Clinical, functional and radiological outcomes of extracorporeal irradiation in limb salvage surgery for bone tumours

AIMS

We present a retrospective review of patients treated with extracorporeally irradiated allografts for primary and secondary bone tumours with the mid- and long-term survivorship and the functional and radiographic outcomes.

PATIENTS AND METHODS

A total of 113 of 116 (97.4%) patients who were treated with extracorporeally irradiated allografts between 1996 and 2014 were followed up. Forms of treatment included reconstructions, prostheses and composite reconstructions, both with and without vascularised grafts. Survivorship was determined by the Kaplan-Meier method. Clinical outcomes were assessed using the Musculoskeletal Tumor Society (MSTS) scoring system, the Toronto Extremity Salvage Score (TESS) and Quality of Life-C30 (QLQ-30) measures. Radiographic outcomes were assessed using the International Society of Limb Salvage (ISOLS) radiographic scoring system.

RESULTS

There were 61 (54%) men with a mean age of 22 years (6 to 70) and 52 (46%) women with a mean age of 26 years (3 to 85). There were 23 deaths. The five-year patient survivorship was 82.3% and the ten-year patient survivorship was 79.6%. The mean follow-up of the 90 surviving patients was 80.3 months (2 to 207). At the last follow-up, 105 allografts (92.9%) were still in place or had been at the time of death; eight (7%) had failed due to infection, local recurrence or fracture. Outcome scores were comparable with or superior to those in previous studies. The mean outcome scores were: MSTS 79% (sd 8); TESS 83% (sd 19); QLQ 82% (sd 16); ISOLS 80.5% (sd 19). Pearson correlation analysis showed a strong relationship between the MSTS and ISOLS scores (r = 0.71, p < 0.001).

CONCLUSION

This study shows that extracorporeal irradiation is a versatile reconstructive technique for dealing with large defects after the resection of bone tumours with good functional and radiographic outcomes. Functional outcomes as measured by MSTS, TESS and QLQ-30 were strongly correlated to radiographic outcomes. Cite this article: Bone Joint J 2017;99-B:1681-8.

Temporal trends in thyroid-stimulating hormone (TSH) and thyroid peroxidase antibody (ATPO) testing across two phases of iodine fortification in Tasmania (1995-2013)

CONTEXT

Tasmania is an island state of the Australian Commonwealth with a well-documented history of mild iodine deficiency. Between 2001 and 2009, Tasmania experienced two incremental phases of iodine fortification.

OBJECTIVE

To examine trends in thyroid-stimulating hormone (TSH) and thyroid peroxidase antibody (ATPO) testing and their relationship to different phases of iodine nutrition in the Tasmanian population between 1995 and 2013.

DESIGN

Retrospective longitudinal study.

SETTING AND PARTICIPANTS

The major primary care and largest public hospital pathology providers in Tasmania submitted data for all TSH and ATPO tests performed between 1995 and 2013. Data linkage methodology was used to determine trends in TSH and ATPO testing.

RESULTS

A total of 1.66 million TSH assessments, involving 389,910 individual patients, were performed in Tasmania between 1995 and 2013. There was approximately a fourfold increase in the overall rate of TSH testing during this period with the rate of incident TSH assessment remaining relatively stable over the study period. The incidence of overt suppression and elevation of TSH (TSH≤0.1 mIU/L and ≥10 mIU/L) declined 62.3% and 59.7%, respectively, with a trend for increased incidence of borderline TSH elevation ≥4.0 mIU/L. The incidence of thyroid autoimmunity as determined by the proportion of abnormal ATPO results remained stable, with the absolute number of positive test results increasing during the study period.

CONCLUSION

Iodine supplementation of this mildly iodine-deficient population was not associated with an obvious increase in incidence of overt thyroid dysfunction or autoimmunity. Whilst the volume of TSH testing increased over the study period, the increase was driven by patients undergoing follow-up TSH assessments.

