A comparison of questionnaires for assessing physical function in patients with lower extremity bone metastases

OBJECTIVES

To assess, (i) the degree to which the: PROMIS Physical Function Cancer, PROMIS Neuro-QoL Mobility, Toronto Extremity Salvage Score (TESS), Lower Extremity Function Score (LEFS), and Musculoskeletal Tumor Society score (MSTS), measure physical function; (ii) differences in coverage and reliability; and (iii) difference in completion time.

METHODS

One hundred of 115 (87%) patients with lower extremity metastases participated in this prospective study. We used exploratory factor analysis-correlating questionnaires with an underlying trait-to assess if questionnaires measure the same. Coverage was assessed by floor and ceiling effect and reliability by the standard error of measurement (SEM). Completion time was compared using the Friedman test.

RESULTS

All questionnaires measured the same concept; demonstrated by high correlations (>0.7). Floor effect was absent, while ceiling effect was present in all, but highest for the PROMIS Neuro-QoL Mobility (7%). The SEM was below the threshold-indicating reliability-over a wide range of ability levels for the PROMIS-Physical Function, TESS, and LEFS. Completion time differed between questionnaires (P < 0.001) and was shortest for the PROMIS questionnaires.

CONCLUSIONS

The PROMIS Physical Function is the most useful questionnaire. This is due to its reliability over a wide range of ability levels, validity, brevity, and good coverage. J. Surg. Oncol. 2016;114:691-696. © 2016 Wiley Periodicals, Inc.

Abstract 4678: Inhibition of CDK4 sensitizes multidrug resistant ovarian cancer cells to paclitaxel by increasing apoptosis

Purpose: Overexpression of cyclin-dependent kinase (CDK) 4 has been shown in a variety of cancers and contributes to tumor cell growth and proliferation. However, the effect of inhibition of CDK4 in ovarian cancer is unknown. Here we investigated the therapeutic effect of CDK4 inhibitor, palbociclib, in combination with paclitaxel in ovarian cancer cells. Experimental Design: Cell viability was determined by MTT assay after incubating with different dosages of palbociclib and/or paclitaxel. Western blot, immunofluorescence, and Calcein AM assays were conducted to determine the potential effects and mechanisms of palbociclib in combination with paclitaxel. CDK4 siRNA was used to validate the outcome of targeting CDK4 in ovarian cancer cells. Immunohistochemistry was performed to evaluate the clinical relevance of CDK4 expression in an ovarian cancer tissue microarray. Results: The combination of palbociclib and paclitaxel significantly enhanced drug sensitivity in both Rb positive (Rb+) and Rb negative (Rb-) ovarian cancer cells. Palbociclib suppressed the phosphorylation of pRb (Ser 807-811, Ser 795, and Ser 780) in multidrug resistant SKOV3TR (Rb+) cells. When combined with paclitaxel, palbociclib induced significant apoptosis in both SKOV3TR (Rb+) and OVCAR8TR (Rb-) cells. Palbociclib also inhibited the activity of P-glycoprotein (Pgp). Additionally, transfection of CDK4 siRNA showed effective knockdown of CDK4 expression and sensitized multidrug resistant SKOV3TR and OVCAR8TR cells to paclitaxel. Furthermore, primary ovarian cancer patients with high expression of CDK4 tended to have unfavorable clinical outcomes. Conclusions: Inhibition of CDK4 either by palbociclib or by specific siRNA can increase the in vitro paclitaxel sensitivity in either Rb+ or Rb- multidrug resistant ovarian cancer cells through increased apoptosis. Therefore, CDK4 may be a promising target in the treatment of ovarian cancer.

Citation Format: YAN GAO, Jacson Shen, Rosemary Foster, Francis J. Hornicek, Zhenfeng Duan. Inhibition of CDK4 sensitizes multidrug resistant ovarian cancer cells to paclitaxel by increasing apoptosis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4678.

Outcome after fixation of metastatic proximal femoral fractures: A systematic review of 40 studies

Endoprosthetic reconstruction, intramedullary nailing, and open reduction internal fixation (ORIF) are the most commonly practiced surgical strategies for treatment of metastatic proximal femoral fractures. This review describes functional outcome, local, and systemic complications. All three surgical strategies result in reasonable function on average; however, wide ranges indicate that both poor and good functional levels are obtained. We found that the overall reoperation rate was comparable for endoprosthesis and intramedullary nailing, but was higher for ORIF. J. Surg. Oncol. 2016;114:507-519. © 2016 Wiley Periodicals, Inc.

