Patient-derived xenografts effectively capture responses to oncology therapy in a heterogeneous cohort of patients with solid tumors

Background

While patient-derived xenografts (PDXs) offer a powerful modality for translational cancer research, a precise evaluation of how accurately patient responses correlate with matching PDXs in a large, heterogeneous population is needed for assessing the utility of this platform for preclinical drug-testing and personalized patient cancer treatment.

Patients and methods

Tumors obtained from surgical or biopsy procedures from 237 cancer patients with a variety of solid tumors were implanted into immunodeficient mice and whole-exome sequencing was carried out. For 92 patients, responses to anticancer therapies were compared with that of their corresponding PDX models.

Results

We compared whole-exome sequencing of 237 PDX models with equivalent information in The Cancer Genome Atlas database, demonstrating that tumorgrafts faithfully conserve genetic patterns of the primary tumors. We next screened PDXs established for 92 patients with various solid cancers against the same 129 treatments that were administered clinically and correlated patient outcomes with the responses in corresponding models. Our analysis demonstrates that PDXs accurately replicate patients' clinical outcomes, even as patients undergo several additional cycles of therapy over time, indicating the capacity of these models to correctly guide an oncologist to treatments that are most likely to be of clinical benefit.

Conclusions

Integration of PDX models as a preclinical platform for assessment of drug efficacy may allow a higher success-rate in critical end points of clinical benefit.

Immune Reconstitution Inflammatory Syndrome Associated With Kaposi's Sarcoma

Purpose

A proportion of patients with HIV infection who subsequently receive highly active antiretroviral therapy (HAART) exhibit a deterioration in their clinical status, despite control of virologic and immunologic parameters. This clinical response, known as the immune reconstitution inflammatory syndrome (IRIS), occurs secondary to an immune response against previously diagnosed pathogens.

Patients and Methods

From our cohort of 5,832 patients treated in the HAART era, we identified 150 therapy-naive patients with a first presentation of Kaposi's sarcoma (KS). Their clinicopathologic features and progress were recorded prospectively.

Results

After commencing HAART, ten patients (6.6%) developed progressive KS, which we identify as IRIS-associated KS. In a comparison of these individuals with those whose KS did not progress, we found that IRIS-KS occurred in patients with higher CD4 counts (P = .03), KS-associated edema (P = .01), and therapy with both protease inhibitors and non-nucleosides together (P = .03). Time to treatment failure was similar for both groups, although the CD4 count declined more rapidly at first, in those patients with IRIS-associated KS. Despite this initial decline, in our clinical experience HAART could be successfully continued in those with IRIS-associated KS.

Conclusion

We have identified IRIS-KS in a cohort of HIV patients with KS who start HAART.

Prognostic performance of inflammation-based prognostic indices in primary operable non-small cell lung cancer

BACKGROUND

At least 30% of patients with primary resectable non-small cell lung cancer (NSCLC) will experience a relapse in their disease within 5 years following definitive treatment. Clinicopathological predictors have proved to be suboptimal in identifying high-risk patients. We aimed to establish whether inflammation-based scores offer an improved prognostic ability in terms of estimating overall (OS) and recurrence-free survival (RFS) in a cohort of operable, early-stage NSCLC patients.

METHODS

Clinicopathological, demographic and treatment data were collected prospectively for 220 patients operated for primary NSCLC at the Hammersmith Hospital from 2004 to 2011. Pretreatment modified Glasgow Prognostic Score (mGPS), neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were tested together with established prognostic factors in uni- and multivariate Cox regression analyses of OS and RFS.

RESULTS

Half of the patients were male, with a median age of 65. A total of 57% were classified as stage I with adenocarcinoma being the most prevalent subtype (60%). Univariate analyses of survival revealed stage (P<0.001), grade (P=0.02), lymphovascular (LVI, P=0.001), visceral pleural invasion (VPI, P=0.003), mGPS (P=0.02) and NLR (P=0.04) as predictors of OS, with stage (P<0.001), VPI (P=0.02) and NLR (P=0.002) being confirmed as independent prognostic factors on multivariate analyses. Patients with more advanced stage (P<0.001) and LVI (P=0.008) had significantly shorter RFS.

