Unilateral axillary adenopathy following COVID-19 vaccination: a multimodality pictorial illustration and review of current guidelines

We present a multimodality pictorial review of axillary lymphadenopathy in patients recently vaccinated against COVID-19. As the mass vaccination programme continues to be rolled out worldwide in an effort to combat the pandemic, it is important that radiologists consider recent COVID-19 vaccination in the differential diagnosis of unilateral axillary lymphadenopathy and are aware of typical appearances across all imaging methods. We review current guidelines on the management of unilateral axillary lymphadenopathy in the context of recent COVID-19 vaccination.

Abstract P6-05-04: mRNA expression of PTK6V1 and PTKV2 in human breast cancer

BACKGROUND:

Protein tyrosine kinase 6 (PTK6) is an intracellular protein that is upregulated in several human cancers and its localization to the plasma-membrane facilitates its various oncogenic roles in breast cancer cell proliferation, survival, and migration. The full length protein (PTK6V1) and alternative splice variant (PTK6V2) seem to play different roles with the latter being negative regulator of the former.

In this study, the level of mRNA expression of PTK6V1 and PTK6V2 were assessed in normal and malignant breast tissue using real time Q-PCR in a cohort of women with breast cancer and correlated to conventional clinico-pathological parameters and clinical outcome.

MATERIALS AND METHODS:

Breast cancer tissues (n = 127) and normal background tissues (n = 33) were collected immediately after excision during surgery. Following RNA extraction, reverse transcription was carried out and transcript levels were determined using real-time quantitative PCR and normalized against beta-actin expression. Transcript levels within the breast cancer specimens were compared to the normal background tissues and analysed against TNM stage, nodal involvement, tumour grade and clinical outcome over a 10 year follow-up period.

RESULTS:

The median copy number of transcripts of PTK6V1 were higher in malignant compared with normal breast tissue (23 vs.7) and overall increased with advancing tumour stage (374 vs. 13 for TNM3 vs. TNM1 respectively p=0.019 and 374 vs.23 for TNM3 vs. TNM2 p=0.0244). however these associations did reach statistical significance. PTK6V1 levels were associated with oestrogen receptor (ER) positivity (p = 0.061). The transcript levels were significantly higher in patients who developed recurrence (p=0.03) or died of breast cancer (p=0.003). PTK6V2 transcript levels were generally higher in normal breast tissue than in malignant tissues and decreased with increasing tumour stage and grade however these associations did not reach stastical significance. After a median follow up of 10 years, there was a trend for higher PTK6V2 expression to be associated with longer overall survival (OS) and disease free survival (DFS). PTK6V2/PTK6V1 ratio was a significant predictor of OS.

Conclusions

Our observations suggest that the two variants of PTK6 play opposing roles in mammary oncogenesis. These findings could have prognostic and therapeutic implications.

Citation Format: El Hage Chehade H, Harvey A, Wazir U, Jiang WG, Mokbel K. mRNA expression of PTK6V1 and PTKV2 in human breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-05-04.

Abstract P4-13-13: The correlation between mastectomy specimen weight and volume- a guide to the choice of implant size in breast reconstruction

Introduction: The concept of “conservative” mastectomy with breast reconstruction has led to a huge positive impact on the quality of life of breast cancer survivors. In 2015, 106,338 breast reconstructions were performed with implant-based reconstruction (IBR) constituting 86,013 (80.9%) of those procedures. Technically speaking, there is still no consensus on the most accurate method of assessing the size of implant used to achieve the desirable aesthetic results and symmetry. Some surgeons use the volume of the mastectomy specimen, believing that the volume of the implant replacing the volume of breast tissue removed is a logical way of thinking. Others prefer to depend on the weight of the specimen owing to the presumption that a mixture of fat and fibroglandular tissue will give an approximate overall density of 1.0g/cm3. To the authors' knowledge, the correlation between the mastectomy specimen volume and weight has been scarcely reported in the literature.

Materials and Methods: Patients undergoing nipple or skin-sparing mastectomy with immediate IBR at the London Breast Institute between January 2014 and December 2016 were included in this study. They were under the care of two senior Oncoplastic breast surgeons. Data on breast weight and volume as well as the size of implants used were prospectively collected. The volume of the breast tissue was assessed by volume displacement method while the weight was measured on a scale in grams. The exclusion criteria included patients with mastectomy specimen weighing more than 2000 grams. Further subgroups were divided into patients younger and those older than 50 years old. The presence or absence of cancer was also reviewed to assess whether the tumor tissue would have heavier weight when compared with volume.

Results: Between January 2014 and December 2016, a total of 236 mastectomies were performed, of which 144 were accompanied with IBR. The mean age of the patients was 45 years (range= 25-74). There were 79 right and 65 left breast specimens. Among these cases, 36 were bilateral. Tissue volume and weight had a strong direct correlation (N=144, R=0.99, P<0.00). Mastectomy volume had a marginally stronger correlation with implant volume/size (N=144, R=0.82, P=<0.00) than weight (N=144, R=0.79, P=<0.00). Further subgroup analysis showed that neither the presence of cancer nor the variation in breast density with age or menopausal status seemed to affect the correlation between the weight and volume of the breast tissue. 75% of reconstructions had implant size within 100 mls or grams of the mastectomy specimen.

Conclusions: Our study has shown that mastectomy specimen weight and volume have close enough correlation. The volume measurement was best estimated to the nearest 25 to 50 mls. On the other hand, the weight assessment was more accurate, objective, easier, and more reproducible with minimal inter-observer error. Hence, we believe that the breast weight can be reliably used to estimate the size of the implant. However, there are many other factors that should be taken into consideration when choosing an implant. For instance, the woman's wish for smaller or larger size, the width and height of the breast base, and the availability of a wide range of implants.

Citation Format: Wazir U, El Hage Chehade H, Choy C, Kasem A, Mokbel K. The correlation between mastectomy specimen weight and volume- a guide to the choice of implant size in breast reconstruction [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-13-13.

Abstract P1-07-27: Prognostic value of programmed death 1/Programmed death ligand 1/ mammalian target of rapamycin/Rictor/Tuberin in human breast cancer

Background:The Mammalian Target of Rapamycin (mTOR) regulates a multitude of cellular processes including metabolism, proliferation and growth. It is known to form two multi-protein complexes - complex 1 (mTORC1) and complex 2 (mTORC2) with Raptor and Rictor being their core proteins vital for their integrity.

Tuberin, the product of the Tuberous Sclerosis Complex gene 2, TSC2, has been characterized as a tumour suppressor and negatively regulates the mTOR pathway.

Programmed Death 1 (PD-1), a transmembrane protein particularly expressed on the surface of tumour cells, acts as an immune checkpoint receptor. Together with its ligand Programmed Death Ligand 1 (PDL-1) they form a pathway which when activated influences anti-tumour immunity and supresses anti-tumour adaptive responses. The expression of PD1/PDL-1 is lightly regulated by the mTOR pathway.

We investigated the value of expression patterns of all these molecules in breast cancer as potential prognostic factors.

Materials and Methods: Quantitative PCR (qPCR) analysis was used to determine the transcript expression profile of the five genes of interest (PD-1, PDL-1, mTOR, Rictor and Tuberin) in 128 breast cancer specimens.The correlation between PD-1 or PDL-1 with mTOR, Rictor and Tuberin was assessed using the Spearman Rank Order Correlation. Subsequently, a combined analysis was performed, where the influence of favourable expression in relation to patient overall (OS) and disease free survival (DFS) using the Kaplan Meier survival curves and multivariate analysis.

Results: The mRNA expression of the molecules showed a varying degree of association with the clinicopathological parameters. PD-1 transcript expression showed a significant correlation with mTOR expression (p < 0.001). PDL-1 transcript expression was seen to correlate with mTOR (p < 0.001), Rictor (p < 0.001) and Tuberin (p < 0.01) transcript expression. However, when the expression profile was analysed using an integrated expression score, the combined predictive value for the clinical outcome of the five genes was highly significant in terms of OS (p < 0.001) and DFS (p = 0.001), and was found to be an independent prognostic factor (p<0.001) for breast cancer related death using a multivariate analysis.