The emerging roles and therapeutic potential of cyclin-dependent kinase 11 (CDK11) in human cancer

Overexpression and/or hyperactivation of cyclin-dependent kinases (CDKs) are common features of most cancer types. CDKs have been shown to play important roles in tumor cell proliferation and growth by controlling cell cycle, transcription, and RNA splicing. CDK4/6 inhibitor palbociclib has been recently approved by the FDA for the treatment of breast cancer. CDK11 is a serine/threonine protein kinase in the CDK family and recent studies have shown that CDK11 also plays critical roles in cancer cell growth and proliferation. A variety of genetic and epigenetic events may cause universal overexpression of CDK11 in human cancers. Inhibition of CDK11 has been shown to lead to cancer cell death and apoptosis. Significant evidence has suggested that CDK11 may be a novel and promising therapeutic target for the treatment of cancers. This review will focus on the emerging roles of CDK11 in human cancers, and provide a proof-of-principle for continued efforts toward targeting CDK11 for effective cancer treatment.

CSPG4 as a prognostic biomarker in chordoma

BACKGROUND

There are currently no generally accepted biomarkers used in the clinical treatment of chordoma tumors. CSPG4 has been associated with disease severity in other tumors.

PURPOSE

This study aimed to characterize the frequency of CSPG4 expression in chordoma tumors and to correlate it with disease severity and clinical outcome.

STUDY DESIGN

A retrospective review of clinical outcomes and immunohistochemical staining using tissue micro-array was carried out.

PATIENT SAMPLE

The sample comprised 86 patients treated for chordoma at a single center (1985-2007).

OUTCOME MEASURES

Survival and incidence of metastases were the outcome measures.

METHODS

Pathologic specimens of chordoma tumors were evaluated for the expression of CSPG4 by immunohistochemical staining with mAbs. Chi-square testing and Cox proportional hazard regression analysis were used to evaluate the impact of CSPG4 expression on survival and incidence of metastases, while controlling for patient age, sex, and surgical margins.

RESULTS

Average patient age at the time of presentation was 59.8 years (standard deviation [SD] 13.7). Average follow-up was 6.5 years (SD 4.8). Twenty (23%) patients developed metastatic disease. At the time of final follow-up, 57 patients (66%) had died. Chordoma tumors from 62 patients (72%) stained positive for CSPG4. CSPG4 expression more than doubled the risk of death (hazard ratio [HR] 2.3; 95% CI 1.04, 5.17). CSPG4 positive tumors were also associated with an increased risk of metastatic disease (31% for CSPG4 positive tumors vs. 0% in CSPG4 negative, p=.02).

CONCLUSIONS

Results presented here support the consideration of using CSPG4 as a biomarker establishing the prognosis for chordoma tumors. A positive CSPG4 stain may be associated with an increased risk of metastasis and mortality from disease.

Cyclin-Dependent Kinase 11 (CDK11) Is Required for Ovarian Cancer Cell Growth In Vitro and In Vivo, and Its Inhibition Causes Apoptosis and Sensitizes Cells to Paclitaxel

Ovarian cancer is currently the most lethal gynecologic malignancy with limited treatment options. Improved targeted therapies are needed to combat ovarian cancer. Here, we report the identification of cyclin-dependent kinase 11 (CDK11) as a mediator of tumor cell growth and proliferation in ovarian cancer cells. Although CDK11 has not been implicated previously in this disease, we have found that its expression is upregulated in human ovarian cancer tissues and associated with malignant progression. Metastatic and recurrent tumors have significantly higher CDK11 expression when compared with the matched, original primary tumors. RNAi-mediated CDK11 silencing by synthetic siRNA or lentiviral shRNA decreased cell proliferation and induced apoptosis in ovarian cancer cells. Moreover, CDK11 knockdown enhances the cytotoxic effect of paclitaxel to inhibit cell growth in ovarian cancer cells. Systemic in vivo administration of CDK11 siRNA reduced the tumor growth in an ovarian cancer xenograft model. Our findings suggest that CDK11 may be a promising therapeutic target for the treatment of ovarian cancer patients. Mol Cancer Ther; 15(7); 1691-701. ©2016 AACR.

