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Biomedical subjects

K Welvaart

Publications and source records attributed to K Welvaart.

At least 55 records · Page 3Linked to original sources
PubMed1990

[The 'freckle bus' campaign; an unhealthy phenomenon or a sensible experiment?].

In the summer of 1989 a screening campaign for skin cancer was organized in four seaside resorts of The Netherlands using a mobile examination room. On 4 consecutive Saturdays 3069 individuals were examined. A total of 65 individuals with a suspected lesion were found. Histological reports were obtained on 46 suspected lesions and showed: 6 melanomas (all with a thickness less than 1 mm), 2 squamous cell carcinomas, 23 basal cell carcinomas, 5 dysplastic naevi and 10 benign skin lesions. The positive predictive value of the clinical examination appeared to be 83%. Much publicity was given to the campaign by the (inter)national media. The effects of this publicity were measured by a questionnaire sent to the general practitioners (856) and dermatologists (25) in the region, of whom 44% and 84%, respectively, responded. It appeared that during and after the campaign there had been an increase in the number of consultations for skin lesions, and an increase in the diagnoses of malignant lesions.

Adolescent↗
PubMed1990

Is long-term follow-up justified after excision of a thin melanoma (less than or equal to 1.5 mm)? A retrospective analysis of 206 patients.

From 1964 to 1988, 231 patients underwent local excision as the single treatment of melanoma with a thickness of less than or equal to 1.5 mm. We investigated the prognostic value of several factors on cancer-specific survival and cancer-specific disease-free survival, from time of excision on, by performing life-table analysis on 206 evaluable patients. Recurrence developed in 11 patients; local recurrence occurred in four patients, hematogenic spread in three patients and lymph node metastases in another four patients. Six patients died as a result of the disease. Tumors with a thickness of less than or equal to 1.5 mm have an excellent prognosis regardless of the localization of the melanoma. At 15 years cancer-specific survival was 92.3% and cancer-specific disease-free survival was 86.9%. Recurrence was successfully treated with hope for cure in 4 patients. This figures does not justify aggressive follow-up for all patients.

Adolescent↗
PubMed1990

Complications of stapled anastomoses in anterior resection for rectal carcinoma: colorectal anastomosis versus coloanal anastomosis.

Postoperative results of 48 patients who underwent anterior resection using the EEA-stapler were evaluated. In all but 2 cases the indication for surgery was colorectal carcinoma. In 24 patients an anastomosis was created above the 5 cm level (above the anal verge: colorectal anastomosis) and in 24 at the 0-5 cm level (coloanal anastomosis). There was no perioperative mortality. The only complication observed in the colorectal anastomosis group was one case of late anastomotic stenosis. In the coloanal anastomosis group there were 4 cases with early anastomosis leaks, 3 cases with late stenosis and 5 cases with various degrees of late fecal incontinence, ultimately resulting in a permanent diverting stoma in 5 (10.4%) patients. We conclude that for rectal tumors the EEA-stapled anterior resection provides excellent functional results in most cases. Stapled coloanal anastomoses more often demonstrate various (early and late) complications. Nevertheless in spite of chronic discomfort, many patients still prefer their complaints to a permanent stoma.

Adult↗
PubMed1990

Assessment of resectability of carcinoma of the pancreatic head by ultrasonography and computed tomography. A retrospective analysis.

In order to establish the reliability of the assessment of tumour stage and hence of resectability of carcinoma of the pancreatic head by ultrasonography (US) and computed tomography (CT) a retrospective analysis was performed on 41 patients. Both direct imaging techniques were very accurate in detecting non-resectable disease, 100 and 85% respectively, but were much less accurate in predicting resectable cancer, 18 and 15% respectively. False-resectable results were established in 58% of US examinations and 42% of CT examinations. As demonstrated in this study, predicting resectability of carcinoma of the pancreatic head with US and CT is an inadequate method of assessing tumour stage and should be complemented by other techniques to ensure a reliable result.

Aged↗
PubMed1990

The effects of negative regional lymph-node dissection on survival and disease-free interval of patients with stage-I malignant melanoma.

