Breast cancer in Colombia: a growing challenge for the healthcare system.

AIM: To provide a comprehensive overview of breast cancer in Colombia. METHODS: Data on breast cancer in Colombia are scarce. We present incidence data from population-based cancer registries that represent 4 distinct regions of the country. Other data originate from non-governmental institutions and healthcare providers within Colombia, official sources, expert opinion, Colombian legislation, and the Cancer Mortality Atlas publishes by Colombian National Cancer Institute. RESULTS: In Colombia, the age-standardized incidence rate remained relatively stable between 2012 and 2020 (43.1 to 47.8 cases per 100,000 women-years); Additionally, survival since 1995 has presented a substantial improvement from 65.7 to 72.1. In 33% of cases, the diagnosis of breast cancer was made in advanced stages, stage III or higher. The health demography survey conducted in 2015 showed that the participation in mammography screening in women aged 40 to 69 remains low 48.1%. Some limitations regarding access to early detection and diagnosis include economic strata, health insurance coverage, origin, and accessibility. On average, a 90-day period was reported from onset of symptoms to diagnosis of breast cancer. CONCLUSION: The first action towards improving outcomes in breast cancer should be to improve stage at diagnosis and timely access to care.

Extending Aromatase-Inhibitor Adjuvant Therapy to 10 Years.

BACKGROUND: Treatment with an aromatase inhibitor for 5 years as up-front monotherapy or after tamoxifen therapy is the treatment of choice for hormone-receptor-positive early breast cancer in postmenopausal women. Extending treatment with an aromatase inhibitor to 10 years may further reduce the risk of breast-cancer recurrence. METHODS: We conducted a double-blind, placebo-controlled trial to assess the effect of the extended use of letrozole for an additional 5 years. Our primary end point was disease-free survival. RESULTS: We enrolled 1918 women. After a median follow-up of 6.3 years, there were 165 events involving disease recurrence or the occurrence of contralateral breast cancer (67 with letrozole and 98 with placebo) and 200 deaths (100 in each group). The 5-year disease-free survival rate was 95% (95% confidence interval [CI], 93 to 96) with letrozole and 91% (95% CI; 89 to 93) with placebo (hazard ratio for disease recurrence or the occurrence of contralateral breast cancer, 0.66; P=0.01 by a two-sided log-rank test stratified according to nodal status, prior adjuvant chemotherapy, the interval from the last dose of aromatase-inhibitor therapy, and the duration of treatment with tamoxifen). The rate of 5-year overall survival was 93% (95% CI, 92 to 95) with letrozole and 94% (95% CI, 92 to 95) with placebo (hazard ratio, 0.97; P=0.83). The annual incidence rate of contralateral breast cancer in the letrozole group was 0.21% (95% CI, 0.10 to 0.32), and the rate in the placebo group was 0.49% (95% CI, 0.32 to 0.67) (hazard ratio, 0.42; P=0.007). Bone-related toxic effects occurred more frequently among patients receiving letrozole than among those receiving placebo, including a higher incidence of bone pain, bone fractures, and new-onset osteoporosis. No significant differences between letrozole and placebo were observed in scores on most subscales measuring quality of life. CONCLUSIONS: The extension of treatment with an adjuvant aromatase inhibitor to 10 years resulted in significantly higher rates of disease-free survival and a lower incidence of contralateral breast cancer than those with placebo, but the rate of overall survival was not higher with the aromatase inhibitor than with placebo. (Funded by the Canadian Cancer Society and others; ClinicalTrials.gov numbers, NCT00003140 and NCT00754845.).

Improving access to high-cost cancer drugs in Latin America: Much to be done.

Lack of access to high-cost medications is a complex issue at the intersection of economics, medicine, politics, and ethics, and it poses a significant threat to global health care. The problem is even more significant in low- and middle-income countries, such as those in Latin America, where governments and individuals struggle to pay for products that are priced at several times the level of their per capita gross domestic product. In this review, we examine the determinants for increasing drug costs and how Latin American countries face this burgeoning crisis. We emphasize that a number of opportunities and strategies to reduce costs and improve access exist and should be identified and implemented, ideally within a regional approach with multiple stakeholders involved and based on systematic and transparent cost-effectiveness analyses. Cancer 2017;123:1313-1323. © 2016 American Cancer Society.

