist. As for the main barriers for fertility preservation, costs were the most frequently mentioned (29.6%), followed by lack of specialists (11.2%), and patient's prognosis according to clinical stage (11.2%).

Conclusions: This represents the first Latinamerican study evaluating the YWBC's caregivers' attitudes and practices towards fertility preservation, as well as their general knowledge concerning oncofertility issues. The fact that only one third of the enquired physicians were aware of the safety of ovulation inductors and use of GnRH analogues in YWBC is striking, which may translate into worse survivorship care. Furthermore, physicians reported that access barriers were the most prevalent factors that hindered appropriate referral. Health-care providers play a major role in the timely detection of the patient's interest in future offspring, thus it is crucial to promote knowledge about this relevant topic and endorse policies that can provide universal access to assisted reproductive technologies.

Citation Format: Villarreal-Garza CM, Barragan-Carrillo R, Bargallo-Rocha JE, Peña-Curiel O, Martinez-Cannon BA, Platas A, Torres J, Mohar A, Rivera S, Garcia-Valdovino VJ, Garcia-Leon GA, Castro-Sanchez A. Physician knowledge and attitudes towards fertility preservation in Mexican young breast cancer patients [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-11-09.

Adherence to tamoxifen in Mexican young women with breast cancer

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Background: Young age has been associated with significantly increased risk of breast cancer (BC) death among women with luminal BC. One contributing factor might be the low rate of tamoxifen (TMX) adherence previously reported in this young group. Given that in Mexico a disproportionate rate of BC is diagnosed among YW, information regarding TMX adherence is particularly relevant. Our study's aim was to report TMX adherence in Mexican YW and its associated determinants. Methods: Consecutive patients ≤40y at diagnosis at the National Cancer Institute in Mexico City, under TMX treatment, completed a multiple-choice survey regarding the use and attitudes about hormonal therapy and adherence. Data of TMX disposal was collected from the pharmacy’s records, and the medication possession ratio (MPR) was calculated; an MPR ≥80% was considered adherent. Results: 135 YW with a median age at diagnosis of 35.7y (24-40) were included. 77% were undergraduate, 28% unpaired and 33% childless. Median follow-up was 26 months. 95% of patients reported a regular TMX intake: 70% did not miss any doses, while 25% missed 1-6 doses a month. Only 45% considered that the information received regarding TMX therapy was sufficient and for 37% was incomprehensive. 43% thought TMX significantly reduced their recurrence-risk and 60% strongly believed that they needed to be on TMX treatment. 73% of women reported adverse effects, being menopausal symptoms the most frequent, but only 27% were worried about the treatment long-term effects. From the 99 patients with a pharmacy record, 73% had an MPR > 80%. No significant factor was statistically associated with TMX adherence. Conclusions: Although Mexican YW and pharmacy data surprisingly sustained higher rates of TMX adherence compared to previous data, still a significant proportion of patients were non-adherent. Two-thirds of our patients reported having adverse effects, which might contribute to late TMX discontinuation. Since the newer recommendations of double hormonal blockade could lead to higher withdrawal rates of endocrine therapy in YW, adherence should be emphasized and closely monitored. Accordingly, hormonal treatment adherence should be a key component in the medical assessment of young luminal BC patients.

Sexual function and satisfaction in Mexican young women undergoing breast cancer treatment

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Background: Compared to other regions, the burden of breast cancer (BC) in Mexico is disproportionately borne by younger women. Yet, their particular needs and concerns have remained understudied, including treatment-related sexual adverse effects. We aim to assess the sexual function and satisfaction in Mexican young women with BC undergoing treatment. Methods: This is a prospective sexual assessment study in BC patients of the pilot phase of the Joven y Fuerte Mexican cohort (N=96). Sexual health was assessed using the Female Sexual Function Index (FSFI) and the Sexual Satisfaction Inventory (SSI) at two points in time: baseline (BL) and 6-months follow-up (6-FU). FSFI and SSI scores lower than 26.55 and 111, respectively, were defined as sexual morbidity. Differences between proportions of BL and 6-FU were examined with Pearson chi-square test. Matched t-tests were used to test for differences in the domains of the FSFI and in the SSI total score. Results: 70 women completed the FSFI at both time points and 69 the SSI. Our results showed a high percentage of sexual dysfunction among Mexican women at BL and 6-FU (61.4% and 74.3%, respectively, p<0.001), as well as an elevated proportion of sexual low satisfaction at both time lines (40.6% and 43.5%, p=0.004). Most 6-FU FSFI domain scores were significantly worse than those at BL (Table 1). There were no significant differences in the SSI total score (102.31 [BL] vs 96.11 [6-FU], p=0.16). Conclusions: Mexican young patients with BC report significant sexual morbidity at BL, which even worsens after the first short follow-up. Reasons for the low sexual performance among Mexican women remain understudied and should be actively sought. In this prospective study, data will be annually collected for five years. This information will provide valuable information in an often-neglected matter of BC patients’ care. [Table: see text]