A group of 46 patients, with stage-1 malignant melanoma of intermediate thickness and histologically proven negative regional lymph nodes, was retrospectively reviewed. The aim of our study was to determine whether the prognosis of these patients had been worsened by the regional lymph-node dissections. There was no influence on the survival or disease-free interval.

Adolescent↗
PubMed1989

Locally advanced breast cancer: radiotherapy alone versus surgery and radiotherapy.

From 1976 through 1984 46 patients with locally advanced breast cancer were treated by either radiotherapy alone or by combination of surgery and postoperative radiotherapy. Eleven of the 21 patients treated by radiotherapy alone had a local or regional recurrence, while no recurrences occurred in the combined treatment group. From this study it was concluded that "locally advanced" breast cancer is a heterogeneous disease and that further study concerning the role of surgery is justifiable for a selected subgroup of patients with non-inflammatory resectable tumours (meeting the criteria of "locally advanced" breast cancer).

Adult↗
PubMed1989

Significance of tumor invasion and lymph node involvement on the prognosis and selection for surgery of adenocarcinoma of the cardia.

Between 1970 and 1983, 66 patients with adenocarcinoma of the cardia underwent resection in our institute. Hospital mortality within 30 days of surgery was 18.2%. Overall hospital mortality irrespective of time was 27.3%. The 4-year survival rate for all patients excluding overall hospital mortality was 29%. There was a significant difference in cumulative survival between T2 (n = 29) and T3 tumours (n = 15) (P = 0.035). Comparison in this 44-patient group of cumulative survival of patients with negative nodes (N0, n = 13) and positive nodes (N+, n = 31) was also significant (P = 0.01). The application of tumor invasion and lymph node involvement as peri-operative parameters for the selection of patients for resection was evaluated in a retrospective study. Forty-four patients were found eligible to be rearranged in a system using the following clinicopathological parameters: T = 3 versus T = 2 and N+ (positive nodes in N1 and/or N2 groups) versus N0. This system revealed no distinct group of patients who should be withheld from resection according to the criteria held in our institute. Resection provided excellent relief of dysphagia in most patients. The various findings are discussed, and further prospective studies will be needed. At present, in the absence of haematogenous metastases, we prefer surgical resection for all patients whose general condition allows major surgery.

Adenocarcinoma↗
PubMed1988

Level of HLA antigens in locoregional metastases and clinical course of the disease in patients with melanoma.

Immunohistochemical staining with monoclonal antibodies showed marked variations in the percentage of melanoma cells stained by anti-HLA Class I and anti-HLA Class II monoclonal antibodies among 48 locoregional metastases removed from 39 patients with malignant melanoma. On the other hand there was limited variation in the percentage of melanoma cells stained by anti-HLA antibodies in autologous locoregional metastases removed from 8 of 9 patients. In the remaining patient marked differences were found in the percentage of melanoma cells stained by anti-HLA Class I antibodies in the two parts of the lymph node metastasis analyzed. Therefore this patient was not included in additional analyses to correlate the level of expression of HLA antigens with the clinical course of the disease. In all the lesions tested the percentage of melanoma cells stained by anti-HLA Class II antibodies was lower than or equal to but never higher than that stained by anti-HLA Class I antibodies. According to the level of expression of HLA Class I and Class II antigens the 38 patients could be divided into three groups: Pattern A included lesions with more than 50% of tumor cells stained by anti-HLA Class I antibodies (mean, 86.1; median, 85) and 50% or less by anti-HLA Class II antibodies (mean, 10.5; median, 5); Pattern B included lesions with 50% or less tumor cells stained by anti-HLA Class I antibodies (mean, 14.9; median, 5) and by anti-HLA Class II antibodies (mean, 4.1; median, 1); Pattern C included lesions with more than 50% tumor cells stained by anti-HLA Class I antibodies (mean, 88.8; median, 92) and by anti-HLA Class II antibodies (mean, 70.0; median, 70). The survival of 21 patients with Pattern A was significantly longer than those of 13 and 4 patients with Patterns B and C, respectively. No difference in the survival of patients in the latter two groups was found. These results suggest that HLA antigens play a role in the biology of melanoma and that analysis of the level of HLA antigens in locoregional metastases of patients with melanoma may provide clinically useful information.

