Invasive lobular carcinoma of the breast; clinicopathologic profile and response to neoadjuvant chemotherapy over a 15-year period.

INTRODUCTION: Invasive lobular carcinoma (ILC) accounts for 5-15% of invasive breast cancers. Typical ILC is oestrogen receptor (ER) positive and human epidermal growth factor receptor 2 (HER2) negative. Atypical biomarker profiles (ER- and HER2+, ER+ and HER2+ or triple negative) appear to differ from typical ILCs. This study compared subtypes of ILC in terms of clinical and pathological parameters, and response to neoadjuvant chemotherapy (NACT) according to biomarker profile. METHODS: All patients with ILC treated in a single centre from January 2005 to December 2020 were identified from a prospectively maintained database. Clinicopathologic and outcome data was collected and analysed according to tumour biomarker profile. RESULTS: A total of 582 patients with ILC were treated. Typical ILC was observed in 89.2% (n = 519) and atypical in 10.8% (n = 63). Atypical ILCs were of a higher grade (35% grade 3 vs 9.6% grade 3, p < 0.001). A larger proportion of atypical ILC received NACT (31.7% vs 6.9% p < 0.001). Atypical ILCs showed a greater response to NACT (mean RCB (Residual Cancer Burden Score) 2.46 vs mean RCB 3.41, p = 0.0365), and higher pathological complete response rates (15% vs 0% p = 0.017). Despite this, overall 5-year disease-free survival (DFS) was higher in patients with typical ILC (91% vs 83%, p = 0.001). CONCLUSIONS: Atypical ILCs have distinct characteristics. They are more frequently of a higher grade and demonstrate a superior response to NACT. Despite the latter, atypical ILCs have a worse 5-year DFS which should be taken into consideration in terms of prognostication and may assist patient selection for NACT.

The association between breast density and breast cancer pathological response to neoadjuvant chemotherapy.

PURPOSE: Mammographic Density (MD) refers to the amount of fibroglandular breast tissue present in the breast and is an established risk factor for developing breast cancer. The ability to evaluate treatment response dynamically renders neoadjuvant chemotherapy (NACT) the preferred treatment option in many clinical scenarios. Previous studies have suggested that MD can predict patients likely to achieve a pathological complete response (pCR) to NACT. We aimed to determine whether there is a causal relationship between BI-RADS breast composition categories for breast density at diagnosis and the pCR rate and residual cancer burden score (RCB) by performing a retrospective review on consecutive breast cancer patients who received NACT in a tertiary referral centre from 2015 to 2021. METHODS: The Mann-Whitney U Test was used to test for differences between two independent groups (i.e. those who achieved pCR and those who did not). A binary logistic regression model was used to estimate odds ratios (OR) and corresponding 95% confidence intervals (CI) for an association between the independent variables of molecular subtype, MD, histological grade and FNA positivity and the dependant variable of pCR. Statistical analysis was conducted with SPSS (IBM SPSS for Mac, Version 26.0; IBM Corp). RESULTS: 292 patients were included in the current study. There were 124, 155 and 13 patients in the BI-RADS MD category b, c and d, respectively. There were no patients in the BI-RADS MD category a. The patients with less dense breast composition (MD category b) were significantly older than patients with denser breast composition (MD category c, d) (p = 0.001) and patients who had a denser breast composition (MD category d) were more likely to have ER+ tumours. There was no significant difference in PgR status, HER2 status, pathological complete response (pCR), FNA positivity, or RCB class dependent upon the three MD categories. A binary logistic regression revealed that patients with HER2-enriched breast cancer and triple-negative breast cancer are more likely to achieve pCR with an OR of 3.630 (95% CI 1.360-9.691, p = 0.010) and 2.445 (95% CI 1.131-5.288, p = 0.023), respectively. CONCLUSION: Whilst dense MD was associated with ER positivity and these women were less likely to achieve a pCR, MD did not appear to independently predict pCR post-NACT.

Real-world analysis of clinical and economic impact of 21-gene recurrence score (RS) testing in early-stage breast cancer (ESBC) in Ireland.

