Hepatocellular Carcinoma Post Embolotherapy: Imaging Appearances and Pitfalls on Computed Tomography and Magnetic Resonance Imaging.

Embolotherapies used in the treatment of hepatocellular carcinoma (HCC) include bland embolization, conventional transarterial chemoembolization (cTACE) using ethiodol as a carrier, TACE with drug-eluting beads and super absorbent polymer microspheres (DEB-TACE), and selective internal radiation therapy (SIRT). Successfully treated HCC lesions undergo coagulation necrosis, and appear as nonenhancing hypoattenuating or hypointense lesions in the embolized region on computed tomography (CT) and magnetic resonance. Residual or recurrent tumours demonstrate arterial enhancement with portal venous phase wash-out of contrast, features characteristic of HCC, in and/or around the embolized area. Certain imaging features that result from the procedure itself may limit assessment of response. In conventional TACE, the high-attenuating retained ethiodized oil may obscure arterially-enhancing tumours and limit detection of residual tumours; thus a noncontrast CT on follow-up imaging is important post-cTACE. Hyperenhancement within or around the treated zone can be seen after cTACE, DEB-TACE, or SIRT due to physiologic inflammatory response and may mimic residual tumour. Recognition of these pitfalls is important in the evaluation embolotherapy response.

Expression of cancer/testis (CT) antigens in squamous cell carcinoma of the head and neck: evaluation as markers of squamous dysplasia.

Cancer/testis (CT) antigens, normally only expressed in germ cells of adult testis, can be activated in malignancy as tumor-specific antigens. The potential value of CT antigens as biomarkers in the evaluation of mucosal squamous precursor lesions of the head and neck has not been investigated. The expression of 8 CT antigens (MAGE-A, GAGE, NY-ESO-1, CT7, CT10, SAGE1, CT45 and NXF2) in 76 cases of invasive head and neck squamous cell carcinoma (SCC) was evaluated immunohistochemically. 65 mucosal biopsies of squamous dysplasia and 55 squamous papillomas with dysplasia were analyzed for 6 CT antigens, using an antibody cocktail. Of invasive SCC, 66% (50/76) expressed at least one CT antigen, most commonly MAGE-A (47%). Among the biopsies, only 1 of 55 squamous papillomas was CT-positive, whereas 8 of 65 (12%) squamous dysplasia lesions were CT-positive. These 8 CT-positive biopsies were from 6 patients, 3 of which had concurrent or subsequent SCC. CT antigens are frequently expressed in head and neck SCC; however, there was no difference in the clinicopathological characteristics or behavior of CT-positive tumors compared to CT-negative tumors. The usefulness of CT antigens as positive predictors for SCC in squamous dysplasia biopsies remains to be determined by long-term follow-up in larger cohorts.

Imaging of blunt vascular neck injuries: a review of screening and imaging modalities.

OBJECTIVE: We will review the epidemiology of blunt cerebrovascular injuries (BCVIs) and the rationale for screening. Current imaging modalities used to screen for BCVIs will be discussed with an emphasis on CT angiography. CONCLUSION: Screening for BCVIs can decrease rates of postinjury complications, such as stroke. The use of standardized screening criteria and the appropriate imaging modalities can allow early detection of BCVIs and effective intervention.

Imaging of blunt vascular neck injuries: a clinical perspective.

OBJECTIVE: We will review the common injuries and anatomic distributions of blunt cerebrovascular injuries (BCVIs) of the neck, explain the grading criteria, and discuss the corresponding management. Artifacts associated with BCVI on CT will also be examined. CONCLUSION: Identifying common injury patterns and anatomic distributions associated with BCVI can help decide the grade and management earlier and reduce the risk for potential complications. Recognizing the common artifacts associated with BCVI helps the reader successfully recognize a true BCVI.

Chromosome X-encoded Cancer/Testis antigens are less frequently expressed in non-seminomatous germ cell tumors than in seminomas.

