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Biomedical subjects

Justin Stebbing

Publications and source records attributed to Justin Stebbing.

At least 19 recordsLinked to original sources

Highly active antiretroviral therapy and human immunodeficiency virus-associated primary cerebral lymphoma.

From a cohort of 9621 human immunodeficiency virus type 1-infected individuals, we identified 61 patients with primary central nervous system lymphoma (PCL) who had a median survival of 1.3 months. We compared clinicopathologic variables of patients who were treated in the pre-highly active antiretroviral therapy (HAART) and HAART eras and investigated whether exposure to antiretroviral agents with differing cerebrospinal fluid penetrations was associated with risk for PCL. All statistical tests were two-sided. Incidence of PCL was lower in the HAART era (1.2 cases per 1000 patient-years, 95% confidence interval [CI] = 0.8 to 1.9) than in the pre-HAART era (three cases per 1000 years, 95% CI = 2.1 to 4.0; P<.001), and overall survival was longer (median survival = 32 days, range = 5-315 days, versus 48 days, range = 15-1136 days; log rank P = .03). In the HAART era, fewer patients had prior acquired immunodeficiency syndrome-defining illnesses than in the pre-HAART era (64% versus 90%; P = .013), and patients were more likely to have the diagnosis of PCL confirmed histologically or by polymerase chain reaction (77% versus 26%; P<.001). Exposure to specific antiretroviral agents was not associated with risk for PCL.

Acquired Immunodeficiency Syndrome↗

A prognostic index for AIDS-associated Kaposi's sarcoma in the era of highly active antiretroviral therapy.

BACKGROUND: AIDS-associated Kaposi's sarcoma remains common in individuals with HIV-1 infection in the era of highly active antiretroviral therapy (HAART). We developed a simple model for predicting mortality on the basis of clinical characteristics present at the time of diagnosis of Kaposi's sarcoma. METHODS: Of 5873 individuals with HIV-1 infection, 326 (6%) developed Kaposi's sarcoma; for 262 (80%) this was their first AIDS-defining illness. We did univariate and multivariate Cox regression analyses to identify covariates predictive of overall survival and validated our model with an independent data set of 446 patients with Kaposi's sarcoma. RESULTS: In the primary model, we developed a prognostic score from 0 to 15 starting at 10. Having Kaposi's sarcoma as the AIDS-defining illness (-3 points) and increasing CD4 count (-1 point for every complete 100 cells per mm3) improved prognosis; age of 50 years or older (2 points) and having another AIDS-associated illness at the same time (3 points) conveyed a poorer prognosis. In individuals with prognostic scores of 0, 5, 10, and 15, probability of survival at 1-year was 0.993, 0.967, 0.834, and 0.378, and at 5 years was 0.984, 0.918, 0.631, and 0.084, respectively. Increasing prognostic score by 1 increased 1-year death hazard ratio by 40% (95% CI 28-53%; bootstrapped hazard ratio 1.39, 1.25-1.51). The index had concordance of 76.8% (71.7-82.3). INTERPRETATION: We identified four prognostic factors that can be used to obtain an accurate prognostic index at diagnosis of AIDS-associated Kaposi's sarcoma. This index is widely applicable and can be used to guide therapeutic options.

AIDS-Related Opportunistic Infections↗

Comparative pharmacogenomics of antiretroviral and cytotoxic treatments.

Few genetic markers are used routinely to predict clinical effectiveness and toxic effects despite the fact that physicians and their patients are consistently confronted with this balance. Because one of the goals of pharmacogenomics is to identify individuals and target populations that might have adverse outcomes, pharmaceutical companies have been reluctant to use a strategy that might identify patients who are not eligible for a particular treatment. This view is changing because drug-discovery programmes and treatments that target specific pathways, are showing improvements in surrogate and survival endpoints. HIV and cancer are now regarded as chronic diseases, which commonly need life-long systemic treatment from the time of diagnosis. HIV and cancer medicine have used pharmacogenomics to some extent in clinical care. Common and classic features of pharmacogenomics that are related to both antiretroviral treatment and to cytotoxic treatment are discussed in this review, providing a framework for individual treatment of these diseases.

Anti-Retroviral Agents↗

Significance of variation within HIV, EBV, and KSHV subtypes.

Since their initial transmission to humans, viruses have diversified extensively through recombination and mutation. The presence of intra- and inter-individual viral diversity influences disease progression, drug resistance, and therapy and presumably explains the conflicting results in many studies, including the failure of peptide-based vaccination strategies. Although HIV is a small RNA virus, coinfection with large DNA viruses, notably the oncogenic gamma-herpesviridae human herpesvirus-8 and Epstein Barr virus, is common. This coinfection occurs secondary to immunosuppression and shared transmission routes with high-risk predisposing behavior. In addition, all 3 of these viruses can lead to chronic infections, long periods of latency, and reactivation characterized by pain and suffering. The efficient targeting of their genetic diversity represents one of the major challenges in their control, both in prophylactic and therapeutic strategies. An understanding of diversity will help delineate whether population-specific vaccine strategies are necessary.

