Christopher Y. Thomas

Candida prosthetic arthritis: report of a case treated with fluconazole and review of the literature

Prosthetic arthritis due to Candida species is uncommon, with only 15 cases reported in the literature. We recently cared for a human immunodeficiency virus-infected patient who developed Candida parapsilosis prosthetic arthritis unresponsive to resection arthroplasty, intravenous amphotericin B, and suppressive ketoconazole therapy. Treatment with fluconazole led to mycologic cure and symptom improvement, although he subsequently underwent above-the-knee amputation due to continued joint instability. Fluconazole may be useful follow-up therapy after a course of amphotericin B combined with resection arthroplasty or when removal of the prosthesis cannot be accomplished.

Activation of the insulin-like growth factor-1 receptor induces resistance to epidermal growth factor receptor antagonism in head and neck squamous carcinoma cells

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) have poor efficacy in head and neck squamous carcinoma cells (HNSCC). Because the IGF-1 receptor (IGF1R) generates potent prosurvival signals and has been implicated in therapeutic resistance, its ability to induce resistance to EGFR-TKIs was studied in vitro. Five HNSCC cell lines showed reduced sensitivity to the EGFR-TKI gefitinib when the IGF1R was activated. In SCC-25 and Cal27 cells, gefitinib inhibited basal and EGF-stimulated EGFR, extracellular signal–regulated kinase (Erk), and Akt phosphorylation and reduced cell number. This correlated with initiation of apoptosis based on a 4-fold increase in PARP cleavage and a 2.5-fold increase in Annexin V positivity. The apoptotic response and reduction in cell number were blocked by IGF1R activation, which resulted in phosphorylation of both Erk and Akt. In both the cell lines, IGF1R-induced Erk, but not Akt, activation was eliminated by gefitinib. IGF1R-induced gefitinib resistance was unaffected by MAP/Erk kinase inhibition with U0126 but was partially impaired by inhibition of phosphoinositide-3-kinase with LY294002. The IGF1R-TKI PQ401 inhibited growth of SCC-25 and Cal27 cells alone and also acted synergistically with gefitinib. Thus, the IGF1R can make HNSCC cells resistant to EGFR-TKI treatment via a prosurvival mechanism. Of the 8 HNSCC tumor samples studied, all samples expressed the IGF1R and 5 showed detectable IGF1R phosphorylation, suggesting that this receptor may be relevant in vivo, and thus, combined EGFR/IGF1R inhibition may be necessary in some patients for effective targeted molecular therapy. Mol Cancer Ther; 10(11); 2124–34. ©2011 AACR.

Intensity‐modulated radiotherapy outcomes for oropharyngeal squamous cell carcinoma patients stratified by p16 status

Patients with oropharyngeal squamous cell carcinoma (OPSCC) treated with intensity‐modulated radiotherapy (IMRT) were stratified by p16 status, neck dissection, and chemotherapy to correlate these factors with outcomes.

Outcomes of Patients With Head-and-Neck Cancer of Unknown Primary Origin Treated With Intensity-Modulated Radiotherapy

PURPOSE To analyze survival, failure patterns, and toxicity in patients with head-and-neck carcinoma of unknown primary origin (HNCUP) treated with intensity-modulated radiotherapy (IMRT). METHODS AND MATERIALS Records from 27 patients with HNCUP treated during the period 2002-2008 with IMRT were reviewed retrospectively. Nodal staging ranged from N1 to N3. The mean preoperative dose to gross or suspected disease, Waldeyers ring, and uninvolved bilateral cervical nodes was 59.4, 53.5, and 51.0 Gy, respectively. Sixteen patients underwent neck dissection after radiation and 4 patients before radiation. Eight patients with advanced nodal disease (N2b-c, N3) or extracapsular extension received chemotherapy. RESULTS With a median follow-up of 41.9 months (range, 25.3-93.9 months) for non deceased patients, the 5-year actuarial overall survival, disease-free survival, and nodal control rates were 70.9%, 85.2%, and 88.5%, respectively. Actuarial disease-free survival rates for N1, N2, and N3 disease were 100%, 94.1%, and 50.0%, respectively, at 5 years. When stratified by non advanced (N1, N2a nodal disease without extracapsular spread) vs. advanced nodal disease (N2b, N2c, N3), the 5-year actuarial disease-free survival rate for the non advanced nodal disease group was 100%, whereas for the advanced nodal disease group it was significantly lower at 66.7% (p = 0.017). Three nodal recurrences were observed: in 1 patient with bulky N2b disease and 2 in patients with N3 disease. No nodal failures occurred in patients with N1 or N2a disease who received only radiation and surgery. CONCLUSION Definitive IMRT to 50-56 Gy followed by neck dissection results in excellent nodal control and overall and disease-free survival, with acceptable toxicity for patients with T0N1 or non bulky T0N2a disease without extracapsular spread. Patients with extracapsular spread, advanced N2 disease, or N3 disease may benefit from concurrent chemotherapy, targeted therapeutic agents, or accelerated radiation regimens in addition to surgery.