Barriers to Primary Debulking Surgery for Advanced Ovarian Cancer in Latin America.

Ovarian cancer is gynecologic tumor with particularly high mortality because it is usually diagnosed in advanced stages. In Latin America and the Caribbean, it is the eighth most common malignancy in women, with an estimated 18,000 new cases and 11,500 deaths annually. Standard of care for women diagnosed with advanced ovarian cancer (AOC) is primary cytoreductive surgery followed by systemic chemotherapy using a combination of paclitaxel plus carboplatin. To pursue upfront surgery, highly specialized and well-trained gynecologic oncologists are required, in addition with well-equipped hospitals. Neoadjuvant chemotherapy (NACT) has been gaining greater acceptance in the past decade for patients with AOC. Two phase III randomized clinical trials have demonstrated that NACT is noninferior to primary cytoreductive surgery for women with stages III and IV epithelial ovarian cancer, and since publication of these results, NACT is more commonly used. Apart from medical reasons of inoperability and unresectability, there may be nonmedical barriers to upfront debulking surgery in clinical practice. These barriers include inadequate expertise of the surgeon, inadequate resources, and/or barriers to access. The aim of this article was to discuss patterns of care and barriers to upfront ovarian debulking surgery, as well as a possible shift toward overuse of NACT as the primary approach for patients with AOC (stages III and IV) in Latin America.

Prolactin and breast cancer: The need to avoid undertreatment of serious psychiatric illnesses in breast cancer patients: A review.

Hyperprolactinemia, defined as a sustained elevation of prolactin (PRL) levels greater than 530 mIU/L in women and greater than 424 mIU/L in men, has been implicated for a long time in breast cancer etiology and prognosis. Elevated PRL values (approximately 2-3 times higher than the reference values) are a common adverse effect of antipsychotic medications, especially with first-generation drugs, and most antipsychotics carry a standard warning regarding PRL elevations on their US product labels. These associations foster undertreatment of serious psychiatric illnesses in both otherwise healthy patients and cancer patients. This review assesses both the preclinical and clinical evidence that has led to the hypothesis of PRL's role in breast cancer risk or breast cancer progression. It is concluded that taken together, the published data are unconvincing and insufficient to deprive cancer patients in general and breast cancer patients specifically of potentially effective antipsychotic or antidepressant medications for serious psychiatric indications. We thus call on revised medication guidelines to avoid the existing undertreatment of serious psychiatric illnesses among cancer patients based on an unproven contraindication to psychiatric medications. Cancer 2016;122:184-188. © 2015 American Cancer Society.

Cervical cancer control in Latin America: A call to action.

Cervical cancer (CC) is second most common cause of cancer in Latin America and is a leading cause of cancer mortality among women. In 2015, an estimated 74,488 women will be diagnosed with CC in Latin America and 31,303 will die of the disease. CC mortality is projected to increase by 45% by 2030 despite human papillomavirus (HPV) vaccination and screening efforts. In this setting, the goal was of the current study was to examine CC control efforts in Latin America and identify deficiencies in these efforts that could be addressed to reduce CC incidence and mortality. The authors found that HPV vaccination has been introduced in the majority of Latin American countries, and there is now a need to monitor the success (or shortcomings) of these programs and to ensure that these programs are sustainable. This topic was also reviewed in light of emerging data demonstrating that visual inspection with acetic acid and HPV DNA testing without Papanicolaou tests have efficacy from a screening perspective and are good alternatives to cytology-based screening programs. Overall, there is a need to build capacity for CC control in Latin America and the best strategy will depend on the country/region and must be tailored to meet the needs of the population as well as available resources.