Conclusions: Our study identifies a molecular signature of 5 genes as a powerful prognostic predictor of OS and DFS in patients with breast cancer.

Citation Format: Uhercik M, Sanders AJ, Owen S, Davies EL, Sharma AK, Jiang WG, Mokbel K. Prognostic value of programmed death 1/Programmed death ligand 1/ mammalian target of rapamycin/Rictor/Tuberin in human breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-07-27.

Abstract P3-17-08: The role of sentinel lymph node biopsy in patients with ductal carcinoma in situ. An updated meta-analysis involving 9803 patients

Background: Ductal carcinoma in situ (DCIS) is the predominant pre-invasive neoplasia of the breast. It was observed that omission of axillary dissection in those with pure DCIS had no adverse effect on survival or recurrence. Therefore, axillary dissection typically does not feature in the management of DCIS. However, it has recently been purported that in some cases of DCIS, the axillary lymph nodes may show evidence of invasive disease. Consequently, there may be a role for sentinel lymph node biopsy (SLNB) in patients with DCIS with a high risk of invasion.

Materials and Methods: Systematic literature review identified 48 studies (9803 DCIS patients who underwent SLNB). Separate analyses for patients diagnosed preoperatively by core sampling and patients diagnosed postoperatively by specimen pathology were conducted to determine the percentage of patients with axillary nodal involvement. Patient factors were analysed for associations with risk of nodal involvement.

Results: The mean percentage of positive SLNBs was higher in the pre-operative group (5.95% vs. 3.02%; p=0.0201). Meta-regression analysis showed a direct association with tumour size (p=0.0333) and grade(p=0.00839), but not median age nor tumour upstage rate.

Conclusions: SLNB should be considered in patients with a pre-operative diagnosis of extensive and/or high-grade DCIS after a careful multidisciplinary discussion in order to identify those patients who have unrecognised axillary spread.

Citation Format: Chehade HEH, Headon H, Wazir U, El Tokhy O, Kasem A, Mokbel K. The role of sentinel lymph node biopsy in patients with ductal carcinoma in situ. An updated meta-analysis involving 9803 patients [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-17-08.

Abstract P3-14-03: Does fat transfer increase the risk of breast cancer recurrence? A meta-analysis involving 2382 patients

Introduction: Lipofilling is an increasingly popular technique for breast reconstruction following both mastectomy and breast conserving surgery. However, concerns remain over its oncological safety and its effect on cancer recurrence.

Methods: A systematic literature review and meta-analysis was carried out. Patients who had undergone mastectomy and patients who had undergone breast conserving surgery (BCS) were looked at separately in order to investigate whether the addition of lipofilling had a significant effect on locoregional recurrence rate.

Results: Eleven studies were used in the analysis yielding a total of 2382 patients. For patients undergoing mastectomy (mean follow up = 36.2 months: range=12-90) or BCS (mean follow up = 30.2 months: range = 12-60) , the addition of lipofilling was not found to significantly affect the locoregional recurrence rate.

Conclusion: This meta-nalysis demonstrates that lipofilling is an oncologically safe procedure to be incorporated into breast reconstruction following either mastectomy or BCS for breast cancer. However a careful oncological follow up is recommended. In the future, more adequately- powered controlled clinical trials are needed in order to fully understand long term outcomes after lipofilling.

Citation Format: Wazir U, Chehade HEH, Headon H, Oteifa M, Kasem A, Mokbel K. Does fat transfer increase the risk of breast cancer recurrence? A meta-analysis involving 2382 patients [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-14-03.

Abstract P2-01-29: In the era of conservative surgery, can patients presenting with node positive breast cancer be spared axillary node dissection post neoadjuvant chemotherapy? A meta-analysis and review of literature

Background:The use of sentinel lymph node biopsy (SLNB) following neoadjuvant chemotherapy (NAC) in patients presenting with clinically positive lymph nodes remains controversial.

Methods: A computer-aided search of the literature regarding SLNB in clinically node-positive breast cancer treated with NAC was carried out to identify the false negative rate (FNR), sentinel lymph node identification rate (IR), and axillary pathological complete response (pCR).

Results: Nineteen articles were used in the analysis yielding 3398 patients. The pooled estimate of the FNR was 13% and that of the IR was 91%. The adjusted pCR rate was 47%.

Conclusions: SLNB after NAC in biopsy-proven node positive patients results in reasonably acceptable FNR and IR making it a valid alternative management strategy to axillary dissection. Although the results are not matched with those in clinically node negative patients, a FNR of 13% is very unlikely to adversely affect overall survival. Its impact on locoregional recurrence should be evaluated in adequately powered future studies. More refined patient selection and optimal techniques can improve the FNR and IR in this patient population.

Citation Format: Headon H, Chehade HEH, El Tokhy O, Wazir U, Heeney J, Kasem A, Mokbel K. In the era of conservative surgery, can patients presenting with node positive breast cancer be spared axillary node dissection post neoadjuvant chemotherapy? A meta-analysis and review of literature [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-01-29.

Abstract P2-13-08: Breast lipofilling: A systematic review of current practice and oncological safety

Background: Lipofilling is a reconstructive and aesthetic technique that has recently grown in popularity and is increasingly being used in breast surgery. Concerns had been raised regarding its safety when used for remodelling and reconstruction of the breast.

Methods: We reviewed the current literature by systematically searching PubMed and Google Scholar databases regarding the current evidence regarding the oncological safety of the procedure in patients seeking aesthetic breast enhancement and in patients requiring oncoplastic reconstruction.

Results: Among the 864 patients included in the currently available studies on breast cancer patients who underwent lipofilling, only 14 (1.6%) recurrences were identified. However, evidence has emerged suggestive that the use of lipofilling in the background of ductal carcinoma in situ (DCIS) may be associated with an increased risk of neoplasia.

Conclusions: Over the subsequent two decades, little evidence has been found to support these early theoretical concerns, and growing numbers of proponents of the procedure are confident in its safety. Further study is required to better delineate the effect of lipofilling on DCIS.

Citation Format: Wazir U, Kasem A, Headon H, Mokbel K. Breast lipofilling: A systematic review of current practice and oncological safety. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-13-08.

Abstract P2-12-11: Does postmastectomy radiotherapy improve survival in patients with 1-3 positive axillary lymph nodes? A systematic review and meta-analysis of the current literature

In breast cancer with more than four positive axillary lymph nodes, it is common practice to deliver radiotherapy to the affected site following a mastectomy. However, less is known about the benefit s this might offer in women with 1-3 positive lymph nodes. In order to assess whether postmastectomy radiotherapy has any benefit in these women, a meta-analysis was performed to assess whether postmastectomy radiotherapy improved overall survival or reduced locoregional recurrence in this group of women. It was found that postmastectomy radiotherapy significantly reduced the risk of locoregional recurrence, with a relative risk ratio of 0.3 (95% confidence interval 0.23-0.38), and resulted in a small benefit in overall survival, with a relative risk ratio of 1.03 (95% confidence interval 1.00-1.07). Therefore, in women with 1-3 positive lymph nodes, postmastectomy radiotherapy reduces the risk of locoregional recurrence and is associated with a small benefit in overall survival, so should be recommended within this group after careful multidisciplinary discussion.

Citation Format: Kasem A, Headon H, Mokbel K. Does postmastectomy radiotherapy improve survival in patients with 1-3 positive axillary lymph nodes? A systematic review and meta-analysis of the current literature. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-12-11.

Abstract P2-13-04: Clinical outcome and patient satisfaction with the use of bovine-derived acellular dermal matrix (SurgiMendTM) in implant-based immediate reconstruction following skin sparing mastectomy: A prospective observational study

The advent of acellular dermal matrix devices (ADMs) has facilitated immediate breast reconstruction (IBR) with mammary implants following skin sparing mastectomy (SSM) for breast cancer treatment or risk reduction.