Abstract P3-07-11: Inhibition of Pin1 or CDK-mediated Smad3 phosphorylation reduces triple negative breast cancer cell EMT, migration and invasion

Introduction: Triple negative breast cancer (TNBC) is an aggressive subtype associated with poor outcomes. Accordingly, there is an urgent need to develop novel and targeted therapeutics for patients with this disease subtype. Cyclins D and E and the corresponding activation of CDK4/2 represent promising therapeutic targets for the treatment of TNBC. CDK4/2 can non-canonically phosphorylate Smad3, a key TGFβ signaling intermediate, and this phosphorylation is associated with the promotion of cell migration and EMT in cyclin-overexpressing breast cancers. Additionally, CDK-mediated Smad3 phosphorylation facilitates an interaction between Smad3 and Pin1. Pin1 is a cis-trans isomerase that is also overexpressed in aggressive breast cancers and can enable TNBC cell migration. Based on these findings, we hypothesized that blockade of the CDK-mediated Smad3-Pin1 interaction, either through inhibition of Pin1 or CDK-mediated Smad3 phosphorylation, would abrogate TNBC cell migration and invasion.

Methods: Pin1 expression was knocked-down (KD) in MDA-MB-231, MDA-MB-436, and Hs578T TNBC cells by transfection with Pin1-targeting siRNA (siPin1) or control non-specific siRNA (siNS). KD efficiency was confirmed with immunoblotting. Pin KD/TNBC cell migration and invasion assays were performed on uncoated or Matrigel-coated trans-wells, respectively. Media containing 10% FBS was used as a chemoattractant. Following Pin1 KD, immunoblotting was used to evaluate EMT-associated protein expression. To inhibit CDK-mediated Smad3 phosphorylation, TNBC cells were treated with 600 nM of CDK2 inhibitor (CDK2i) for 72 hours. Immunoblotting was then performed to determine Smad3 phosphorylation and EMT-associated protein expression. Co-immunoprecipitation assays were used to examine the impact of CDK2i treatment on the Smad3-Pin1 interaction. Finally, following CDK2i treatment, assays were performed to determine the ability of TNBC cells to migrate and invade.

Results: KD of Pin1 expression in TNBC cells resulted in a decrease in cell migration and invasion when compared to control cells in all the study cell lines. This corresponded with changes in EMT-associated protein expression, including increased levels of ZO-1 and claudin and decreased β-catenin. CDK2i treatment produced a decrease in Smad3 T179 site non-canonical phosphorylation and inhibited Smad3-Pin1 binding. CDK2i treatment also abrogated TNBC cell migration and invasion, paralleling expression changes in EMT-associated proteins with an increase in claudin and decrease in β-catenin.

Conclusions: Inhibition of the Smad3-Pin1 interaction, through KD of Pin1 expression or CDK2i-mediated blockade of non-canonical Smad3 phosphorylation, reduced TNBC cell EMT-type changes, demonstrated by increased expression of the tight junction proteins ZO-1 and claudin and decreased β-catenin, a key player in the WNT pathway. These findings also correlated to a reduction in TNBC cell migration and invasion. Collectively, these data show that the Smad3-Pin1 interaction, facilitated by CDK-mediated Smad3 phosphorylation, is associated with pro-migratory TGFβ signaling. Inhibition of this interaction, with CDK2 inhibitor treatment, may provide an important therapeutic option for TNBC patients.

Citation Format: Thomas AL, Hamdan R, Hong A, Lind H, Oppat K, Rosenthal E, Thomas AJ, Jeruss JS. Inhibition of Pin1 or CDK-mediated Smad3 phosphorylation reduces triple negative breast cancer cell EMT, migration and invasion [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 P3-07-11.

