Abstract P2-08-23: A combined score of tumour budding and tumour necrosis has prognostic value for cancer specific survival in both ER positive and ER negative primary operable breast cancer

Background: As new systemic therapies emerge for the treatment of breast cancer, new prognostic markers are required to help stratify patients into higher and lower risk groups to aid treatment decision making. Features of the tumour microenvironment, such as tumour necrosis, tumour-stroma percentage (TSP), and tumour budding have been shown to have prognostic value in some cancers. However, their role in breast cancer is unclear.

Methods: Patients who underwent surgery for primary operable breast cancer in 2 centres between 1995-2007 and who had paraffin-embedded tissue blocks available were identified. Clinicopathological details and survival data were obtained from patient records. Haematoxylin & Eosin-stained slides were visually assessed within a set visual field for TSP (<50% or >50% tumour stroma), tumour necrosis (<25% or >25% necrosis) and tumour budding (<20 buds or >20 buds). A combined score of tumour necrosis and tumour budding was then created. A score of 0 was assigned to tumours where both components were low, 1 to those where only one component was high, and 2 to those where both were high. Multivariate cox regression analysis was carried out for cancer specific survival (CSS).

Results: A breast cancer cohort of 1301 patients was utilised, from which 1186 H&E slides were scored for necrosis, TSP and tumour budding. Median follow up was 158 months (26-183) and there were 234 breast cancer deaths. In the full cohort, necrosis (p<0.0001), high TSP (p=0.010) and high budding (p<0.0001) were associated with CSS and all 3 were independently prognostic on multivariate analysis (necrosis HR 1.54, 95%CI 1.15-2.07, p=0.004; high TSP HR 1.49, 95%CI 1.12-1.98; p=0.006; high budding HR 1.38, 95%CI 1.02-1.87, p=0.035). In ER positive disease (n=826), necrosis was associated with worse CSS (p<0.0001) and was independently prognostic (HR 1.46, 95%CI 1.03-2.08, p=0.033). In ER negative disease (n=359), necrosis, high TSP and high budding were associated with worse CSS (p=0.001, p=0.002, p<0.0001 respectively) and were independently prognostic (necrosis HR 2.44, 95%CI 1.34-4.43, p=0.003; high TSP HR 1.64, 95%CI 1.06-2.53, p=0.026; high budding HR 2.47, 95%CI 1.56-3.89, p<0.0001) . To assess if combining these markers added additional prognostic power a combined budding/necrosis score was established. This was associated with worse CSS in ER positive disease (p<0.0001) and a score of 2 was independently associated with worse CSS compared to a score of 0 (HR 1.96, 95%CI 1.19-3.23, p=0.008). This was potentiated in node-negative patients (HR 5.14, 95%CI 2.18-12.08, p<0.0001). In ER negative disease, an increasing score was associated with worse CSS (p<0.0001) and was independently prognostic (combined score 1 vs. 0: HR 2.37, 95%CI 1.13-5.00, p=0.023; score 2 vs. 0: HR 5.93, 95%CI 2.62-13.40, p<0.0001).

Conclusions: A combined score of tumour necrosis and budding shows promise as a readily-available prognostic tool to aid treatment decision making in primary operable breast cancer, both by stratifying risk in ER negative disease, and by identifying a high-risk group in ER positive, node negative disease.

Citation Format: Morrow ES, Gujam F, Mohammed Z, McMillan DC, Horgan PG, Roseweir AK, Edwards J. A combined score of tumour budding and tumour necrosis has prognostic value for cancer specific survival in both ER positive and ER negative primary operable breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-08-23.

Abstract P3-10-13: Dual targeting of androgen receptor and IKK alpha is a potential therapeutic strategy for triple negative breast cancer

Background

There are limited treatments for triple negative breast cancer (TNBC) patients and an unmet need for targeted approaches in these patients. In the last 4-5 years, the prevalence of high androgen receptor (AR) expression in TNBCs has been noted in up to 50% of tumors suggesting it has clinical relevance. The non-canonical NF-kB pathway is also upregulated in this patient group and it has been reported that that there is crosstalk between these pathways. Therefore the aim of this study was to examine the expression of IKKα and AR in breast cancer tissue samples, to assess if combining these markers increased prognostic power.

