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M W van Beek

Publications and source records attributed to M W van Beek.

10 recordsLinked to original sources
PubMed1997

Prognostic implications of different cell cycle analysis models of flow cytometric DNA histograms of 1,301 breast cancer patients: results from the Multicenter Morphometric Mammary Carcinoma Project (MMMCP).

Conflicting prognostic results with regard to DNA flow cytometric cell cycle variables have been reported for breast cancer patients. An important reason for this may be related to differences in the interpretation of DNA histograms. Several computer programs based on different cell cycle fitting models are available resulting in significant variations in percent S-phase and other cell cycle variables. Our present study evaluated the prognostic value of percent S-phase cells obtained using 5 different cell cycle analysis models. Flow cytometric DNA histograms obtained from 1,301 fresh frozen breast cancer samples were interpreted with 5 different cell cycle analysis models using a commercially available computer program. Model 1 used the zero order S-phase calculation and "sliced nuclei" debris correction, model 2 added fixed G2/M- to G0/G1-phase ratio, and model 3 added correction for aggregates. Model 4 applied the first-order S-phase calculation and sliced debris correction. Model 5 fixed the coefficients of variation CVs of the G0/G1- and G2/M-phases in addition to applying the sliced nuclei debris correction and zero order S-phase calculation. The different models yielded clearly different prognostic results. The average percent S-phase cells of the aggregate correction model (model 3) provided the best prognostic value in all cases for overall survival (OS) as well as disease-free survival (DFS) (OS: p < 0.0001; DFS: p < 0.0001), in lymph node-positive cases (OS: p < 0.0001; DFS: p = 0.004) and in DNA-diploid subgroups (OS: p = 0.004; DFS: p = 0.001). For the lymph node negative and DNA-non-diploid subgroups, the percent S-phase of the second cell cycle reached slightly better prognostic significance than the average percent S-phase cells. In multivariate analysis, the average percent S-phase of the aggregate correction model had the best additional prognostic value to tumor size and lymph node status. In conclusion, different cell cycle analysis models yield clearly different prognostic results for invasive breast cancer patients. The most important prognostic percent S-phase variable was the average percent S-phase cells when aggregate correction was included in cell cycle analysis.

Adult↗
PubMed1997

Changing attitudes towards breast-conserving treatment of early breast cancer in the south-eastern Netherlands: results of a survey among surgeons and a registry-based analysis of patterns of care.

To see whether personal preferences of surgeons can explain the trends in the use of breast-conserving therapy (BCT) of early breast cancer, questionnaires were sent to the surgeons of seven community hospitals in the south-eastern Netherlands in 1987 and 1995. The answers were set against the actual use of breast-conserving therapy in the hospitals in the period 1984-94, as monitored by the Eindhoven Cancer Registry. The proportion of surgeons who were willing to use BCT for tumours < or =3 cm increased from 43% in 1987 to 93% in 1995. In 1995, the majority of the surgeons considered multicentric tumour growth, diffuse microcalcifications on the mammogram and an extensive intraductal component around the tumour as contraindications for breast-conserving therapy. The proportion of patients with an operable, non-metastasized breast tumour of < or =5 cm in diameter undergoing breast-conservative surgery increased from 31% in 1984 to 60% in 1989 (P<0.01) and remained at that level in 1990 and 1991. Between 1991 and 1993, the proportion receiving breast-conservative surgery decreased significantly for patients younger than 50 years and a tumour 2.1-3.0cm in diameter, and also for those 50-69 years old with a tumour < or =2.0cm or 3.1-5.0cm across. The observed decrease in BCT in the south-eastern Netherlands in some subgroups seems to reflect the growing awareness of potential risk factors for local recurrence following BCT.

Adult↗
PubMed1997

Prognostic value of DNA ploidy using flow cytometry in 1301 breast cancer patients: results of the prospective Multicenter Morphometric Mammary Carcinoma Project.

The literature on breast cancer reports conflicting prognostic results with respect to DNA ploidy of flow cytometric DNA histograms. This might result from different DNA ploidy classification methods. Our study evaluated the prognostic power of DNA ploidy, using different classification methods, in a large prospective group (n = 1301) of breast cancer patients. Flow cytometric DNA histograms obtained from fresh frozen material were interpreted with use of a commercially available computer program. On the basis of the number of stemlines and the DNA Index, we classified the DNA ploidy by different methods. In all of the cases, the classification method "DNA diploid versus DNA nondiploid" provided the best prognostic significance for overall survival (OS) (Mantel-Cox (MC) = 5.4, P = .02; relative risk (RR) = 1.3, P = .05) and for disease-free survival (DFS) (MC = 11.8, P = .0006; RR = 1.3, P < .05). This was also true for the OS of the lymph node-positive (but not the lymph node-negative) subgroup (MC = 4.1, P = .04; RR = 1.3, P = .05). In subgroups classified on the basis of tumor size, DNA ploidy showed prognostic significance for DFS only in the subgroup of tumors smaller than 2 cm and larger than 5 cm. In multivariate analysis, DNA ploidy showed no additional prognostic power to lymph node status and tumor size. The classification "DNA diploid versus DNA nondiploid" was mostly consistent with respect to prognostic power for OS and DFS, especially in small or lymph node-positive tumors. The RR of DNA nondiploid patients was only marginally higher, however, so large study groups are required to reach statistical significance. This could partly explain the disagreements in the literature. Therefore, DNA ploidy seems to be of little clinical importance in breast cancer patients, compared with other prognostic parameters.