This is a prospective observational single institution study of 118 consecutive patients undergoing a total of 164 SSM and IBR procedures using an implant and bovine-derived ADM (SurgiMend) for breast cancer or risk reduction purposes during 2012-2014. The primary endpoint was the explantation rate and secondary endpoints included patient quality of life, patient satisfaction, objective assessment of aesthetic outcome, surgical complications, recurrence and mortality.

The mean age of the patients was 50.1 years (median age of 48, range of 27-78). Median follow up time was 21 months (mean of 21.4 months, range of 2-40 months). 46 patients had a bilateral SSM and IBR, 5 of whom had bilateral breast cancer and 3 for risk reduction due to a significant genetic mutation. The remaining 37 patients had unilateral breast cancer and a contralateral risk reducing mastectomy. 27 (37.5%) of the 72 patients who had unilateral SSM underwent contralateral adjustment procedures to optimise symmetry, including 9 augmentation mammoplasty, 12 mastopexy and 4 reduction mammaplasty procedures and 2 combined augmentation-mastopexies. 61 patients (51.7%) received chemotherapy, 5 of whom had primary systemic therapy prior to surgery. 32 (27.1%) patients received radiotherapy (10 patients had prior radiotherapy and 22 patients had post mastectomy radiation: PMR). Those with ER positive disease received hormonal therapy. Those with Her2 positivity received Herceptin +/- Pertuzumab.

Over the study period, 2 implants had to be removed resulting in an explantation rate of 1.2%. Overall, wound complications were observed in 6 (3.7%) cases. There were 2 cases of local recurrence (1.7%), one distant recurrence (0.8%) and one patient died of metastatic breast cancer (0.8%). Overall survival was 99.2% and locoregional disease free survival (LRFS) was 98.3%. One patient (0.8%) developed a mild inflammatory reaction secondary to the underlying mesh. Wound complications were observed in 3 other patients (2 haematomas and wound dehiscence/persistent seroma requiring implant replacement).

Patient satisfaction with the procedure was very high. The mean Breast Q Score was 85 and mean overall patient satisfaction was 9 out of a possible 10. The mean objective assessment score was 8.9 out of a possible 10 and the mean subjective capsular contracture severity score was 2.9 out of 10.

In patients undergoing reoperations, the incorporation rate of the mesh was found to be very high almost approaching 95%.

SurgiMendTM is an effective adjunct to IBR using implants following SSM for breast cancer or risk reduction, with a very low rate of implant loss and a high level of patient satisfaction. Furthermore, this ADM seems to incorporate readily and is associated with a very low incidence of inflammatory reactions. Neither prior radiotherapy nor PMR radiation represents a contraindication to its use.

Citation Format: Wazir U, Kasem A, Headon H, Choy C, Manson A, Heeney J, Mead O, Mokbel K. Clinical outcome and patient satisfaction with the use of bovine-derived acellular dermal matrix (SurgiMendTM) in implant-based immediate reconstruction following skin sparing mastectomy: A prospective observational study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-13-04.

Abstract P6-02-02: mRNA expression of death associated protein 3 (DAP3) and human breast cancer: Clinical correlations and in vitro evidence

BACKGROUND: To our knowledge, this study is the first to focus on the potential role for death-associated protein 3 (DAP3) in human breast cancer.

MATERIAL AND METHODS: mRNA expression of DAP3 in breast cancer tissues (n = 127) and normal background tissues (n = 33) were determined using quantitative polymerase chain reaction (qPCR) and were correlated with clinico-pathological data accumulated over a 10-year follow-up period.

Furthermore the effects of DAP3 knock down in breast cancer cell lines (MCF-7 and MDA-MB-231) were investigated. The cells were subjected to conventional growth, adhesion and invasion assays.

In addition to the above, electric cell-substrate impedance sensing (ECIS) assay and annexin V/propidium iodide binding apoptosis assay were performed. For the apoptosis assay, the cells were subjected to 48 to 72 hours of serum hunger (depending on cell line) before being analyzed using a flow cytometer.

RESULTS: The expression of DAP3 mRNA was demonstrated to decrease with increasing Nottingham Prognostic Index (NPI2 vs. NPI3, p = 0.036), TNM stage (TNM1 vs. 3, p = 0.07), and tumour grade (grade 1 vs. 3, p = 0.08). Lower DAP3 expression levels were significantly associated with local recurrence (p = 0.013), distant metastasis (p = 0.0057) and mortality (p = 0.019).

Kaplan-Meier plot analysis suggests that patient with higher levels of DAP3 expression had better overall survival compared to patients with lower levels of DAP3 expression (p = 0.075).

DAP3 knock down strains in both cell lines demonstrated increased growth and migration compared to controls during ECIS.

In addition, DAP3 knock down strains of MCF-7 appeared more resistant to serum hunger when compared to controls during the apoptosis assay.

CONCLUSIONS: This study demonstrates an inverse association between DAP3 mRNA levels and tumour stage and clinical stage in breast cancer. This is in keeping with the role of DAP3 as a pro-apoptotic protein. The in vitro evidence lends further credence to this hypothesis. The role of DAP3 may require further investigation to better understand the role of apoptosis in breast carcinogenesis, and may potentially serve as a prognostic marker for human breast cancer.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-02-02.

Abstract P6-04-14: mRNA expressions of lamin B1 and lamin B receptor: Clinical correlations with human breast cancer

BACKGROUND: Lamin B (LMNB) and lamin B receptor (LBR) are key components of the nuclear envelope, with roles in chromosomal stability, DNA repair, and cell differentiation. Lamins provide structural support to the nuclear envelope, while LBR is believed to anchor lamin B to the envelope. In addition, LBR also has a number of downstream mediators which affect cell cycle and cell differentiation.

Classically, they have been implicated in a spectrum of largely congenital ailments including certain forms of muscle dystrophy and progeria. These conditions are collectively referred to as “laminopathies”.

More recently, defects in the expression of lamins have been implicated in neoplasias of the colon, prostate, liver and ovaries.

In this study, we have endeavoured to elucidate the relationships between the mRNA expressions of LMNB1 and LBR and the clinicopathological parameters of human breast cancer.

METHODS: Breast cancer tissues (n = 115) and associated non-cancerous tissue (ANCT) (n = 30) underwent reverse transcription and quantitative PCR. Transcript levels were correlated with clinicopathological data.

RESULTS: LMNB1 mRNA expression was higher in ANCT as compared to cancerous tissue (ANCT vs. cancerous tissue: 0.12 vs. 0.00; p = <0.0001). This difference remained highly significant in all patient categories by tumour grade and clinical stage.

In addition, the expression of LMNB1 declined with worsening clinical outcome. This association was statistically significant when comparing patient with disease-free survival with disease related mortalities (Disease-free vs. mortalities: 0.0011 vs. 0.000; p = 0.0177).

LBR mRNA expression was found to be directly associated with tumour grade (grade 1 vs.3: 0.00 vs. 0.00; p = 0.0479) and the Nottingham Prognostic Index (NPI1 vs. 3: 0.00 vs. 0.00; p = 0.0551).

CONCLUSIONS: To our knowledge, this is the first study to suggest such a role for LMNB1 and LBR in human breast cancer.

The contrasting relationships of LMNB1 and LBR expressions with the clinicopathological parameters of human breast cancer may suggest that disruptions in the physiologically normal interactions between these molecules in the nuclear envelope may serve as pathway leading towards the pathogenesis of human breast cancer. Potentially this may be a significant pathway requiring further investigation to be better understood, in order to identify further potential areas for therapeutic intervention.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-04-14.

Observations on the effects of Suppressor of Cytokine Signaling 7 (SOCS7) knockdown in breast cancer cells: their in vitro response to Insulin Like Growth Factor I (IGF-I)

PURPOSE

Suppressor of cytokine signaling 7 (SOCS7) is a member of the SOCS family and is known to interact with phospholipase Cγ-1 (PLCγ-1), one of the insulin-like growth factor-I (IGF-I) receptor downstream molecules. In this study, we sought to observe the effect of knocking down SOCS7 gene on breast cancer cells in vitro growth and migration and to elucidate whether this involves IGF-I-PLCγ1 route using the PLCγ-1 blocker U73122.