CONCLUSIONS

An elevated NLR identifies operable NSCLC patients with a poor prognostic outlook and an OS difference of almost 2 years compared to those with a normal score at diagnosis. Our study validates the clinical utility of the NLR in early-stage NSCLC.

An open-label study of tenofovir in HIV-1 and Hepatitis B virus co-infected individuals

BACKGROUND

Tenofovir is a novel nucleotide analogue recommended for use in HIV-1 infected treatment-experienced patients. Recent data suggest an effect on Hepatitis B virus (HBV) replication. We therefore investigated the use of tenofovir in HIV-1 and HBV co-infected individuals.

METHODS

Twenty HIV-1/HBV co-infected patients with a median of 108 weeks lamivudine experience (range, 0-270 weeks) received tenofovir 245 mg daily in addition to or as part of their combination antiretroviral therapy. Their immunologic parameters and HIV-1 RNA and HBV DNA viral loads were followed over a period of 52 weeks. In addition, their HBV DNA polymerase was sequenced at baseline to measure the frequency of YMDD mutations that are associated with lamivudine resistance.

FINDINGS

A significant decrease in HBV DNA viral load (4 x log ) and alanine aminotransferase levels was observed. There were no significant overall differences between the lamivudine-experienced (n = 15) and -naive (n = 5) individuals and tenofovir was well tolerated. Five patients (25%) underwent HBe antigen seroconversion during the study period. Out of the 15 lamivudine-experienced individuals, 10 had YMDD mutations and one had YIDD mutations in HBV DNA.

INTERPRETATION

These results indicate that 52 weeks of tenofovir in addition to antiretroviral therapy is active against HBV, and it appears to overcome lamivudine resistance.

Genomic modelling of the ESR1 Y537S mutation for evaluating function and new therapeutic approaches for metastatic breast cancer

Drugs that inhibit estrogen receptor-α (ER) activity have been highly successful in treating and reducing breast cancer progression in ER-positive disease. However, resistance to these therapies presents a major clinical problem. Recent genetic studies have shown that mutations in the ER gene are found in >20% of tumours that progress on endocrine therapies. Remarkably, the great majority of these mutations localize to just a few amino acids within or near the critical helix 12 region of the ER hormone binding domain, where they are likely to be single allele mutations. Understanding how these mutations impact on ER function is a prerequisite for identifying methods to treat breast cancer patients featuring such mutations. Towards this end, we used CRISPR-Cas9 genome editing to make a single allele knock-in of the most commonly mutated amino acid residue, tyrosine 537, in the estrogen-responsive MCF7 breast cancer cell line. Genomic analyses using RNA-seq and ER ChIP-seq demonstrated that the Y537S mutation promotes constitutive ER activity globally, resulting in estrogen-independent growth. MCF7-Y537S cells were resistant to the anti-estrogen tamoxifen and fulvestrant. Further, we show that the basal transcription factor TFIIH is constitutively recruited by ER-Y537S, resulting in ligand-independent phosphorylation of Serine 118 (Ser118) by the TFIIH kinase, cyclin-dependent kinase (CDK)7. The CDK7 inhibitor, THZ1 prevented Ser118 phosphorylation and inhibited growth of MCF7-Y537S cells. These studies confirm the functional importance of ER mutations in endocrine resistance, demonstrate the utility of knock-in mutational models for investigating alternative therapeutic approaches and highlight CDK7 inhibition as a potential therapy for endocrine-resistant breast cancer mediated by ER mutations.

The role of immune suppression and HHV-8 in the increasing incidence of HIV-associated multicentric Castleman's disease

BACKGROUND

In HIV cohorts with access to highly active antiretroviral therapy (HAART), the incidence of Kaposi's sarcoma (KS) is falling; however, the incidence of multicentric Castleman's disease (MCD) in HIV has not previously been described.