Cancer/Testis (CT) antigens are normally only expressed in germ cells and yet are aberrantly activated in a wide variety of human cancers. Most chromosome X-encoded CT antigens (CT-X) show restricted expression in pre-meiotic germ cells in adult testis, except for the expression of SPANX in post-meiotic germ cells. In the present study, the expression of eight CT-X antigens (MAGE-A, NY-ESO-1, GAGE, MAGE-C1/CT7, MAGE-C2/CT10, CT45, SAGE1, and SPANX) in non-seminomatous germ cell tumors was evaluated immunohistochemically, including 24 embryonal carcinomas, 20 yolk sac tumors, 9 teratomas, and 3 choriocarcinomas, and the results were compared to our previous study of 77 classic seminomas and 2 spermatocytic seminomas. SPANX was not detected in any germ cell tumors tested. Spermatocytic seminoma showed strong expression of all CT-X antigens tested (except SPANX), reflecting their origin from adult CT-Xpositive pre-meiotic germ cells. Classic seminomas, originating from prenatal gonocytes, showed widely variable frequency of CT-X antigen expression, ranging from > 80% (CT7, CT10, CT45, and GAGE), 63% (MAGE-A), 18% (NY-ESO-1) to only 4% (SAGE1). In comparison, non-seminomatous germ cell tumors expressed CT-X antigens much less frequently and usually only in small subsets of tumor cells. Intratubular germ cell neoplasia (ITGCN) were mostly CT-X-negative, even in CT-X positive classic seminomas. These findings indicate that CT-X antigens are not expressed in the fetal precursor cells for germ cell tumors, and their expression likely reflects germ cell differentiation of the neoplastic cells (in seminomas) or aberrant gene activation as cancer antigens (in non-seminomatous tumors).

A Pilot Study of Anti-CTLA4 Antibody Ipilimumab in Patients with Synovial Sarcoma.

Background. Patients with recurrent synovial sarcomas have few options for systemic therapy. Since they express large amounts of endogenous CT (cancer testis) antigens such as NY-ESO-1, we investigated the clinical activity of single agent anti-CTLA4 antibody ipilimumab in patients with advanced or metastatic synovial sarcoma. Methods. A Simon two-stage phase II design was used to determine if there was sufficient activity to pursue further. The primary endpoint was tumor response rate by RECIST 1.0. Patients were treated with ipilimumab 3 mg/kg intravenously every 3 weeks for three cycles and then restaged. Retreatment was possible for patients receiving an extra three-week break from therapy. Sera and peripheral blood mononuclear cells were collected before and during therapy to assess NY-ESO-1-specific immunity. Results. Six patients were enrolled and received 1-3 cycles of ipilimumab. All patients showed clinical or radiological evidence of disease progression after no more than three cycles of therapy, for a RECIST response rate of 0%. The study was stopped for slow accrual, lack of activity, and lack of immune response. There was no evidence of clinically significant either serologic or delayed type hypersensitivity responses to NY-ESO-1 before or after therapy. Conclusion. Despite high expression of CT antigens by synovial sarcomas of patients treated in this study, there was neither clinical benefit nor evidence of anti-CT antigen serological responses. Assessment of the ability of synovial sarcoma cell lines to present cancer-germ cell antigens may be useful in determining the reason for the observed lack of immunological or clinical activity.

Risk-benefit analysis of pulmonary CT angiography in patients with suspected pulmonary embolus.

OBJECTIVE: The objective of our study was to estimate the mortality benefit-to-risk ratio of pulmonary CT angiography (CTA) by setting (ambulatory [emergency department or outpatient] or inpatient), age, and sex. MATERIALS AND METHODS: A retrospective evaluation of 1424 consecutive pulmonary CTA examinations was performed and the following information was recorded: examination setting, patient age, patient sex, pulmonary CTA interpretation for pulmonary embolus (PE), and CT radiation exposure (dose-length product). We estimated mortality benefit of pulmonary CTA by multiplying the rate of positive pulmonary CTA examinations by published estimates of mortality of untreated PE in ambulatory and inpatient settings. We estimated the lifetime attributable risk of cancer mortality due to radiation from pulmonary CTA by calculating the estimated effective dose and using sex-specific polynomial equations derived from the Biological Effects of Ionizing Radiation VII report. We calculated benefit-to-risk ratios by dividing the mortality benefit of preventing a fatal PE by the mortality risk of a radiation-induced cancer. RESULTS: Pulmonary CTA diagnosed PE in 188 of 1424 patients (13.2%). Both inpatients (101/723, 14.0%) and emergency department patients (74/509, 14.5%) had significantly higher rates of PE than outpatients (13/192 [6.8%]). Males received significantly (p = 0.02451) higher radiation dose (9.7 mSv) than females (8.4 mSv), but males had a significantly (p < 0.0001) lower lifetime attributable risk of cancer mortality than females. Assuming an untreated PE mortality rate of 5% for ambulatory patients and 30% for inpatients, the benefit-to-risk ratio ranged from 25 for ambulatory patients to 187 for inpatients. Ambulatory women had the lowest benefit-to-risk ratio. CONCLUSION: The benefit-to-risk ratio of pulmonary CTA in patients with suspected PE ranges from 25 to 187 and can be increased by optimizing the radiation dose.