Activity and safety of radiotherapy with anti-PD-1 drug therapy in patients with metastatic melanoma

The anti-PD-1 antibodies nivolumab and pembrolizumab are active in metastatic melanoma; however, there is limited data on combining anti-PD-1 antibody and radiotherapy (RT). We sought to review clinical outcomes of patients receiving RT and anti-PD-1 therapy. All patients receiving anti-PD-1 antibody and RT for metastatic melanoma were identified. RT and systemic treatment, clinical outcome, and toxicity data were collected. Fifty-three patients were included; 35 patients received extracranial RT and/or intracranial stereotactic radiosurgery (SRS) and 21 received whole brain radiotherapy (WBRT) (three of whom also received SRS/extracranial RT). Patients treated with extracranial RT or SRS received treatment either sequentially (RT then anti-PD-1, n = 11), concurrently (n = 16), or concurrent "salvage" treatment to lesions progressing on anti-PD-1 therapy (n = 15). There was no excessive anti-PD-1 or RT toxicity observed in patients receiving extracranial RT. Of six patients receiving SRS, one patient developed grade 3 radiation necrosis. In 21 patients receiving WBRT, one patient developed Stevens-Johnson syndrome, one patient developed acute neurocognitive decline, and one patient developed significant cerebral edema in the setting of disease. Response in irradiated extracranial/intracranial SRS lesions was 44% for sequential treatment and 64% for concurrent treatment (p=0.448). Likewise there was no significant difference between sequential or concurrent treatment in lesional response of non-irradiated lesions. For progressing lesions subsequently irradiated, response rate was 45%. RT and anti-PD-1 antibodies can be safely combined, with no detectable excess toxicity in extracranial sites. WBRT and anti-PD-1 therapy is well tolerated, although there are rare toxicities and the role of either anti-PD-1 or WBRT in the etiology of these is uncertain.

Abstract P5-04-13: Pin1 negatively impacts Smad3 tumor suppression in triple negative breast cancer cell lines

Introduction: Triple negative breast cancer (TNBC) is an aggressive subtype associated with poor outcomes. Accordingly, there is an urgent need to develop novel and targeted therapeutics for patients with this disease subtype. Cyclins D and E and the corresponding activation of CDK4/2 represent promising therapeutic targets for the treatment of TNBC. CDK4/2 can non-canonically phosphorylate Smad3, a key TGFβ signaling intermediate, to promote the transition from tumor suppressive to oncogenic TGFβ activity in cyclin-overexpressing breast cancers. We identified a Smad3 interaction with Pin1, a cis-trans isomerase also overexpressed in aggressive breast cancers and associated with CDK-mediated Smad3 phosphorylation. Smad3 interaction with Pin1 can influence protein function and fidelity through recruitment of Smurf2 and subsequent proteasomal degradation. Based on these findings, we hypothesized that inhibition of the CDK-mediated Smad3-Pin1 interaction would stabilize Smad3 protein expression and restore tumor-suppressive Smad3 activity.

Methods: Pin1 expression was knocked-down (KD) in MDA-MB-231 TNBC cells by transfecting with Pin1-targeting siRNA (siPin1) or control non-specific siRNA (siNS). KD efficiency was confirmed by immunoblotting. To assay Smad3 transcriptional activity with Pin1 KD, luciferase reporter studies were performed. Also, following Pin1 KD, immunoblotting was used to determine expression of Smad3 and associated protein targets. MTS assays were utilized to determine cellular proliferation after Pin1 KD. Transwell migration assays were used to assay the effect of Pin1 KD or CDK2 inhibitor treatment, which blocked non-canonical Smad3 Thr179 phosphorylation, on TNBC cell migration.

Results: KD of Pin1 expression in TNBC cell lines resulted in an increase in Smad3 transcriptional activity compared to control cells, and correlated with an increase in expression of cdki p15 and a decrease in c-myc, Smad3-target genes and cell cycle regulators. Additionally, Pin1 KD resulted in a significant decrease in TNBC cell proliferation compared to siNS control TNBC cells. Smad3 protein levels increased following Pin1 KD, suggesting Pin1 action may negatively impact Smad3 stability. We also found that KD of Pin1 or treatment with a CDK2 inhibitor, which blocked Smad3 noncanonical Thr179 phosphorylation, resulted in significantly reduced TNBC cell migration.