PURPOSE: Results from TAILOR-X suggest that up to 70% of hormone receptor-positive (HR+) node-negative (N0) ESBC patients (pts) may avoid chemotherapy (CT) with RS ≤ 25. We assess clinical and economic impacts of RS testing on treatment using real-world data. METHODS: From October 2011 to February 2019, a retrospective, cross-sectional observational study was conducted of HR+ N0 ESBC pts who had RS testing in Ireland. Pts were classified low risk (RS ≤ 25) and high risk (RS > 25). Clinical risk was calculated. Data were collected via electronic patient records. Cost data were supplied by the National Healthcare Pricing Regulatory Authority. RESULTS: 963 pts. Mean age is 56 years. Mean tumour size is 1.7 cm. 114 (11.8%), 635 (66%), 211 (22%), 3 (0.2%) pts had G1, G2, G3 and unknown G, respectively. 796 pts (82.8%) low RS, 159 (16.5%) high RS and 8 pts (0.7%) unknown RS. 263 pts (26%) were aged ≤ 50 at diagnosis; 117 (45%) had RS 0-15, 63 (24.5%) 16-20, 39 (15.3%) 21-25 and 40 (15.2%) RS 26-100. 4 pts (1.5%) had unknown RS. Post-RS testing, 602 pts (62.5%) had a change in CT decision; 593 changed to hormone therapy (HT) alone. In total, 262 pts received CT. Of pts receiving CT; 138 (53%) had RS > 25, 124 (47%) had RS ≤ 25. Of pts aged ≤ 50, 153 (58%) had high clinical risk, of whom 28 had RS 16-20. Assay use achieved a 62.5% change in treatment with 73% of pts avoiding CT. This resulted in savings of €4 million in treatment costs. Deducting assay costs, savings of €1.9 million were achieved. CONCLUSION: Over the 8 years of the study, a 62.5% reduction in CT use was achieved with savings of over €1,900,000.

Value of a 21-gene expression assay on core biopsy to predict neoadjuvant chemotherapy response in breast cancer: systematic review and meta-analysis.

BACKGROUND: A recurrence score based on a 21-gene expression assay predicts the benefit of adjuvant chemotherapy in oestrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer. This systematic review aimed to determine whether the 21-gene expression assay performed on core biopsy at diagnosis predicted pathological complete response (pCR) to neoadjuvant chemotherapy. METHODS: The study was performed according to PRISMA guidelines. Relevant databases were searched to identify studies assessing the value of the 21-gene expression assay recurrence score in predicting response to neoadjuvant chemotherapy in patients with breast cancer. The Newcastle-Ottawa Scale was used to assess the quality of the studies. Results are reported as risk ratio (RR) with 95 per cent confidence interval using the Cochrane-Mantel-Haenszel method for meta-analysis. Sensitivity analyses were carried out where appropriate. RESULTS: Seven studies involving 1744 patients reported the correlation between pretreatment recurrence score and pCR. Of these, 777 patients (44.6 per cent) had a high recurrence score and 967 (55.4 per cent) a low-intermediate score. A pCR was achieved in 94 patients (5.4 per cent). The pCR rate was significantly higher in the group with a high recurrence score than in the group with a low-intermediate score (10.9 versus 1.1 per cent; RR 4.47, 95 per cent c.i. 2.76 to 7.21; P < 0.001). A significant risk difference was observed between the two groups (risk difference 0.10, 0.04 to 0.15; P = 0.001). CONCLUSION: A high recurrence score is associated with higher pCR rates and a low-intermediate recurrence score may indicate chemoresistance. Routine assessment of recurrence score by the 21-gene expression assay on core biopsy might be of value when considering neoadjuvant chemotherapy in patients with ER-positive, HER2-negative breast cancer.

The approach to an isolated close anterior margin in breast conserving surgery.

INTRODUCTION: Although close radial margins after breast-conserving surgery routinely undergo re-excision, appropriate management of patients with close anterior margins remains a topic of controversy. An increasing body of literature suggests that re-excision of close anterior margins yields low rates of residual malignancy and may only be necessary in selected patients. The aim of this study was to examine the management of close anterior margins after breast conserving surgery in a single institution and to analyse the rate of residual disease in re-excised anterior margins. METHODS: All patients having breast conserving surgery at St Vincent's University Hospital from January 2008 to December 2012 were reviewed retrospectively. Data collected included patient demographics, tumour characteristics, margin positivity, re-excision rates and definitive histology of the re-excision specimens. A close margin was defined as les than 2 mm. RESULTS: A total of 930 patients were included with an average age of 65 years (range 29-94 years). Of these, 121 (13%) had a close anterior margin. Further re-excison of the anterior margin was carried out in 37 patients (30.6%) and a further 16 (13.2%) proceeded to mastectomy. Residual disease was found in 18.5% (7/36) of those who underwent re-excision and 7/16 (43.75%) of those who underwent mastectomy. Overall, 11.57% (14/121) of patients with close anterior margins were subsequently found to have residual disease. CONCLUSION: The low yield of residual disease in re-excised anterior margins specimens supports the concept that routine re-excision of close anterior margins is not necessary. Further research is required to definitively assess its influence on the risk of local recurrence.