Predicting Residual Neck Disease in Patients With Oropharyngeal Squamous Cell Carcinoma Treated With Radiation Therapy: Utility of p16 Status

OBJECTIVE To identify factors that predict complete response of cervical nodal disease to radiation therapy (RT) in patients with oropharyngeal squamous cell carcinoma (OP-SCCA). DESIGN Histologic analysis of prospectively collected specimens and retrospective medical chart review. SETTING Tertiary referral center. SUBJECTS Sixty-nine patients with OP-SCCA treated from January 1, 2002, through June 1, 2008. INTERVENTION Definitive RT, with or without chemotherapy and with or without neck dissection (ND). MAIN OUTCOME MEASURE Presence of a viable tumor in post-RT ND specimen. RESULTS Tissue specimens from 69 patients with OP-SCCA treated primarily with RT, with or without chemotherapy, were evaluated. Of these, 47 (68.1%) were strongly and diffusely positive for p16 expression by immunohistochemical analysis, signifying human papillomavirus positivity. Patients with p16-positive and p16-negative tumors (hereinafter, p16+ and p16-, respectively) had similarly sized primary tumors on presentation, but p16+ primary tumors were associated with more advanced neck disease (nodal stages N2c-N3; 31.9% vs 4.5% for p16- tumors) and more contralateral nodes (27.7% vs 4.5% for p16- tumors). Forty-seven patients (59.0%) underwent planned posttreatment ND (a total of 55 NDs). The NDs performed for p16- tumors were significantly more likely to have viable tumor in the specimen (50.0% vs 18.0% for p16+ tumors; P = .02). In addition, p16+ necks with residual viable cancer were characterized by incomplete response on post-RT imaging, tobacco and alcohol use, and extracapsular spread on pretreatment imaging. CONCLUSIONS In conjunction with other clinical parameters, p16 status can help predict the need for post-RT ND in patients with OP-SCCA. Although close observation may be warranted in selected patients with p16+ tumors, patients with p16- tumors are at much higher risk for residual neck disease, even when initial nodal disease is less advanced.

p16, Cyclin D1, and HIF-1α Predict Outcomes of Patients with Oropharyngeal Squamous Cell Carcinoma Treated with Definitive Intensity-Modulated Radiation Therapy

We evaluated a panel of 8 immunohistochemical biomarkers as predictors of clinical response to definitive intensity-modulated radiotherapy in patients with oropharyngeal squamous cell carcinoma (OPSCC). 106 patients with OPSCC were treated to a total dose of 66–70 Gy and retrospectively analyzed for locoregional control (LRC), disease-free survival (DFS), and overall survival (OS). All tumors had p16 immunohistochemical staining, and 101 tumors also had epidermal growth factor receptor (EGFR) staining. 53% of the patients had sufficient archived pathologic specimens for incorporation into a tissue microarray for immunohistochemical analysis for cyclophilin B, cyclin D1, p21, hypoxia-inducible factor-1α (HIF-1α), carbonic anhydrase, and major vault protein. Median followup was 27.2 months. 66% of the tumors were p16 positive, and 34% were p16 negative. On univariate analysis, the following correlations were statistically significant: p16 positive staining with higher LRC (P = 0.005) and longer DFS (P < 0.001); cyclin D1 positive staining with lower LRC (P = 0.033) and shorter DFS (P = 0.002); HIF-1α positive staining with shorter DFS (P = 0.039). On multivariate analysis, p16 was the only significant independent predictor of DFS (P = 0.023). After immunohistochemical examination of a panel of 8 biomarkers, our study could only verify p16 as an independent prognostic factor in OPSCC.

Molecular markers of prognosis and novel therapeutic strategies for urothelial cell carcinomas

