Mark B. Peter

Combined analysis of eIF4E and 4E-binding protein expression predicts breast cancer survival and estimates eIF4E activity

Increased eukaryotic translation initiation factor 4E (eIF4E) expression occurs in many cancers, and makes fundamental contributions to carcinogenesis by stimulating the expression of cancer-related genes at post-transcriptional levels. This key role is highlighted by the facts that eIF4E levels can predict prognosis, and that eIF4E is an established therapeutic target. However, eIF4E activity is a complex function of expression levels and phosphorylation statuses of eIF4E and eIF4E-binding proteins (4E-BPs). Our hypothesis was that the combined analyses of these pathway components would allow insights into eIF4E activity and its influence on cancer. We have determined expression levels of eIF4E, 4E-BP1, 4E-BP2 and phosphorylated 4E-BP1 within 424 breast tumours, and have carried out analyses to combine these and relate the product to patient survival, in order to estimate eIF4E activity. We show that this analysis gives greater prognostic insights than that of eIF4E alone. We show that eIF4E and 4E-BP expression are positively associated, and that 4E-BP2 has a stronger influence on cancer behaviour than 4E-BP1. Finally, we examine eIF4E, estimated eIF4E activity, and phosphorylated 4E-BP1 as potential predictive biomarkers for eIF4E-targeted therapies, and show that each determines selection of different patient groups. We conclude that eIF4Es influence on cancer survival is modulated substantially by 4E-BPs, and that combined pathway analyses can estimate functional eIF4E.

Surgery induced immunosuppression

Surgery and anaesthesia result in a variety of metabolic and endocrine responses, which result in a generalised state of immunosuppression in the immediate post-operative period. Surgery induced immunosuppression has been implicated in the development of post-operative septic complications and tumour metastasis formation. In addition the effectiveness of many treatments in the adjuvant setting is dependent on a functioning immune system. By understanding the mechanisms contributing to surgery-induced immunosuppression, surgeons may undertake strategies to minimise its effect and reduce potential short-term and long-term consequences to patients.

Carcinoembryonic antigen cell adhesion molecule 6 predicts breast cancer recurrence following adjuvant tamoxifen.

Purpose: Tamoxifen remains therapy of choice for premenopausal estrogen receptor α–positive breast cancer. However, resistance and recurrence are serious problems. Our previous work indicated that carcinoembryonic antigen cell adhesion molecule 6 (CEACAM6) was significantly up-regulated in tamoxifen-resistant (TAMr) MCF-7 derivatives. The aim of this study was to determine the functional role of CEACAM6 in endocrine-resistant breast cancer and to retrospectively test whether it was predictive of resistance in a large cohort of breast cancers with long-term follow-up. Experimental Design: siRNA silencing of CEACAM6 was done in TAMr cells and effects on clonogenicity and endocrine sensitivity were determined. CEACAM6 immunohistochemistry was done on a tissue microarray comprising 108 relapsed primary human breast cancers and 243 tamoxifen-sensitive controls. Results: siRNA-mediated silencing of CEACAM6 reduced both clonogenicity and anchorage-dependent and anchorage-independent growth of TAMr cells. Importantly, CEACAM6 silencing restored sensitivity of TAMr cells to 4-hydroxytamoxifen and proliferative response to 17β-estradiol. Immunohistochemistry showed significantly more CEACAM expression in the relapsed group compared with nonrelapsed controls [35 of 108 (33.3%) and 32 of 243 (13.2%), respectively; odds ratio, 3.16 (95% confidence interval, 1.83-5.47); P < 0.0001]. Additionally, we derived an outcome predictor model based on CEACAM expression that restratified patients in the Nottingham prognostic index intermediate-risk group into either higher-risk or lower-risk group. Conclusions: Our data support an important role for CEACAM6 in endocrine resistance, which can serve as a powerful predictor of future recurrence.