METHODS

The incidence of HIV-associated MCD was calculated from a prospective HIV database with 56 202 patient-years of follow-up and compared with KS. Univariate and multivariate analyses were carried out to identify factors associated with MCD. Plasma human herpesvirus (HHV)-8 DNA levels were measured in HIV-seropositive individuals with newly diagnosed MCD (n = 24), KS (n = 72), HIV-associated lymphoma (n = 74) and HIV-positive controls (n = 53).

RESULTS

From 24 cases of HIV-associated MCD, the incidence measured 4.3/10,000 patient-years [95% confidence interval (CI) 2.7-6.4]. The incidence in the pre-HAART (1983-1996), early-HAART (1997-2001) and later HAART (2002-2007) eras were 2.3 (95% CI 0.02-4.2), 2.8 (95% CI 0.9-6.5) and 8.3 (95% CI 4.6-12.6), respectively, representing a statistically significant increase over time (P < 0.05). In contrast, from 1180 cases of KS, the incidence in this cohort decreased with time. Multivariate analysis demonstrated that a nadir CD4 count >200/mm(3), increased age, no previous HAART exposure and non-Caucasian ethnicity were all associated with an increased risk of MCD. Plasma HHV-8 DNA levels were higher in patients with newly diagnosed MCD than with KS, lymphomas or HIV-positive controls (Mann-Whitney U-test, P < 0.0001).

CONCLUSIONS

The incidence of HIV-associated MCD is increasing. It appears to occur more frequently in older HIV-positive individuals with well-preserved immune function.

Extracellular vesicles swarm the cancer microenvironment: from tumor-stroma communication to drug intervention

Intercellular communication sets the pace for transformed cells to survive and to thrive. Extracellular vesicles (EVs), such as exosomes, microvesicles and large oncosomes, are involved in this process shuttling reciprocal signals and other molecules between transformed and stromal cells, including fibroblasts, endothelial and immune cells. As a result, these cells are adapted or recruited to a constantly evolving cancer microenvironment. Moreover, EVs take part in the response to anticancer therapeutics not least by promoting drug resistance throughout the targeted tumor. Finally, circulating EVs can also transport important molecules to remote destinations in order to prime metastatic niches in an otherwise healthy tissue. Although the understanding of EV biology remains a major challenge in the field, their characteristics create new opportunities for advances in cancer diagnostics and therapeutics.

The value of anal cytology and human papillomavirus typing in the detection of anal intraepithelial neoplasia: a review of cases from an anoscopy clinic

BACKGROUND

Previous studies have reached differing conclusions about the utility of anal cytology as a screening tool for anal intraepithelial neoplasia (AIN). There is a need also to establish whether HPV typing offers a useful adjunct to screening.

METHODS

We analysed data from 99 consecutive homosexual/bisexual male patients (89 HIV-1 positive) who underwent high resolution anoscopy. Follow up visits for these patients were also included, giving a total of 160 anoscopic procedures. Comparison was made between results of anal cytology using the sampling method of Palefsky, and histological findings of biopsies taken from abnormal areas seen on high resolution anoscopic examination of the anal canal. Swabs taken concurrently with the cytology were analysed for the presence of human papillomavirus (HPV) DNA and compared with the cytological and histological findings.

RESULTS

The sensitivity of the cytology was 83%, and the specificity 38% when compared with histology. At screening of 34 asymptomatic men, 83% had anal cytological dysplasia and 78% had AIN. There were no significant differences in the prevalence of hrHPV genotypes between different cytological or histological grades of abnormalities.

CONCLUSION

Anal cytology by the Palefsky method is simple to undertake, has a sensitivity and specificity comparable with cervical cytology, and can therefore be used as the basis of a pilot screening project in centres with large cohorts of HIV positive homosexual men who have a high risk of developing anal carcinoma. HPV genotyping is not a useful adjunct to cytological screening.