Progress and remaining challenges for cancer control in Latin America and the Caribbean.

Cancer is one of the leading causes of mortality worldwide, and an increasing threat in low-income and middle-income countries. Our findings in the 2013 Commission in The Lancet Oncology showed several discrepancies between the cancer landscape in Latin America and more developed countries. We reported that funding for health care was a small percentage of national gross domestic product and the percentage of health-care funds diverted to cancer care was even lower. Funds, insurance coverage, doctors, health-care workers, resources, and equipment were also very inequitably distributed between and within countries. We reported that a scarcity of cancer registries hampered the design of credible cancer plans, including initiatives for primary prevention. When we were commissioned by The Lancet Oncology to write an update to our report, we were sceptical that we would uncover much change. To our surprise and gratification much progress has been made in this short time. We are pleased to highlight structural reforms in health-care systems, new programmes for disenfranchised populations, expansion of cancer registries and cancer plans, and implementation of policies to improve primary cancer prevention.

Long-term hazard of recurrence in HER2+ breast cancer patients untreated with anti-HER2 therapy.

INTRODUCTION: Worldwide, many patients with HER2+ (human epidermal growth factor receptor 2-positive) early breast cancer (BC) do not receive adjuvant trastuzumab. Hazards of recurrence of these patients with respect to hormone receptor status of the primary tumor have not been described. METHODS: Using data from 1,260 patients randomized to placebo in the adjuvant TEACH trial, we report 10-year annual hazards of recurrence in HER2+ patients not treated with anti-HER2 therapy. RESULTS: Disease-free survival (DFS) was 75% after 5 and 61% after 10 years, respectively. Patients with HER2+ hormone receptor-positive (HR+ (hormone receptor-positive); ER+ (estrogen receptor-positive) or PR+ (progesterone receptor-positive)) disease had a significantly better DFS than patients with HER2+ HR- (ER-/PR-) disease (hazard ratio 0.72, P=0.02). This difference was explainable by a significantly higher hazard of recurrence in years 1 to 5 in HER2+ HR- compared to HER2+ HR+ patients, with a mean risk of recurrence of 9%/year for HR- versus 5%/year in HR+ patients (hazard ratio 0.59, P=0.002 for years 1 to 5). The high early risk of recurrence of HER2+ HR- patients declined sharply over time, so that it was similar to that seen in HER2+ HR+ patients in years 6 to 10 (hazard ratio 0.97, P=0.92 for years 6 to 10). CONCLUSIONS: Our results show that outcomes in HER2+ patients with early BC not receiving anti-HER2 therapy strongly depend on HR expression. The very high early risk of relapse seen in HER2+ HR- patients is particularly relevant in health care settings with limited access to adjuvant anti-HER2 treatment. The event rates shown for subpopulations of HER2+ BC patients suggest that in resource-constrained environments patients with HER2+ HR- early BC should be prioritized for consideration of adjuvant anti-HER2 therapy.

Pregnancy-associated breast cancer in women from Shanghai: risk and prognosis.

Breast cancer (BC) has been associated with pregnancy if diagnosed within 5-10 years after delivery (pregnancy-associated BC, PABC). PABC carries a poor prognosis compared to sporadic BC in Western populations. Data are limited regarding PABC in Asian populations, where longer periods of breastfeeding, higher birth rates and a lower median age of BC at diagnosis have been noted, all of which are known to influence prognosis. We used two datasets of women treated for early BC in Shanghai 1990-2012 (n = 10,161 and n = 7,411). For the analysis of BC risk after pregnancy we compared the distribution of pregnancy in our dataset to that in Shanghai using age-specific fertility rates. For disease-free survival (DFS) evaluation, we restricted our data to women ≤45 years. Women <30 years had a significantly elevated BC risk within 5 years of completing a pregnancy compared to women who had not been pregnant in the previous 5 years. In women aged 20-24 the relative risk (RR) was 3.33 (P = 0.012), and for women aged 25-29 the RR was 1.76 (P = 0.0074). For women >30, the RR was decreased. Patients with PABC had a higher risk of recurrence or death (hazard ratio (HR) for DFS 1.72, P = 0.019) compared to women with non-PABC by univariable analysis. Age was eliminated from the multivariable model by backward selection, resulting in tumor stage (3 versus 1, HR 3.08, P < .001) and recent pregnancy (HR 1.62, P < 0.05) as significant independent prognosticators. Having had a full-term pregnancy in the previous 5 years was associated with a 62 % increased risk of recurrence. We show that recent full-term pregnancy significantly elevates BC risk in women <30 in Shanghai, and that women diagnosed with PABC have a particularly adverse prognosis. Health care providers and women in Asian populations should be made aware of these results.