Methods

Immunohistochemistry was performed on tissue microarray of 410 patients to assess proteins level of IKK alpha and AR. Protein expression levels were assessed using the weighted histoscore (WHS) method. The median was employed as the cut off for IKK alpha and 1% as cut off for AR. Expression was analyzed for associations with cancer-specific survival (CSS) and recurrence-free survival (RFS).

Results

In a cohort of 370 breast cancers nether AR nor IKK alpha alone or combined were associated with CSS or RFS. Stratifying patients by ER status did not impact CSS or RFS. However, in TNBC patients (n=82) high expression of AR was associated with shorter CSS (HR 2.55 95 CI 1.61-5.59, p=0.013). To assess if combining AR and IKK alpha increased prognostic power, AR and IKK alpha were combined into a single score: 0= low expression of both or high expression of one and 1= high expression of both. In the full cohort or when stratified by ER status the score was not associated with CSS or RFS, however in TNBC the combined score potentiated the effect observed with AR alone, (HR 1.68 95 CI 1.20-2.33, p=0.001). Patient CSS was stratified from 11.5 years to 4.6 years and was independently associated with CSS when compared with common clinicopathological factors (HR 1.56 95CI 1.11-2.21, p=0.011). In addition, the combined score was associated with decrease radiotherapy use (p=0.032), increased recurrence rate (p=0.014), decreased cytotoxic T cells (p=0.007), B cells (p=0.043) and macrophages (p=0.037).

Conclusions

A combined AR and IKK alpha score is an independent prognostic classification for patients with TNBC. Patients with high expression of both AR and IKK alpha a significantly reduced survival and were immune cell cold. This study suggests that this patient group will not benefit from immunotherapy but dual targeting with anti-androgens and IKK alpha selective inhibitors could offer a novel therapeutic strategy for this patient group.

Citation Format: Roseweir AK, Khongthong P, Dickson K, Bennett L, Edwards J. Dual targeting of androgen receptor and IKK alpha is a potential therapeutic strategy for triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-10-13.

A novel tumor-based epithelial-to-mesenchymal transition score that associates with prognosis and metastasis in patients with Stage II/III colorectal cancer

It is increasingly appreciated that host factors within the tumor center and microenvironment play a key role in dictating colorectal cancer (CRC) outcomes. As a result, the metastatic process has now been defined as a result of epithelial-mesenchymal transition (EMT). Establishment of the role of EMT within the tumor center and its effect on the tumor microenvironment would be beneficial for prognosis and therapeutic intervention in CRC. The present study assessed five immunohistochemical EMT markers within the tumor center on a 185 Stage II/III CRC patient tissue microarray. In 185 patients with CRC, cytoplasmic snail (HR 1.94 95% confidence interval [CI] 1.15-3.29, p = 0.012) and a novel combined EMT score (HR 3.86 95% CI 2.17-6.86, p < 0.001) were associated with decreased cancer-specific survival. The combined EMT score was also associated with increased tumor budding (p = 0.046), and systemic inflammation (p = 0.007), as well as decreased memory T-cells within the stroma (p = 0.030) and at the invasive margin (p = 0.035). Furthermore, the combined EMT score was associated with cancer-specific survival independent of TNM-stage (HR 4.12 95% CI 2.30-7.39, p < 0.001). In conclusion, a novel combined EMT score stratifies patient's survival in Stage II/III CRC and associates with key factors of tumor metastasis. Therefore, the combined EMT score could be used to identify patients at risk of micrometastases and who may benefit from standard adjuvant therapy, potentially in combination with EMT blockade.