Primary intra-articular sarcoma: a clinicopathological study of 15 cases

AIMS

To assess the clinical and histopathological spectrum of primary intra-articular sarcomas.

METHODS AND RESULTS

Fifteen patients were identified as having primary intra-articular sarcomas and the clinical and pathological features were evaluated. There were nine males and six females who ranged in age from 16 to 84 (mean 44) years. All tumours originated in the knee joint. The pathological diagnoses included: five synovial sarcoma, three extraskeletal myxoid chondrosarcomas, two high-grade myxofibrosarcoma (one conventional, one epithelioid), two undifferentiated pleomorphic sarcoma (one with giant cells) and one each myxoinflammatory fibroblastic sarcoma, conventional hyaline chondrosarcoma, and high-grade myofibroblastic sarcoma. All tumours were treated by segmental resection or amputation. Adjuvant therapy was given in selected cases. Follow-up ranged from 11 to 150 months. Of patients with follow-up, two died of disease; one developed pulmonary metastases after 6 years and was then lost to follow-up. Nine patients were alive and free of disease 12-150 months after diagnosis.

CONCLUSIONS

Primary sarcomas of the joints are very rare and most frequently affect the knee. Our experience indicates that synovial sarcoma and extraskeletal myxoid chondrosarcoma are the most common intra-articular sarcomas.

Targeting EZH2-mediated methylation of H3K27 inhibits proliferation and migration of Synovial Sarcoma in vitro

Synovial sarcoma is an aggressive soft tissue sarcoma genetically defined by the fusion oncogene SS18-SSX. It is hypothesized that either SS18-SSX disrupts SWI/SNF complex inhibition of the polycomb complex 2 (PRC2) methyltransferase Enhancer of Zeste Homologue 2 (EZH2), or that SS18-SSX is able to directly recruit PRC2 to aberrantly silence target genes. This is of potential therapeutic value as several EZH2 small molecule inhibitors are entering early phase clinical trials. In this study, we first confirmed EZH2 expression in the 76% of human synovial sarcoma samples. We subsequently investigated EZH2 as a therapeutic target in synovial sarcoma in vitro. Knockdown of EZH2 by shRNA or siRNA resulted in inhibition of cell growth and migration across a series of synovial sarcoma cell lines. The EZH2 selective small-molecule inhibitor EPZ005687 similarly suppressed cell proliferation and migration. These data support the hypothesis that targeting EZH2 may be a promising therapeutic strategy in the treatment of synovial sarcoma; clinical trials are initiating enrollment currently.

The experience of accommodating privacy restrictions during implementation of a large-scale surveillance study of an osteoporosis medication

Purpose

To explore whether privacy restrictions developed to protect patients have complicated research within a 15‐year surveillance study conducted with US cancer registries.

Methods

Data from enrolling 27 cancer registries over a 10‐year period were examined to describe the amount of time needed to obtain study approval. We also analyzed the proportion of patients that completed a research interview out of the total reported by the registries and examined factors thought to influence this measure.

Results

The average length of the research review process from submission to approval of the research was 7 months (range, <1 to 24 months), and it took 6 months or more to obtain approval of the research at 41% of the cancer registries. Most registries (78%) required additional permission steps to gain access to patients for research. After adjustment for covariates, the interview response proportion was 110% greater (ratio of response proportion = 2.1; 95% confidence interval: 1.3, 3.3) when the least restrictive versus the most restrictive permission steps were required. An interview was more often completed for patients (or proxies) if patients were alive, within a year of being diagnosed, or identified earlier in the study.

Conclusions

Lengthy research review processes increased the time between diagnosis and provision of patient information to the researcher. Requiring physician permission for access to patients was associated with lower subject participation. A single national point of entry for use of cancer registry data in health research is worthy of consideration to make the research approval process efficient. © 2016 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons Ltd.

MicroRNA-155 expression is independently predictive of outcome in chordoma

Background

Chordoma pathogenesis remains poorly understood. In this study, we aimed to evaluate the relationships between microRNA-155 (miR-155) expression and the clinicopathological features of chordoma patients, and to evaluate the functional role of miR-155 in chordoma.