Abstract P3-10-05: Successful implementation of a novel breast cancer navigation program in Nuevo León, México

Introduction: Although the overall incidence of breast cancer (BC) is lower in Latin America than in high-income countries, the mortality burden is greater, mainly due to presentation at more advanced stages. Advanced BC presentation has been directly associated to delays by the patient and provider. In Mexico, it has been previously shown that the longest delay occurs within the health system interval, with a median of 5 months. Navigation programs have been proved to be a valuable strategy to assist individuals in overcoming barriers for care across the cancer care continuum. However, its implementation has been limited to date in low-income settings.

Objectives: The aim of this project was to propose a novel BC navigation program to overcome different common barriers for access to accurate diagnosis and early treatment in a limited setting in Nuevo Leon, Mexico. The secondary objectives were to educate and involve medical students by being part of the navigation process and raising women awareness about BC.

Methodology: Through an alliance with the local Ministry of Health, during 18 months, we invited women who had their mammogram done in a referral mammographic center to participate in this Navigation Program. Two weeks after recruitment women were taken by a designated transportation to a specialized BC diagnostic unit, participated in a BC self-awareness educational session (increment in knowledge was measured by pre and post tests), received a clinical breast exam and were provided with their mammography report (interpreted by a breast radiologist). When appropriate, core biopsies were performed and onward referrals to a BC Treatment Center were provided. Along with this process, a Navigator Training Program took place as part of the medical students' 5th year curricula in the ITESM Medical School, within their academic clinical practice (knowledge increment was measured by pre and post tests). This project was supported by Susan G. Komen Foundation.

Results: 1632 low-income uninsured women were navigated and 37 BC were diagnosed. All BC patients started treatment within 3 months from their initial mammogram. 55% were diagnosed at early stages (0-IIA) and 45% at II-B to IV stages (vs. 26% and 74%, respectively, from the overall report from the Ministry of Health in 2014). Patient BC awareness knowledge increased by 22%. 170 students participated in the navigation process, and their knowledge rose by 18% from baseline. The BC Navigation Training Program is now part of the official academic curricula of the ITESM Medical School.

Conclusions: Our Navigation Program was intended to break down medical care barriers to reduce delays and improve quality of care, by guiding Mexican women through the whole continuum of BC diagnosis and early treatment. This successful implementation resulted in shorter health system intervals and BC down staging. Well-designed patient navigation projects should be implemented in low- and middle-income countries to establish their value and feasibility. Due to a lack of educated patient navigators in these regions, health care professionals should be trained to provide navigation guidance through the complex health care systems frequently encountered in underserved settings.

Citation Format: Mireles-Aguilar T, Tamez-Salazar JJ, Villarreal-Garza CM, Rodriguez y Silva M, Romero C, Pérez-Reyes P. Successful implementation of a novel breast cancer navigation program in Nuevo León, México [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-10-05.

Abstract P5-12-10: Pathological characteristics and patterns of recurrence and mortality among young Mexican breast cancer patients

Background: In Mexico, it is recognized that breast cancer (BC) is diagnosed at younger ages than that reported in the US and other populations. Although national data is not available regarding BC age of diagnosis distribution, data from the INCAN, the main referral center in Mexico, showed that 17% of the total 893 newly diagnosed BC patients seen in 2012 were younger than 40 years old (which is more than twice that -7%- reported for US BC patients). We conducted a retrospective study in order to describe the frequency of BC among young Mexican BC patients, as well as their pathological characteristics at diagnosis and patters of recurrence.

