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Tumor Growth Rate (tumor + growth_rate)

Distribution by Scientific Domains

Medical Sciences	80%

Selected Abstracts

Proliferative activity and diagnostic delay in oral cancer

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 10 2010
Juan Seoane PhD
Abstract Background Tumor stage may relate to the chronology of neoplasm growth and has been used as an outcome variable when studying diagnostic delay in oral cancer. However, tumor growth rate may act as a confounding factor. Methods We reviewed a total of 63 incident cases of oral cancer. The variables considered for the study included age, sex, smoking history, tumor site, TNM stage, Ki-67 score, and diagnostic delay. Results Significant differences between survivors and exitus were found in terms of tumor stage at diagnosis (I,II vs III,IV), sex, and Ki-67 scores. When the analysis was adjusted for tumor stage at diagnosis (I,II vs III,IV), proliferative activity resulted to be an independent prognostic factor for survival, whereas diagnostic delay did not influence survival. Conclusion These results seem to suggest that survival from oral cancer is affected more by the biology of the cancer (rapid tumor growth) than by diagnostic delay. © 2010 Wiley Periodicals, Inc. Head Neck, 2010 [source]

Conservative Management of Vestibular Schwannomas: An Effective Strategy,

THE LARYNGOSCOPE, Issue 6 2008
Gian Gaetano Ferri MD
Abstract Objectives: Stimulated by the availability of a larger sample of patients and a longer follow-up period, we update our experience with conservative management of vestibular schwannomas. Study Design: Patients with intracanalicular and small/medium-sized tumors have been followed prospectively at a tertiary referral center. Methods: One hundred twenty-three patients affected by sporadic vestibular schwannoma were primarily observed by means of magnetic resonance imaging scans. In case of significant tumor growth (,2 mm), patients were either surgically treated or submitted to radiotherapy, but, not rarely, they continued to follow the "wait-and-scan" policy. Tumor-size changes over time were also evaluated with hearing function. Statistical analysis with predictive growth factors was performed. Results: Almost two thirds (64.5%) of the cases did not show tumor growth during the entire period of observation (mean follow-up period, 4.8 yrs). Among growing tumors, 16 patients were surgically treated with no complications or facial nerve palsy. Less than half (45.5%) of the patients presented useful hearing (classes A and B of the American Academy of Otolaryngology,Head and Neck Surgery classification) at diagnosis, and 41 (73.2%) patients had preserved hearing during follow-up independently from the tumor growth rate. Conclusions: Conservative management of vestibular schwannoma appears to be a safe procedure because most tumors do not grow and surgical outcomes are not affected by possible delays. In the great majority of cases, useful hearing is maintained over time. Because of the irregular behavior of the tumor, periodic neuroradiologic scans are mandatory to limit late surgical risks. [source]

Distinguishing Effects on Tumor Multiplicity and Growth Rate in Chemoprevention Experiments

BIOMETRICS, Issue 4 2000
David B. Dunson
Summary. In some types of cancer chemoprevention experiments and short-term carcinogenicity bioassays, the data consist of the number of observed tumors per animal and the times at which these tumors were first detected. In such studies, there is interest in distinguishing between treatment effects on the number of tumors induced by a known carcinogen and treatment effects on the tumor growth rate. Since animals may die before all induced tumors reach a detectable size, separation of these effects can be difficult. This paper describes a flexible parametric model for data of this type. Under our model, the tumor detection times are realizations of a delayed Poisson process that is characterized by the age-specific tumor induction rate and a random latency interval between tumor induction and detection. The model accommodates distinct treatment and animal-specific effects on the number of induced tumors (multiplicity) and the time to tumor detection (growth rate). A Gibbs sampler is developed for estimation of the posterior distributions of the parameters. The methods are illustrated through application to data from a breast cancer chemoprevention experiment. [source]

Comparison of ACINUS, caspase-3, and TUNEL as apoptotic markers in determination of tumor growth rates of clinically localized prostate cancer using image analysis

THE PROSTATE, Issue 15 2009
Swaroop S. Singh
Abstract BACKGROUND The balance between apoptotic and proliferative processes determines the enlargement of a tumor. Accurate measurement of apoptotic and proliferative rates from diagnostic prostate biopsies would allow calculation of tumor growth rates in a population-based prostate cancer (CaP) study. Automated image analysis may be used if proliferation and apoptotic biomarkers provide clearly resolved immunostained images. METHODS Clinical CaP aggressiveness was assigned as low, intermediate or high using clinical criteria for 46 research subjects with newly diagnosed CaP. Diagnostic biopsy sections from the research subjects were dual-labeled for proliferation biomarker, Ki-67 and apoptotic biomarker, apoptotic chromatin condensation inducer in the nucleus (ACINUS). Apoptotic biomarkers, caspase-3 and terminal deoxyribonucleotidyltransferase mediated dUTP-biotin nick end labeling (TUNEL) were labeled separately. Images from immunostained sections were analyzed using automated image analysis and tumor growth rates computed. Association between clinical CaP aggressiveness and tumor growth rates was explored. RESULTS Sixteen subjects had high, 17 had intermediate, and 13 had low clinical CaP aggressiveness. Positive immunostaining was localized to the nucleus for Ki-67, ACINUS, and TUNEL. A statistically significant linear trend across clinical CaP aggressiveness categories was found when tumor growth rates were calculated using ACINUS (P,=,0.046). Logistic regression and ROC plots generated showed ACINUS (AUC,=,0.677, P,=,0.048) and caspase-3 (AUC,=,0.694, P,=,0.038) to be better predictors than TUNEL (AUC,=,0.669, P,=,0.110). CONCLUSIONS ACINUS met the criteria for automated image analysis and for calculation of apoptotic rate. Tumor growth rates determined using automated image analysis should be evaluated for clinical prediction of CaP aggressiveness, treatment response, recurrence, and mortality. Prostate 69: 1603,1610, 2009. © 2009 Wiley-Liss, Inc. [source]