Breast cancer in China.

The health burden of cancer is increasing in China, with more than 1·6 million people being diagnosed and 1·2 million people dying of the disease each year. As in most other countries, breast cancer is now the most common cancer in Chinese women; cases in China account for 12·2% of all newly diagnosed breast cancers and 9·6% of all deaths from breast cancer worldwide. China's proportional contribution to global rates is increasing rapidly because of the population's rising socioeconomic status and unique reproductive patterns. In this Review we present an overview of present control measures for breast cancer across China, and emphasise epidemiological and socioeconomic diversities and disparities in access to care for various subpopulations. We describe demographic differences between China and high-income countries, and also within geographical and socioeconomic regions of China. These disparities between China and high-income countries include younger age at onset of breast cancer; the unique one-child policy; lower rates of provision and uptake for screening for breast cancer; delays in diagnosis that result in more advanced stage of disease at presentation; inadequate resources; and a lack of awareness about breast cancer in the Chinese population. Finally, we recommend key measures that could contribute to improved health outcomes for patients with breast cancer in China.

Challenges to effective cancer control in China, India, and Russia.

Cancer is one of the major non-communicable diseases posing a threat to world health. Unfortunately, improvements in socioeconomic conditions are usually associated with increased cancer incidence. In this Commission, we focus on China, India, and Russia, which share rapidly rising cancer incidence and have cancer mortality rates that are nearly twice as high as in the UK or the USA, vast geographies, growing economies, ageing populations, increasingly westernised lifestyles, relatively disenfranchised subpopulations, serious contamination of the environment, and uncontrolled cancer-causing communicable infections. We describe the overall state of health and cancer control in each country and additional specific issues for consideration: for China, access to care, contamination of the environment, and cancer fatalism and traditional medicine; for India, affordability of care, provision of adequate health personnel, and sociocultural barriers to cancer control; and for Russia, monitoring of the burden of cancer, societal attitudes towards cancer prevention, effects of inequitable treatment and access to medicine, and a need for improved international engagement.

Planning cancer control in Latin America and the Caribbean.

Non-communicable diseases, including cancer, are overtaking infectious disease as the leading health-care threat in middle-income and low-income countries. Latin American and Caribbean countries are struggling to respond to increasing morbidity and death from advanced disease. Health ministries and health-care systems in these countries face many challenges caring for patients with advanced cancer: inadequate funding; inequitable distribution of resources and services; inadequate numbers, training, and distribution of health-care personnel and equipment; lack of adequate care for many populations based on socioeconomic, geographic, ethnic, and other factors; and current systems geared toward the needs of wealthy, urban minorities at a cost to the entire population. This burgeoning cancer problem threatens to cause widespread suffering and economic peril to the countries of Latin America. Prompt and deliberate actions must be taken to avoid this scenario. Increasing efforts towards prevention of cancer and avoidance of advanced, stage IV disease will reduce suffering and mortality and will make overall cancer care more affordable. We hope the findings of our Commission and our recommendations will inspire Latin American stakeholders to redouble their efforts to address this increasing cancer burden and to prevent it from worsening and threatening their societies.

Emergence of immune-related adverse events correlates with pathological complete response in patients receiving pembrolizumab for early triple-negative breast cancer.