Recent technical advances have allowed for more detailed analysis of the phenotypic and genotypic characteristics of urothelial cell carcinomas (UCC) and have helped elucidate the molecular pathogenesis of these tumors. This presents a welcome challenge to investigators on how best to exploit this information to improve the care of patients aZicted with these cancers. Here, we brieXy review how these advances have impacted two major areas of investigation, the development of clinical useful prognostic molecular markers and novel therapies. The latter encompasses the identiWcation of new therapeutic targets as well as the application of recently developed targeted therapies. For more detailed discussions of the molecular basis of UCC, the reader is directed to excellent recent reviews of this topic [35, 72, 110, 159, 198, 200]. The conversion of a normal urothelial cell to a superWcial tumor (stage Ta, T1, and Tis) and the progression to a higher grade muscle-invasive cancer (stage T2 and above) results from the sequential acquisition of somatic gene mutations [72, 110, 200]. The current consensus is that these tumors evolve down one of two major genetic pathways [4, 72, 86, 172, 198, 200]. One is associated with low-grade papillary and non-invasive cancers (Ta or T1, G1-2; G = grade) that infrequently progress to invasive UCCs. The characteristics of these tumors include mutational activation of growth factor signaling pathways, loss of heterozygosity (LOH) of chromosome nine sequences, the expression of functional p53 and retinoblastoma (Rb) tumor suppressor proteins, and relative genetic stability (Fig. 1). The other pathway is typiWed by in situ or higher grade superWcial tumors (Tis; T1G2-3) that frequently recur and progress to higher grade and muscleinvasive disease. Molecular markers of this group include mutational or functional inactivation of p53 and Rb, LOH of regions of chromosome 9, and genetic instability. In both pathways, the progression from lower stage tumors to muscle-invasive disease is accompanied by the acquisition of additional non-random chromosomal aberrations [10, 73, 133]. A recent study suggests that the two genetic pathways merge at the level of high grade but non-invasive disease (T1G3) since some of these tumors contain markers of both pathways, i.e. mutations of the p53 and Wbroblast growth factor receptor-3 (FGFR3) genes [58]. The types of mutations and their association with diVerent stages of development provide important clues as to the contribution of speciWc biochemical alterations to tumorigenesis.

Oncogenicity and U3 region sequences of class II recombinant MuLVs of CWD mice

The pathogenic potential of Class II env recombinant murine leukemia viruses (MuLV) found in the high leukemia strain CWD has not been defined. We found that neonatal CWD mice that were injected with the phenotypic mixture of the spontaneous CWD class II env recombinant, CWM-T-15, and the AKR endogenous ecotropic virus, Akv 623, developed non-T-cell lymphomas more rapidly than controls inoculated with either virus alone or with a CWD ecotropic virus. In contrast, CWN-T-25, a class II env MuLV that was recovered from a CWD mouse injected with the AKR ecotropic virus SL3-3, dramatically accelerated the onset of T-cell lymphomas in the same assay. Southern blots of the tumor DNAs from each set of animals revealed the integration of recombinant and ecotropic proviruses. We also found that there were differences in the nucleotide sequences of the viral enhancer elements of the CWD viruses. The results indicate that (1) the two CWD class II env recombinants that were tested contained oncogenic determinants; (2) phenotypic mixing with ecotropic viruses was required for the full expression of the pathogenic potential of the CWM-T-15 recombinant; and (3) the distinct phenotypes of the CWD viruses likely reflected the differences in the origin of the viral enhancer element.

Molecular Pathogenesis of Urothelial Carcinoma and the Development of Novel Therapeutic Strategies

The elucidation of the molecular pathogenesis of urothelial cancers (UC) has helped classify these tumors and identify candidate biomarkers and therapeutic targets. Superficial non-aggressive tumors are characterized by the expression of mutationally activated growth factor signaling molecules whereas the loss of tumor suppressor genes is a typical feature of the higher grade and more invasive tumors. Thus, assays to detect genetic anomalies or associated phenotypic markers assist in the diagnosis and management of the early stage of the disease. For more advanced diseases, the development of agents that interrupt the aberrant growth factor signals or other biochemical effects induced by specific genetic mutations may lead to novel and more effective medical therapies.

Abstract B102: Zibotentan (ZD4054), a specific antagonist of the endothelin A receptor, suppresses the metastatic phenotype of bladder cancer cells in vivo

There is mounting evidence that endothelin‐1(ET‐1) / endothelin receptor axis contributes to the pathogenesis of urothelial bladder cancer. In a previous study, reduced expression of the metastasis suppressor protein RhoGDI2 in bladder cancer cell lines and tumors was associated with increased expression of ET‐1 (Titus B et al, Ca Res 65:7320, 2005). This suggests that ET‐1 acts down‐stream of repressed RhoGDI2 expression to promote the metastatic phenotype. If so, then blocking activation of endothelin receptor A (ETAR) by ET‐1 would suppress this phenotype. To test this hypothesis, Zibotentan, a specific inhibitor of ETAR (IC50 = 21 nM), was evaluated for anti‐tumor activity in a xenograft metastasis model. To screen for toxicity, 40 athymic nu/nu female received 12.5 to 50 mg/kg/d of zibotentan by gastric lavage for 97 days. The drug was well tolerated at all dose levels and produced no significant changes in body weight, behavior, or general physical condition. In a separate experiment, T24T bladder cancer cells (106 cells suspended in 0.1 mL of medium) were inoculated into the tail veins of a second group of 40 mice. One week later, 20 of animals were treated with zibotentan 50 mg/Kg/d and 20 controls received vehicle only. After 90 days, the animals were euthanized and the lungs were removed, fixed with Bouin9s solution, stained, and examined by microscopy to determine the number and size of metastasis (large ≥3mm, small Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B102.