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Results for “multivariate analysis”

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At least 1,243 records · Page 69Linked to original sources
PubMed1994

Predictors of axillary lymph node metastases in patients with T1 breast cancer. A multivariate analysis.

BACKGROUND: In T1 tumors, the reported incidence of lymph node metastases ranges from 21% to 35%. The authors analyzed the pathology parameters of T1 tumors for their association with the likelihood of axillary lymph node metastases. METHODS: Two hundred sixty-three patients with T1 unilateral invasive breast cancer were studied. All underwent axillary dissection, and the pathologic status of the nodes was known. The parameters of the primary tumor evaluated included size, histologic subtype, nuclear grade, DNA ploidy, S-phase fraction (SPF), hormone receptor status, lymphatic/vascular invasion (LVI), and host reaction. RESULTS: Seventy-two (27%) patients had nodes that were positive for metastasis. Univariate analysis showed that lymph node metastases were associated with tumors larger than 1 cm (P = 0.001), moderate or poorly differentiated nuclear grade (P = 0.005), high SPF (P = 0.041), presence of LVI (P < 0.001) and patients younger than 60 years (P = 0.01). However, independent predictors of lymph node metastasis in the multivariate logistic regression analyses were tumor size and LVI. Twenty-five patients had tumors larger than 1.0 cm and presence of LVI; of these, 17 (68%) had lymph node metastases. Of the 79 patients who had neither of these features, only 7 (9%) had lymph node metastases. CONCLUSIONS: The authors conclude that characteristics of the primary tumor can help assess the risk for axillary lymph node metastases. Selected patients who are assessed to be at minimal risk might be spared routine axillary dissection or radiation therapy to the axilla.

Adult↗
PubMed1998

Potential prognostic factors of relapse-free survival in childhood optic pathway glioma: a multivariate analysis.

There is still no consensus on the natural history and optimal management of optic pathway gliomas (OPG) in children. In order to tackle optimal management issues, we need to clearly understand the prognostic and confounding factors affecting relapse of OPG. We propose the use of the Cox proportional hazards (PH) model in a retrospective study of childhood OPG of 69 children seen from 1977 to 1994. We have developed a comprehensive model capable of multivariate analyses and handling time-dependencies. Our studies showed that relapse-free survival improves with increasing age, the presence of neurofibromatosis 1 (NF1), and chemotherapy and radiotherapy (p < 0.0005). Sex, tumor position and surgery do not significantly affect survival. Older children with NF1 have extremely good prognosis. We noted behavior that departs from the strictly proportional hazards model, but results were inconclusive.

Adolescent↗
PubMed1989

Multivariate analysis of a tissue CEA, TPA, and CA 19.9 quantitative study in colorectal cancer patients. A preliminary finding.

Tissue CEA, TPA, and CA 19.9 concentrations from samples of surgical specimens were measured in 47 evaluable colorectal cancer patients (median follow-up, 20 months, 13 recurrences) and correlated with individual patient follow-up status. The quantitative method appeared to be sensitive, easily reproducible, and standardizable. The tissue marker concentration was analyzed by means of the multivariate discriminant analysis, to evaluate the risk of relapse in each patient; the tumor CEA (CEA T) showed the best discriminant capacity (P = .005). The relative Fisher function provided a reliable prognostic patient index, independently of other recognized prognostic factors (Dukes' stage and cellular differentiation grade). The Cox model showed a statistical significance analyzing the tumor (T) and healthy mucosa (M) CEA values (P = .001 and P = .006, respectively). The combination of these two variables allowed for identification of three classes of patients according to CEA T and M threshold values of 216 and 85 ng/mg of protein, respectively, and different disease-free curves were obtained for each group. The two-year disease-free rate was 81 percent for patients with low values of both CEA T and M, and 21.4 percent for the group with both values above these thresholds (P = .0008). In the third class (CEA T or M higher than the reported cut-off levels), the two-year disease-free rate was 65.9 percent.

Antigens, Neoplasm↗
PubMed1983

Multivariate analysis of prognostic factors in metastatic breast cancer.