Myocardial MiR-30 downregulation triggered by doxorubicin drives alterations in β-adrenergic signaling and enhances apoptosis

The use of anthracyclines such as doxorubicin (DOX) has improved outcome in cancer patients, yet associated risks of cardiomyopathy have limited their clinical application. DOX-associated cardiotoxicity is frequently irreversible and typically progresses to heart failure (HF) but our understanding of molecular mechanisms underlying this and essential for development of cardioprotective strategies remains largely obscure. As microRNAs (miRNAs) have been shown to play potent regulatory roles in both cardiovascular disease and cancer, we investigated miRNA changes in DOX-induced HF and the alteration of cellular processes downstream. Myocardial miRNA profiling was performed after DOX-induced injury, either via acute application to isolated cardiomyocytes or via chronic exposure in vivo, and compared with miRNA profiles from remodeled hearts following myocardial infarction. The miR-30 family was downregulated in all three models. We describe here that miR-30 act regulating the β-adrenergic pathway, where preferential β1- and β2-adrenoceptor (β1AR and β2AR) direct inhibition is combined with Giα-2 targeting for fine-tuning. Importantly, we show that miR-30 also target the pro-apoptotic gene BNIP3L/NIX. In aggregate, we demonstrate that high miR-30 levels are protective against DOX toxicity and correlate this in turn with lower reactive oxygen species generation. In addition, we identify GATA-6 as a mediator of DOX-associated reductions in miR-30 expression. In conclusion, we describe that DOX causes acute and sustained miR-30 downregulation in cardiomyocytes via GATA-6. miR-30 overexpression protects cardiac cells from DOX-induced apoptosis, and its maintenance represents a potential cardioprotective and anti-tumorigenic strategy for anthracyclines.

The regulatory roles of phosphatases in cancer

The relevance of potentially reversible post-translational modifications required for controlling cellular processes in cancer is one of the most thriving arenas of cellular and molecular biology. Any alteration in the balanced equilibrium between kinases and phosphatases may result in development and progression of various diseases, including different types of cancer, though phosphatases are relatively under-studied. Loss of phosphatases such as PTEN (phosphatase and tensin homologue deleted on chromosome 10), a known tumour suppressor, across tumour types lends credence to the development of phosphatidylinositol 3-kinase inhibitors alongside the use of phosphatase expression as a biomarker, though phase 3 trial data are lacking. In this review, we give an updated report on phosphatase dysregulation linked to organ-specific malignancies.

Herceptin (trastuzamab) in advanced breast cancer

Herceptin (trastuzamab, Genentech, San Francisco, CA, USA) prolongs survival in metastatic breast cancer patients whose tumours overexpress the HER2/neu protein. Compared with chemotherapy alone, patients receiving chemotherapy and Herceptin have a significantly longer time to progression, a higher response rate and a longer duration of response. These effects are most marked in first-line treatment of metastatic disease. The addition of Herceptin is associated with few additional side-effects, apart from cardiac toxicity in patients concurrently receiving anthracyclines. As such, it seems reasonable for Herceptin to become considered as one of the routine treatment options in metastatic breast cancer. It would therefore be appropriate for HER2 status testing to be incorporated into the assessment of all patients with metastatic disease. The use of this medication will be limited by its cost. Furthermore, data are lacking on appropriate treatments durations in responders.

The treatment of advanced renal cell cancer with high-dose oral thalidomide

Thalidomide is reported to suppress levels of several cytokines, angiogenic and growth factors including TNF-alpha, basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6). The resulting anti-angiogenic, immunomodulatory and growth suppressive effects form the rationale for investigating thalidomide in the treatment of malignancies. We have evaluated the use of high-dose oral thalidomide (600 mg daily) in patients with renal carcinoma. 25 patients (all men; median age, 51 years; range 34-76 years) with advanced measurable renal carcinoma, who had either progressed on or were not suitable for immunotherapy, received thalidomide in an escalating schedule up to a maximum dose of 600 mg daily. Treatment continued until disease progression or unacceptable toxicity were encountered. 22 patients were assessable for response. 2 patients showed partial responses (9%; 95% CI: 1-29), 7 (32%; 95% CI: 14-55) had stable disease for more than 6 months and a further 5 (23%; 95% CI: 8-45) had stable disease for between 3 and 6 months. We also measured levels of TNF-alpha, bFGF, VEGF, IL-6 and IL-12 before and during treatment. In patients with SD > or = 3 months or an objective response, a statistically significant decrease in serum TNF-alpha levels was demonstrated (P = 0.05). The commonest toxicities were lethargy (> or = grade II, 10 patients), constipation (> or = grade II, 11 patients) and neuropathy (> or = grade II, 5 patients). Toxicities were of sufficient clinical significance for use of a lower and well tolerated dose of 400 mg in currently accruing studies.