Meta-analysis of sentinel lymph node biopsy after neoadjuvant chemotherapy in patients with initial biopsy-proven node-positive breast cancer.

BACKGROUND: Neoadjuvant chemotherapy for breast cancer has the potential to achieve a pathological complete response in up to 40 per cent of patients, converting disease that was initially node-positive to node-negative. This has raised the question of whether sentinel lymph node biopsy could be an alternative to axillary lymph node dissection in these patients. The aim was to undertake a systematic review and meta-analysis of the accuracy and reliability of sentinel lymph node biopsy after neoadjuvant chemotherapy in patients with initial biopsy-proven node-positive breast cancer. METHODS: A literature search was conducted using PubMed, Ovid MEDLINE, Embase and Web of Science databases up to 30 April 2017. Inclusion criteria for studies were pathological confirmation of initial node-positive disease, and sentinel lymph node biopsy performed after neoadjuvant chemotherapy followed by axillary lymph node dissection. RESULTS: A total of 13 studies met the inclusion criteria and were included in the analysis (1921 patients in total). The pooled estimate of identification rate was 90 (95 per cent c.i. 87 to 93) per cent and the false-negative rate was 14 (11 to 17) per cent. In subgroup analysis, the false-negative rate with use of dual mapping was 11 (6 to 15) per cent, compared with 19 (11 to 27) per cent with single mapping. The false-negative rate was 20 (13 to 27) per cent when one node was removed, 12 (5 to 19) per cent with two nodes removed and 4 (0 to 9) per cent with removal of three or more nodes. CONCLUSION: Sentinel lymph node biopsy after neoadjuvant chemotherapy in patients with biopsy-proven node-positive breast cancer is accurate and reliable, but requires careful patient selection and optimal surgical techniques.

Cycling Injuries Presenting to an Irish Emergency Department.

There is little published data on cycling injuries in Ireland and the present study aims to describe the cycling related injuries presenting to the emergency department (ED), of a tertiary urban university hospital. This is a retrospective review of cycling-related injuries presenting to the ED of St. Vincent's University Hospital (SVUH) from 1st of January to 31st of December 2014. There were 534 cycling related injuries presenting to the ED during the study period. Just over 71% of the patients were male, and 14.8% of patients presented following a collision with a motor vehicle. Forty patients required admission to hospital following their injury with 6 of these patients spending time in the intensive care unit. Cycling is now a very popular means of transport and exercise activity in Ireland and using hospital based data, it is possible that EDs may provide a vector for guiding injury prevention strategies in the future.

A Positive Node on Ultrasound-Guided Fine Needle Aspiration Predicts Higher Nodal Burden Than a Positive Sentinel Lymph Node Biopsy in Breast Carcinoma.

INTRODUCTION: Axillary status remains an important prognostic indicator in breast cancer. Certain patients with a positive sentinel node (SLNB) may not benefit from axillary clearance (AC). Uncertainty remains if this approach could be applied to patients diagnosed with axillary metastases on ultrasound-guided fine needle aspiration cytology (USFNAC). The aim of this study was to compare nodal burden in patients with positive USFNAC and a positive SLNB. METHODS: A retrospective study was performed involving all BC patients between 2007 and 2014 who had either pre-operative USFNAC or a SLNB. Patient/tumour characteristics and nodal burden were examined in all patients proceeding to AC. RESULTS: 974 patients were eligible for analysis. 439 patients (45 %) had positive USFNAC and 535 (55 %) had a positive SLNB. USFNAC-positive patients were more likely to undergo mastectomy (Chi-square test; p < 0.001), have extra-nodal extension (p < 0.001), be oestrogen receptor negative (p < 0.001) and be HER2 positive (p < 0.001). The median total number of lymph nodes (LNs) excised during AC was higher in the USFNAC group (Mann-Whitney test; 23 vs. 21; p < 0.001). The median total number of involved LNs was 3 (range 1-47) in FNAC-positive patients versus 1 (range 1-37) in SLNB-positive patients (p < 0.001). The median number of involved LNs in level 1 was 3 in FNAC-positive patients versus 1 in SLNB-positive patients (p < 0.001). Within the SLN-positive group, 49 % of the patients had only one involved LN, 28 % had two nodes involved and 23 % had ≥3. In comparison, within the FNAC-positive group only 13 % of the patients had one involved LN, 12 % had two nodes involved and 74 % had ≥3. CONCLUSION: Patients with positive USFNAC have more aggressive clinico-pathological characteristics and higher nodal burden compared to SLNB-positive patients. Currently, the authors advocate that patients not receiving neoadjuvant chemotherapy, with a positive USFNAC, should proceed directly to an axillary ALND.