Based upon results of the KEYNOTE-522 trial and following approval by regulatory authorities, the addition of pembrolizumab to chemotherapy is now the standard-of-care for the treatment of early triple-negative breast cancer (eTNBC) (Clinical stage II-III). Pembrolizumab is a programmed cell death protein 1 monoclonal antibody, known to cause immune-related adverse events (irAEs) in a significant subset of patients. Real-world data on incidence, type and treatment strategies of irAEs in the setting of eTNBC treatment are sparse. In this multicenterretrospective analysis, we characterized real-world incidence of irAEs and treatment outcomes such as pathological complete response (pCR) from the combination of pembrolizumab and chemotherapy as neoadjuvant treatment for eTNBC. We found a rate of irAEs of all grades of 63.9% and of 20% for irAEs of grade 3 or higher. In the overall population, a pCR rate of 57.1% was observed. The emergence of irAEs correlated significantly with pCR (72.2% versus 30.8%; p =.03). Discontinuation of neoadjuvant chemotherapy before week 12 correlated significantly with a lower pCR rate. To our knowledge, this is the first study evaluating the real-world efficacy and safety of a neoadjuvant combination of chemotherapy and pembrolizumab in eTNBC, demonstrating a significant correlation between irAEs and pCR. Early discontinuation of neoadjuvant therapy due to AEs resulted in a lower pCR rate.

Evaluation of diagnostic and treatment approaches towards acute dyspnea in a palliative care setting among medical students at the University of Vienna.

BACKGROUND: Dyspnea is common in advanced cancer patients with opioids as first line treatment. OBJECTIVES: To evaluate the level of knowledge about diagnosis and treatment of dyspnea in palliative care patients among 4th year students. METHODS: A case report was distributed to the students describing acute dyspnea in a lung cancer patient. Students were asked to rank their diagnosis and treatment options by importance. RESULTS: 633 medical students in their 4th year attended a seminar about palliative care. Of these, 423 (77%) completed the case report. The most frequent diagnostic option was measuring patient's oxygen saturation (n = 388), followed by auscultation (n = 339). As treatment options, students chose the delivery of oxygen (n = 393) as most important. The application of opioids was suggested by a total of 138 students. CONCLUSION: Although students did not have practical skills in treating advanced cancer patients with acute dyspnea, 32.6% would suggest an opioid as treatment option.

Austrian treatment algorithms in HER2-positive metastatic breast cancer: a 2022 update.

In the past 12 months a plethora of relevant novel data for the treatment of metastatic HER2 positive breast cancer were published. To bring this new evidence into a clinical perspective, a group of Austrian breast cancer specialists updated their previously published treatment algorithm for those patients. For this consensus paper a total of eight scenarios were developed in which treatment strategies appropriate for specific patient profiles were evaluated. Consensus was established by detailed discussions of each scenario and by reaching full consensus.

Psychosocial QOL is an independent predictor of overall survival in newly diagnosed patients with multiple myeloma.

Only few studies have analyzed quality of life (QOL) and its association with prognosis in patients with multiple myeloma. We studied QOL at start of conventional treatment to evaluate the impact of symptomatic myeloma on QOL and to determine the prognostic significance of various dimensions of QOL. Our study provided further evidence of the significant impairment of QOL in patients with multiple myeloma at onset of therapy. Furthermore, our data showed a closer correlation between the more physical QOL scales such as pain, fatigue, physical functioning and global QOL with the activity of the disease than between psychosocial dimensions such as role, emotional, social, and cognitive functioning and the status of the disease. Multivariate analyses including each a QOL scale and known prognostic parameters (response to therapy, creatinine level, calcium, LDH, Hb, beta2-microglobulin, and albumin) revealed a marked difference in the prognostic significance between psychosocial and other QOL scales. All psychosocial dimensions of QOL were found to be independent prognostic factors, while physical QOL and global QOL were eliminated by disease-associated prognosticators. Taken together, QOL was found to be significantly impaired in myeloma patients at start of therapy. Psychosocial, but not physical dimensions of QOL were found to be independent prognostic factors.