Univariate and multivariate analyses were conducted on data collected from the records of 619 patients with metastatic breast cancer in whom an Adriamycin-containing chemotherapeutic regimen was used. Using a forward, stepwise logistic regression procedure, several models or equations in which a small number of pretreatment factors were incorporated were generated and the probability of response to therapy was accurately predicted. The predictive ability of these models was tested retrospectively in 546 of the 619 patients from whom the data were derived and prospectively in a new population of 200 patients with metastatic breast cancer also treated with a therapeutically equivalent Adriamycin combination. Using similar univariate techniques, pretreatment factors were correlated with the length of survival after therapy. The proportional hazard model of Cox was used to develop a regression model relating survival to pretreatment characteristics in much the same manner as that of the response model. The total population of the initial group of patients was divided according to four levels of hazard ratio, and survival distributions were compared. This model also was tested progressively and its predictive capability was confirmed. The prediction of individual outcome is a valuable capability in the comparison of clinical trials and the continuing evaluation of biologic changes in patients with metastatic carcinoma; such a method is described in this paper.

Analysis of Variance↗
PubMedDate not supplied

Characterizing patients with multiple sexually acquired infections: a multivariate analysis.

It has long been recognized that sexually transmitted diseases (STDs) may occur concurrently hence necessitating screening in individuals attending Genito-Urinary Medicine (GUM) clinics. However there are few data on individuals with more than one concurrent STD. Individuals attending the GUM Department in the Royal Infirmary of Edinburgh between 1990 and 1994 with the diagnosis of HIV infection, genital warts, genital herpes, non-specific genital infection (NSGI), gonorrhoea and syphilis were included in the study. A multivariate comparison was made between those presenting with multiple concurrent STDs and a control group comprising individuals with a solitary STD with respect to year of attendance, social class, location of acquisition of infection, sex, sexual orientation and age using a logistic regression model. A total of 680 of 9265 patients in the study period had more than one concurrent STD. Individuals in lower socio-economic class were at higher risk and older individuals at lower risk of multiple concurrent STDs. Multiple sexually acquired infections are common in individuals who attend GUM clinics. Age and socio-economic class were the only significant variables. Identification of populations at highest risk for multiple infection can direct interventions against all STDs.

Adult↗
PubMed1991

Multivariate analysis of flow cytometric deoxyribonucleic acid parameters and histological features for prognosis of bladder cancer patients.

We studied whether flow cytometry provides significant prognosticators beyond the classical histological evaluation in the patient with bladder cancer. A total of 203 patients with untreated bladder cancer was evaluated using fresh bladder tumor specimens. Tumor grading and stage were the histological prognostic parameters. Deoxyribonucleic acid (DNA) index, percentage S-phase cells, percentage G2/M-phase cells and hypertetraploid cell presence were assessed as flow cytometric prognostic parameters. Multivariate survival analysis was performed using Cox's proportional regression model to study statistical individual prognostic values of histological and flow cytometric parameters. Hypertetraploid cell presence was the single most important prognostic factor (p less than 0.01), with tumor grade being nearly as important (p less than 0.01), followed by tetraploidy (p less than 0.01) and tumor stage (p less than 0.05). No other parameters, including the DNA index or cell phase fractions, contributed to the model. These results indicated that combined use of histological and flow cytometric parameters may provide additional information regarding the clinical outcome for bladder cancer patients.

Adult↗
PubMed1997

[Uni- and multivariate analysis of predictive survival factors in hepatocellular carcinoma. A study of a series of 122 patients].

The files of 122 patients hospitalized for hepatocellular carcinoma (HCC) were reviewed retrospectively to study survival as a function of treatment and different peri-therapeutic factors. Cirrhosis was certain or probable in 69 cases. Laparotomy was performed 77 times (13 exploratory, 64 excisions). Chemoembolization with Adriamycine was performed 18 times. Median survival was 11.6 months. The factors influencing survival in monovariate analysis were the Child-Pugh stage (p < 0.0001), the Okuda stage (p < 0.0001), ascites (p < 0.001), a post-operative complication (p < 0.0001), gamma-glutamyltransferase level (p < 0.0037), tumor site (p < 0.004), albuminemia (p < 0.008), alkaline phosphatase concentration (p < 0.0087), number of tumors (p < 0.01), portal thrombosis (p < 0.01) and alpha-foetoprotein level (p < 0.01). In multivariate study, the Okuda stage (p < 0.001), age (p < 0.001) and portal thrombosis (p < 0.037) remained significant. The Okuda 1 group was also considered in multivariate study, in which case only patient age and the possibility of therapeutic excision were significant factors. In our opinion, the Okuda classification, which is easy to establish, should be adopted for pretherapeutic evaluation of patients with hepatocellular carcinoma.