Conclusions: Inhibiting the Smad3-Pin1 interaction by knock-down of Pin1 expression in TNBC cells restored Smad3 transcriptional activity, which correlated to an increase in expression of the Smad3 associated protein cdki p15, decrease in c-myc, and a decrease in cellular proliferation. Additionally, Pin1 KD enhanced Smad3 protein levels, suggesting a role of Pin1 in mediating Smad3 stability. Inhibiting the Smad3-Pin1 interaction with Pin1 KD or CDK2 inhibitor treatment also reduced TNBC cell migration. Collectively, these data suggest that the Smad3-Pin1 interaction, facilitated by noncanonical CDK-mediated Smad3 phosphorylation, is associated with pro-tumorigenic and pro-migratory TGFβ signaling, and inhibition of this interaction may provide an important therapeutic option for TNBC patients.

Citation Format: Thomas AL, Hamdan R, Hong A, Rosenthal E, Thomas AJ, Jeruss JS. Pin1 negatively impacts Smad3 tumor suppression in triple negative breast cancer cell lines. [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 P5-04-13.

Loss of Fas apoptosis inhibitory molecule leads to spontaneous obesity and hepatosteatosis

Altered hepatic lipogenesis is associated with metabolic diseases such as obesity and hepatosteatosis. Insulin resistance and compensatory hyperinsulinaemia are key drivers of these metabolic imbalances. Fas apoptosis inhibitory molecule (FAIM), a ubiquitously expressed antiapoptotic protein, functions as a mediator of Akt signalling. Since Akt acts at a nodal point in insulin signalling, we hypothesize that FAIM may be involved in energy metabolism. In the current study, C57BL/6 wild-type (WT) and FAIM-knockout (FAIM-KO) male mice were fed with normal chow diet and body weight changes were monitored. Energy expenditure, substrate utilization and physical activities were analysed using a metabolic cage. Liver, pancreas and adipose tissue were subjected to histological examination. Serum glucose and insulin levels and lipid profiles were determined by biochemical assays. Changes in components of the insulin signalling pathway in FAIM-KO mice were examined by immunoblots. We found that FAIM-KO mice developed spontaneous non-hyperphagic obesity accompanied by hepatosteatosis, adipocyte hypertrophy, dyslipidaemia, hyperglycaemia and hyperinsulinaemia. In FAIM-KO liver, lipogenesis was elevated as indicated by increased fatty acid synthesis and SREBP-1 and SREBP-2 activation. Notably, protein expression of insulin receptor beta was markedly reduced in insulin target organs of FAIM-KO mice. Akt phosphorylation was also lower in FAIM-KO liver and adipose tissue as compared with WT controls. In addition, phosphorylation of insulin receptor substrate-1 and Akt2 in response to insulin treatment in isolated FAIM-KO hepatocytes was also markedly attenuated. Altogether, our data indicate that FAIM is a novel regulator of insulin signalling and plays an essential role in energy homoeostasis. These findings may shed light on the pathogenesis of obesity and hepatosteatosis.

Radiotherapy for lentigo maligna: a literature review and recommendations for treatment

Lentigo maligna (LM) incidence is increasing. LM frequently involves the face near critical anatomical structures and as a consequence clinical management is challenging. Nonsurgical therapies, including radiotherapy (RT), are increasingly used. Evidenced-based treatment guidelines are lacking. We conducted a review of previously published data analysing RT treatment of LM. A search of PubMed, Embase and Medline databases to June 2012 identified nine clinical studies that examined the use of RT for LM treatment in at least five patients. Nine studies described 537 patients with LM treated with definitive primary RT, between 1941 and 2009, with a median reported follow-up time of 3 years. Eight articles could be reviewed for oncological outcome data. There were 18 recurrences documented in a total of 349 assessable patients (5%). Salvage was successful in the majority of recurrent LM cases by using further RT, surgery or other therapies. Progression to LM melanoma (LMM) occurred in five patients (five out of 349, 1.4%) who all had poor outcomes. There were five marginal recurrences documented out of 123 assessable patients (4%). There were eight in-field recurrences documented with either LM (five) or LMM (three) out of 171 assessable patients (5%). A series of recommendations were then developed for RT parameters for treatment of LM. These parameters include treatment volume, dose, dose per fraction and outcome measures. These may be of use in prospective data collection.