A comparison of patients with relapsed and chemo-refractory gestational trophoblastic neoplasia

The majority of women requiring chemotherapy for gestational trophoblastic disease (GTN) are cured with their initial chemotherapy treatment. However, a small percentage either become refractory to treatment, or relapse after the completion of treatment. This study investigates the characteristics and outcome of these patients. Patients were identified from the Charing Cross Hospital GTD database. The outcome of these patients with relapsed disease was compared to those with refractory disease. Between 1980 and 2004, 1708 patients were treated with chemotherapy for GTN. Sixty (3.5%) patents relapsed following completion of initial therapy. The overall 5-year survival for patients with relapsed GTN was 93% (95% CI 86-100%). The overall survival for patients with low-risk and high-risk disease at presentation, who subsequently relapsed was 100% (n=35), and 84% (n=25) (95% CI: 66-96%: P<0.05), respectively. Eleven patients were identified who failed to enter remission and had refractory disease. These patients had a worse outcome compared to patients with relapsed disease (5-year survival 43% (95% CI:12-73% P<0.01)). The outcome of patients with relapsed GTN is good. However, patients with primary chemo-refractory disease do poorly and novel therapies are required for this group of patients.

Test characteristics of immunofluorescence and ELISA tests in 856 consecutive patients with possible ANCA-associated conditions

OBJECTIVE

To examine the test characteristics of immunofluorescence (IF) and enzyme-linked immunosorbent assays (ELISA) in a consecutive series of patients under evaluation for anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

METHODS

Using stored sera, we performed a cross-sectional study on 856 consecutive patients tested prospectively for ANCA by IF, Based on guidelines from the 1994 Chapel Hill Consensus Conference (CHCC), we determined each patient's underlying diagnosis by a medical records review without regard to their ANCA status (the CHCC guidelines do not require ANCA as a prerequisite for diagnosis). We grouped patients with forms of vasculitis commonly associated with ANCA into one of 4 types of AAV: Wegener's granulomatosis (n = 45), microscopic polyangiitis (n = 12), Churg-Strauss syndrome (n = 4), and pauci-immune glomerulonephritis (n = 8). We also classified patients without clinical evidence of AAV (92% of all patients tested) into 5 predefined categories of disease (including "other") and an additional category for no identifiable disease. In a blinded fashion, we then performed ELISAs on the stored serum for antibodies to proteinase-3 (PR3) and myeloperoxidase (MPO) and calculated the test characteristics for both ANCA assay techniques.

RESULTS

Sixty-nine of the 856 patients (8.1%) had clinical diagnoses of AAV based on CHCC guidelines. The positive predictive value (PPV) of ELISA for AAV was superior to that of IF, 83% versus 45%. For patients with both positive IF tests and positive ELISA tests, the PPV increased to 88%. Both IF and ELISA had high negative predictive values (97% and 96%, respectively). Positive ELISA tests were associated with higher likelihood ratios (LR) than IF (54.2 [95% CI = 26.3, 111.5] versus 9.4 [95% CI = 6.9, 12.7]). The LR of both a positive IF and a positive ELISA was 82.1 (95% CI = 33.3, 202.5).

CONCLUSIONS

Compared with IF, an ELISA test fo ANCA was associated with a substantially higher PPV and LR for AAV. This fact, combined with the greater sensitivity of IF, suggests that an effective testing strategy is to perform ELISA tests only on samples that are positive for ANCA by IF.