Chromosome X-encoded cancer/testis antigens show distinctive expression patterns in developing gonads and in testicular seminoma.

BACKGROUND: Cancer/testis (CT) antigens are cancer antigens normally expressed in adult testicular germ cells. The expression of chromosome X-encoded CT antigens (CT-X antigens) in human fetal gonads and in testicular seminomas was examined. METHODS: The expression of 10 CT-X antigens (MAGEA, NY-ESO-1, GAGE, CT7/MAGEC1, CT10/MAGEC2, CT45, SAGE1, SSX2, NXF2 and SPANX) was studied immunohistochemically. RESULTS: In adult human testis, SPANX is expressed in late spermatids and spermatozoa, whereas all other CT-X antigens are predominantly expressed in spermatogonia or primary spermatocytes. All CT-X antigens except SPANX are expressed in human fetal germ cells. CT-X-positive germ cells appear as early as 13 weeks after gestation, increase with age and reach a plateau at around 22 weeks. In the fetal ovary, CT-X-positive oogonia are most abundant at around 24 weeks and sharply decrease subsequently. CT-X antigens are almost exclusively expressed in OCT3/4-negative gonocytes and their expression appears to coincide with the loss of pluripotency. Spermatocytic seminoma, a neoplasm derived from adult pre-meiotic germ cells, showed uniform expression of all CT-X antigens except SPANX. In contrast, most seminomas (>80%) express CT7, CT45, GAGE and CT10 but express MAGEA, NXF2 and NY-ESO-1 at lower frequency, and very rarely express SSX2 and SAGE1. CONCLUSIONS: Most CT-X antigens are expressed in human fetal germ cells after they have lost stem cell characteristics, with predominant expression in pre-meiotic germ cells. Spermatocytic seminomas showed expression of all CT-X antigens except SPANX, whereas classical seminomas only express some CT-X antigens, reflecting their different origins from adult versus fetal germ cells.

Multiple cancer/testis antigens are preferentially expressed in hormone-receptor negative and high-grade breast cancers.

BACKGROUND: Cancer/testis (CT) antigens are protein antigens normally expressed only in germ cells of testis, and yet are expressed in a proportion of a wide variety of human cancers. CT antigens can elicit spontaneous immune responses in cancer patients with CT-positive cancers, and CT antigen-based therapeutic cancer vaccine trials are ongoing for "CT-rich" tumors. Although some previous studies found breast cancer to be "CT-poor", our recent analysis identified increased CT mRNA transcripts in the ER-negative subset of breast cancer. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we performed a comprehensive immunohistochemical study to investigate the protein expression of eight CT genes in 454 invasive ductal carcinomas, including 225 ER/PR/HER2-negative (triple-negative) carcinomas. We found significantly more frequent expression of all eight CT antigens in ER-negative cancers, and five of them--MAGEA, CT7, NY-ESO-1, CT10 and CT45, were expressed in 12-24% of ER-negative cancers, versus 2-6% of ER-positive cancers (p<0.001 to 0.003). In comparison, GAGE, SAGE1 and NXF2 were only expressed in 3-5% of ER-negative and 0-2% of ER-positive cancers. ER-negative cancers were also more likely to simultaneously co-express multiple CT antigens, with 27% (34/125) of ER-negative, CT-positive tumors expressing three or more CT antigens. HER2 status had no consistent effect on CT expression, and triple-negative carcinomas showed similar frequencies of MAGEA and NY-ESO-1 expression as ER-negative/HER2-positive carcinomas. More frequent CT expression was also found in tumors with higher nuclear grade (p<0.001 to p = 0.01) and larger in size (>2 cm). CONCLUSIONS/SIGNIFICANCE: CT antigens are preferentially expressed in hormone receptor-negative and high-grade breast cancer. Considering the limited treatment options for ER/PR/HER2 triple-negative breast cancer, the potential of CT-based immunotherapy should be explored.

Nitric oxide initiates progression of human melanoma via a feedback loop mediated by apurinic/apyrimidinic endonuclease-1/redox factor-1, which is inhibited by resveratrol.

