Proteomic identification of putative biomarkers of neo-adjuvant chemotherapy resistance in luminal (ER+) breast cancer

Background:Neoadjuvant chemotherapy is a standard treatment for locally advanced breast cancer however chemoresistance can be a major obstacle in ER+ cancers. Using comparative proteomic approaches (antibody microarray/AbMA and 2D-PAGE with MALDI-TOF/TOF MS) to investigate a pilot series of breast cancer samples our research group recently identified 14-3-3 theta/tau, tBID and BcL-XL as putative biomarkers of response to neoadjuvant chemotherapy (Hodgkinson et al J Prot 2012, 75:1276-1283 and 75:2745-2752). Here we aimed to analyse further samples using the AbMA approach and to re-analyse the combined data.Methods:Samples from chemoresistant and chemosensitive breast cancers were selected following anthracycline-taxane chemotherapy and 4 experiments were performed using ductal ER+ tumours. Differential protein expression was compared between chemoresistant and chemosensitive samples using the Panorama XPRESS Profiler725 AbMA kit. The combined data from 9 AbMA assays and 3 2D-PAGE/MS experiments was then analysed using Ingenuity Pathway Analysis (IPA; Ingenuity Systems). A pilot series of archival samples was used for clinical validation of putative predictive biomarkers.Results:89 differentially expressed proteins (DEPs) were seen in the 4 further AbMA experiments. In the combined dataset (12 experiments from 2 proteomic platforms), 8 DEPs were seen in at least 3 experiments. These were 14-3-3 theta, 14-3-3 epsilon, 14-3-3 gamma, Bcl-xl, Bid, Phosphokinase B, Vimentin and FAK. 121 DEPs from the combined data were analysed using IPA; 13 DEPs were mapped onto the PI3K/AKT pathway. Clinical validation in a pilot series of archival samples revealed AkT-1 Ser473 and FAKY397 alongside the previously identified and validated 14-3-3 theta/tau, and tBID to be significantly associated with chemotherapy resistance.Conclusion: We have now identified at least 8 proteins which could play a role in breast chemoresistance. We propose a potential role for AkT-1, FAK, 14-3-3 theta/tau and tBID as predictive biomarkers of neoadjuvant chemotherapy resistance in breast cancer. Further validation in a larger sample series is now required

Proteomic identification of putative biomarkers of neo-adjuvant chemotherapy resistance in luminal (ER+) breast cancer

Background: Neoadjuvant chemotherapy is a standard treatment for locally advanced breast cancer however chemoresistance can be a major obstacle in ER+ cancers. Using comparative proteomic approaches (antibody microarray/AbMA and 2D-PAGE with MALDI-TOF/TOF MS) to investigate a pilot series of breast cancer samples our research group recently identified 14-3-3 theta/tau, tBID and BcL-XL as putative biomarkers of response to neoadjuvant chemotherapy (Hodgkinson et al J Prot 2012, 75:1276-1283 and 75:2745-2752). Here we aimed to analyse further samples using the AbMA approach and to re-analyse the combined data. Methods: Samples from chemoresistant and chemosensitive breast cancers were selected following anthracycline-taxane chemotherapy and 4 experiments were performed using ductal ER+ tumours. Differential protein expression was compared between chemoresistant and chemosensitive samples using the Panorama XPRESS Profiler725 AbMA kit. The combined data from 9 AbMA assays and 3 2D-PAGE/MS experiments was then analysed using Ingenuity Pathway Analysis (IPA; Ingenuity Systems). A pilot series of archival samples was used for clinical validation of putative predictive biomarkers. Results: 89 differentially expressed proteins (DEPs) were seen in the 4 further AbMA experiments. In the combined dataset (12 experiments from 2 proteomic platforms), 8 DEPs were seen in at least 3 experiments. These were 14-3-3 theta, 14-3-3 epsilon, 14-3-3 gamma, Bcl-xl, Bid, Phosphokinase B, Vimentin and FAK. 121 DEPs from the combined data were analysed using IPA; 13 DEPs were mapped onto the PI3K/AKT pathway. Clinical validation in a pilot series of archival samples revealed AkT-1 Ser473 and FAKY397 alongside the previously identified and validated 14-3-3 theta/tau, and tBID to be significantly associated with chemotherapy resistance. Conclusion: We have now identified at least 8 proteins which could play a role in breast chemoresistance. We propose a potential role for AkT-1, FAK, 14-3-3 theta/tau and tBID as predictive biomarkers of neoadjuvant chemotherapy resistance in breast cancer. Further validation in a larger sample series is now required

Clinical response to primary letrozole therapy in elderly patients with early breast cancer : possible role for p53 as a biomarker