Aged↗
PubMed1997

Prognosis of acute renal failure in children: a multivariate analysis.

Various factors were analyzed in 80 consecutive children under 16 years who had acute renal failure (ARF), for various prognostic factors. Overall mortality was 42.5%, with significantly higher levels seen in hemolytic uremic syndrome (68%, P < 0.05) and associated with cardiac surgery (90.9%, P < 0.01). Anuria (67.6% vs. 43.5%, P < 0.05), need for dialysis (85.3% vs. 56.5%, P < 0.05), neurological complications (50% vs. 6.3%, P < 0.01), and respiratory complications (35.2% vs. 2.1%, P < 0.01) were significantly higher in nonsurvivors than survivors. Multiple regression analysis showed the presence of neurological and respiratory complications to be poor prognostic factors.

Acute Kidney Injury↗
PubMed2000

Multivariate analysis of prognostic determinants after surgery for renal cell carcinoma at Himeji National Hospital.

A clinico-pathological study was performed retrospectively on 62 patients who underwent surgery for renal cell carcinoma between January 1992 and October 1998 at Himeji National Hospital to clarify the prognostic determinants for survival. The median follow-up period was 32 months and the cause-specific survival rates at 1, 3 and 5 years were 86.7, 81.3, 81.3%, respectively. Of the 62 patients, 11 (17.7%) patients died of renal cell carcinoma and 2 (3.2%) patients died of unrelated causes. Of the variables related to survival, presenting symptoms, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), alkaline phosphatase (ALP), tumor size, pathological tumor grade, infiltration pattern, pathological tumor stage, N classification and M classification were significant risk factors for survival by univariate analysis. However, ALP, N classification and M classification were significant for survival as determined by the step-wise procedure and M classification was the most significant factor according to Cox's proportional hazard model analysis.

Adult↗
PubMed1991

[Use of a multivariate analysis method for determining the interconnection of genetic markers with gene clusters and solution of taxonomy problems for the recombinant influenza A virus model].

The collection of influenza A viral recombinants has been studied for determining interconnection of the definite genetical marker (pneumovirulence for mice) with genes constellation by the technique of image identification. Pneumovirulence is found to be defined by correlation of polymerase complex M-, NS- and NA-genes. The data on NA influence on pneumovirulence were obtained for the first time, the phenomenon being found only with the use of image identification technique. The used methods of image identification (the method of correlation plaiads and cluster analysis) are recommended for use in studying the specificity of the gene control for different genetical features.

Animals↗
PubMed2003

Improved methods for performing multivariate analysis and deriving background spectra in atmospheric open-path FT-IR monitoring.

Open-path Fourier transform infrared spectrometry (OP/FT-IR) may improve the temporal and spatial resolution in air pollutant measurements compared to conventional sampling methods. However, a successful OP/FT-IR operation requires an experienced analyst to resolve chemical interference as well as to derive a suitable background spectrum. The present study aims at developing a systematic method of handling the OP/FT-IR derived spectra for the measurement of photochemical oxidants and volatile organic compounds (VOCs) in urban areas. A classical least-squares (CLS) method, the most frequently used regression method in OP/FT-IR, is modified to constrain all the analyzed chemical species concentrations within a physically reasonable range. This new CLS method, named constrained CLS, may save the effort of predetermining the chemical species to be analyzed. A new background spectrum generation method is also introduced to more efficiently handle chemical interferences. Finally, CLS is shown to be prone to propagating errors in the case that a few data points contain a significant amount of error. The LI-norm minimization method reduces this error propagation to considerably increase the stability compared to CLS. The presently developed analysis software based on these approaches is compared with the other conventional CLS method using an artificially made single-beam spectrum as well as a field single-beam spectrum.

Air Pollutants↗