METHODS

Suitable breast cancer cells (MCF7 and MDA-MB-231) were transfected with anti-SOCS7 ribozymal transgene, to create sub-lines with SOCS7 knockdown verified by RT-PCR. The growth and migration of the cells were evaluated in the presence or absence of IGF-I and PLCγ-1 inhibitor using growth assay, scratch-wound and electrical cell impedance sensing (ECIS) migration assays.

RESULTS

IGF-I treatment produced more pronounced influence on MCF7 growth and migration and on MDA-MB-231 migration when SOCS7 gene was knocked down in both lines (p < 0.05). The absence of IGF-I-induced growth response in MDA-MB-231 could be due to the intrinsic characteristics of these cells. PLCγ-1 pharmacological inhibition during their in vitro migration seemed to only occur when SOCS7 gene was knocked down.

CONCLUSIONS

To the best of our knowledge, this is the first report of the SOCS7 regulatory role in IGF-I induced in vitro functions in ER-positive and ER-negative breast cancer cells. IGF-I treatment and SOCS7 loss have synergistically resulted in increased growth and migration of MCF7 and in increased migration of MDA-MB-231 cells. The migratory effects could be due to a precise anti-PLCγ-1 role.

Prognostic and therapeutic implications of mTORC1 and Rictor expression in human breast cancer

The mammalian target of rapamycin (mTOR) plays a key role in the regulation of cellular metabolism, growth and proliferation. It forms two multi-protein complexes known as complex 1 (mTORC1) and 2 (mTORC2). Raptor and Rictor are the core proteins for mTORC1 and mTORC2, respectively. This study examines the relationship between mTORC1, Rictor and Raptor mRNA expression and human breast cancer. Furthermore, the correlation between mTORC1 and hTERT was investigated. Breast cancer tissues (n=150) and normal tissues (n=31) were analysed using reverse transcription and quantitative PCR. Transcript levels were correlated with clinicopathological data. Higher mTOR expression was noted in breast cancer tissue (P=0.0018), higher grade tumours (grade 2 vs. 3, P=0.047), in ductal tumours (P=0.0014), and was associated with worse overall survival (P=0.01). Rictor expression was significantly higher in background breast tissues compared with tumours and was inversely related to the Nottingham Prognostic Index (NPI1 vs. 2, P=0.03) and tumour grade (grade 1 vs. 3, P=0.01) and was associated with better overall (P=0.037) and disease-free survival (P=0.048). The mRNA expression of Raptor was higher in tumours compared with normal tissues. Furthermore, the expression of Raptor was associated with a higher tumour grade (grade 1 vs. 3, P=0.027). A highly significant positive correlation between mTOR and hTERT (P<0.00001) was observed. These observations are consistent with the role of mTORC1 in the anti-apoptosis pathway and suggest that selective inhibitors of mTORC1 may be more efficacious in human breast cancer. Our findings support the hypothesis that mTORC1 is an important upregulator of telomerase in breast cancer.

Abstract P1-04-07: The mRNA Expression of DAP1 in Human Breast Cancer: Correlation with Clinicopathological Parameters

BACKGROUND: This pilot study is the first to focus on the potential role for death-associated protein 1 (DAP1) in human breast cancer.

MATERIAL AND METHODS: mRNA expression of DAP1 in breast cancer tissues (n = 127) and normal background tissues (n = 33) were determined using quantitative polymerase chain reaction (qPCR) and correlated with clinicopathological data accumulated over a 10-year follow-up period. Furthermore the effects of DAP1 knockout in breast cancer cell lines were investigated.

RESULTS: The expression of DAP1 mRNA was demonstrated to decrease with increasing Nottingham Prognostic Index (NPI2 vs. NPI3, p = 0.0026), and TNM stage (TNM1 vs. 4, p = 0.0039). Lower DAP1 expression levels were significantly associated with local recurrence (p = 0.02) and distant metastasis (p = 0.001).

The knockout of the DAP1 gene in MCF-7 cell lines resulted in a significant decrease in the mRNA expression of P-21 and DELE compared with controls, p = 0.04). However, the knockout of DAP1 had no effect on the expression of caspase 8 and 9.

CONCLUSIONS: This study demonstrates an inverse association between DAP1 mRNA levels and tumour stage and clinical outcome in breast cancer. This may be suggestive of a relationship between oncogenesis and the autophagy pathway meriting further investigation. These results also indicate that the pro-apoptotic function seems to be estrogen-dependent but independent of caspase 8 and 9. The DAP1 pro-apoptotic pathway may involve P-21 and DELE proteins.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-04-07.

Abstract P1-04-08: Evidence for anti-apoptosis function of GNB1 in human breast cancer

INTRODUCTION: Guanine nucleotide binding protein beta polypeptide 1 (GNB1) integrates signals between receptors and effector proteins and regulates certain signal transduction receptors and effectors. We have hypothesised that GNB1 is involved in the anti-apoptosis pathway mediated by mTor. Therefore, this protein may play role in human carcinogenesis, however, there has been no investigations of this potential role published in the literature. The aim of the study was to investigate the mRNA expression of GNB1 in human breast cancer and examine the relationship between its expression and the tumour characteristics and disease outcome. Furthermore, the correlation between GNB1 and mTORC1 was also investigated.

METHODS: Specimens of breast cancer (BC) tissues (N = 136) and normal tissues (N = 30) underwent RNA extraction and reverse transcription. GNB1 transcript levels were determined using real-time quantitative PCR. Expression levels were analysed against clinicopathological data accrued over a 10 year follow-up period.

RESULTS: Significantly higher mRNA transcript levels were found in the breast cancer specimens compared to normal glandular tissue in paired samples (p = 0.0029). The expression of GNB1 mRNA was demonstrated to increase with increasing TNM stage (from 0.01 to 15.9) and this reached statistical significance when comparing TNM1 vs. TNM2/3/4 (p = 0.036). Furthermore, the expression levels increased with increasing tumour grade and this reached statistical significance when comparing grade 2 vs. grade 3 (p = 0.006). GNB1 expression was found to be higher in ductal tumours compared with non-ductal tumours (p = 0.0081). The patients who developed recurrent disease or died from breast cancer had higher expression levels than those who had been disease-free after a median follow-up period of 10 years (p = 0.017). Those who died from breast cancer had significantly higher levels than those who have remained disease-free (33.9 vs. 0.01, p = 0.0009). GNB1 showed a significantly positive correlation with mTORC1 mRNA levels (r = 0.57, p &lt; 0.000001).

CONCLUSION: GNB1 expression was found to be significantly higher in BC specimens compared to normal breast tissue. Higher transcript levels were significantly associated with unfavourable pathological parameters and adverse clinical outcomes. These observations in addition to the positive correlation with mTORC1 levels support the hypothesis that GNB1 is an important upstream component of the anti-apoptosis pathway and, therefore, can be a potential target for therapeutic intervention in human breast cancer.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-04-08.

Abstract P1-04-03: Knocking down Suppressor of Cytokine Signaling 7 in breast cancer: The role in Insulin-like Growth Factor - I/Phospholipase Cγ-1 signaling

BACKGROUND: Suppressor of Cytokine Signaling 7 (SOCS7) is a member of the SOCS family and is known to interact with Phospholipase Cγ-1 (PLCγ-1), one of the Insulin like Growth Factor - I (IGF-I) receptor downstream molecules. In the present study, we sought to examine the effect of knocking down SOCS7 gene on breast cancer cells growth and migration and to elucidate whether this has involved IGF-I — PLCγ-1 signaling using the PLCγ-1 blocker U73122.

METHODS: Suitable breast cancer cells (MCF7 and MDA-MB-231) were transfected with anti-SOCS7 ribozymal transgene, to create sublines with SOCS7 knockdown that was verified by RT-PCR. The growth and migration of the cells were evaluated in the presence or absence of IGF-I and PLCγ-1 inhibitor using in vitro growth assay and Electrical Cell Impedance Sensing (ECIS) migration assay.