Intramammary lymph node metastasis predicts poorer survival in breast cancer patients

Involvement of an intramammary lymph node with metastatic breast cancer is an uncommon clinical or radiological presentation. Previously reported series of patients are small in number and the clinical advice is unclear. We identified 100 patients on our pathology database with intramammary lymph nodes in association with a primary breast cancer. Ten were identified pre-operatively on breast imaging and 90 were first discovered on pathological assessment of excised breast tissue. Twenty one contained metastasis. Factors that predicted for intramammary node metastasis were increasing age (p=0.017), lymphovascular invasion (p=0.002) and grade of tumour (p=0.012). The presence of metastasis within the intramammary lymph node was associated with a poorer disease free survival (p=0.007) and reduced overall survival (p=0.035). Sixty seven percent of patients with intramammary node metastasis had further axillary metastases. One patient had an intramammary node metastasis but uninvolved axillary sentinel node. She presented 19 months later with an axillary nodal recurrence. The presence of intramammary lymph node metastasis is associated with poorer outcome in breast cancer patients. Pre-operative detection of intramammary lymph node metastasis is helpful to guide breast and axillary surgeries. Intramammary lymph node metastasis predicts strongly for axillary metastatic disease and axillary node clearance is recommended.

Phosphorylation of Estrogen Receptor β at Serine 105 Is Associated with Good Prognosis in Breast Cancer

Estrogen receptor (ER) action is modulated by posttranslational modifications. Although ERalpha phosphorylation correlates with patient outcome, ERbeta is similarly phosphorylated but its significance in breast cancer has not been addressed. We investigated whether ERbeta that is phosphorylated at serine 105 (S105-ERbeta) is expressed in breast cancer and assessed potential clinical implications of this phosphorylation. Following antibody validation, S105-ERbeta expression was studied in tissue microarrays comprising 108 tamoxifen-resistant and 351 tamoxifen-sensitive cases and analyzed against clinical data. S105-ERbeta regulation in vitro was assessed by Western blot, flow cytometry, and immunofluorescence. Nuclear S105-ERbeta was observed in breast carcinoma and was associated with better survival (Allred score > or =3), even in tamoxifen-resistant cases, and additionally correlated with ERbeta1 and ERbeta2 expression. Distinct S105-ERbeta nuclear speckles were seen in some higher grade tumors. S105-ERbeta levels increased in MCF-7 cells in response to 17beta-estradiol, the ERbeta-specific agonist diarylpropionitrile, and the partial ERbeta-agonist genistein. S105-ERbeta nuclear speckles were also seen in MCF-7 cells and markedly increased in size and number at 24 hours following 17beta-estradiol and, in particular diarylpropionitrile, treatment. These speckles were coexpressed with ERbeta1 and ERbeta2. Presence of S105-ERbeta in breast cancer and association with improved survival, even in endocrine resistant breast tumors suggest S105-ERbeta might be a useful additional prognostic marker in this disease.

Differential regulation of oestrogen receptor β isoforms by 5′ untranslated regions in cancer

Oestrogen receptors (ERs) are critical regulators of the behaviour of many cancers. Despite this, the roles and regulation of one of the two known ERs – ERβ– are poorly understood. This is partly because analyses have been confused by discrepancies between ERβ expression at mRNA and proteins levels, and because ERβ is expressed as several functionally distinct isoforms. We investigated human ERβ 5′ untranslated regions (UTRs) and their influences on ERβ expression and function. We demonstrate that two alternative ERβ 5′UTRs have potent and differential influences on expression acting at the level of translation. We show that their influences are modulated by cellular context and in carcinogenesis, and demonstrate the contributions of both upstream open reading frames and RNA secondary structure. These regulatory mechanisms offer explanations for the non‐concordance of ERβ mRNA and protein. Importantly, we also demonstrate that 5′UTRs allow the first reported mechanisms for differential regulation of the expression of the ERβ isoforms 1, 2 and 5, and thereby have critical influences on ERβ function.

Circulating tumour cells in breast cancer: Prognostic indicators, metastatic intermediates, or irrelevant bystanders? (Review).