Surveillance for treatment failure of lentigo maligna with dermoscopy and in vivo confocal microscopy: new descriptors

BACKGROUND

Nonsurgical treatment (radiotherapy, imiquimod) is increasingly employed for the management of lentigo maligna (LM). While the diagnosis of LM remains difficult, the detection of treatment failure is even more challenging.

OBJECTIVES

To describe the sensitivity and specificity for the diagnosis of LM of individual features and methods using dermoscopy and in vivo reflectance confocal microscopy (RCM) to aid in the detection of treatment failure of LM following nonsurgical treatment.

METHODS

A retrospective study of dermoscopy and RCM images (blinded to the correlation with pathology) in patients with biopsy-confirmed LM who were undergoing nonsurgical treatment in two referral institutions - one in Sydney, Australia, and the other in Barcelona, Spain. Ninety-eight patients were treated nonsurgically for LM during the period 2006-2012. Thirty-one patients had abnormal dermoscopy or RCM evaluation, and had a biopsy that identified LM recurrence in 15 patients and nonmelanoma diagnoses in 16 patients (one Bowen disease, 15 solar changes).

RESULTS

The diagnosis of treatment failure was difficult with dermoscopy, with a sensitivity of 80% and specificity of 56%, even with the interpretation of an expert. The best criterion was asymmetric hyperpigmented follicular openings, but this was present in only 47% of treatment failure LM. Isolated, very fine brown dots ('dust' appearance) correlated highly with the diagnosis of treatment failure LM (73% sensitivity and 88% specificity) and with pagetoid cells seen with RCM. The LM score, comprising six criteria, had a specificity of 94% and sensitivity of 100%.

CONCLUSIONS

These methods and descriptors should help to manage the diagnosis of treatment failure.

Heparin-binding EGF-like growth factor and miR-1192 exert opposite effect on Runx2-induced osteogenic differentiation

Osteoblast differentiation is a pivotal event in bone formation. Runt-related transcription factor-2 (Runx2) is an essential factor required for osteoblast differentiation and bone formation. However, the underlying mechanism of Runx2-regulated osteogenic differentiation is still unclear. Here, we explored the corresponding mechanism using the C2C12/Runx2(Dox) subline, which expresses Runx2 in response to doxycycline (Dox). We found that Runx2-induced osteogenic differentiation of C2C12 cells results in a sustained decrease in the expression of heparin-binding EGF-like growth factor (HB-EGF), a member of the epidermal growth factor (EGF) family. Forced expression of HB-EGF or treatment with HB-EGF is capable of reducing the expression of alkaline phosphatase (ALP), a defined marker of early osteoblast differentiation. HB-EGF-mediated inhibition of ALP depends upon activation of the EGFR and the downstream extracellular signal-regulated kinase, c-Jun N-terminal kinase mitogen-activated protein kinase pathways as well as phosphatidylinositol 3-kinase/Akt pathway. Runx2 specifically binds to the Hbegf promoter, suggesting that Hbegf transcription is directly inhibited by Runx2. Runx2 can upregulate miR-1192, which enhances Runx2-induced osteogenic differentiation. Moreover, miR-1192 directly targets Hbegf through translational inhibition, suggesting enhancement of Runx2-induced osteogenic differentiation by miR-1192 through the downregulation of HB-EGF. Taken together, our results suggest that Runx2 induces osteogenic differentiation of C2C12 cells by inactivating HB-EGF-EGFR signaling through the downregulation of HB-EGF via both transcriptional and post-transcriptional mechanisms.