Methods

The miRNA expression profiles were analyzed using miRNA microarray assays. Regulatory activity of miR-155 was assessed using bioinformatic tools. miR-155 expression levels were validated by reverse transcription-polymerase chain reaction. The relationships between miR-155 expression and the clinicopathological features of chordoma patients were analyzed. Proliferative, migratory and invasive activities were assessed by MTT, wound healing, and Matrigel invasion assays, respectively.

Results

The miRNA microarray assay revealed miR-155 to be highly expressed and biologically active in chordoma. miR-155 expression in chordoma tissues was significantly elevated, and this expression correlated significantly with disease stage (p = 0.036) and the presence of metastasis (p = 0.035). miR-155 expression also correlated significantly with poor outcomes for chordoma patients (hazard ratio, 5.32; p = 0.045). Inhibition of miR-155 expression suppressed proliferation, and the migratory and invasive activities of chordoma cells.

Conclusions

We have shown miR-155 expression to independently affect prognosis in chordoma. These results collectively indicate that miR-155 expression may serve not only as a prognostic marker, but also as a potential therapeutic target in chordoma.

Complications after surgery for metastatic humeral lesions

BACKGROUND

Knowledge of surgical outcome and its predictors helps inform patients and aids in surgical decision-making. We aimed to assess the outcome-reoperation and systemic complication rate-of surgery for humeral metastases, myeloma, or lymphoma. Our null hypothesis was that there are no factors associated with these outcomes.

METHODS

We included 295 consecutive patients in this retrospective study: 134 (45%) proximal, 131 (44%) diaphyseal, and 30 (10%) distal impending or pathologic fractures. Proximal lesions were treated by intramedullary nailing (43%, n = 57), prosthesis (34%, n = 46), plate-screw fixation (22%, n = 30), and a combination (n = 1). Diaphyseal lesions were treated by intramedullary nailing (69%, n = 91), plate-screw fixation (30%, n = 39), and a combination (n = 1). Distal lesions were treated by plate-screw fixation (97%, n = 29) and intramedullary nailing (3.3%, n = 1).

RESULTS

We found 25 (8.5%) reoperations, and 17 (5.8%) patients had 18 systemic complications: pneumonia (3.7%, n = 11), pulmonary embolism (1.3%, n = 4), sepsis (0.68%, n = 2), and fat embolism (0.34%, n = 1). No factors were independently associated with reoperation. Logistic regression analysis demonstrated that favorable cancer status (i.e., a higher modified Bauer score: odds ratio, 0.48; 95% confidence interval, 0.29-0.80; P = .005) was independently associated with a decreased systemic complication rate.

CONCLUSION

Poor cancer status was an independent predictor of postoperative systemic complications. This could help inform the patient and anticipate postoperative problems.

NVP-TAE684 reverses multidrug resistance (MDR) in human osteosarcoma by inhibiting P-glycoprotein (PGP1) function

BACKGROUND AND PURPOSE

Increased expression of P-glycoprotein (PGP1) is one of the major causes of multidrug resistance (MDR) in cancer, including in osteosarcoma, which eventually leads to the failure of cancer chemotherapy. Thus, there is an urgent need to develop effective therapeutic strategies to override the expression and function of PGP1 to counter MDR in cancer patients.

EXPERIMENTAL APPROACH

In an effort to search for new chemical entities targeting PGP1-associated MDR in osteosarcoma, we screened a 500+ compound library of known kinase inhibitors with established kinase selectivity profiles. We aimed to discover potential drug synergistic effects among kinase inhibitors and general chemotherapeutics by combining inhibitors with chemotherapy drugs such as doxorubicin and paclitaxel. The human osteosarcoma MDR cell lines U2OSR2 and KHOSR2 were used for the initial screen and secondary mechanistic studies.

KEY RESULTS

After screening 500+ kinase inhibitors, we identified NVP-TAE684 as the most effective MDR reversing agent. NVP-TAE684 significantly reversed chemoresistance when used in combination with doxorubicin, paclitaxel, docetaxel, vincristine, ET-743 or mitoxantrone. NVP-TAE684 itself is not a PGP1 substrate competitive inhibitor, but it can increase the intracellular accumulation of PGP1 substrates in PGP1-overexpressing cell lines. NVP-TAE684 was found to inhibit the function of PGP1 by stimulating PGP1 ATPase activity, a phenomenon reported for other PGP1 inhibitors.