Circulating tumour cells (CTCs) have been of considerable interest for many years. The rarity of these cells presents the main challenge associated with their analysis. Current detection methods use antibody and nucleic acid techniques and are sensitive for CTC detection but limited in their utility by the occurrence of false-positive results. Despite this, there are a number of clinical studies which show that the presence of CTCs is an important prognostic indicator, particularly in the metastatic setting. Current efforts to phenotype CTCs may provide a valuable insight into the metastatic process and may also allow the development of specific CTC-targeted treatment strategies in the future.

Practical advice on clinical decision making during neoadjuvant chemotherapy for primary breast cancer

Neoadjuvant chemotherapy (NACT) is a useful approach in the treatment of many breast cancers. One of the main advantages of NACT is the possibility of breast conservation surgery in patients who would otherwise require a mastectomy. Most literature on NACT focuses on the effectiveness of different chemotherapy regimen and subsequent mastectomy rates. There is little guidance in the literature on aspects of individual patient management and decision making during NACT. This paper considers practical management advice where NACT is considered and adopted.

Perioperative reductions in circulating lymphocyte levels predict wound complications after excisional breast cancer surgery.

OBJECTIVE Postoperative wound complications after excisional surgery for primary breast cancer can result in patients requiring additional treatments and delay adjuvant therapy and are associated with worse prognoses.We investigated factors that might predispose patients to wound complications. BACKGROUND A number of patient characteristics have been associated with wound complications, but there is currently no quantitative measure of the risk of their occurrence. Our hypothesis was that wound complications are related, in part, to the immune status of patients. METHODS We recruited patients undergoing surgery for primary breast cancer and determined their circulating levels of various immune cells shortly before and after surgery as a measure of immune status. RESULTS One hundred seventeen patients were recruited; 16 (13.7%) developed wound complications. The following patient and tumor characteristics were associated with higher wound complication rates: diabetes (P = 0.02); larger tumors (T2/3 vs T1; P = 0.02); metastatic axillary nodes (P = 0.006). With respect to immune status, no significant differences in preoperative levels of circulating immune cells were detected between patients who developed wound complications and those who did not. However, patients who developed complications showed greater reductions in lymphocyte levels 4 hours postoperatively than those who did not (P <0.001). Multivariate analyses demonstrated that falls in lymphocyte levels of greater than 20% or 50% 4 hours postoperatively acted as a significant and independent predictor of wound complications (P < 0.005 and P < 0.0001,respectively). CONCLUSIONS Perioperative changes in lymphocyte levels could provide a practical predictive marker for wound complications on which selective antibiotic prophylaxis could be based.

Investigating and critically appraising the expression and potential role of androgen receptor in breast carcinoma.

Abstract The potential role of the androgen receptor (AR) as a predictive or prognostic factor in breast cancer remains unclear. We aimed to determine the prognostic significance of AR in a cohort of breast carcinomas with long-term follow-up and to critically appraise this in the context of existing literature. Four hundred and eight cases of invasive breast cancer were incorporated into tissue microarrays (TMAs). All received tamoxifen and comprised 108 cases which relapsed and 300 cases which did not. Mean follow-up time for the former was 84 months (range 1–142, SD 38.8) and for the latter was 77 months (range 11–229, SD 49.7). TMAs were immunohistochemically stained with AR and scored as a continuous variable and using the Allred score. AR expression was significantly associated with grade, recurrence on tamoxifen, non-breast cancer death estrogen receptor alpha (ERα) and progesterone receptor (PR). AR correlated significantly with better overall survival (OS) and disease-free survival (DFS) using an Allred cut-off of 4 (log rank=0.0053 and 0.0044, respectively), and 20% positive tumor cells (log rank=0.0027 and 0.0059, respectively). AR expression was additionally associated with a reduced risk of recurrence following endocrine therapy. In summary, AR positive breast tumors have better OS and DFS and are less likely to recur following endocrine treatment.