Animals↗

Non-Hodgkin's lymphoma and the CNS: prophylaxis and therapy in immunocompetent and HIV-positive individuals.

The involvement of the CNS in individuals with non-Hodgkin's lymphoma is a well-recognised complication. Despite the progress that has been made in controlling cancer at most sites in the body, the outcome of individuals affected by meningeal infiltration is dismal and few patients survive for more than a few months. There are few studies that have addressed the management of CNS disease in AIDS-associated non-Hodgkin's lymphoma, and treatment algorithms have been formulated secondary to protocols in immunocompetent individuals. The prevention and treatment of CNS disease is an important aspect of lymphoma management, and new medications, such as a sustained-release formulation of intrathecal cytarabine, will have an increasingly relevant role.

Algorithms↗

Epigenetics: an emerging technology in the diagnosis and treatment of cancer.

Transcriptional silencing resulting from changes in epigenetic regulation of gene expression is the most frequent mechanism by which tumor suppressor genes are inactivated in human cancer. Genes participating in numerous functional groups and pathways leading to malignancy are subject to aberrant CpG methylation, with associated downregulation of expression, in human carcinogenesis. Methylation profiling can identify distinct subtypes of common human cancers and may have utility in predicting clinical phenotypes in individual patients, including sensitivity to chemotherapeutic agents. Hypomethylating agents have clinical activity in some hematological malignancies, and there is accumulating evidence correlating clinical response with demethylation and concomitant reactivation of expression of specific target genes. Epigenetic analysis is likely to have an increasingly important part to play in the diagnosis, prognostic assessment and treatment of malignant disease.

Animals↗

Chemotherapy for advanced cholangiocarcinoma: what is standard treatment?

Cholangiocarcinoma is a relatively uncommon malignancy, that presents late in the vast majority of cases. Overall survival rates are extremely poor and treatment options remain limited in patients with inoperable, recurrent or metastatic disease. Systemic chemotherapy has historically had little impact on the natural history of this disease, owing to both the absence of agents with substantial activity and the overall morbidity of treatment in this patient population. Response rates with 5-fluorouracil have been 10% at best, with a median survival of 6 months. However, there has been interest in the use of newer cytotoxic drugs and combination regimens in advanced cholangiocarcinoma, and Phase II trials have reported much improved results. This review examines this data and assesses whether a new standard of care for advanced cholangiocarcinoma can be found.

Bile Duct Neoplasms↗

A prognostic index for systemic AIDS-related non-Hodgkin lymphoma treated in the era of highly active antiretroviral therapy.

BACKGROUND: The established International Prognostic Index for lymphomas has not included patients with systemic AIDS-related non-Hodgkin lymphoma. OBJECTIVE: To establish the most appropriate prognostic index for use in patients with systemic AIDS-related non-Hodgkin lymphoma. DESIGN: A prospective study involving univariate and multivariable analyses of patients with AIDS-related non-Hodgkin lymphoma whose data were used to examine standard and new criteria for survival after diagnosis. SETTING: The Chelsea and Westminster cohort of HIV-1-infected persons. PATIENTS: 9621 HIV-positive patients, 111 in whom AIDS-related non-Hodgkin lymphoma was treated after 1996, in the era of highly active antiretroviral therapy (HAART). INTERVENTION: Cox proportional hazards regression analysis to determine the prognostic significance of multiple clinicopathologic variables. RESULTS: Survival of patients with AIDS-related non-Hodgkin lymphoma has increased in the HAART era (log-rank chi-square, 9.23; P = 0.002). Univariate analyses using the established International Prognostic Index factors of age, tumor stage, lactate dehydrogenase level, Eastern Cooperative Oncology Group performance status, and number of extranodal sites were confirmed to be significant variables. Regression modeling for patients in whom disease was diagnosed after 1996 revealed only 2 independent predictors of death: International Prognostic Index risk group and CD4 cell count. These predictors yielded 4 internally validated risk strata with predicted 1-year survival rates of 82%, 47%, 20%, and 15% (P < 0.001). Prognostic risk scores in the highest quartile yielded a likelihood ratio for death of 7.90 (hazard ratio, 1.0), whereas a prognostic score less than 1.0 yielded a likelihood ratio of 0.23 (hazard ratio, 0.15 [95% CI, 0.06 to 0.33]). LIMITATIONS: The sample was small, and different HAART regimens were used. CONCLUSIONS: For patients with AIDS-related non-Hodgkin lymphoma that was diagnosed in the era of HAART, application of the International Prognostic Index remains useful. The addition of CD4 cell count provides further independent prognostic information. Patients who present with AIDS-related non-Hodgkin lymphoma and a low CD4 cell count have a poor prognosis; this information can be used to guide therapeutic options.

Antiretroviral Therapy, Highly Active↗