Adult↗
PubMed1988

The effect of radiotherapy on dysphagia and survival in patients with esophageal cancer.

A group of 127 patients with esophageal cancer treated with radiotherapy at different dose levels was retrospectively analysed. It was found that 70.5% of the patients showed improvement of dysphagia and that 54% remained palliated with respect to food passage until their death. The two major prognostic variables with respect to the palliative effect on dysphagia as well as survival were the passage score and the radiation dose. Patients with severe dysphagia (PASS 0 or 1) had a median actuarial DFI and SURV of 3.7 and 6.4 months, respectively, in contrast to 16.0 and 8.7 months for patients who were able to use (semi)solid food (PASS 2 and 3). The median actuarial DFI and SURV of patients treated with a relatively low dose (less than 50 Gy in 5 weeks) were 2.5 and 4.8 months, respectively, compared to 10.1 and 8.3 months, respectively, for patients treated with a relatively high dose.

Adenocarcinoma↗
PubMed1988

Differential expression of HLA-DR, DQ, and DP antigens in primary and metastatic melanoma.

Fifty-five primary and 33 metastatic surgically removed melanoma lesions were stained in indirect immunoperoxidase with anti HLA-DR, DQ, and DP monoclonal antibodies and with the monoclonal antibody CL203.4 to a 96-K melanoma associated antigen (MAA). The latter antigen may represent a marker to monitor susceptibility of melanoma cells to modulation by IFN-gamma, because it is highly susceptible to induction by IFN-gamma. In primary melanomas 44%, 29%, 10%, and 55% of the lesions tested were evidently stained by anti HLA-DR, DQ, DP, and 96-K MAA monoclonal antibodies, respectively. A statistically significant association (P less than 0.01) was demonstrated between the degree of intratumoral lymphocytic infiltrate and the expression of HLA-DR and HLA-DQ antigens. In addition, a high degree of concordance in the reactivity pattern of individual lesions stained for HLA-DR antigens and for the 96-K MAA was found. In metastases 64%, 33%, 47%, and 100% of the lesions tested were evidently stained by anti HLA-DR, DQ, DP, and 96-K MAA monoclonal antibodies, respectively. This study indicates that HLA-DR and HLA-DP antigens are expressed in a higher percentage of metastatic than of primary melanomas and that there is no marked difference in the expression of HLA-DQ antigens between primary and metastatic melanomas. The data suggest that the regulatory mechanisms which control the expression of HLA-DR and DP antigens in primary and metastatic melanoma lesions are different. Locally produced IFN-gamma may play a role in the regulation of HLA Class II antigens in primary melanomas.

Antibodies, Monoclonal↗
PubMed1988

To perfuse or not to perfuse? A retrospective comparative study to evaluate the effect of adjuvant isolated regional perfusion in patients with stage I extremity melanoma with a thickness of 1.5 mm or greater.

The use of isolated regional perfusion in an adjuvant setting for stage I melanoma of the extremity continues to be controversial. The present retrospective study evaluates the past 20 years' experience by comparing 227 perfused patients from Groningen with 238 matched controls from five hospitals in The Netherlands and Westphalia (a region of West Germany bordering the Netherlands). All patients underwent wide local excision for a primary extremity melanoma of 1.5 mm or greater in thickness. A proportional hazards regression analysis for recurrence of disease and survival identified the significant prognostic factors, of which tumor thickness was the most important. Corrected for these factors, it was not possible to demonstrate a statistically significant effect for perfusion in terms of time to limb recurrence (P = .61), time to regional lymph node metastasis (P = .11), time to distant metastasis (P = .73), disease-free interval (P = .42), and survival (P = .90). No statistically significant differences were seen for adjuvant perfusion in any of the subgroups.

Adult↗