Stimulation of growth hormone by kisspeptin antagonists in ewes

Kisspeptin signalling is indispensable for fertility, stimulating gonadotropin-releasing hormone (GnRH) secretion and mediating gonadal steroid feedback on GnRH neurons. Moreover, kisspeptin neurons have been implicated in other non-reproductive neuroendocrine roles. Kisspeptin appears to also regulate growth hormone secretion but much of the data appear contradictory. We sought to clarify a potential role of kisspeptin in growth hormone (GH) regulation by examining the effect of kisspeptin antagonists on GH secretion in ewes under various physiological conditions. Our data show clear and robust increases in GH secretion following lateral ventricle or third ventricle infusion of kisspeptin antagonists p-234 and p-271 in either ovariectomized or anestrous ewes. Central infusion of kisspeptin-10 had no effect on GH secretion. To determine the level at which kisspeptin may influence GH secretion, we examined expression of the cognate kisspeptin receptor, GPR54, in pituitary cells and showed by immunocytochemistry that the majority of somatotropes express GPR54 while expression was largely negative in other pituitary cells. Overall, we have demonstrated that blocking kisspeptin signalling by antagonists stimulates GH secretion in ewes and that this is likely mediated by inhibiting endogenous kisspeptin activation of GPR54 expressed on somatotropes. The findings suggest that endogenous kisspeptin inhibits GH secretion through GPR54 expressed on somatotropes.

Kisspeptin-10 inhibits cell migration in vitro via a receptor-GSK3 beta-FAK feedback loop in HTR8SVneo cells

Kisspeptin inhibits cancer cell metastasis and placental trophoblast cell migration. Kisspeptin gene expression in the placenta and circulating kisspeptin levels change during normal pregnancy and they are altered in preeclampsia. We therefore assessed the effect of kisspeptin-10 on the in vitro migration of a human placental cell line derived from first trimester extravillious trophoblasts (HTR8SVneo). HTR8SVneo cells specifically bound 125I-Kisspeptin-10 but kisspeptin-10 did not induce inositol phosphate production. Cell migration was inhibited by kisspeptin-10 with a maximal inhibition at 100nM. The signaling pathways involved in inhibition of cell migration were examined. Treatment with kisspeptin-10 elicited phosphorylation of GSK3 beta at Ser9 (which inhibits activity), with a 3-fold increase at 5 min. Transient phosphorylation of ERK1/2 and p38MAPK peaked at 10min. Phosphorylation of focal adhesion kinase (FAK) at Tyr925 increased 3-fold at 10 min. Inhibition of GSK3 beta correlated with release of beta-catenin into the cytoplasm. These signaling events were differentially blocked by inhibitors of G(q/11), Src, EGFR, PI(3)K, PKC and MEK. The data suggest that kisspeptin/GPR54 EGF-receptor transactivation leads to phosphorylation of ERK1/2, causing activation of p90rsk which in turn inhibits GSK3 beta via Ser9 phosphorylation. Inactivation of GSK3 beta results in release of beta-catenin into the cytoplasm, affecting cell-cell adhesion and Tyr925 phosphorylation of FAK, which increases phosphorylation of ERK1/2 via RAS/Raf-1 creating a feedback loop to enhance the effects on migration. These findings indicate that kisspeptin-10 inhibits the migration of human placental trophoblast-derived HTR8SVneo cells by stimulating complex ERK1/2-p90rsk-GSK3 beta-FAK feedback interactions.

Kisspeptin-10 is a potent stimulator of LH and increases pulse frequency in men

CONTEXT

Kisspeptins stimulate GnRH and thus gonadotropin secretion. Kisspeptin-10 is the minimal kisspeptin sequence with full intrinsic bioactivity, but it has not been studied in man.

OBJECTIVE

We investigated our hypothesis that kisspeptin-10 increases GnRH and thus LH pulse frequency.

DESIGN AND PARTICIPANTS

The dose response of kisspeptin-10 was investigated by administering iv bolus doses (0.01-3.0 μg/kg) and vehicle to healthy men. Effects on LH pulse frequency and size were determined by deconvolution analysis during infusion of kisspeptin-10 for up to 22.5 h.