CONCLUSIONS AND IMPLICATIONS

The application of NVP-TAE684 to restore sensitivity of osteosarcoma MDR cells to the cytotoxic effects of chemotherapeutics will be useful for further study of PGP1-mediated MDR in human cancer and may ultimately benefit cancer patients.

Development and potential applications of CRISPR-Cas9 genome editing technology in sarcoma

Sarcomas include some of the most aggressive tumors and typically respond poorly to chemotherapy. In recent years, specific gene fusion/mutations and gene over-expression/activation have been shown to drive sarcoma pathogenesis and development. These emerging genomic alterations may provide targets for novel therapeutic strategies and have the potential to transform sarcoma patient care. The RNA-guided nuclease CRISPR-Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-associated protein-9 nuclease) is a convenient and versatile platform for site-specific genome editing and epigenome targeted modulation. Given that sarcoma is believed to develop as a result of genetic alterations in mesenchymal progenitor/stem cells, CRISPR-Cas9 genome editing technologies hold extensive application potentials in sarcoma models and therapies. We review the development and mechanisms of the CRISPR-Cas9 system in genome editing and introduce its application in sarcoma research and potential therapy in clinic. Additionally, we propose future directions and discuss the challenges faced with these applications, providing concise and enlightening information for readers interested in this area.

Characteristics and Patterns of Metastatic Disease from Chordoma

Chordoma is a rare, slow-growing malignant tumor arising from notochordal remnants. A retrospective review of patient records at two major referral centers was undertaken to assess the incidence, location, and prognostic factors of metastatic disease from chordoma. 219 patients with chordoma (1962-2009) were identified. 39 patients (17.8%) developed metastatic disease, most frequently to lung (>50%). Median survival from the time of initial diagnosis was 130.4 months for patients who developed metastatic disease and 159.3 months for those who did not (P = 0.05). Metastatic disease was most common in the youngest patients (P = 0.07), and it was 2.5 times more frequent among patients with local recurrence (26.3%) than in those without (10.8%) (P = 0.003). Patient survival with metastatic disease was highly variable, and it was dependent on both the location of the tumor primary and the site of metastasis. Metastasis to distal bone was the most rapid to develop and had the worst prognosis.

Targeting protein kinases to reverse multidrug resistance in sarcoma

Sarcomas are a group of cancers that arise from transformed cells of mesenchymal origin. They can be classified into over 50 subtypes, accounting for approximately 1% of adult and 15% of pediatric cancers. Wide surgical resection, radiotherapy, and chemotherapy are the most common treatments for the majority of sarcomas. Among these therapies, chemotherapy can palliate symptoms and prolong life for some sarcoma patients. However, sarcoma cells can have intrinsic or acquired resistance after treatment with chemotherapeutics drugs, leading to the development of multidrug resistance (MDR). MDR attenuates the efficacy of anticancer drugs and results in treatment failure for sarcomas. Therefore, overcoming MDR is an unmet need for sarcoma therapy. Certain protein kinases demonstrate aberrant expression and/or activity in sarcoma cells, which have been found to be involved in the regulation of sarcoma cell progression, such as cell cycle, apoptosis, and survival. Inhibiting these protein kinases may not only decrease the proliferation and growth of sarcoma cells, but also reverse their resistance to chemotherapeutic drugs to subsequently reduce the doses of anticancer drugs and decrease drug side-effects. The discovery of novel strategies targeting protein kinases opens a door to a new area of sarcoma research and provides insight into the mechanisms of MDR in chemotherapy. This review will focus on the recent studies in targeting protein kinase to reverse chemotherapeutic drug resistance in sarcoma.

The emerging roles and therapeutic potential of microRNAs (miRs) in liposarcoma

Liposarcoma (LPS) is a common subtype of soft tissue sarcoma and accounts for approximately 20% of adult sarcomas. Despite the progress in diagnosis and treatment of LPS, there is still a high mortality rate due to local recurrence or metastasis. The mechanisms underlying the development of recurrence and metastasis of LPS remain elusive. MicroRNAs (miRNAs or miRs) are non-coding RNAs that regulate target gene expression, influencing many cellular functions, including cell proliferation, apoptosis, differentiation, oncogenesis, and drug resistance in malignant cells. The dysregulation of miRs is involved in the initiation and progression of human cancers, including LPS. Functional studies have shown the potent pro- and anti-tumorigenic activity of specific miRs both in vitro and in vivo. miR signatures that are unique to specific types of LPS have been proposed. Several lines of evidence have shown that miRs can act either as oncogenes or tumor suppressor genes, as well as diagnostic and prognostic biomarkers for LPS. In addition, miRs may be a powerful therapeutic target in LPS, although obstacles such as delivery of miRs in vivo need to be overcome. In this review, we discuss the emerging roles of miRs in different histological subtypes of LPS.

