The global status of research in breast cancer liver metastasis: a bibliometric and visualized analysis

This study aimed to investigate the distribution laws and research frontiers of international literature, so as to present a holistic bibliometric evaluation of the studies on breast cancer liver metastasis(BCLM). Data were collected from the Web of Science Core Collection database, including publications, year, country, journal, author and keywords. The software VOSviewer and CiteSpace were used for bibliometric coupling, co-authorship, co-citation and co-occurrence analysis. In total, 1,031 publications were analyzed from 2004 to 2020 on BCLM. The year with the highest number of publications was 2006, with 103 papers. The United States, followed by China and Germany were the leading countries on BCLM, accounting for 59% of the whole. The journals that published about BCLM were mainly located in Q1/Q2. Keywords co-occurrence analysis divides BCLM into five clusters:"basic research", "auxiliary diagnosis and therapy", "liver resection", "clinical trial" and "prognosis". Main treatment therapies were the latest focus. Burst detection indicated that the trends in BCLM concentrated on subtype and SEER. There is apparently brighter perspective for BCLM research in the coming years, especially in liver resection, subtype and bioinformatics. The consequence of our study as the exclusive scientific evaluation offered an integral overview of BCLM, particularly for research focus and future directions, which can further accurately guide scholars on diagnosis, treatment, and personalized prevention.

Survival Outcomes Among Patients with Metastatic Breast Cancer: Review of 47,000 Patients

BACKGROUND

Although metastatic breast cancer (MBC) remains incurable, advances in therapies have improved survival. Using a contemporary dataset of de novo MBC patients, we explore how overall (OS) and cancer-specific survival (CSS) changed over time.

METHODS

All patients with de novo MBC from 1988 to 2016 were selected from Surveillance, Epidemiology, and End Results (SEER) 18. Unadjusted OS and CSS were estimated by Kaplan-Meier method and stratified by disease characteristics. Cox proportional hazards models determined factors associated with survival.

RESULTS

47,034 patients were included, with median OS of 25 months and CSS of 27 months. Survival steadily improved over time (1988: 1-year OS 62%, CSS 65%; 2015: 1-year OS 72%, CSS 74%). Patients with triple-negative breast cancer (TNBC) had the worst prognosis and were most likely to die from MBC [versus human epidermal growth factor receptor 2 (HER2)+ and hormone receptor (HR)+/HER2-]. Those with ≥ 4 sites of metastatic disease were also more likely to die from MBC with nearly identical OS and CSS (5-year OS 9%, CSS 9%), when compared with those with 1 site (5-year OS 31%, CSS 35%). After adjustment, improved CSS was associated with bone-only disease [hazard ratio (HR) 0.88, 95% confidence interval (CI) 0.83-0.94], while TNBC (versus HER2+: HR 3.12, 95% CI 2.89-3.36) and > 3 sites of metastatic disease (versus 1 site: HR 3.24, 95% CI 2.68-3.91) were associated with worse CSS (all p < 0.001).

CONCLUSIONS

Accurate prognostic estimates are essential for patient care. As treatments for patients with MBC have expanded, OS and CSS have improved, and more patients, particularly with limited distant disease or favorable tumor subtypes, are also dying from non-MBC causes.

Risk and prognostic factors of breast cancer with liver metastases

Background

Liver metastasis is a significant adverse predictor of overall survival (OS) among breast cancer patients. The purpose of this study was to determine the risk and prognostic factors of breast cancer with liver metastases (BCLM).

Methods

Data on 311,573 breast cancer patients from the Surveillance, Epidemiology, and End Results (SEER) database and 1728 BCLM patients from Fudan University Shanghai Cancer Center (FUSCC) were included. Logistic regression was used to identify risk factors for liver metastasis. Cox proportional hazards regression model was adopted to determine independent prognostic factors in BCLM patients.