RESULTS

Intravenous bolus kisspeptin-10 resulted in a rapid and dose-dependent rise in serum LH concentration, with maximal stimulation at 1 μg/kg (4.1 ± 0.4 to 12.4 ± 1.7 IU/liter at 30 min, P < 0.001, n = 6). Administration of 3 μg/kg elicited a reduced response vs. 1 μg/kg (P < 0.05). Infusion of kisspeptin-10 at 4 μg/kg · h for 22.5 h elicited an increase in LH from a mean of 5.4 ± 0.7 to 20.8 ± 4.9 IU/liter (n = 4; P < 0.05) and serum testosterone increased from 16.6 ± 2.4 to 24.0 ± 2.5 nmol/liter (P < 0.001). LH pulses were obscured at this high rate of secretion, but a lower dose infusion of kisspeptin-10 (1.5 μg/kg · h) increased mean LH from 5.2 ± 0.8 to 14.1 ± 1.7 IU/liter (n = 4; P < 0.01) and increased LH pulse frequency from 0.7 ± 0.1 to 1.0 ± 0.2 pulses/h (P < 0.05) and secretory burst mass from 3.9 ± 0.4 to 12.8 ± 2.6 IU/liter (P < 0.05).

CONCLUSIONS

Kisspeptin-10 boluses potently evoke LH secretion in men, and continuous infusion increases testosterone, LH pulse frequency, and pulse size. Kisspeptin analogues have therapeutic potential as regulators of LH and thus testosterone secretion.

Critical roles of kisspeptins in female puberty and preovulatory gonadotropin surges as revealed by a novel antagonist

Kisspeptins (Kp) have recently emerged as master regulators of the reproductive axis and among the most potent elicitors of GnRH-gonadotropin secretion. Despite their paramount importance in reproductive physiology and their potential therapeutic implications, development of Kp antagonists has remained elusive, and only recently has the first compound with the ability to block Kp actions in vitro and in vivo, namely p234, been reported. However, previous in vivo studies all used acute central injections, whereas characterization of the effects of the antagonist after continuous or systemic administration, which poses pharmacological challenges, is still pending. We report herein a comprehensive series of analyses on the impact of continuous intracerebroventricular infusion of p234 on puberty onset and the preovulatory surge of gonadotropins in the female rat. In addition, the effects of systemic (ip) administration of a tagged p234-penetratin, with a predicted higher permeability at the blood-brain barrier, on Kp-10 induced gonadotropin secretion were evaluated. Central infusion of p234 to pubertal females delayed vaginal opening and decreased uterine and ovarian weights at the expected time of puberty, without affecting body weight. Likewise, chronic intracerebroventricular administration of p234 for 4 d prevented the preovulatory surges of LH and FSH. In addition, systemic (ip) administration of p234-penetratin significantly attenuated acute LH and FSH responses to Kp-10, either after intracerebroventricular or ip injection of Kp. Our data document the validity of p234 for antagonizing Kp actions in vivo and provide direct experimental evidence for the important role of Kp signaling in the key events of female reproduction, such as puberty onset and the preovulatory surge of gonadotropins.

The role of kisspeptin in the control of gonadotrophin secretion

BACKGROUND

Kisspeptins, and their cognate receptor gpr-54, were first found to regulate the hypothalamic-pituitary-gonadal (HPG) axis in 2003, when two groups demonstrated that mutations in gpr-54 cause idiopathic hypogonadotropic hypogonadism characterized by delayed or absent puberty. This review aims to highlight discoveries in the KiSS-1/gpr-54 system, focusing on their regulation of the HPG axis in male and female reproductive systems of both mammalian and non-mammalian vertebrates.

METHODS

A search of PUBMED and the authors' files was done without limitations by language or species for citations relevant to kisspeptin, reproduction and signal transduction.

RESULTS

Kisspeptins and gpr-54 are critical for puberty and the regulation of reproduction. Kisspeptins have been implicated in mediating many of the important signals relayed to the gonadotrophin-releasing hormone (GnRH) neuron such as positive and negative feedback, metabolic input and photoperiod. The ability of kisspeptin neurons to co-ordinate different signals impinging on the HPG axis makes it one of the most important regulators of GnRH and the reproductive axis.

CONCLUSIONS

Kisspeptins are pivotal regulators of the HPG axis and reproduction, with the ability to integrate signals from both internal and external sources. Knowledge about the signalling mechanisms involved in kisspeptin stimulation of GnRH would help improve the understanding of the importance of this critical pathway in reproduction.