Antibodies to selected minor target antigens in patients with anti-neutrophil cytoplasmic antibodies (ANCA)

In patients with anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis, indirect immunofluorescence (IF) distinguishes between cytoplasmic (C-ANCA) and perinuclear (P-ANCA) neutrophil staining patterns. In patients with primary systemic vasculitis such as Wegener's granulomatosis, microscopic polyangiitis and Churg-Strauss syndrome, these IF staining patterns correspond broadly with antibodies to the two major antigens: the C-ANCA pattern is associated generally with antibodies to serine protease 3 (PR3) and the P-ANCA pattern with antibodies to myeloperoxidase (MPO). However, some sera positive for ANCA by IF are negative for anti-PR3 and anti-MPO antibodies, suggesting the presence of antibodies to minor antigens of PMN granules. We tested sera from a previously well-defined clinical cohort of patients for antibodies to four possible minor antigens: bactericidal permeability increasing protein, elastase, cathepsin G and lactoferrin. IF-positive (+) sera had significantly higher antibody frequencies to the minor antigens than did the IF-negative (-) sera (P < 0.01). Patients with IF(+) PR3(-)MPO(-) sera showed the most varied reactivity to the minor antigens. Among the IF(+) groups, the IF(+) PR3(+)/MPO(-) sera showed the lowest reactivity to the minor antigens. Patients with well-defined ANCA specificities, e.g. the PR3-ANCA response associated with Wegener's granulomatosis, are less likely than are other patient subsets to have antibodies to minor antigen targets. Autoantibodies to these minor antigens contribute to the overall pattern of ANCA identified by IF and help to explain why the correlation between IF and enzyme immunoassays show discrepancies. While the pathophysiological significance of antibodies to minor target antigens needs further evaluation, they may be markers of inflammation associated with disease processes.

Paclitaxel for anthracycline-resistant AIDS-related Kaposi's sarcoma: clinical and angiogenic correlations

BACKGROUND

Murine data indicate that angiogenesis is central to the aetiopathogenesis of Kaposi's sarcoma (KS). Therefore, we measured angiogenic cytokines and growth factors in patients with AIDS-related KS during treatment with both antiretrovirals and second-line paclitaxel chemotherapy. Cytokines measured included tumour necrosis factor-alpha (TNF-alpha), basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF) and the interleukins IL-2, -6 and -12.

PATIENTS AND METHODS

Enzyme-linked immunosorbent assays (ELISAs) were carried out to measure plasma cytokine levels in 17 patients with AIDS-related KS who had progressed within 6 months of receiving liposomal anthracyclines and were treated with paclitaxel 100 mg/m(2) every 2 weeks. Measurements were carried out before progression, at commencement and at the completion of paclitaxel.

RESULTS

The objective response rate to paclitaxel was 71% (95% confidence interval 60% to 81%). In 17 patients with AIDS-related KS, we observed eight partial responses and four complete responses. Patients with AIDS Clinical Trial Group stage T1 disease had higher plasma VEGF (P = 0.05) and lower plasma TNF-alpha levels (P = 0.05) than patients with earlier stage T0 KS. There were no correlations between plasma cytokines (bFGF, VEGF, TNF-alpha, and IL-2,-6 and -12) and the CD4 and CD8 cell counts or HIV-1 RNA viral load. Response to paclitaxel was associated with a fall in plasma IL-6 levels (P = 0.04) but no change in other cytokines. There were no significant changes in CD4, CD8, CD16/56, CD19 cell counts and HIV-1 viral loads during chemotherapy.

CONCLUSIONS

Angiogenic cytokines may correlate with KS disease extent but not with cellular immune function or HIV viraemia. Response to paclitaxel therapy correlates with a fall in plasma IL-6 levels and recent data indicate this may be a surrogate marker of KS-associated herpesvirus viral load. Overall, clinical response in KS correlates poorly with known angiogenic cytokines.