RESULTS: MCF7ΔSOCS7 and MDA-MB-231ΔSOCS7 (SOCS7 knockdown) were constructed. Both sublines showed a higher rate of growth compared to control cells with and without IGF-I stimulation. U73122 treatment did not appear to change this growth outcome. Using ECIS migration assay, it was shown that knocking down SOCS7 had a significant positive effect on the migration of MCF7 and MDA-MB-231 cells, and that both IGF-I treatment and SOCS7 knockdown had a synergistic positive influence on their migration (p &lt; 0.05). We further demonstrated that the impact of U73122 on the IGF-I migratory effect was dependent upon SOCS7 knockdown as it has significantly blocked the stimulatory effect of IGF-I on MCF7ΔSOCS7 and MDA-MB-231ΔSOCS7 migration but not that of the control cells. While SOCS7 has acted to control the IGF-I effect, it appeared to cancel the inhibitory function of U73122, indicating a specific anti - PLCγ-1 role for SOCS7 in IGF-I induced breast cancer cellular migration.

CONCLUSION: SOCS7 loss resulted in increased growth and migration of breast cancer cells and this had a synergistic effect on their response to IGF-I. This role could be related to its interaction with PLCγ-1 during the cellular migration but not the growth. It may be possible that SOCS7 acts through different mechanism to control the cellular growth.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-04-03.

Abstract P6-05-11: Leptin and Leptin receptor expression in human breast cancer

INTRODUCTION: Leptin is a protein that plays a key role in regulating energy intake and energy expenditure, including appetite and metabolism. It is one of the most important adipose derived hormones and has been suggested to act as a growth factor in neoplasms. Obesity has been linked to increased risk of breast cancer in postmenopausal women. Increased peripheral production of oestrogen has been regarded as the main cause for this association, but other factors affecting fat metabolism may be implicated. There is recent evidence that Leptin stimulates cancer cell proliferation in MCF-7 cancer cells. Both Cox2 and hTERT have been proposed as mediators of Leptin's carcinogenic role.

Our objective was to determine, using quantitative PCR, whether the mRNA expression levels of Leptin and Leptin receptor were consistent with a tumour proliferative function and whether levels from these genes were positively correlated with clinical outcome in breast cancer.

METHODS: A total of 153 samples were analysed. The levels of transcription of Leptin and its receptor were determined using quantitative PCR and normalised against (CK19). Transcript levels within breast cancer specimens were compared to normal background tissues and analysed against conventional pathological parameters and clinical outcome over a 10 year follow-up period.

RESULTS: The levels of Leptin and Leptin receptor mRNA were significantly higher in malignant samples (p = 0.0011 and 0.0014 respectively). This difference remained statistically significant when comparing levels between normal samples and all malignant subgroups according to their NPI, grade, stage, local recurrence, and distant metastasis in both ER receptor positive and negative samples. It was also present across all histological types for both Leptin and its receptor.

There was no significant change in mRNA transcription levels correlating with tumour grade, stage, disease free survival, or development of loco regional recurrence.

There was also no statistically significant difference in levels of expression of both Leptin and its receptor when comparing ER positive to negative patients (p = 0.74 and 0.27 respectively).

Leptin levels showed a significantly positive correlation with Leptin receptors (r = 0.504, 0.0000000222). We have observed no significant correlations between Leptin and hTERT or Cox2.

CONCLUSION: This study demonstrates compelling evidence that both Leptin and Leptin receptor mRNA transcription levels are more readily expressed in cancerous tissues providing further evidence that it plays a significant role in the process of breast carcinogenesis. However, Leptin levels did nor correlate with tumor's stage, clinical outcome, hTERT or Cox-2 levels.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-05-11.

Abstract P1-04-09: mTORC1 and Rictor expression in human breast cancer: correlations with clinicopathological parameters and disease outcome

BACKGROUND: mTOR (the mammalian target of rapamycin) plays a key role in regulation of cellular metabolism, growth, and proliferation. It forms two multi-protein complexes known as complex 1 (mTORC1) and 2 (mTORC2). Raptor and Rictor are the core proteins for mTORC1 and mTORC2 respectively. There is a growing body of evidence that mTORC1 is up-regulated in many cancers and plays a role in carcinogenesis. The aim of the study was to investigate the mRNA expression of mTOR and Rictor in human breast cancer and examine the relationship between their expression and clinicopathological parameters.

METHODS: Specimens of breast cancer (BC) tissues (N = 150) and normal tissues (N = 31) underwent RNA extraction and reverse transcription. mTOR and Rictor transcript levels were determined using real-time quantitative PCR. Expression levels were analyzed against tumor size, grade, nodal involvement, TNM stage, and clinical outcome over a 10 year follow-up period.

RESULTS: Significantly higher mRNA transcript levels of mTOR were found in the breast cancer specimens compared to normal glandular tissue (p = 0.0018). The expression of mTOR mRNA was demonstrated to increase with increasing NPI (53 for NPI1 to 219 for NPI3) and tumor grade (37 for grade 2 vs. 159 for grade 3, p = 0.047). mTOR expression was found to be higher in ductal tumors compared with non-ductal tumors (p = 0.0014). The patients who developed recurrent disease or died from breast cancer had higher expression levels than those who had been disease-free after a median follow-up period of 10 years (p = 0.17). Higher expression levels were significantly associated with worse overall survival (p = 0.01).

In contrast, higher levels of Rictor mRNA expression were found in normal breast tissue, lower NPI stage (NPI1 vs. 2: p = 0.03) and lower tumor grade (grade 1 vs. grade 3: p = 0.01). Patients with higher Rictor expression had a significantly better overall (p = 0.037) and disease-free (p = 0.048) survival.

CONCLUSIONS: mTOR expression was found to be significantly higher in BC specimens compared to normal breast tissue. Higher transcript levels were significantly associated with unfavorable pathological parameters and adverse clinical outcomes. The core protein of the less predominant mTORC2 was associated with favorable pathological parameters and clinical outcome. Taken together these observations are consistent with mTORC1 role in the anti-apoptosis pathway and suggest that selective inhibitors of mTORC1 are likely to be a more effective therapeutic strategy than dual inhibitors in human breast cancer.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-04-09.

The mRNA expression of DAP1 in human breast cancer: correlation with clinicopathological parameters

This pilot study is the first to focus on the potential role of death-associated protein 1 (DAP1) in human breast cancer.

MATERIALS AND METHODS

A total of 153 samples were studied. DAP1 transcription levels were determined using quantitative polymerase chain reaction (qPCR). Transcript levels within breast cancer specimens were compared to those of normal background tissues and correlated with clinicopathological data accumulated over a 10-year follow-up period.

RESULTS

The expression of DAP1 mRNA was demonstrated to decrease with increasing Nottingham Prognostic Index (NPI2 vs. NPI3, p=0.0026), and TNM stage (TNM1 vs. 4, p=0.0039). Lower DAP1 expression levels were significantly associated with local recurrence (p=0.02) and distant metastasis (p=0.001).

CONCLUSION

This study demonstrates an inverse association between DAP1 mRNA levels and tumour stage and clinical outcome in breast cancer; thus, providing evidence that DAP1 plays a pro-apoptotic role in human breast cancer. The relationship between oncogenesis and the autophagy pathway merits further investigation.

The mRNA expression of DAP3 in human breast cancer: correlation with clinicopathological parameters

BACKGROUND

This pilot study is the first to focus on the potential role for death-associated protein 3 (DAP3) in human breast cancer.

MATERIALS AND METHODS

A total of 153 samples were studied. The levels of transcription of DAP3 were determined using quantitative polymerase chain reaction (qPCR). Transcript levels within breast cancer specimens were compared to those of normal background tissues and correlated with clinicopathological data accumulated by over a 10-year follow-up period.

RESULTS

The expression of DAP3 mRNA was demonstrated to decrease with increasing Nottingham Prognostic Index (NPI2 vs. 3, p=0.036), TNM stage (TNM1 vs. 3, p=0.07), and tumour grade (grade 1 vs. 3, p=0.08). Lower DAP3 expression levels were significantly associated with local recurrence (p=0.013), distant metastasis (p=0.0057) and mortality (p=0.019).