Surgical management of Gorham-Stout disease of the pelvis refractory to medical and radiation therapy

Gorham-Stout disease (GSD) is a rare condition characterized by spontaneous idiopathic bone resorption that can affect any part of the skeleton. Treatment is aimed at halting osteolysis and alleviating complications associated with bone loss. Often this can be achieved via observation and supportive management, medical treatment, and/or radiation therapy. We report a case of GSD of the pelvis that was refractory to medical and radiation therapy and was managed successfully with surgery. A 30-year-old man presented to our clinic 3 years after being diagnosed at an outside institution with GSD of the pelvis that was managed with medical treatments and radiation therapy. Despite aggressive, multimodality treatment, he was unable to ambulate without crutches and was in significant pain. The patient opted for intralesional surgery and spinopelvic fusion. Sixteen months after surgery, the patient had only mild pain and was able to ambulate with a cane. Very few cases have been reported of GSD involving the pelvis that necessitated surgical management. Significant functional impairment can occur as a result of pelvic osteolysis, and traditional management strategies focused on halting resorption may not be adequate. Surgical stabilization of the affected areas is an important treatment strategy for patients who have exhausted other options.

2015 Marshall Urist Young Investigator Award: Prognostication in Patients With Long Bone Metastases: Does a Boosting Algorithm Improve Survival Estimates?

BACKGROUND

Survival estimation guides surgical decision-making in metastatic bone disease. Traditionally, classic scoring systems, such as the Bauer score, provide survival estimates based on a summary score of prognostic factors. Identification of new factors might improve the accuracy of these models. Additionally, the use of different algorithms--nomograms or boosting algorithms--could further improve accuracy of prognostication relative to classic scoring systems. A nomogram is an extension of a classic scoring system and generates a more-individualized survival probability based on a patient's set of characteristics using a figure. Boosting is a method that automatically trains to classify outcomes by applying classifiers (variables) in a sequential way and subsequently combines them. A boosting algorithm provides survival probabilities based on every possible combination of variables.

QUESTIONS/PURPOSES

We wished to (1) assess factors independently associated with decreased survival in patients with metastatic long bone fractures and (2) compare the accuracy of a classic scoring system, nomogram, and boosting algorithms in predicting 30-, 90-, and 365-day survival.

METHODS

We included all 927 patients in our retrospective study who underwent surgery for a metastatic long bone fracture at two institutions between January 1999 and December 2013. We included only the first procedure if patients underwent multiple surgical procedures or had more than one fracture. Median followup was 8 months (interquartile range, 3-25 months); 369 of 412 (90%) patients who where alive at 1 year were still in followup. Multivariable Cox regression analysis was used to identify clinical and laboratory factors independently associated with decreased survival. We created a classic scoring system, nomogram, and boosting algorithms based on identified variables. Accuracy of the algorithms was assessed using area under the curve analysis through fivefold cross validation.

RESULTS

The following factors were associated with a decreased likelihood of survival after surgical treatment of a metastatic long bone fracture, after controlling for relevant confounding variables: older age (hazard ratio [HR], 1.0; 95% CI, 1.0-1.0; p < 0.001), additional comorbidity (HR, 1.2; 95% CI, 1.0-1.4; p = 0.034), BMI less than 18.5 kg/m(2) (HR, 2.0; 95% CI, 1.2-3.5; p = 0.011), tumor type with poor prognosis (HR, 1.8; 95% CI, 1.6-2.2; p < 0.001), multiple bone metastases (HR, 1.3; 95% CI, 1.1-1.6; p = 0.008), visceral metastases (HR, 1.6; 95% CI, 1.4-1.9; p < 0.001), and lower hemoglobin level (HR, 0.91; 95% CI, 0.87-0.96; p < 0.001). The survival estimates by the nomogram were moderately accurate for predicting 30-day (area under the curve [AUC], 0.72), 90-day (AUC, 0.75), and 365-day (AUC, 0.73) survival and remained stable after correcting for optimism through fivefold cross validation. Boosting algorithms were better predictors of survival on the training datasets, but decreased to a performance level comparable to the nomogram when applied on testing datasets for 30-day (AUC, 0.69), 90-day (AUC, 0.75), and 365-day (AUC, 0.72) survival prediction. Performance of the classic scoring system was lowest for all prediction periods.