Methods: Clinical and pathologic data from young pts (≤42 years old) who were newly diagnosed with invasive BC between January 2007 and December 2010 at the INCAN in Mexico and were followed for at least 2 years were identified. Clinical stage at diagnosis was recorded and estrogen receptor, progesterone receptor and HER2 expression were determined by immunohistochemistry and/or FISH. Proportion differences were tested using the Chi-square test.

Results: 445 young patients were identified from a total of 2919 BC patients (15%). A total of 320 patients met the inclusion criteria for analysis. Median age of diagnosis was 36 years (19-42). 49% of patients were very young patients (≤ 35 years). 19% were diagnosed as early disease, 67.5% as locally advanced BC and 13.5% as metastatic. 32% of patients had triple negative BC disease, while 27% were HER2 positive. From the non-metastatic patients at diagnosis, 31% developed recurrence (65% systemic, 21% loco regional and 14% both). After a median follow-up of 26 months, 18% of the 320 patients died secondary to BC disease progression.

Conclusions: Although this series corresponds to patients treated at a reference national center, the data reported in this study suggests that BC among young women is very prevalent in Mexico compared to other populations. The causes underlying the striking difference in age at diagnosis in Mexican BC patients are unknown and have not been investigated, including the genetic contributing factors. As reported in non-Hispanic population studies, BC among young women is diagnosed in more advanced stages, and triple-negative and HER2 positive diseases are more frequent. It is associated with a high proportion of systemic and loco regional recurrence, with a dismal prognosis. Due to the substantial number of BC cases among young women in Mexico, its prospective study is more than justified. In order to meet with this goal, our group is preparing the establishment of the Mexican Young Women's Breast Cancer Cohort Program at the INCAN in Mexico and to launch the related scientific projects related to this plan.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-12-10.

Pathologic response and disease-free survival (DFS) after neoadjuvant trastuzumab (T) for HER2+ breast cancer (BC): Results from the National Cancer Institute (NCI) of Mexico

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Background: The most accurate definition of pathologic complete response (pCR) in HER2+ BC patients (pts) receiving T-based neoadjuvant chemotherapy associated with improved DFS is controversial, particularly regarding the role of residual ductal carcinoma in situ (ypTis) and focal invasive residuals (ypT1mic). The effect of pCR on DFS in various subgroups of HER2+ BC is also uncertain. Methods: Pts with localized HER2+ BC that received T-based neoadjuvant chemotherapy at NCI between January 2007 and May 2012 were identified. We conducted an exploratory analysis of DFS in pts according to their tumor response. DFS curves were derived from Kaplan-Meier estimates and compared by log-rank test. Multivariate analysis was performed using Cox’s regression model. Results: 243 pts were included for analysis. Median follow-up was 39 months (mo). 49% of pts had no invasive and no in situ residuals at surgery (ypT0), 14.4% had ypTis/ypT1mic residuals and 36.6% had gross residual BC. DFS was significantly superior in pts with both ypT0 and ypTis/ypT1mic (no gross invasive residual BC) compared with those with gross residual disease (60.6 and 62.7 mo respectively vs. 51.6 mo, p=0.011 and 0.017). There was no difference in DFS between ypT0 and ypTis/ypT1mic pts (p=0.402). The rate of no gross invasive residual BC was significantly superior in pts with ER-PR- tumors compared with patients with ER+/PR+ tumors (69.9% vs. 56.7%, p=0.034). No gross invasive residual BC was associated with improved DFS in pts with HER2+ ER-/PR- (60.3 vs. 49.0 mo; p=0.005), as opposed to HER2+ ER+/PR+ tumors (61.0 vs. 51.6 mo; p=0.100). Multivariate analysis showed that tumor size (p=0.013) and no gross invasive residual BC (p=0.13) were associated with improved DFS in all subgroups. Conclusions: The absence of gross invasive residual BC was associated with improved DFS in pts with HER2+ BC treated with T-based neoadjuvant chemotherapy, particularly in those with HER2+ ER-/PR- BC. Our data suggest a comparable DFS in HER2+ BC patients with no gross invasive residual BC regardless of the presence or absence of both ypTis and ypT1mic disease after neoadjuvant treatment.