Role of bone scan in addition to CT in patients with breast cancer selected for systemic staging.

BACKGROUND: The majority of women with breast cancer present with localized disease. The optimal strategy for identifying patients with metastatic disease at diagnosis remains unclear. The aim of this study was to evaluate the additional diagnostic yield from isotope bone scanning when added to CT staging of the thorax, abdomen and pelvis (CT-TAP) in patients with newly diagnosed breast cancer. METHODS: All patients diagnosed with breast cancer who underwent staging CT-TAP and bone scan between 2011 and 2013 were identified from a prospective database of a tertiary referral breast cancer centre that provides a symptomatic and population-based screening breast service. Criteria for staging included: biopsy-proven axillary nodal metastases; planned neoadjuvant chemotherapy or mastectomy; locally advanced or inflammatory breast cancer and symptoms suggestive of metastases. RESULTS: A total of 631 patients underwent staging by CT-TAP and bone scan. Of these, 69 patients (10·9 per cent) had distant metastasis at presentation, with disease confined to a single organ in 49 patients (71 per cent) and 20 (29 per cent) having metastatic deposits in multiple organs. Bone metastasis was the most common site; 39 of 49 patients had bone metastasis alone and 12 had a single isolated metastatic deposit. All but two of these were to the axial skeleton. No preoperative histological factors identified a cohort of patients at risk of metastatic disease. Omission of the bone scan in systemic staging would have resulted in a false-negative rate of 0·8 per cent. CONCLUSION: For patients diagnosed with breast cancer, CT-TAP is a satisfactory stand-alone investigation for systemic staging.

A comparison of clinical-pathological characteristics between symptomatic and interval breast cancer.

BACKGROUND: An association between interval breast cancers (cancer detected after a normal mammogram and before the next scheduled mammogram) and tumour aggressiveness has been postulated which may reflect their relatively poor overall prognosis. The aim of this study was to evaluate known prognostic features of screen detected breast cancers compared to interval breast cancers. METHODS: Patients diagnosed with breast cancer between January 2010 and 2013 at a single unit of the National Breast Screening Program (NBSP) in Ireland and those between the ages of 50 and 65 diagnosed at a symptomatic breast clinic were included in the study. Patients who had not had a screening mammogram within the proceeding two years or had a previous history of breast cancer were excluded. Data were retrospectively collected on patient demographics, tumour type, grade, hormone receptor status and stage of disease at presentation. RESULTS: There were 915 patients included in the study, with 92% (n = 844) diagnosed through the NBSP. Ductal carcinoma in-situ accounted for 19% (n = 160) of screen-detected breast cancers but only 2.8% of interval cancers (p < 0.05). The most common type of invasive cancer was invasive ductal carcinoma. Tumour grade was significantly higher in interval breast cancers (p < 0.05). Interval cancers were identified at a significantly higher stage (Stage 1 versus 2; p < 0.001) than screen-detected cancers. Interval breast cancers were less likely to be ER positive (76% versus 81%; p < 0.05) and significantly more likely to over-express HER2 (20% vs 10%, p < 0.05) than screen-detected cancers. CONCLUSION: This study highlights the fact that interval cancers appear to have a number of adverse prognostic markers for overall breast cancer survival when compared to women with screen-detected breast cancers. Interval cancers were more likely to be invasive, of a higher grade and stage and with a greater predominance of HER2 and triple negative molecular subtypes. Therefore this heterogeneous group of tumours may be biologically more aggressive and account disproportionately to overall breast cancer mortality.

Axillary nodal burden in primary breast cancer patients with positive pre-operative ultrasound guided fine needle aspiration cytology: management in the era of ACOSOG Z011.