Results

Young age, invasive ductal carcinoma, higher pathological grade, and subtype of triple-negative and human epidermal growth factor receptor 2 positive (HER2+) were risk factors for developing liver metastasis. The median OS after liver metastasis was 20.0 months in the SEER database and 27.3 months in the FUSCC dataset. Molecular subtypes also played a critical role in the survival of BCLM patients. We observed that hormone receptor-positive (HR+)/HER2+ patients had the longest median OS (38.0 for SEER vs. 34.0 months for FUSCC), whereas triple-negative breast cancer had the shortest OS (9.0 vs. 15.6 months) in both SEER and FUSCC. According to the results from the FUSCC, the subtype of HR+/HER2+ (hazard ratio (HR) = 2.62; 95% confidence interval (CI) = 1.88–3.66; P < 0.001) and HR−/HER2+ (HR = 3.43; 95% CI = 2.28–5.15; P < 0.001) were associated with a significantly increased death risk in comparison with HR+/HER2- patients if these patients did not receive HER2-targeted therapy. For those who underwent HER2-targeted therapy, however, HR+/HER2+ subtype reduced death risk compared with HR+/HER2- subtype (HR = 0.74; 95% CI = 0.58–0.95; P < 0.001).

Conclusions

Breast cancer patients at a high risk for developing liver metastasis deserve more attention during the follow-up. BCLM patients with HR+/HER2+ subtype displayed the longest median survival than HR+/HER2- and triple-negative patients due to the introduction of HER2-targeted therapy and therefore it should be recommended for HER2+ BCLM patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07968-5.

Predictive Nomogram of Subsequent Liver Metastasis After Mastectomy or Breast-Conserving Surgery in Patients With Nonmetastatic Breast Cancer

Background:

Metastasis accounts for the majority of deaths in patients with breast cancer. Liver metastasis is reported common for breast cancer patients. The purpose of this study was to construct a nomogram to predict the likelihood of subsequent liver metastasis in patients with nonmetastatic breast cancer, thus high-risk patient populations can be prevented and monitored.

Methods:

A total of 1840 patients with stage I-III breast cancer were retrospectively included and analyzed. A nomogram was constructed to predict liver metastasis based on multivariate logistic regression analysis. SEER database was used for external validation. C-index, calibration curve and decision curve analysis were used to evaluate the predictive performance of the model.

Results:

The nomogram included 3 variables related to liver metastasis: HER2 status (odds ratio (OR) 1.86, 95%CI 1.02 to 3.41; P = 0.045), tumor size (OR 3.62, 1.91 to 6.87; P < 0.001) and lymph node metastasis (OR 2.26, 1.18 to 4.34; P = 0.014). The C index of the training cohort, internal validation cohort and external validation cohort were 0.699, 0.814 and 0.791, respectively. The nomogram was well-calibrated, with no statistical difference between the predicted and the observed probabilities.

Conclusion:

We have developed and validated a robust tool enabled to predict subsequent liver metastasis in patients with nonmetastatic breast cancer. Distinguishing a population of patients at high risk of liver metastasis will facilitate preventive treatment or monitoring of liver metastasis.

Extended time interval between diagnosis and surgery does not improve the outcome in patients operated for resection or ablation of breast cancer liver metastases

BACKGROUND

Breast cancer liver metastases (BCLM) is considered a systemic disease with poorly defined selection criteria for surgery and little evidence for the appropriate timing of surgery.

METHODS

Postoperative outcomes of patients operated for BCLM were retrospectively reviewed and compared based on the timing of surgery, with the early surgery (ES) group treated ≤12 months after BCLM diagnosis, and late surgery (LS) group operated >12 months after diagnosis.

RESULTS

Seventy-two patients with BCLM underwent liver surgery, including 37 and 35 in the ES and LS groups, respectively. Demographic and preoperative characteristics were similar between the groups, except that multifocal liver disease was more frequent in the LS group (p = 0.008). The LS group had a morbidity rate of 38%, compared to 11% in the ES group (p = 0.015). No postoperative deaths occurred. In the whole cohort, median progression-free (PFS) and overall survival (OS) were 19 and 50 months, respectively, and 1-, 3- and 5-year PFS and OS were 63%, 41%, 24% and 93%, 66%, 43%, respectively, with no significant difference observed between the ES and LS groups. Multivariate analysis revealed that breast cancer progesterone receptor negativity (HR = 3.34, p = 0.03) and a size of LM > 40 mm (HR = 3.11, p = 0.01) were significant negative prognostic factors for PFS. Only a size of LM > 40 mm (HR = 2.79, p = 0.008) was significantly associated with shorter OS.