CONCLUSIONS

Comorbidity status and BMI are newly identified factors associated with decreased survival and should be taken into account when estimating survival. Performance of the boosting algorithms and nomogram were comparable on the testing datasets. However, the nomogram is easier to apply and therefore more useful to aid surgical decision making in clinical practice.

LEVEL OF EVIDENCE

Level III, prognostic study.

High-dose proton-based radiation therapy in the management of spine chordomas: outcomes and clinicopathological prognostic factors

OBJECT

Spinal chordomas can have high local recurrence rates after surgery with or without conventional dose radiation therapy (RT). Treatment outcomes and prognostic factors after high-dose proton-based RT with or without surgery were assessed.

METHODS

The authors conducted a retrospective review of 126 treated patients (127 lesions) categorized according to disease status (primary vs recurrent), resection (en bloc vs intralesional), margin status, and RT timing.

RESULTS

Seventy-one sacrococcygeal, 40 lumbar, and 16 thoracic chordomas were analyzed. Mean RT dose was 72.4 GyRBE (relative biological effectiveness). With median follow-up of 41 months, the 5-year overall survival (OS), local control (LC), locoregional control (LRC), and distant control (DC) for the entire cohort were 81%, 62%, 60%, and 77%, respectively. LC for primary chordoma was 68% versus 49% for recurrent lesions (p = 0.058). LC if treated with a component of preoperative RT was 72% versus 54% without this treatment (p = 0.113). Among primary tumors, LC and LRC were higher with preoperative RT, 85% (p = 0.019) and 79% (0.034), respectively, versus 56% and 56% if no preoperative RT was provided. Overall LC was significantly improved with en bloc versus intralesional resection (72% vs 55%, p = 0.016), as was LRC (70% vs 53%, p = 0.035). A trend was noted toward improved LC and LRC for R0/R1 margins and the absence of intralesional procedures.

CONCLUSIONS

High-dose proton-based RT in the management of spinal chordomas can be effective treatment. In patients undergoing surgery, those with primary chordomas undergoing preoperative RT, en bloc resection, and postoperative RT boost have the highest rate of local tumor control; among 28 patients with primary chordomas who underwent preoperative RT and en bloc resection, no local recurrences were seen. Intralesional and incomplete resections are associated with higher local failure rates and are to be avoided.

Percutaneous Acetabuloplasty Compared With Open Reconstruction for Extensive Periacetabular Carcinoma Metastases

For destructive metastatic periacetabular disease, options include open acetabular reconstruction or percutaneous cement acetabuloplasty (PA). We reviewed 28 consecutive patients with Harrington grade II or III lesions, 17 who underwent Harrington-type or anti-protrusio reconstruction and 11 who underwent PA. Primary outcome measures were performance status (PS), ambulatory status (0=unassisted ambulation, 1=assisted ambulation, 2=nonambulatory), and 10-point VAS score. The surgery group had better pain reduction than the PA group at 3 months (3.6 vs. 1.5 points, P=0.04), and a trend at final follow-up (3.8 vs. 1.4 points, P=0.06). Improvement in ambulatory status was better in the surgery group at 3 months only (0.53 vs. -0.14, P=0.03). Thus compared with PA, open reconstruction may provide improved pain relief and ambulation.

Abstract 352: Up-regulation of CD44 in the development of metastasis, recurrence and drug resistance of ovarian cancer

Purpose: The clinical significance of Cluster of differentiation 44 (CD44) remains controversial in human ovarian cancer. The aim of this study is to evaluate the clinical significance of CD44 expression by using a unique tissue microarray, and then to determine the biological functions of CD44 in ovarian cancer.