INTRODUCTION: Recent years have seen a dramatic shift to more conservative management of the axilla in patients with a positive sentinel lymph node biopsy (SLNB). Identification of nodal disease with positive pre-operative ultrasound guided axillary fine needle aspiration cytology (AUS/FNAC) may represent a higher axillary disease burden mandating an axillary clearance and thus an upfront SLNB may be avoided. The aims of this study were to quantify nodal burden in patients with positive pre-operative AUS/FNAC and identify patients who may have been able to avoid an axillary clearance (ALND) based on ACOSOG Z011 criteria. METHODS: A retrospective review of a prospectively maintained database identified patients with positive pre-operative AUS/FNAC between 2007 and 2012. Core biopsies were excluded. Demographic and tumour characteristics were analysed. Eligibility for ACOSOG Z011 criteria was assessed and patients who may have avoided ALND were identified. RESULTS: 432 patients were identified with positive AUS/FNAC. 85 patients were excluded leaving 347 for analysis. Median age was 56 years (22-87), median tumour size was 25 mm (1.5 mm-150 mm) and median tumour pathology was grade 3 (50%) and invasive ductal carcinoma (82%). Median number of nodes removed at ALND was 23 (1-55) with a median number of positive nodes being 4 (1-47). 134 (39%) patients had ≤2 positive nodes identified on ALND making them eligible for the ACOSOG Z011 study. When other ACOSOG Z011 exclusion factors were applied only 27 (7.8%) patients may have avoided ALND. CONCLUSIONS: Nodal positivity on AUS/FNAC is associated with higher axillary disease burden. Few patients would satisfy ACOSOG/Z011 criteria and avoid ALND making an upfront SLNB unnecessary.

Malignant melanoma: factors affecting the surgical interval from excision biopsy to definitive surgical management.

INTRODUCTION: Surgery remains the mainstay of treatment for malignant melanoma. Despite previous studies examining the surgical interval (SI) between the diagnostic excision biopsy (DEB) and definitive surgical management there remains few guidelines regarding an optimal time interval. The aim of this study was to determine the SI between DEB and definitive surgery and elucidate factors associated with delays in management of malignant melanoma. METHODS: A retrospective study of 107 consecutive patients who had a DEB and subsequent wide local excision between January 2011 and June 2012 was performed. Mode of referral and dates of diagnostic biopsy/definitive surgery were documented. Patient demographics and tumour characteristics were reviewed. RESULTS: The mean age was 59.6 years, and male:female ratio was 1:1.3. Median duration of the SI was 41 ± 27 days (range 6-137 days). The SI was increased when dermatologists performed the DEB as opposed to general surgeons (p = 0.035). The anatomic location of the lesion predicted the SI, with lesions of the head/neck undergoing definitive excision 48 ± 32.3 days after DEB vs. 37.5 ± 22.6 days for all other sites (p = 0.001). Neither demographic factors nor histopathological prognostic features affected the SI. Reasons for a prolonged SI included referrals to different services and time for pre-operative planning. CONCLUSIONS: Significant variations were noted in the SI predominantly accounted for by mode of referral and location of the malignant melanoma. Further investigation is required to elucidate factors affecting the SI and its subsequent effect on patient outcomes.

Postmastectomy radiotherapy: indications and implications.

BACKGROUND: Although breast conservation surgery, when combined with radiotherapy, has been shown to provide excellent locoregional control for breast cancer, approximately one third of women with breast cancer require mastectomy. Many of these women are offered immediate reconstruction. Postmastectomy radiotherapy (PMRT) is indicated in some cases, but is associated with side-effects, including its impact on the reconstructed breast. OBJECTIVE: To review the pertinent issues surrounding PMRT, including patient selection for radiotherapy and the effect of radiotherapy on reconstructive decisions. METHODS: A literature review was performed using the Medline database. CONCLUSIONS: PMRT is indicated in patients who are deemed to have a high risk of loco-regional recurrence. Although PMRT is strongly recommended for patients with four or more positive lymphnodes, other indications for PMRT remain controversial. Immediate reconstruction post mastectomy has been shown to have favorable outcomes. However, PMRT may increase the need for revision surgery post immediate reconstruction. There are few randomized trials looking at these key issues, and the evidence is largely derived from observational retrospective studies. Patients should be carefully counseled before a decision is made to proceed with immediate reconstruction, where there is a high chance that PMRT may be indicated.

Ultrasound predictors of malignancy in indeterminate thyroid nodules.