Circulating sphingosine-1-phosphate and erythrocyte sphingosine kinase-1 activity as novel biomarkers for early prostate cancer detection

BACKGROUND

Current markers available for screening normal populations and for monitoring prostate cancer (PCa) treatment lack sensitivity and selectivity. Sphingosine-1-phosphate (S1P) is a circulating lipid second messenger involved in cell growth and migration, the immune response, angiogenesis, and malignant transformation.

METHODS

Eighty-eight patients with localised, locally advanced, or metastatic PCa were recruited into this prospective single-centre study. Plasma S1P levels were measured and compared with age-matched controls with benign prostate hyperplasia (BPH) (n=110) or with young healthy males with the very small chance of having PCa foci (n=20).

RESULTS

Levels of circulating S1P were significantly higher in healthy subjects (10.36 ± 0.69 pmol per mg protein, P<0.0001) and patients with BPH (9.39 ± 0.75, P=0.0013) than in patients with PCa (6.89 ± 0.58, ANOVA, P=0.0019). Circulating S1P levels were an early marker of PCa progression to hormonal unresponsiveness and correlated with prostate-specific antigen (PSA) levels and lymph node metastasis. During the course of the study, nine patients have died of PCa. Importantly, their circulating S1P levels were significantly lower (5.11 ± 0.75) than in the surviving patients (7.02 ± 0.22, n=79, P=0.0439). Our data suggest that the decrease in circulating S1P during PCa progression may stem from a highly significant downregulation of erythrocyte sphingosine kinase-1 (SphK1) activity (2.14 ± 0.17 pmol per mg protein per minute in PCa patients vs 4.7 ± 0.42 in healthy individuals, P<0.0001), which may be a potential mechanism of cancer-induced anaemia.

CONCLUSION

This current study has provided a potential mechanism for cancer-related anaemia and the first evidence that plasma S1P and erythrocyte SphK1 activity are the potential markers for the diagnosis, monitoring, and predicating for PCa mortality.

Impact of antiretroviral choice on hypercholesterolaemia events: the role of the nucleoside reverse transcriptase inhibitor backbone

BACKGROUND

The use of highly active antiretroviral therapy (HAART) has profoundly altered the life expectancy of individuals infected with HIV. Metabolic abnormalities associated with antiretrovirals and cumulative exposure to combination antiretroviral therapy, including dyslipidaemia and insulin resistance, have been linked to an increased risk of myocardial infarction.

METHODS

Longitudinal data from a large prospectively collected clinical database were analysed. All patients who commenced first antiretroviral therapy (ART) [two nucleoside reverse transcriptase inhibitors (NRTIs)+one nonnucleoside reverse transcriptase inhibitor (NNRTI) or one active protease inhibitor (PI)] since 1996 were identified. Patients with elevated cholesterol levels [>5.5 mmol/L (215 mg/dL)] prior to therapy initiation were excluded. Quantitative data were categorized into quartiles and presented stratified by individuals developing abnormal levels of cholesterol during first-line HAART. Event time was defined as time from commencing first-line ART to either development of cholesterol level >6.5 mmol/L (254 mg/dL) or switch of first-line therapy. The Kaplan-Meier product limit survival method was used to estimate time to abnormal cholesterol level, and the chi2 test was used for comparisons between drug classes. Cox's proportional hazards regression analysis was used to identify factors predicting a likelihood of raised cholesterol level.

RESULTS

A total of 1664 patients were included in the study: 57.1% on two NRTIs+one NNRTI, 38.4% on two NRTIs+one PI, and 4.4% on two NRTIs+a boosted PI regimen. Regimens containing stavudine or PIs were associated with a significantly higher event risk and earlier time to event. No differences between efavirenz and nevirapine or between didanosine and lamivudine were observed. In 28 patients exposed to the combination of tenofovir+lamivudine+efavirenz, there were no episodes of elevated cholesterol level.

CONCLUSION

Dyslipidaemia has emerged as an important issue in HIV-infected individuals receiving antiretroviral therapy. This study demonstrates that age at start of therapy, baseline cholesterol level, stavudine use and PI use are all associated with increased risk of hypercholesterolemia on initial therapy. Both NRTI and NNRTI/PI choice influence risk of hypercholesterolaemia.