CONCLUSION

A prolonged preoperative observational period does not improve long-term outcomes after liver surgery in patients with resectable BCLM, suggesting that early management can safely be proposed to those patients, with good oncological outcomes.

A Population-Based Study on Liver Metastases in Women with Newly Diagnosed Breast Cancer

BACKGROUND

Population-based estimates for prognosis among patients with liver metastases in newly diagnosed breast cancer are not generally available.

METHODS

Within the Surveillance, Epidemiology and End Results (SEER) database, we identified 298,370 patients with breast cancer and 4,285 patients diagnosed with initial liver metastases between 2010 and 2014. Data were stratified according to subtype, age, and race. Multivariate logistic and Cox regression were used to identify predictors for the presence of initial liver metastases and prognostic factors, respectively. Kaplan-Meier procedure was used for survival analysis.

RESULTS

A total of 4,285 patients with initial liver metastases (1.4% of the entire cohort, 29.6% of the subset with metastatic disease) were identified. Patients with hormone receptor (HR)-negative human epidermal growth factor receptor 2 (HER2)-positive (4.4% of entire cohort, 52.5% of patients with metastatic disease to any distant site) and HR-positive HER2-positive (2.8% of entire cohort, 40.4% of patients with metastatic disease to any distant site) subtypes had highest incidence proportions. The median survival of patients with liver metastases in the entire cohort was 15.0 months. Patients with HR-positive HER2-positive subtype showed the longest median survival (31.0 months); however, patients with triple-negative subtype showed the shortest median survival (8.0 months).

CONCLUSIONS

Our findings provide population-based estimates of epidemiologic characteristics and prognosis in breast cancer patients diagnosed with initial liver metastases.

IMPACT

This study lends support to the diagnosis of the liver among patients at high risk of liver metastases, including those with HER2-positive and other systemic metastases.

Incidence and prognostic factors of patients with synchronous liver metastases upon initial diagnosis of breast cancer: a population-based study

Background

The purpose of this study was to analyze the incidence and prognostic factors of patients with breast cancer liver metastases (BCLM) at initial diagnosis.

Methods

We utilized the Surveillance, Epidemiology, and End Results database to extract data on patients with primary invasive breast cancer from 2010 to 2014. Multivariate logistic regression was conducted to determine factors associated with the presence of liver metastases upon initial diagnosis of breast cancer. Univariate and multivariate Cox regression analyses were performed to identify the prognostic factors in these patients.

Results

In total, 3,276 patients with liver metastases were identified upon initial diagnosis of breast cancer. Patients with hormone receptor-negative (HR−), human epidermal growth factor receptor 2-positive (HER2+) breast cancer had the highest incidence (4.6% among the entire population, 46.5% among the metastatic subgroup). Age, gender, race, pathological grade, extrahepatic metastases, tumor subtype, and marital status were identified as factors associated with the presence of liver metastases upon initial diagnosis of breast cancer. The median overall survival among the entire population with BCLM was 20.0 months. Patients with HR+/HER2+ breast cancer had the longest median survival of 36.0 months. The survival analyses indicated that older age, higher pathological grade, extrahepatic metastases, triple-negative subtype, unmarried status, and uninsured status were independent prognostic factors for a poorer prognosis.

Conclusion

The study provides insight into the incidence and prognostic factors for patients with BCLM at initial diagnosis, which is important clinical information for risk evaluation and prognostic assessment.