Predictive factors for pathologic complete response (pCR) to trastuzumab (T)-based neoadjuvant chemotherapy in HER2+ breast cancer (BC) women treated in the National Cancer Institute (NCI) of Mexico

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Background: Neoadjuvant treatment identifies subgroups of patients (pts) with different prognosis. In HER2+ BC, some tumors have been reported to be more sensitive to anti-HER2 therapy than others. We conducted an exploratory analysis in HER2+ BC women who received T-based neoadjuvant chemotherapy. Methods: Clinico-pathologic data from HER2+ BC pts who received neoadjuvant chemotherapy and T between January 2007 and May 2012 at the NCI were identified. Estrogen receptor (ER), progesterone receptor (PR) and HER2 expression were determined by immunohistochemistry and/or FISH. pCR was defined as complete absence of invasive tumor in breast and axillary nodes. Proportion differences were tested using the Chi-square test. A generalized linear model was used for multivariate analysis. Results: 243 pts received T-based neoadjuvant chemotherapy for localized HER2+ BC tumors. Median age was 49 (26-72) years. 96% had positive axillary nodes at diagnosis and median tumor size was 5.5 (1.5-20) cm. 49.4% had hormone receptor (HR) + (ER+ and/or PR+) and 50.6% HR negative (ER- and PR-) tumors. 63.4% pts achieved pCR. HR negative tumors reached significantly higher pCR rates than HR + tumors (69.9% vs. 56.7%, p=0.034). Pts with inflammatory BC (n=27) had a trend to achieve pCR less frequently than the non-inflammatory tumors (48.1% vs. 65.3%). Those who received taxane-anthracyline sequence chemotherapy (n=20) achieved pCR in 70% of the cases vs. 62.8% with anthracycline-taxane sequence. Differences among other variables (age, tumor size, nodes and HER2 positivity ++/+++) were not significant. Variables that positively influenced pCR were HR negative status (p=0.015), non-inflammatory BC (p=0.082) and chemotherapy sequence (p=0.086). Conclusions: HR negative HER2+ BC tumors were associated with higher pCR, consistent with neoadjuvant trial reports. Preclinical data suggest bi-directional crosstalk between HER2 and ER pathways, which might influence anti-HER2 agents and chemotherapy sensitivity for tumors co-expressing both receptors. New strategies are needed to overcome resistance for HER2+ HR+ BC tumors.

Impact of obesity and overweight in the prognosis of women diagnosed with non metastatic breast cancer in a Mexican cohort

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Background: Mexico positions right up at the top with U.S. in worldwide rankings of the most obese countries. In addition, breast cancer (BrCa) is the main type of cancer among women in this country. Studies have shown inconsistent results regarding obesity as a prognostic factor for worse outcome. Methods: Our aim is to identify if overweight and obesity confer poor prognosis in non-metastasic BrCa patients (pts). We identified 1799 Hispanic women with newly diagnosed BrCa who attended the National Cancer Institute in Mexico from 2004-2008 and compared clinical and pathological features and overall survival (OS) between pts with a body mass index (BMI) > or ≤ than 25. Results: The median age at diagnosis was 51 years. A BMI>25 was found in 71% of pts. Postmenopausal women comprised 52%, and had a greater proportion of cases with a BMI>25 than premenopausal pts (75% vs. 67%, p<0.0001). Pts with BMI>25 presented with more advanced TNM stages and nodal involvement than their counterparts (73% vs. 67%, p=0.005 and 76% vs. 71%, p=0.017; respectively). Overall prevalence of hormone-receptor (HR), triple-negative (TN) and HER2 positive disease was 62%, 23%, and 27%, respectively. Differences according to receptor status between pre and postmenopausal pts and BMI are shown in table. There was no difference in disease-free survival and OS according to overweight and obesity in the overall population, but when menopausal status was considered, premenopausal pts with BMI>25 had a worse OS compared to pts with BMI<25 (HR 1.6, p=0.037). This difference was not seen in the postmenopausal group. Conclusions: Obesity may influence BrCa outcomes via several hormonal and inflammatory mechanisms. In this study, overweight and obesity confer a poor prognosis in premenopausal patients, possibly related to excess estrogen availability and higher prevalence of TN BrCa. Therefore, overweight and obesity deserve additional attention to assess possible causal relationships that potentially could be modified to improve outcomes in premenopausal patients. [Table: see text]