CONCLUSION

This study demonstrates an inverse association between DAP3 mRNA levels and tumour stage and clinical outcome in breast cancer, consistent with the pro-apoptosis function of DAP3. Further research is required in order to confirm our findings and clarify the mechanisms that regulate DAP3 expression in human breast cancer.

Does post-mastectomy radiotherapy represent a contraindication to skin-sparing mastectomy and immediate reconstruction: an update

The use of skin-sparing mastectomy (SSM) to facilitate breast reconstruction is increasing due to a wide acceptance of improved cosmetic outcomes and evidence of equivalence in oncologic outcomes. The rates of patients undergoing mastectomy for whom post-mastectomy radiotherapy (PMRT) will be recommended is increasing as evidence of decreased loco-regional recurrence and increased survival mounts. PMRT may adversely effect complication rates and cosmetic outcomes for patients undergoing immediate breast reconstruction and PMRT--although the evidence for this is methodologically flawed. This article summarises the above evidence and highlights a reconstructive algorithm that may be used to mitigate the possible deleterious effects of PMRT on results.

P2-11-02: Brain-Derived Neurotrophic Factor Expression Is Associated with Poor Prognosis in Human Breast Cancer

Background: Brain-derived neurotrophic factor (BDNF) belongs to the neurotrophin superfamily of polypeptide growth factors whose physiological roles primarily relate to the development and function of the vertebrate nervous system. However, BDNF is also expressed in non-neuronal tissues and has been implicated in breast cancer, in addition to several other human malignancies, including: neuroblastoma, myeloma, ***ovarian, lung, prostate, hepato-cellular, pancreatic, head and neck squamous cell carcinomas and pulmonary carcinoid tumours. Although increased neurotrophin and cognate receptor expression have been demonstrated in breast cancer, the emerging role of BDNF in tumour biology and its utility as a novel biomarker have yet to be fully elucidated. In this study, the mRNA and protein expression of BDNF are evaluated in women with primary operable breast cancer in a well annotated cohort with extended follow-up.

Methods: Breast cancer tissues (n=127) and normal/benign tissues (n=33) underwent RNA extraction and reverse transcription. Transcript levels of BDNF were determined using real-time quantitative PCR and protein expression was assessed using standardised semi-quantitative immuno-histochemical techniques. Expression levels in neoplastic tissues were compared with adjacent normal/benign samples and evaluated against conventional pathological parameters, including: tumour size, grade, nodal involvement, TNM stage, in addition to Nottingham Prognostic Index (NPI), disease free and overall survival over a 10 year follow-up period.

Results: BDNF was found to be expressed in both normal breast tissue and breast cancer specimens. Significantly greater BDNF expression was identified in neoplastic cells, compared to normal mammary epithelial cells, by immuno-histochemical analysis. In keeping with this, higher mRNA transcript levels of BDNF were also found in breast cancers compared to normal samples (p=0.007). Increased BDNF transcript levels were found to be significantly associated with nodal positivity (p=0.047) and increased with NPI; NPI-1 vs. NPI-2 (p=0.009). Higher BDNF expression was significantly associated with local recurrence (p=0.0014), death from breast cancer (p=0.018) and poor prognosis overall (p=0.013), when compared to patients who remained disease free. Higher transcript levels were significantly associated with poorer overall survival (106 vs. 136 months, p=0.006) after a median follow up of 10 years.

Conclusion: Neurotrophins and their receptors are increasingly being implicated as novel mediators of carcinogenesis in neuronal and non-neuronal tissues. BDNF is overexpressed in breast cancer and significantly associated with adverse pathological parameters, including nodal positivity and increasing NPI. Higher BDNF expression was significantly associated with poorer clinical outcomes, including local recurrence, death, poor prognosis and reduced overall survival. The present study adds to the literature in support of the oncogenic function of BDNF in breast cancer and is the first to quantitatively evaluate expression in a large cohort. BDNF expression may offer prognostic utility as a biomarker and further mechanistic studies are warranted to explore the potential for targeted therapeutic manipulation.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-11-02.

P1-05-05: Prognostic Utility of Histone Modifier Gene Expression Profiles in Human Breast Cancer

Background: Gene expression is stringently controlled under physiological conditions by epigenetic mechanisms, including the specific methylation of cytosine residues within CpG dinucleotides and orchestrated adjustments in the histone dependent organisation of chromatin. The organisation of DNA within the chromatin template depends upon highly conserved histone proteins, the properties of which continue to exceed the simplistic packaging role originally assigned to them. Histone modifier enzymes impart a dynamic histone code and specific permutations have significant implications for chromatin topology and the functional configuration of promoters. This study follows our initial report describing potential tumour suppressor function associated with the histone methyltransferase SETD2 in human breast cancer. The objective was to evaluate the expression profiles of sixteen additional histone modifier genes in women with primary operable breast cancer within a well annotated cohort with extended follow-up.

Methods: Primary breast cancer tissues (n= 127) and adjacent benign/normal tissues (n=33) underwent RNA extraction and reverse transcription. The transcript levels of histone modifier genes were evaluated using real-time quantitative PCR, these included: histone acetyltransferases (CREBBP), Class 1 (HDAC1 and HDAC2), II (HDAC5) and III (SIRT1) histone deacetylases and histone methyltransferases (SUV39H1 and SUV39H2) amongst others. Transcript levels were analysed against a range of clinico-pathological variables, including: tumour size, grade, nodal involvement, histological subtype, receptor status, TNM stage, Nottingham Prognostic Index, disease free and overall survival over a 10 year follow-up period.

Results: Transcript levels of the histone modifier genes in breast cancer tissues differed significantly from non-malignant samples (HDAC5, HDAC1, KDM4A and KDM6A). Amongst breast cancers, significant differences in transcript levels were associated with established pathological parameters and prognostic indices: tumour grade (KAT5, HDAC1, KDM4A, SUV39H1 and KDM6A), receptor status (KAT5, SMYD3 and KDM1A), histological type (KAT5, KDM5C, MYST1, KDM4A and MLL), TNM stage (SUV39H1, KAT2B, KDM1A, KDM4A, KDM5C, MYST1, HDAC5 and KAT5), Nottingham Prognostic Index (KDM5C, MLL, MYST1 and SMYD3), disease free survival (SUV39H1, SMYD3, HDAC5, KDM6A, HDAC1, KDM1A, KDM4A, MYST1, KDM5C, KAT5 and MLL) and overall survival (MYST1). Interestingly, significant correlations were also identified between the differential expression profiles of particular histone modifying genes.

Conclusion: The expression profiles of histone modifier genes differ significantly between breast cancer tissues and normal/benign samples. Particular expression profiles in breast cancer are significantly associated with established pathological parameters, prognostic indices, disease free and overall survival. The biological significance and clinical relevance of altered expression of specific histone modifier genes and particular permutations of misexpression remain to be fully elucidated and further study is warranted. Epigenetic signatures derived from histone modifier genes may offer utility as biomarkers and histone modifier enzymes have potential for targeted therapeutic strategies.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-05-05.

Evidence for a tumour suppressor function of SETD2 in human breast cancer: a new hypothesis

BACKGROUND

SET domain containing protein 2 (SETD2) is a histone methyltransferase that is involved in transcriptional elongation. We previously demonstrated SETD2 to be a potential tumour suppressor gene in breast cancer. The aim of this study was to compare SETD2 expression in breast cancer with that in adjacent non-cancerous breast tissue (ANCT) in paired samples. A hypothesis is proposed that explains the mode of action of SETD2 as a tumour suppressor gene.

MATERIALS AND METHODS

Paired samples of tumour and adjacent non-cancerous tissue (ANCT) from 25 patients were analysed. The levels of transcription of SETD2 were determined using quantitative polymerase chain reaction and normalized against cytokeratin 19. Immunohistochemical staining with appropriate antibodies against SETD2 protein was also performed in selected samples.

RESULTS

Levels of SETD2 mRNA were significantly higher in ANCT when compared to those in tumour samples (p=0.01). Immunohistochemistry also demonstrated a higher protein expression in ANCT.