A Model of Dormant-Emergent Metastatic Breast Cancer Progression Enabling Exploration of Biomarker Signatures

Breast cancer mortality predominantly results from dormant micrometastases that emerge as fatal outgrowths years after initial diagnosis. In order to gain insights concerning factors associated with emergence of liver metastases, we recreated spontaneous dormancy in an all-human ex vivo hepatic microphysiological system (MPS). Seeding this MPS with small numbers (<0.05% by cell count) of the aggressive MDA-MB-231 breast cancer cell line, two populations formed: actively proliferating ("growing"; EdU+), and spontaneously quiescent ("dormant"; EdU-). Following treatment with a clinically standard chemotherapeutic, the proliferating cells were eliminated and only quiescent cells remained; this residual dormant population could then be induced to a proliferative state ("emergent"; EdU+) by physiologically-relevant inflammatory stimuli, lipopolysaccharide (LPS) and epidermal growth factor (EGF). Multiplexed proteomic analysis of the MPS effluent enabled elucidation of key factors and processes that correlated with the various tumor cell states, and candidate biomarkers for actively proliferating (either primary or secondary emergence) versus dormant metastatic cells in liver tissue. Dormancy was found to be associated with signaling reflective of cellular quiescence even more strongly than the original tumor-free liver tissue, whereas proliferative nodules presented inflammatory signatures. Given the minimal tumor burden, these markers likely represent changes in the tumor microenvironment rather than in the tumor cells. A computational decision tree algorithm applied to these signatures indicated the potential of this MPS for clinical discernment of each metastatic stage from blood protein analysis.

Long-term survival and cure model following liver resection for breast cancer metastases

INTRODUCTION

Long-term survival is still rarely achieved with current systemic treatment in patients with breast cancer liver metastases (BCLM). Extended survival after hepatectomy was examined in a select group of BCLM patients.

PATIENTS AND METHODS

Hepatectomy for BCLM was performed in 139 consecutive patients between 1985 and 2012. Patients who survived < 5 years were compared to those who survived ≥ 5 years from first diagnosis of hepatic metastases. Predictive factors for survival were analyzed. Statistically cured, defined as those patients who their hazard rate returned to that of the general population, was analyzed.

RESULTS

Of the 139, 43 patients survived ≥ 5 years. Significant differences between patient groups (< 5 vs. ≥ 5 years) were mean time interval between primary tumor and hepatic metastases diagnosis (50 vs. 43 months), mean number of resected tumors (3 vs. 2), positive estrogen receptors (54% vs. 79%), microscopic lymphatic invasion (65% vs. 34%), vascular invasion (63% vs. 37%), hormonal therapy after resection (34% vs. 74%), number of recurrence (40% vs. 65%) and repeat hepatectomy (1% vs. 42%), respectively. The probability of statistical cure was 14% (95% CI 1.4-26.7%) in these patients.

CONCLUSIONS

Hepatectomy combined with systemic treatment can provide a chance of long-term survival and even cure in selected patients with BCLM. Microscopic vascular/lymphatic invasion appears to be a novel predictor for long-term survival after hepatectomy for BCLM and should be part of the review when discussing multidisciplinary treatment strategies.

Stereotactic Radiofrequency Ablation for Breast Cancer Liver Metastases

PURPOSE

To evaluate outcomes in patients with liver metastases from breast cancer treated with stereotactic radiofrequency (RF) ablation.

MATERIALS AND METHODS

A retrospective analysis of 29 stereotactic RF ablation treatment sessions in 26 consecutive patients with 64 biopsy-proven breast cancer liver metastases (BCLMs) was conducted. Patients were included only if systemic treatment failed and all visible BCLMs were treatable.