Quality of Life From Canadian Cancer Trials Group MA.17R: A Randomized Trial of Extending Adjuvant Letrozole to 10 Years.

Purpose MA.17R was a Canadian Cancer Trials Group-led phase III randomized controlled trial comparing letrozole to placebo after 5 years of aromatase inhibitor as adjuvant therapy for hormone receptor-positive breast cancer. Quality of life (QOL) was a secondary outcome measure of the study, and here, we report the results of these analyses. Methods QOL was measured using the Short Form-36 (SF-36; two summary scores and eight domains) and menopause-specific QOL (MENQOL; four symptom domains) at baseline and every 12 months up to 60 months. QOL assessment was mandatory for Canadian Cancer Trials Group centers but optional for centers in other groups. Mean change scores from baseline were calculated. Results One thousand nine hundred eighteen women were randomly assigned, and 1,428 women completed the baseline QOL assessment. Compliance with QOL measures was > 85%. Baseline summary scores for the SF-36 physical component summary (47.5 for letrozole and 47.9 for placebo) and mental component summary (55.5 for letrozole and 54.8 for placebo) were close to the population norms of 50. No differences were seen between groups in mean change scores for the SF-36 physical and mental component summaries and the other eight QOL domains except for the role-physical subscale. No difference was found in any of the four domains of the MENQOL Conclusion No clinically significant differences were seen in overall QOL measured by the SF-36 summary measures and MENQOL between the letrozole and placebo groups. The data indicate that continuation of aromatase inhibitor therapy after 5 years of prior treatment in the trial population was not associated with a deterioration of overall QOL.

Effects of Celecoxib and Low-dose Aspirin on Outcomes in Adjuvant Aromatase Inhibitor-Treated Patients: CCTG MA.27.

Background: Celecoxib and low-dose aspirin might decrease risk of breast cancer recurrence. Methods: In the Canadian Cancer Trials Group MA.27, postmenopausal hormone receptor-positive breast cancer patients were randomly assigned (2 × 2) to adjuvant exemestane or anastrozole, and celecoxib or placebo. Low-dose aspirin of 81 mg or less was a stratification factor. Due to concerns about cardiac toxicity, celecoxib use was stopped in December 2004, while stratification by aspirin use was removed through protocol amendment. We examined the effects of celecoxib and low-dose aspirin on event-free survival (EFS), defined as time from random assignment to time of locoregional or distant disease recurrence, new primary breast cancer, or death from any cause; distant disease-free survival (DDFS); and overall survival (OS). All statistical tests were two-sided. Results: Random assignment to celecoxib (n = 811, 50.0%) or placebo (n = 811, 50.0%) was discontinued after 18 months (n = 1622). At a median of 4.1 years' follow-up, among 1622 patients, 186 (11.5%) patients had an EFS event: 80 (4.9%) had distant relapse, and 125 (7.7%) died from any cause. Celecoxib did not statistically significantly impact EFS, DDFS, or OS in univariate analysis (respectively, P = .92, P = .55, and P = .56) or multivariable analysis (respectively, P = .74, P = .60, and P = .76). Low-dose aspirin use (aspirin users n = 476, 21.5%; non-aspirin users n = 1733, 78.5%) was associated in univariate analyses with worse EFS (hazard ratio [HR] = 1.48, 95% confidence interval [CI] = 1.12 to 1.96, P = 0.006) and worse OS (HR = 1.87, 95% CI = 1.35 to 2.61, P < .001). After adjusting for baseline characteristics and treatment arm, aspirin use showed no statistical association with EFS (P = .08) and DDFS (P = .82), but was associated with statistically worse OS (HR = 1.67, 95% CI = 1.13 to 2.49, P = .01). Conclusion: Random assignment to short-term (≤18 months) celecoxib as well as use of low-dose aspirin showed no effect on DDFS and EFS in multivariable analysis. Low-dose aspirin increased "all-cause" mortality, presumably because of higher preexisting cardiovascular risks.