Adult↗
PubMed1994

Management of early breast cancer in southeast Netherlands since 1984. A population-based study. Regional Breast Cancer Study Group.

We studied changes in staging and treatment of patients with early breast cancer (TNM stage I and II) in eight community hospitals in southeast Netherlands between 1984 and 1991 and related these changes to the guidelines for the management of breast cancer drawn up by the regional Breast Cancer Study Group. Since 1984, the proportion of patients that underwent breast-conserving therapy (local tumour excision, axillary dissection, and irradiation of the breast) increased from 26% to 53%. Although the mean number of axillary lymph nodes examined by the pathologists increased significantly, the proportion of patients with positive lymph nodes remained unchanged. The proportion of patients with involved axillary nodes receiving any form of adjuvant systemic therapy increased from 49% to 82%. Therapeutic policy initially varied significantly from one hospital to another but gradually became more uniform. We conclude that, except for elderly patients, treatment of early breast cancer corresponded increasingly to the guidelines of the regional Breast Cancer Study Group.

Adult↗
PubMed1992

[Increased incidence of breast cancer in southeast Netherlands between 1960 and 1989].

Trends in incidence, stage distribution and mortality of breast cancer were determined in the Southeastern Netherlands in 1960-1989. First and second primary breast cancers were analyzed separately. The incidence and mortality rates were age-standardised according to the European Standard Population. The incidence rate of first primary invasive breast cancer increased from 50 per 100,000 women per year in 1960-61 to 96 in 1988-89, and of second primary invasive breast cancer from 3.2 in 1965-66 to 7.8 in 1988-89. The incidence rate of first primary ductal carcinoma in situ (DCIS) increased from 0.3 per 100,000 women per year in 1975-76 to 2.8 in 1988-89 and of second primary DCIS from 0.06 in 1975-79 to 0.4 per 100,000 in 1985-89. The increase in first invasive primaries was observed in all age groups, but mostly at age 75 and over. The percentage with stage I tumours of the patients with a first primary invasive breast cancer increased from 7% in the sixties to 27% in the eighties, whereas the percentage of stage III and IV tumours combined, decreased from 39% in the sixties to 26% in the eighties. While age-adjusted incidence of first primaries almost doubled in the past thirty years, breast cancer mortality rose only slightly. However, breast cancer mortality showed a proportionate increase of total mortality from 4.5% in 1970-71 to 6.3% in 1988-89.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

The Multicenter Morphometric Mammary Carcinoma Project (MMMCP). A nationwide prospective study on reproducibility and prognostic power of routine quantitative assessments in The Netherlands.

The Multicenter Morphometric Mammary Carcinoma Project (MMMCP) has been set up to investigate prospectively the prognostic value and reproducibility of routine assessments of the morphometric Multivariate Prognostic Index (MPI) and other quantitative parameters in comparison with classical prognosticators and steroid receptors in breast cancer patients. In this project, 34 hospitals participate, divided over six geographically different regions. Of each patient entering in the study, multiple clinical and classical pathological parameters (including tumor size and lymph node status) as well as several quantitative parameters such as mean nuclear area, DNA index and mitotic activity index will be evaluated. Of all patients, the MPI will be assessed with tumour size, lymph node status and mitotic activity index. The quantitative assessments are performed in all consecutive breast cancers which enter the participating pathology laboratories, and all measurements are controlled in Amsterdam. The patient intake time will be from January 1, 1988 until January 1, 1990. It is expected that 3000 patients will enter in this study. Follow up data will be gathered up to 10 years. However, two to five years after the initiation of the Project, a first evaluation of the reproducibility and prognostic significance of routine MPI and other assessments in breast cancer patients will be possible. A detailed description of this project is given.

Breast Neoplasms↗
PubMed1987

[Lymph nodes 1987].

Explore the source record for details and available documents.

AIDS-Related Complex↗
PubMed1985

Polyneuropathy due to polyangiitis overlap syndrome.

A patient presented with a mild polyneuropathy, developed a large intra-abdominal haemorrhage and died of cardiac arrest within a few days. Microscopic examination revealed a polyangiitis overlap syndrome (Fauci) with lesions in many organs, including the peripheral nerves and the heart. A myocarditis was considered to be the cause of death.

Humans↗
PubMed1981

Mesenteric cysts.

7 new cases of cysts in the mesentery of the small bowel are presented, together with 54 clinically and histologically well documented cases from the literature. Most cysts are found in laparotomy for an acute abdomen. Almost half of the patients are under the age of 11 years. The cysts can be unilocular, multilocular or multiple. Cysts in the mesentery of the jejunum always had a chylous content. Most often the wall consists of an endothelial lining, smooth muscle, lymphatic tissue and lymphatic vessels. Inflammation and/or bleeding destroyed the endothelial lining and added granulation tissue to the histologic picture. With the exception of 7 cases, the cysts are probably of congenital and lymphatic origin. Trauma, infection, bleeding or volvulus can make a silent cyst manifest.

Abdomen, Acute↗