RESULTS

Primary and secondary technical success rates were 96.9% (62 of 64) and 100%, respectively. There were no perioperative mortalities. Local recurrence was identified in 5 tumors (7.8%), with no significant differences among tumor sizes (P = .662): < 3 cm (9.3%), 3-5 cm (0%), and > 5 cm (8.3%). Median estimated overall survival (OS) from first stereotactic ablation treatment was 29.3 months ± 8.9 (95% confidence interval [CI], 11.9-46.8 mo; mean, 28.7 mo) after a median follow-up of 23.1 months (mean, 31.3 mo; range, 0.1-100.8 mo). No significant differences in OS (P = .223) were observed among tumor volumes < 50 cm³ (median, 84.9 mo ± 53.1; mean, 58.4 mo), 50-100 cm³ (median, 37.8 mo ± 5.7; mean, 36.3 mo), and > 100 cm³ (median, 17.1 mo ± 3.5; mean, 21.8 mo). Numbers of metastases did not affect estimated OS, with a median OS of 32.7 months ± 10.4 (mean, 35.8 mo) for single lesions vs 17.7 months ± 3.2 (mean, 25.9 mo) for 2/3 lesions and a mean of 68.4 months ± 17.23 for > 3 lesions (P = .113).

CONCLUSIONS

Multiple-electrode stereotactic RF ablation proved to be a safe minimally invasive alternative to surgical liver resection in selected patients with BCLMs.

New insights into the metastatic behavior after breast cancer surgery, according to well-established clinicopathological variables and molecular subtypes

Despite advances in treatment, up to 30% of patients with early breast cancer (BC) experience distant disease relapse. However, a comprehensive understanding of tumor spread and site-specific recurrence patterns remains lacking. This retrospective case-control study included 103 consecutive patients with metastatic BC admitted to our institution (2000–2013). Cases were matched according to age, tumor biology, and clinicopathological features to 221 patients with non-metastatic BC (control group). The median follow-up period among the 324 eligible patients was 7.3 years. While relatively low values for sensitivity (71%) and specificity (56%) were found for axillary lymph node (ALN) involvement as an indicator of risk and pattern of distant relapse, nodal status remained the most powerful predictor of metastases (OR: 3.294; CL: 1.9–5.5). Rates of dissemination and metastatic efficiency differed according to molecular subtype. HER2-positive subtypes showed a stronger association with systemic spread (OR: 2.127; CL: 1.2–3.8) than other subgroups. Classification as Luminal or Non-Luminal showed an increased risk of lung and distant nodal recurrence, and a decreased risk in bone metastases in the Non-Luminal group (OR: 2.9, 3.345, and 0.2, respectively). Tumors with HER2 overexpression had a significantly high risk for distant relapse (OR: 2.127) compared with HER2-negative tumors and also showed higher central nervous system (CNS) and lung metastatic potential (OR: 5.6 and 2.65, respectively) and low risk of bone disease progression (OR: 0.294). Furthermore, we found significant associations between biological profiles and sites of recurrence. A new process of clinical/diagnostic staging, including molecular subtypes, could better predict the likelihood of distant relapses and their anatomical location. Recognition and appreciation of clinically distinct molecular subtypes may assist in evaluation of the probability of distant relapses and their sites. Our analysis provides new insights into management of metastatic disease behavior, to lead to an optimal disease-tailored approach and appropriate follow-up.

Pattern of metastatic spread and subcategories of breast cancer

PURPOSE

The development of metastases is the most aggressive attribute of breast cancer. In this retrospective multicenter study, we evaluated if and how the different pathological breast cancer subtypes influence the spreading of tumor cells, the development of metastasis and the survival of breast cancer patients.

METHODS

This retrospective German multicenter study is based on the BRENDA collective including 9625 breast cancer patients treated in the adjuvant setting. We used the χ ² tests for the analysis of the categorical variables between groups of patients with different sites of metastasis. Survival distributions and median survival times were estimated using the Kaplan-Meier product-limit method. The log-rank test was applied to compare survival rates. The Cox proportional hazards model was used to estimate the hazard ratio and confidence intervals.

RESULTS

886 women developed metastases during a time interval of 53 months after primary diagnosis. Luminal A tumor patients were more likely to get bone metastases than lung, liver or CNS metastases. Patients with a triple-negative subtype were, however, the least affected by metastasis in the skeleton. They were most likely to develop visceral metastases. Location, numbers of metastases herein and the subtype influenced the overall survival (OAS). Altogether, the best OAS was found in patients with the luminal A subtype, the worst in patients with the triple-negative subtype.