BACKGROUND: Asymptomatic thyroid nodules are an increasingly common clinical problem. Lesions greater than a centimetre require cytological assessment. Indeterminate lesions often need surgical excision to establish a definitive diagnosis and plan further management. If a definitive diagnosis could be accurately predicted pre-operatively, the most appropriate surgical procedure could be performed at the initial operation. AIM: The aim of this study was to identify whether specific thyroid ultrasound features could predict malignancy in indeterminate thyroid nodules. METHODS: A retrospective review of all patients undergoing surgery for an indeterminate thyroid lesion between 2006 and 2012 was performed. Demographic features, surgical intervention and final histological findings were determined. Pre-operative ultrasound findings and final histology were correlated and the ultrasonic markers predictive of malignancy were determined. RESULTS: A total of 40 patients were identified as having undergone surgical intervention for indeterminate thyroid nodules. The majority of patients were diagnosed with a follicular adenoma (n = 22; 55 %). Papillary thyroid carcinoma was identified in three patients (7.5 %) and follicular carcinoma in a further 3 (7.5 %). Ultrasound features associated with malignancy included poorly defined nodule borders and increased vascularity. The presence of malignancy was not related to nodule size, echogenicity or the presence of calcifications. CONCLUSIONS: The majority of indeterminate thyroid lesions are benign on final histological assessment. High nodule vascularity associated with ill-defined borders is associated with malignancy. Further research is warranted to identify predictors of malignancy in indeterminate nodules in order to avoid unnecessary or repeated procedures.

mTOR in breast cancer: differential expression in triple-negative and non-triple-negative tumors.

Triple-negative breast cancer (TNBC) is defined by the absence of estrogen receptors (ER), progesterone receptors (PR) and overexpression of HER2. Targeted therapy is currently unavailable for this subgroup of breast cancer patients. mTOR controls cancer cell growth, survival and invasion and is thus a potential target for the treatment of patients with TNBC. Using immunohistochemistry, mTOR and p-mTOR were measured in 89 TNBCs and 99 non-TNBCs. While mTOR expression was confined to tumor cell cytoplasm, p-mTOR staining was located in the nucleus, perinuclear area and in the cytoplasm. Potentially important, was our finding that nuclear p-mTOR was found more frequently in triple-negative than non triple-negative cancers (p < 0.001). These results suggest that mTOR may play a more important role in the progression of TNBC compared to non-TNBC. Based on these findings, we conclude that mTOR may be a new target for the treatment of triple-negative breast cancer.

Focal thyroid incidentalomas identified with whole-body FDG-PET warrant further investigation.

Fluorodeoxyglucose (FDG) whole body positron emission computed tomography (PET-CT) detects clinically occult malignancy. The aim of this study was to assess the prevalence and significance of focal thyroid 18F - fluorodeoxyglucose uptake. A retrospective review of all patients who had FDG PET-CT examinations, in a single tertiary referral centre was performed. PET scan findings and the final pathological diagnosis were collated. 2105 scans were reviewed. Focal uptake was identified in 35 (1.66%) patients. Final surgical histology was available on eight patients, which confirmed papillary carcinoma in four (20%) patients and lymphoma and metastatic disease in two patients respectively. This gave an overall malignancy rate in focal thyroid uptake of at least 33%. Thyroid incidentalomas occurred with a frequency of 2.13%, with an associated malignancy rate of at least 33% in focal thyroid uptake. The high malignancy rate associated with focal thyroid uptake mandates further investigation in medically fit patients.

Src: a potential target for the treatment of triple-negative breast cancer.

BACKGROUND: Triple-negative breast cancers lack expression of estrogen and progesterone receptors and overexpression of human epidermal growth factor receptor 2 (HER2). Unlike other subgroups of patients with breast cancer, targeted therapy is currently unavailable for these patients. The aim of this study was to investigate v-src sarcoma viral oncogene homolog (Src) as a potential target for the treatment of triple-negative breast cancer. METHODS: Expression of Src was measured in 87 triple-negative and 93 non-triple-negative breast cancers. Dasatinib (an inhibitor of Src) was tested in a panel of breast cancer cell lines. RESULTS: Cytoplasmic expression of Src was detected in 83 (95%) triple-negative samples versus 78 (84%) non-triple-negative samples (P = 0.012), while membrane Src was detected in 78% triple-negative compared with 38% of non-triple-negative specimens (P < 0.0001). Dasatinib inhibited growth in three of five triple-negative cell lines (IC(50) < 1 µM). Dasatinib combined with cisplatin was synergistic in the three dasatinib-sensitive cell lines (combination index < 0.9). Dasatinib, in combination with 5'-deoxy-5'-fluoruridine, displayed synergy or additivity. Moderate synergy was observed with docetaxel (Taxotere) in two cell lines but the combination was antagonistic in HCC-1143 cells. CONCLUSIONS: We conclude that dasatinib with cisplatin is a rational drug combination for testing in triple-negative breast cancer.