Primary tamoxifen therapy has been widely used to treat elderly women with ER-positive breast cancer in the past. Aromatase inhibitors may be more beneficial than tamoxifen when used as primary endocrine therapy in elderly patients. We aimed to retrospectively evaluate a series of elderly women with ER-positive breast cancer treated with primary letrozole therapy as sole therapy with a minimum of 5 years follow up. To identify possible predictive biomarkers a pilot immunohistochemical analysis was performed to assess the expression of PR, HER2, EGFR, BCL2 and p53. A total of 45 women, aged more than 70 years with a diagnosis of ER-positive breast cancer that was treated with primary letrozole therapy were identified. A case note review was undertaken to obtain clinical information. Formalin fixed paraffin embedded tumour tissue from diagnostic core biopsies was available for all patients. Immunohistochemical analysis was performed to establish the protein expression status of p53, PR, HER2, EGFR and BCL2. The mean age of the 45 patients was 87 years (range 70–101). Clinical benefit was seen in 60% of the patients. Median progression free survival was 53 months (95% CI – 34–72) and the median time to progression was 43 months (95% CI – 22–64). BCL2 was expressed in 45/45 (100%); PR in 38/45 (84%); EGFR in 13/45 (28%); HER2 in 9/45 (20%) and p53 in 5/45 (11%) of tissue samples. Positive expression of p53 was associated with poor progression free survival (p = 0.03) in this pilot study. This study demonstrates that letrozole as sole treatment appears to be a suitable treatment option for elderly patients with ER-positive breast cancer who are not fit for, or decline, surgery. The analysis of p53 in a larger study is warranted in order to assess its role as a biomarker in this patient group

Feasibility of Use of a Barbed Suture (V-Loc 180) for Quilting the Donor Site in Latissimus Dorsi Myocutaneous Flap Breast Reconstruction

BackgroundLatissimus dorsi (LD) myocutaneous flap is a popular method of breast reconstruction which can be associated with high incidence of seroma formation. Quilting sutures at the harvest site are used to reduce this. Barbed sutures are self anchoring sutures which avoid multiple knotting and can be useful in quilting.MethodsA retrospective analysis of prospectively maintained database of patients who underwent LD flap breast reconstruction between January 2009 and January 2011 was carried out. Seroma formation at the harvest site, wound related complications, inpatient stay and duration of surgery were analysed and a comparison was made between two groups where quilting was done with barbed (V-Loc) suture and conventional polydioxanone (PDS) II sutures.ResultsFifty-seven patients were included of which 33 had quilting by V-Loc sutures and in 24 patients PDS II suture was used. Median age in the PDS group was 55 years (interquartile range [IQR)], 45 to 61 years) which was comparable to the V-Loc group (53 years [IQR, 48 to 59 years]; P-value 0.948). Sixteen patients (28%) had significant seroma formation and 5 (9%) patients developed superficial wound dehiscence. Incidences of seroma or wound complications were comparable (P-value 0.378 and 1.00, respectively). Secondary outcomes such as total duration of surgery, total inpatient stay, total amount of drain at the donor site were also similar in two groups.ConclusionsUse of barbed sutures for quilting the donor site in LD flap reconstruction is a feasible option and the associated seroma formation and wound complications are comparable with conventional sutures

Gastric obstruction secondary to metastatic breast cancer: a case report and literature review

<p>Abstract</p> <p>Introduction</p> <p>Gastrointestinal tract soft tissues metastasis is a well-known occurrence with invasive lobular breast cancer subtypes. Gastric involvement is more common, with reports of both diffuse and localized involvements. Usually, a gastric localized involvement presents as wall thickening with an appearance similar to that of a gastrointestinal stromal tumour; rarely does a localized metastatic deposit grow aggressively to present as a large tumour causing obstructive symptoms. Our case highlights one such unusual presentation in a patient presenting with non-specific gastrointestinal symptoms. To the best of our knowledge, there have been no previous reports on a similar presentation occurring from a localized metastasis.</p> <p>Case presentation</p> <p>A 65-year-old Caucasian woman awaiting an outpatient oral gastroduodenoscopy for symptoms of intermittent vomiting, epigastric pains and weight loss of six weeks’ duration presented acutely with symptoms of haematemesis and abdominal distension. An initial contrast-enhanced computed tomography scan showed a grossly dilated stomach with a locally advanced stenosing tumour mass at the pylorus. Our patient had a history of left mastectomy and axillary clearance followed by adjuvant endocrine therapy for an oestrogen receptor- and progesterone receptor-positive, grade 2, invasive lobular breast cancer. The oral gastroduodenoscopy confirmed the computed tomography findings; biopsies of the pyloric mass on immunohistochemistry stains were strongly positive for pancytokeratin and gross cystic disease fluid proteins, consistent with an invasive lobular breast cancer metastasis. She received a palliative gastrojejunal bypass and her adjuvant endocrine treatment was switched over to exemestane.</p> <p>Conclusion</p> <p>Our case highlights the aggressive behaviour of a localized gastric metastasis that is unusual and unexpected. Gastrointestinal symptomatology can be non-specific and, at times, non-diagnostic on conventional mucosal biopsies. A high index of clinical suspicion in patients with a previous history of invasive lobular breast cancer can aid in an early diagnosis and treatment. A combined treatment approach with chemoendocrine therapies achieves remission and improves patient survival.</p