CONCLUSION

This study offers further evidence that SETD2 behaves like a tumour suppressor gene. Our hypothesis links SETD2 mode of action with telomerase regulation through human telomerase reverse transcriptase (hTERT). Several studies have emphasised the importance of histone methylation of hTERT promotor in telomerase regulation. SETD2 function of histone methylation could be the missing link in this chain which could explain the potential tumour suppressor function of SETD2.

The evolving role of radiofrequency ablation therapy of breast lesions

BACKGROUND

The potential for radiofrequency ablation (RFA) therapy is an area of increasing interest in the context of breast conserving therapy for breast cancer. This non surgical technique potentially provides a non invasive, cosmetically pleasing result that is preferable to surgeon and patient.

MATERIALS AND METHODS

A literature review was carried out facilitated by PubMed and Medline databases. Cross referencing of the obtained articles was used to identify other relevant studies. A total of 17 studies were reviewed.

RESULTS

RFA is emerging as a promising treatment for breast cancer. Pilot and phase II studies have shown RFA to be effective at ablation with few complications or adverse effects experienced by patients. However, complete ablation of tumours is still not achieved in all patients.

CONCLUSION

RFA represents a promising therapeutic modality for breast lesions. However, there is a clear need for further research and refinement of the procedure before it can be offered as a therapeutic alternative to surgical excision for operable breast cancer.

Surgical excision for B3 breast lesions diagnosed by vacuum-assisted core biopsy

The aim of this retrospective study was to assess whether open surgical excision is required following a B3 diagnosis on 11-gauge vacuum-assisted core biopsy (VACB) of radiologically indeterminate breast lesions.

PATIENTS AND METHODS

Twenty-four women with a histological diagnosis of the B3 category on VACB of radiologically indeterminate breast lesions were identified over a 3-year period. The VACB procedure was performed under stereotactic (n=21), ultrasound (n=2) or magnetic resonance imaging (MRI) (n=1) guidance using the Suros system. Nineteen patients underwent open surgical excision. The remaining 5 patients who had 'complete' removal of the radiological abnormality using VACB under ultrasound (n=2, papilloma) or stereotactic (n=4, atypical ductal hyperplasia) guidance were followed up clinically and radiologically.

RESULTS

The median patient age was 49 years. The disease status in three patients was upgraded to ductal carcinoma in situ at open surgical excision. The VACB showed atypical lobular hyperplasia in these 3 patients, associated with microcalcification (n=2) or mass lesion (n=1). No single case of upgrading to invasive breast cancer was identified in our series. The remaining patients (16 out of 19) had a benign biopsy. The upgrade to malignancy was significantly associated with the presence of atypical lobular hyperplasia, a BI-RADS category of 4 and incomplete removal of the radiological abnormality by VACB. After a mean follow-up of 18 months, no malignancy was detected in the 5 patients who did not undergo open surgical biopsy.

CONCLUSION

Open surgical excision is strongly recommended for atypical lobular hyperplasia identified in VACB specimens. VACB can be a safe alternative to surgery in the treatment of B3 lesions in selected cases, providing thorough multidisciplinary discussion has taken place.

Evidence of a tumour suppressor function for DLEC1 in human breast cancer

DLEC1 (deleted in lung and oesophageal cancer), located on 3p22.3, is a candidate tumour suppressor gene in lung, esophageal, and renal cancer. The aim of this study was determine whether the mRNA expression levels of DLEC1 were consistent with a tumour suppressive function.

MATERIALS AND METHODS

A total of 153 samples were analysed. The levels of transcription of DLEC1 were determined using quantitative PCR and normalised against (CK19). Transcript levels within breast cancer specimens were compared to normal background tissues.

RESULTS

Levels of transcription were lower [corrected] in tumour samples compared to adjacent non cancerous tissue (ANCT) samples but this was not statistically significant (median 0.167 vs. 0.03; p=0.138). DLEC1 expression levels were significantly lower in samples from patients who developed metastasis, local recurrence, or died of breast cancer when compared to those who were disease free for >10 years (p=0.041).

DISCUSSION

These findings are consistent with a possible tumour suppressor function of DLEC1 in breast cancer.

Gene Transcripts in the Tumor Suppressor Region of Chromosome 3 (3p21)

Background:There is increasing evidence that the short arm of chromosome 3 has a tumour suppressor region that has been associated with permanent growth arrest of tumour cells. We have identified 9 closely related genes in this region (CCDC12, KLH9, KLH18, MYL3, NBEAL2, PTPN23, SCAP, SETD2, and TESSP2) located which could be possible candidates for tumour suppressor genes (TSG).Our objective was to determine, using quantitative PCR, whether the mRNA expression levels of these genes were consistent with a tumour suppressive function in human breast cancer.Methods:A total of 153 samples were analysed. The levels of transcription of all 9 genes were determined using quantitative PCR and normalized against (CK19).Transcript levels within breast cancer specimens were compared with non-cancerous breast tissue and analyzed against conventional pathological parameters and clinical outcome over a 10 year follow-up period.Results:Quantification of CCDC12, KLH9, KLH18, MYL3, NBEAL2, PTPN23, and SCAP mRNA expression after CK19 normalisation showed no statistically significant difference between malignant and normal breast tissue (p=0.23, 0.46, 0.3, 0.141, 0.8, 0.696, and 0.11 respectively). The mRNA expression of TESSP2 was higher in normal samples compared with malignant lesions (347 vs. 35, p=0.0061) but showed no significant associations with clinical outcome.The levels of SETD2 mRNA were significantly lower in malignant samples (406 vs. 17, p=0.0345) and decreased with increasing tumour stage. SETD2 expression levels were significantly lower in samples from patients who developed metastasis, local recurrence, or died from breast cancer when compared to those who were disease free for &gt; 10 years (p=0.041).Conclusion:These findings are consistent with a possible tumour suppressor function of SETD2 in human breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6139.

Suppressors of Cytokine Signaling and Their Role in Human Breast Cancer

BACKGROUND:Suppressors of cytokine signaling (SOCS) are important negative feedback regulators of the JAK/STAT signaling pathway, and have been recently investigated for their role in the development of different cancers. In this study, we examined the expression of SOCS 1-7 genes in normal and breast cancer tissue and correlated this with several clinico-pathological and prognostic factors.PATIENTS AND METHODS:SOCS 1-7 mRNA extraction and reverse transcription were performed on breast cancer tissue samples (n= 127) and normal background breast tissue (n= 31). Transcript levels of expression were determined using real-time PCR and analyzed against TNM stage, tumour grade and clinical outcome over a 10 year follow-up period.RESULTS:SOCS 1,4,5,6 and 7 expression decreased with increased TNM stage (TNM1 vs. TNM3 p= 0.039, TNM1 vs. TNM4 p= 0.016, TNM1 vs. TNM3 p= 0.012 and TNM1 vs. TNM3 p= 0.044 respectively). SOCS 2 and 3 expression decreased with increased Nottingham Prognostic Index (NPI) (NPI1 vs. NPI3 p=0.033 and NPI2 vs. NPI3 p=0.041 respectively). SOCS-7 expression decreased with higher tumour grade (Grade 3 vs. Grade 2 p=0.037). After a median follow up period of 10 years, we found higher levels of SOCS 1, 2 and 7 expression among those patients who remained disease-free compared to those who developed local recurrence (p= 0.0073, p= 0.021 and p= 0.039 respectively). Similarly, we found higher levels of SOCS 2, 4 and 7 expression in those who remained disease-free compared to those who developed distant recurrence (p= 0.022, p=0.024 and p= 0.033 respectively). Patients who remained disease-free had higher levels of SOCS 1 and 2 expression compared to those who died from breast cancer (p= 0.02 and p=0.033 respectively). The disease free survival (DFS) and overall survival (OS) curves showed that higher levels of SOCS 1, 3 and 7 were significant predictors of higher DFS (p=0.015, p=0.024 and p=0.03 respectively) and OS (p=0.005, p=0.013 and p= 0.035 respectively). Higher levels of SOCS 4 were significant in predicting better OS (p=0.007) but not DFS.CONCLUSIONHigher mRNA expression levels of SOCS 1, 3, 4 and 7 are significantly associated with earlier tumour stage and better clinical outcomes in human breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3157.