Experimental Design: A unique ovarian cancer tissue microarray (TMA) was constructed with paired primary, metastatic, and recurrent tumor tissues from 26 individual patients. CD44 expression in TMA was assessed by immunohistochemistry. Western blotting and Immunofluorescence assay determined the expression of CD44 and/or P-glycoprotein (Pgp) in ovarian cancer cell lines and the tumor tissues of a paclitaxel treated ovarian cancer xenograft mouse model. MTT assay, wound healing assay, and matrigel invasion assay were utilized to assess the proliferation, drug sensitivity, and migration/invasion ability, respectively.

Results: Both the metastatic and recurrent ovarian cancer tissues expressed higher level of CD44 than the patient-matched primary tumor. A significant association has been shown between CD44 expression and both the disease free survival and overall survival. A strong increase of CD44 was found in the tumor recurrence of mouse model. Finally, when CD44 was knocked down, proliferation, migration/invasion activity, and spheroid formation were significantly suppressed, while drug sensitivity was enhanced.

Conclusions: Up-regulation of CD44 represents a crucial event in the development of metastasis, recurrence, and drug resistance to current treatments in ovarian cancer. Developing strategies to target CD44 may prevent metastasis, recurrence, and drug resistance in ovarian cancer.

Citation Format: Yan Gao, Rosemary Foster, Francis J. Hornicek, Mansoor M. Amiji, Zhenfeng Duan. Up-regulation of CD44 in the development of metastasis, recurrence and drug resistance of ovarian cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 352. doi:10.1158/1538-7445.AM2015-352

Abstract LB-102: Layer-by-layer engineering of upconversion nanoparticle based siRNA and miRNA delivery system for cancer therapy

Purpose: Nanoparticle based drug delivery systems have shown promising applications in cancer treatments. Among various nanoparticles, upconversion nanoparticles (UCNPs) allow for the conversion of near infrared (NIR) excitation to localized UV/visible emission providing unprecedented control over UCNP based delivery platforms for deep tissue therapeutic payload release, both spatially and temporally. This study reports the layer-by-layer engineering of UCNP based siRNA and miRNA delivery systems for application in cancer therapy. Experimental Design: To obtain the nanoparticle core, NaYF4:Yb,Er UCNPs were synthesized via thermal decomposition method. The morphology and size of the UCNPs were assessed by transmission electron microscopic (TEM). The upconversion fluorescence property was studied by fluorescence spectroscopy using a 980 nm laser as the excitation source. To enable gene delivery, the naked UCNPs were then surface functionalized with biocompatible polymers using polyacrylic acid (PAA) and poly allylamine hydrochloride (PAH). Surface functionalization was accomplished through layer-by-layer assembly of polyelectrolyte multilayers. Successful surface functionalization was demonstrated by measuring zeta potential after assembly of each layer. Biocompatibility of the developed delivery system was tested by MTT assay. Gel electrophoresis was employed to determine the loading capacity of the delivery system. We then tested the siRNA, miRNA, and EGFP expression vector transfection efficiency in different cancer cell lines. Results: The diameter of the synthesized UCNPs was ∼40 nm. Upon 980 nm excitation, green emission and red emission were identified from the fluorescence spectrum. Zeta potential of the delivery system was ∼+38 mV, indicating its capability to absorb negatively charged siRNA, miRNA, or EGFP vector by electrostatic interaction. The MTT assay demonstrated good biocompatibility. Significant retardation of siRNA, miRNA, or EGFP plasmid in gel electrophoresis assay was observed when mixed with PAA and PAH coated UCNPs. In contrast, UCNP-PAA without PAH coating did not retard siRNA, miRNA, or EGFP plasmid. Confocal laser scanning microscopy results provided direct evidence of siRNA, miRNA, or EGFP plasmid transfection. Conclusions: In this proof-of-concept study, a layer-by-layer engineered UCNP based siRNA and miRNA delivery system was successfully developed. Our novel delivery system opens up preparation of advanced UCNP based photoresponsive delivery systems that allow remote, precise, and trackable control over therapeutic payload (e.g., drug, gene) release for better cancer theranostics.

Citation Format: Lin Min, YAN GAO, Francis J. Hornicek, Mansoor M. Amiji, Zhenfeng Duan. Layer-by-layer engineering of upconversion nanoparticle based siRNA and miRNA delivery system for cancer therapy. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-102. doi:10.1158/1538-7445.AM2015-LB-102