Combination treatment with aromatase inhibitor and capecitabine as first- or second-line treatment in metastatic breast cancer

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Background: Preclinical studies have shown that the combination of an aromatase inhibitor (AI) and oral fluoropyrimidines in estrogen receptor (ER)-positive cell lines enhance antitumor efficacy. This might be explained by reduction of ER-induced growth signaling in addition to decrease in estrogen production. This retrospective analysis of a cohort of patients with metastatic breast cancer (MBC) evaluates the efficacy and safety of combined AI with capecitabine. Methods: Patients with hormone receptor-positive MBC treated with this combination were evaluated and outcomes were compared to women treated with capecitabine (conventional dose) or AI as monotherapy. The administered total dose of capecitabine was 2000 mg. per day in combination with AI. Results: Of 93 patients evaluated, 37 received the combination treatment, 27 capecitabine and 29 an AI. Combination was used in 26 patients as first-line treatment and 11 as second-line. At the time of progression, 92% had a performance status of ≤2 and 58% of patients had visceral disease. No significant difference was observed between the three groups according to clinical and pathological features. Mean follow-up was 23 months (m). The median PFS of first-line treatment was significantly better for the combination (PFS not-reached vs.3.0 m for capecitabine and 13.0 m for AI, p<0.0001). For second-line treatment, the PFS was longer in the combination compared to capecitabine and AI (PFS not reached vs. 6.0 m vs.13.0 m, respectively, p=0-041). For the entire cohort, OS was not reached. The most common adverse events for the combination group were grade 1 and 2 hand-foot syndrome (65%), grade 1 fatigue (52%) and grade 1 diarrhea (5%). Only one grade 3 hand-foot syndrome event was reported. Conclusions: Combination treatment with capecitabine and AI used as first-line treatment or second-line improved PFS compared to treatment with either single agent. The combination was safe and rendered dismal toxicity. Prospective randomized clinical trials should evaluate the use of the combination of capecitabine and an AI in advanced breast cancer in order to confirm our findings.

Impact of diabetes and hyperglycemia on outcomes in advanced breast cancer patients

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Background: Clinical experience and previous studies suggest that women with diabetes and breast cancer (BrCa) have worse outcomes than their non-diabetic counterparts. However, analysis of the contribution of diabetes to BrCa specific mortality is difficult because of the substantial mortality attributed to diabetes alone and because diabetes is commonly associated with adverse prognostic factors specific to BrCa. The purpose of this study was to examine the impact of diabetes and hyperglycemia on cancer-specific survival of patients with metastatic or recurrent BrCa. Methods: We performed a retrospective analysis of patients with advanced BrCa receiving palliative chemotherapy from 2006 to 2011 at the National Cancer Institute in Mexico, and compared breast cancer-specific mortality in diabetic and non-diabetic patients, as well as in patients that presented hyperglycemia during palliative treatment. Results: A total of 265 patients receiving palliative therapy were eligible for inclusion. Previous diagnosis or detection of diabetes at recurrence was recorded in 40 patients (15%). No difference was observed between diabetic and non-diabetic patients in terms of overall survival (OS). A statistically significant difference in OS was observed between patients without diabetes and diabetics who had hyperglycemia (p=0.003). OS in diabetic patients with proper metabolic control was shown to be superior compared to diabetics with hyperglycemia (p=0.01). Hyperglycemia was identified in 14% of non-diabetics at some point while receiving palliative treatment. For patients that experienced hyperglycemia during treatment or who had a mean glucose level > 130, either in the diabetic or non-diabetic subgroups, a worse outcome was noted compared to normoglycemic patients, with a HR of 1.5 (p=0.029) and HR of 2.04 (p=0.006) for death, respectively. Conclusions: Elevated glucose levels confer a poor outcome in diabetic and non-diabetic patients in contrast with patients with normoglycemic levels, conferring an elevated risk of death. According to these results, clinicians must monitor glucose levels during treatment for advanced BrCa disease, and should take action in order to maintain normal glucose levels.