Oncological Outcome and Patient's Satisfaction of Skin-Sparing Mastectomy and Immediate Breast Reconstruction: A Prospective Observational Study

INTRODUCTION: The management of early breast cancer with skin-sparing mastectomy (SSM) and immediate breast reconstruction (IBR) is not based on evidence from randomised controlled trials. The purpose of this study is to evaluate the oncological safety, post-operative morbidity and patients' satisfaction with SSM and IBR using the latissimus dorsi (LD) myocutaneous flap and/or breast prosthesis. METHODS: One hundred and twenty five consecutive women underwent 137 SSMs with IBR (12 bilateral), using the LD flap plus implant (n=85) or implant alone (n=42), indications included breast cancer (n=130)and prophylaxis (n=7). Most tumours (99.2%) were Tis, T1, or T2 and only one tumour was T3 stage. Nipple reconstruction was performed in 69 patients, using a small local flap technique (n=61), nipple sharing (n=6), free skin graft (n=1) or Monocryl mesh (n=1). Thirty patients underwent contra-lateral surgery in order to optimise symmetry, including 19 augmentations and 11 mastopexy/reduction mammoplasties. Patient satisfaction with the outcome of surgery was assessed on a linear visual analogue scale ranging from 0 (not satisfied) to 10 (most satisfied). RESULTS: There was no local recurrence (LR) after a mean follow-up of 33.2 months (range=3-98 months). Overall survival was 99.2%, seven patients developed distant disease and one patient died of metastatic breast cancer. No case of partial or total LD flap loss was observed. Morbidities included infection, requiring implant removal in two patients and one patient developed marginal ischaemia of the skin envelope. Significant capsule formation, requiring capsulotomy, was observed in 87% of patients who had either PMR or prior RT compared with 13% for those who did not have RT. Eighty two (65.6%) of 125 patients completed the questionnaire with a median satisfaction scores of 9 (range=5-10). CONCLUSION: SSM with IBR is associated with low morbidity, high levels of patient satisfaction and is oncologically safe for T(is), T1 and T2 tumours without extensive skin involvement.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3113.

The mRNA expression of SETD2 in human breast cancer: correlation with clinico-pathological parameters

Background

SET domain containing protein 2 (SETD2) is a histone methyltransferase that is involved in transcriptional elongation.

There is evidence that SETD2 interacts with p53 and selectively regulates its downstream genes. Therefore, it could be implicated in the process of carcinogenesis. Furthermore, this gene is located on the short arm of chromosome 3p and we previously demonstrated that the 3p21.31 region of chromosome 3 was associated with permanent growth arrest of breast cancer cells. This region includes closely related genes namely: MYL3, CCDC12, KIF9, KLHL18 and SETD2. Based on the biological function of these genes, SETD2 is the most likely gene to play a tumour suppressor role and explain our previous findings.

Our objective was to determine, using quantitative PCR, whether the mRNA expression levels of SETD2 were consistent with a tumour suppressive function in breast cancer. This is the first study in the literature to examine the direct relationship between SETD2 and breast cancer.

Methods

A total of 153 samples were analysed.

The levels of transcription of SETD2 were determined using quantitative PCR and normalized against (CK19).

Transcript levels within breast cancer specimens were compared to normal background tissues and analyzed against conventional pathological parameters and clinical outcome over a 10 year follow-up period.

Results

The levels of SETD2 mRNA were significantly lower in malignant samples (p = 0.0345) and decreased with increasing tumour stage.

SETD2 expression levels were significantly lower in samples from patients who developed metastasis, local recurrence, or died of breast cancer when compared to those who were disease free for > 10 years (p = 0.041).

Conclusion

This study demonstrates a compelling trend for SETD2 transcription levels to be lower in cancerous tissues and in patients who developed progressive disease. These findings are consistent with a possible tumour suppressor function of this gene in breast cancer.

Expression of MDA7/IL-24 human breast cancer and the molecular impact

Abstract #2060

INTRODUCTION. MDA-7 (melanoma differentiation associated gene-7), also known as IL-24, was initially identified from cancer cells and was found to be up-regulated in melanoma cells. Forced expression of MDA7 in cancer cells was found to be growth inhibitory. MDA7/IL-24 operates in cells via its receptor, MDA7R/IL-24R, which includes at least the IL-20Rα and IL-20Rβ complex and the IL-22R and IL20Rβ complex. The present study investigated the impact of MDA7 on the growth and motility of breast cancer cells and the clinical relevance of MDA7 expression in mammary tumour tissues.&#x2028; MATERIALS AND METHODS. Human breast cancer cell lines MDA MB-231 and MCF-7 were used for in vitro testing. The response of cancer cells to rhMDA7 in growth and cellular motility was determined using growth assay and ECIS (electric cell impedance sensing, and confirmed by wounding assay). Localisation of MDA7 in mammary issues was assessed using conventional immunohistochemical method. Levels of MDA7 transcript in fresh frozen breast tissues were determined using quantitative PCR analysis and analysed against clinical and pathological information.&#x2028; RESULTS. Recombinant human MDA-7 only had a marginal effect on the in vitro growth of the breast cancer cell lines used. However, rhMDA had a significant effect on the migration of breast cancer cells. Cells treated with rhMDA-7 showed a slower rate of migration (electrical resistance 80.1±24.3Ω), when compared with control cells (130±24.3Ω) (p=0.024). Normal mammary epithelial cells showed a good degree of staining of MDA-7, a staining greatly reduced in cancer cells. Using the Nottingham Prognostic Index as a predictor of prognosis, tumours from patients with poor prognosis showed a significantly lower level of MDA-7 transcript compared with tumours from those with good prognosis (p=0.049). A significant difference was seen between tumours from patients who died of breast cancer and tumours from patients who remained disease free (p=0.035), the later showing a higher levels of MDA7 transcript. Using the Kaplan-Meier survival analysis, it was revealed that low levels of MDA-7 were significantly correlated with a shorter disease free survival (mean survival for low level group 121.7 (108.5-134.9) months compared with high levels 140.4 (133.7 – 147.1, 95% CI) months, p=0.0287. ER positive tumours showed a lower but levels of MDA-7 expression compared with ER-negative tumours, although this was not statistically significant (p=0.094).&#x2028; CONCLUSIONS. MDA-7 is a potential regulator of cellular motility of breast cancer cells. The aberrant expression of the molecule is linked to the prognosis and long term survival of patients, indicating the potential clinical implication of MDA-7 in cancer therapies.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2060.

SATB1: a 'master genome organizer' in mammary carcinogenesis

Abstract #3070

Background: SATB1 is a nuclear protein that has been recently reported to be a 'genome organizer' that delinates specific epigenetic modifications at target gene loci, directly up-regulating metastasis-associated genes while down-regulating tumor-suppressor genes. This study aimed to examine the level of mRNA expression of SATB1 gene in normal and malignant breast tissue and correlate the level to the clinico-pathological parameters.&#x2028; Material and Methods: One hundred and fifteen breast cancer tissue and 31 normal breast tissues were analyzed. Levels of transcription of SATB1 were determined using real-time quantitative PCR and were analyzed against TNM stage, nodal involvement, tumor grade and clinical outcome.&#x2028; Results: The levels of SATB1 mRNA were significantly higher in malignant compared with normal breast tissue (p=0.0167). The expression of SATB1 mRNA was demonstrated to increase with increasing TNM stage (TNM1 vs. TNM2, p=0.0264; TNM2 vs. TNM3, p=0.024) and increasing tumor grade (grade 1 vs. grade 3, p=0.017; grade 2 vs. grade 3, p=0.0437; grade 1 vs. grade 2&3, p=0.021). After a median follow up of 10 years, there was a trend for tumors with higher SATB1 expression levels to be associated with shorter overall survival times.&#x2028; Discussion: These results are consistent with the notion that SATB1 acts as the 'master genome organizer' in tumorigenesis of human breast cancer.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3070.