Multicenter study of human immunodeficiency virus-related germ cell tumors

PURPOSE

Testicular germ cell tumors (GCT) occur at increased frequency in men with human immunodeficiency virus (HIV). This multicenter study addresses the characteristics of these tumors.

PATIENTS AND METHODS

Patients with HIV-related GCT were identified from six HIV treatment centers. The incidence was calculated from the center with the most complete linked oncology and HIV databases.

RESULTS

Thirty-five patients with HIV-related GCT were identified. The median age at GCT diagnosis was 34 years (range, 27 to 64 years). The median CD4 cell count was 315/mm3 (range, 90 to 960/mm3) at this time. The histologic classification was seminoma in 26 patients (74%) and nonseminomatous GCT in nine patients (26%). Twenty-one patients (60%) had stage I disease and 14 patients had metastatic disease. Overall six patients relapsed, three died from GCT, and seven died from HIV disease, resulting in a 2-year overall survival rate of 81%. HIV-related seminoma occurred more frequently than in the age- and sex-matched HIV-negative population, with a relative risk of 5.4 (95% confidence interval, 3.35 to 8.10); however, nonseminomatous GCT did not occur more frequently, and there was no change in the incidence of GCT since the introduction of highly active antiretroviral therapy.

CONCLUSION

Testicular seminoma occurs significantly more frequently in HIV-positive men than in the matched control population. Patients with HIV-related GCTs present and should be treated in a similar manner to those in the HIV-negative population. After a median follow-up of 4.6 years, 9% of the patients died from GCT. Most of the mortality relates to HIV infection.

Management of complex colonic polyps in the English Bowel Cancer Screening Programme

BACKGROUND

Large sessile or flat colonic polyps, defined as polyps at least 20  mm in size, are difficult to treat endoscopically and may harbour malignancy. The aim of this study was to describe their current management to provide insight into optimal management.

METHODS

This retrospective observational study identified patients with large sessile or flat polyps detected in the English Bowel Cancer Screening Programme between 2006 and 2009. Initial therapeutic modality (surgical or endoscopic), subsequent management and outcomes were recorded. The main outcome measures analysed were: presence of malignancy, need for surgical treatment, complications, and residual or recurrent polyp at 12 months.

RESULTS

In total, 557 large sessile or flat polyps with benign appearance or initial histology were identified in 557 patients. Some 436 (78.3 per cent) were initially managed endoscopically and 121 (21.7 per cent) were managed surgically from the outset. Seventy of those initially treated endoscopically subsequently required surgery owing to the presence of malignancy (19) or not being suitable for further endoscopic management (51). Residual or recurrent polyp was present at 12 months in 26 (6.0 per cent) of 436 patients managed endoscopically. There was wide variation between centres in the use of surgery as a primary therapy, ranging from 7 to 36 per cent. Endoscopic complications included bleeding in 13 patients (3.0 per cent) and perforation in two (0.5 per cent).

CONCLUSION

Management of large sessile or flat colonic polyps is safe and effective in the English Bowel Cancer Screening Programme. Wide variation in the use of surgery suggests a need for standardized management algorithms. Presented to a meeting of the British Society of Gastroenterology, Birmingham, U.K., March 2011.

A review of the ethnic differences in breast cancer

Women of African descent have a lower incidence of breast cancer than their white counterparts; however, the overall age-adjusted breast cancer mortality rates are higher. They also present at a younger age, and have more advanced disease that exhibits poor prognostic features including significantly larger tumors of higher grade, higher rates of estrogen receptor and progesterone receptor negativity and a higher rate of p53 mutations and HRAS1 proto-oncogene expression, all of which confer a poor prognosis. While there are many possible contributory factors to the discrepancies in outcome in women of African descent, there is no satisfactory explanation as to why women of African origin tend to present at a younger age with hormone receptor-negative tumors and more adverse prognostic features.