CONCLUSIONS

Knowledge of the typical metastatic pattern of the subtypes of breast cancer will help to personalize therapeutic options and follow-up examinations of cancer patients.

Predictive Profile-Nomogram for Liver Resection for Breast Cancer Metastases: An Aggressive Approach with Promising Results

BACKGROUND

Breast cancer liver metastases (BCLM) are considered the most lethal compared with other sites of metastases in patients with breast cancer. This study aimed to evaluate the outcome after hepatectomy for BCLM within current multidisciplinary treatment and to develop a clinically useful nomogram to predict survival.

METHODS

Between January 1985 and December 2012, 139 consecutive female patients underwent liver resection for BCLM at the authors' institution. Clinicopathologic data were collected and analyzed for survival outcome with determination of prognostic factors. A nomogram to predict survival was developed based on a multivariate Cox model. The predictive performance of the model was assessed according to the C-statistic and calibration plots.

RESULTS

After a median follow-up period of 55 months, the overall 3- and 5-year survival rates after hepatectomy were respectively 58 and 47 %. The median overall survival period was 56 months, and the median disease-free survival period after surgical resection was 33 months. A single hepatic metastasis, no triple negative tumors, no microscopic vascular invasion, and perioperative hormonal or targeted therapy were related to improved overall survival. The model achieved good discrimination and calibration, with a C-statistic of 0.80.

CONCLUSIONS

Liver resection for selected patients with breast cancer metastases can provide significant survival benefit. It should be part of a multidisciplinary treatment program in experienced liver surgery centers. The authors' nomogram facilitates personalized assessment of prognosis for these patients.

Real-world effectiveness of everolimus-based therapy versus endocrine monotherapy and chemotherapy in patients of HR+/HER2- breast cancer with liver metastasis in the USA

OBJECTIVE

This study investigated the comparative effectiveness of everolimus-based therapy (EVE) versus endocrine monotherapy (ET) and chemotherapy (CT) in the treatment of hormone-receptor-positive human-epidermal-growth-factor-receptor-2-negative (HR+/HER2-) metastatic breast cancer (mBC) patients with liver metastasis.

METHODS

Medical charts of patients treated by community oncologists were examined. Eligible patients included postmenopausal women with HR+/HER2- mBC with liver metastasis who received EVE, ET or CT between 1 July 2012 and 15 April 2013 after non-steroidal aromatase inhibitor use. Time on treatment (TOT) and progression-free survival (PFS) were compared between EVE and ET or CT using Kaplan-Meier analyses and Cox proportional hazards models.

RESULTS

Among the 202 patients in the study, 82 received EVE, 49 ET, and 71 CT. After adjusting for baseline characteristics, EVE was associated with significantly longer TOT than ET (hazard ratio [HR]: 0.49; 95% CI: 0.28 - 0.86) or CT (HR: 0.35; 95% CI: 0.22 - 0.55), and significantly longer PFS than ET (HR: 0.48; 95% CI: 0.27 - 0.87). PFS was not significantly different with EVE versus CT (HR: 0.76; 95% CI: 0.44 - 1.32).

CONCLUSIONS

EVE had significantly longer TOT and PFS than ET and longer TOT than CT among postmenopausal HR+/HER2- mBC patients with liver metastasis.

Alterations in hormonal receptor expression and HER2 status between primary breast tumors and paired nodal metastases: discordance rates and prognosis

BACKGROUND

We aimed to evaluate the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression discordance in matched pairs of primary breast cancer and lymph node metastasis specimens and determine the effect of discordance on prognosis.

MATERIALS AND METHODS

Among all patients diagnosed with lymph node metastases from 2004 to 2007, primary tumors and paired lymph node metastases were resected from 209 patients. The status of ER, PR, and HER2 expression was analyzed immunohistochemically in 200, 194, and 193 patients, respectively. Discordance was correlated with prognosis.