Increased angiogenesis in chronic idiopathic myelofibrosis: vascular endothelial growth factor as a prominent angiogenic factor.

Increased angiogenesis has been suggested to be implicated in the pathogenesis of chronic idiopathic myelofibrosis (CIMF). We hypothesized that vascular endothelial growth factor (VEGF) drives CIMF-associated angiogenesis, and thus, we aimed to determine its expression and biologic impact in newly diagnosed patients. All patients with CIMF diagnosed between 1990 and 2001, for whom adequate bone marrow specimens and clinical data were available, were deemed eligible. Each case was reclassified according to World Health Organization criteria. Microvessel density (MVD), as assessed by CD34 staining, and VEGF expression were examined by standard immunohistochemistry on paraffin-embedded trephine bone marrow biopsy specimens. The cytogenetic phenotype was determined by fluorescence in situ hybridization. Appropriate summary statistics were used for comparisons between groups; survival was calculated using Kaplan-Meier estimates. Parameters found to be of prognostic significance in univariate analysis were verified in a multivariate Cox regression model. Fifty-five patients with CIMF were investigated. With a median of 43 vascular lumina per 0.747 mm(2), patients with CIMF displayed significantly greater MVD than did age-matched controls (n = 10; median MVD, 19; P < .001) with equal distribution between the various fibrosis stages. Moreover, VEGF expression was significantly increased in CIMF (median, 12 cells/0.747 mm(2) versus 1.4 cells/0.747 mm(2); P = .01) and correlated with MVD (P = .001). However, neither MVD nor VEGF expression correlated with cytogenetics or clinical outcome. We conclude that in CIMF, increased MVD is detectable even in early (pre-)fibrotic stages. Moreover, we found significantly elevated VEGF expression correlating with MVD, thus suggesting VEGF to play a prominent angiogenic role and representing a novel potential therapeutic target in CIMF.

Effects of liarozole fumarate (R85246) in combination with tamoxifen on N-methyl-N-nitrosourea (MNU)-induced mammary carcinoma and uterus in the rat model.

BACKGROUND: Liarozole fumarate (liarozole--R85246) is a novel compound with characteristics of both aromatase inhibitor (AI) and a retinoic acid metabolism blocking agent (RAMBA). Our objective was to determine the effects of liarozole alone or in combination with tamoxifen on the N-methyl-N-nitrosourea (MNU)-induced rat mammary carcinoma model, as well as on the uterus in ovariectomized immature rats. METHODS: (1) Tumor burden experiments: Animals bearing one or more tumors greater than 10 mm in diameter were treated for 56 consecutive days with 20 mg/kg or 80 mg/kg of liarozole by oral gavage, tamoxifen 100 mug/kg by subcutaneous injection, or a combination of liarozole and tamoxifen. At the end of the treatment period, total cumulative tumor volume as well as retinoic acid levels were measured. (2) Uterotrophic assay and proliferation experiments: 21-day-old ovariectomized (OVX) Sprague-Dawley rats were treated with 20 mg/kg or 80 mg/kg of liarozole by oral gavage, tamoxifen 1 mg/kg by subcutaneous injection, and combination of both for 4 consecutive days. At the end of the treatment period, uterine weight, epithelial lining cell height and indices of proliferation cell nuclear antigen (PCNA) were measured. RESULTS: The tumor burden experiments in rats bearing estrogen receptor (ER) positive mammary tumours showed that liarozole has a marked anti-tumour effect. In combination with tamoxifen, liarozole had neither an additive nor an antagonistic effect. However, liarozole markedly reduced the uterotrophic effects induced by tamoxifen. CONCLUSION: Liarozole's antitumor effects on ER positive mammary tumors and its protective effect on the uterus merit further studies to confirm its clinical value in combination with tamoxifen in ER positive postmenopausal breast cancer. Liarozole and other retinomimetics might also be suitable chemoprevention drugs in combination with tamoxifen because of their favorable toxicity profile.