It is well recognized that nitric oxide (NO) is involved in tumor progression, including melanoma. Measurement of proliferative and metastatic capacity by MTS and Matrigel invasion assays, respectively, was done and showed that NO-treated melanoma cells exhibited a higher capacity compared with control, especially metastatic Lu1205 cells. Apurinic/apyrimidinic endonuclease-1/redox factor-1 (APE/Ref-1) is a multifunctional protein and its role in tumor biology has attracted considerable attention. To determine whether APE/Ref-1 plays a role in mediating NO stimulation of melanoma progression, we investigated the effect of DETA/NO on levels of APE/Ref-1 and related downstream targets [activator protein-1 (AP-1)/JunD, matrix metalloproteinase-1 (MMP-1), Bcl-2, and inducible nitric oxide synthase (iNOS)] by Western blot and reverse transcription-PCR analysis. Following DETA/NO treatment, APE/Ref-1 and other downstream molecules were induced. Knockdown of APE/Ref-1 or AP-1/JunD by specific small interfering RNA markedly reversed the induction by NO stress of target proteins. These results present evidence for the existence of a functional feedback loop contributing to progression and metastasis of melanoma cells. Resveratrol has been shown to be an APE/Ref-1 inhibitor and significant decreases in AP-1/JunD, MMP-1, Bcl-2, and iNOS protein levels occurred after exposure to resveratrol. This phenolic antioxidant may be an appropriate choice for combining with other compounds that develop resistance by up-regulation of these molecules.

Common and distinct mechanisms of different redox-active carcinogens involved in the transformation of mouse JB6P+ cells.

We transformed JB6P+ cells with prolonged intermittent low-dose UVB radiation or prolonged exposure to low-dose H(2)O(2) or CdCl(2). Stable transformation was confirmed by an anchorage-independence assay. The JB6P+ transformants formed more colonies (approximately six folds) in soft agar as compared to their JB6P+ parent cells and were associated with increased intracellular reactive oxygen species (ROS) levels. Activating protein-1 (AP-1) is a family of transcription factors that are rapidly activated by elevated intracellular ROS levels, and their composition is important in the process of cellular transformation and/or tumor progression. To investigate if carcinogenesis induced by distinct carcinogens was via similar molecular mechanisms in these transformants, gel mobility shift and immunoblot analyses were utilized to determine the distinct AP-1 compositions. Compared to parent JB6P+ cells, the gain of JunB and Fra-1 in AP-1 DNA binding complexes was markedly increased in all transformed cells, which might contribute to a more proliferative phenotype, while loss of Fra-2 occurred in JB6P+/H(2)O(2) and JB6P+/Cd cells. Differential AP-1 components in the transformants suggested that their transformations might be mediated by distinct transcription signalings with distinct AP-1 dimer compositions. However, all three transformants exhibited increased activation of pathways involved in cell proliferation (ERK/Fra-1/AP-1 and JNK/c-jun/AP-1) and anti-apoptosis (Bcl-xl). The development of the JB6P+ transformants (JB6P+/UVB; JB6P+/H(2)O(2); JB6P+/Cd) provides a unique tool to study the mechanisms that contribute to different redox-active carcinogens in a single model.

Redox effector factor-1, combined with reactive oxygen species, plays an important role in the transformation of JB6 cells.

Apurinic/apyrimidinic endonuclease/redox effector factor-1 (APE/Ref-1) is a multifunctional protein involved both in DNA base excision repair and redox regulation. Studies have suggested that abnormal Ref-1 levels and/or activities are associated with tumor progression and sensitivities to treatment, but no direct evidence has yet been published regarding the role of Ref-1 in malignant transformation. We utilized the well-documented tumor promotor-sensitive JB6 mouse epithelial cell model as well as new transformants [by ultraviolet light B (UVB), H2O2 or Cd] to study this phenomenon. Significant increases of reactive oxygen species (ROS) were observed in JB6P+ and all the transformants compared with promotor-resistant JB6P- cells. These increases were paralleled by a sustained elevation of Ref-1 expression. Further analysis exhibited a strong inverse correlation between oxidative DNA lesions [8-oxodeoxyguanosine (8-oxo-dG)] and Ref-1 levels in all JB6 cells. Notably, apoptosis occurred after knock-down of Ref-1 by small interfering RNA (siRNA)] demonstrated by a approximately 2-fold increase of Annexin V-positive JB6P+ cells. Ref-1 depletion also inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced anchorage-independent growth of JB6P+ by 40% and reduced the colony numbers of JB6P+/H2O2 and JB6P+/Cd cells. Mechanistic studies revealed that Ref-1 reduction was associated with an increase of intracellular ROS levels and a marked decrease of activator protein-1 (AP-1) transcription activities in JB6P+/H2O2 cells. This is the first report of the novel role of Ref-1 in cellular transformation. Based on the data presented here, we propose that induction of Ref-1, serving as an adaptive response to elevated ROS, plays a critical role in transformation and protects cells from excess ROS stresses through both DNA repair and activation of transcription factors such as activator protein-1.