RESULTS

Biomarker discordance between primary tumors and paired lymph node metastases was 25.0% (50/200) for ER status, 28.9% (56/194) for PR status, and 14.0% (27/193) for HER2 status. ER positivity was a significant independent predictor of improved survival when analyzed in primary tumors and lymph node metastases. Patients with PR-positive primary tumors and paired lymph node metastases displayed significantly enhanced survival compared to patients with PR-positive primary tumors and PR-negative lymph node metastases. Patients with ER- and PR-positive primary tumors and paired lymph node metastases who received endocrine therapy after surgery displayed significantly better survival than those not receiving endocrine therapy. Similalry treated patients with PR-negative primary tumors and PR-positive paired lymph node metastases also displayed better survival than those not receiving endocrine therapy.

CONCLUSIONS

Biomarker discordance was observed in matched pairs of primary tumors and lymph node metastases. Such cases displayed poor survival. Thus, it is important to reassess receptor biomarkers used for lymph node metastases.

Immunohistochemistry subtypes (ER/PR/HER) of breast cancer: where do we stand in the West of Saudi Arabia?

In Saudi Arabia, cancer of breast is ranked the most frequent neoplasm and second source of cancer death in the female population. Breast cancer (BC) fast diagnosis, prognosis and medication management necessitate, these days, immunohistochemistry (IHC) assessment of hormone receptors and HER2 expression profile. The present report defines the IHC profile of ER, PR and HER2 in Saudi female breast neoplasms of ductal and lobular types and associations ER, PR and HER2 expression patterns with various clinicopathological factors (age, type of tumor, size, laterality, histological grade, and involvement of axillaries lymph nodes). Ninety nine cases of breast tumors were recruited from the pathology department archive of King Abdulaziz University Hospital, Kingdom of Saudi Arabia. ER, PR and HER2 expression was assessed using IHC staining. Ductal carcinomas with a variety of histological grades constituted 88 (88.8%) of total cases. Seventy four (77.8%), 59 (62.1%), and 35 (36.8%) of ductal carcinomas showed positive staining for ER, PR and HER2, in that order. Remaining breast cancer cases were four (4%) lobular carcinomas and two (2%) mixed form of ductal and lobular types, which were ER+, PR+, and HER2-. Breast cancer expression pattern of ER, PR and HER2 in Saudi female is different from that of Tunisian and Jordanian female populations and closer to the expression pattern of Egyptian, Lebanese, Iraqi and western country females. Furthermore, the present study found two IHC patterns of breast cancer ER+/PR-/HER2+ (5%) and ER+/PR-/HER2- (11.1%), which had not been reported in other Arabic studies. Thus the rates of IHC expression patterns in breast cancer show some variation among Arabic female populations.

Comparison of inhibitory effects of 17-AAG nanoparticles and free 17-AAG on HSP90 gene expression in breast cancer

BACKGROUND

HSP90 may be overexpressed in cancer cells which are greatly dependent on Hsp90 function. Geldanamycin derivative 17 allylamino-17-demethoxygeldanamycin (17-AAG) inhibits the function and expression of HSP90. 17-AAG has poor water-solubility which is a potential problem for clinical practice. In this study for improving the stability and solubility of molecules in drug delivery systems we used a β-cyclodextrin- 17AAG complex.

MATERIALS AND METHODS

To assess cytotoxic effects of β-cyclodextrin-17AAG complexes and free 17AAG, colorimetric cell viability (MTT) assays were performed. Cells were treated with equal concentrations of β-cyclodextrin- 17AAG complex and free 17AAG and Hsp90 gene expression levels in the two groups was compared by real-time PCR.

RESULTS

MTT assay confirmed that β-cyclodextrin- 17AAG complex enhanced 17AAG cytotoxicity and drug delivery in T47D breast cancer cells. The level of Hsp90 gene expression in cells treated with β-cyclodextrin- 17AAG complex was lower than that of cells treated with free 17AAG (P=0.001).

CONCLUSIONS

The results demonstrated that β-cyclodextrin- 17AAG complexes are more effective than free 17AAG in down-regulating HSP90 expression due to enhanced β-cyclodextrin-17AAG uptake by cells. Therefore, β-cyclodextrin could be superior carrier for this kind of hydrophobic agent.