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Biomedical subjects

K M Tveit

Publications and source records attributed to K M Tveit.

At least 37 records · Page 2Linked to original sources
PubMed1998

Changes in folate status as determined by reduction in total plasma homocysteine levels during leucovorin modulation of 5-fluorouracil therapy in cancer patients.

We measured plasma total homocysteine (tHcy) in 14 patients (13 patients with colorectal cancer and 1 patient with breast cancer) during their first treatment with 5-fluorouracil (5-FU) plus leucovorin [LV (5-FULV)]. Eight of these patients were investigated a second time after 3-10 cycles (median, 4 cycles) with 5-FULV. Each cycle consisted of two administrations of 5-FU (500 mg/m2) and LV (60 mg/m2) given 24 h apart. The first administration of 5-FULV on day 1 of the first cycle induced a rapid reduction of the tHcy level from 12.5 micromol/liter (10.4-15.1 micromol/liter; geometric mean with 95% confidence interval of the mean) to 9.1 micromol/liter (7.5-11.1 micromol/liter) in 24 h. tHcy remained stable at this level after the second administration of 5-FULV. In addition, the 5-FULV regimen caused a concurrent 4-fold increase in both serum and erythrocyte folate. The fifth cycle with 5-FULV had only marginal effects on the tHcy level. 5-FU without LV modulation had no effect on the plasma tHcy or folate status in eight breast cancer patients. Our data establish the reduction of tHcy as a responsive indicator of LV pharmacodynamics.

Aged↗
PubMed1997

Screening for ESR mutations in breast and ovarian cancer patients.

In the present study, leukocyte DNA from 143 patients with familial clustering of breast and/or ovarian cancer and tumour DNA from 96 breast carcinomas were screened for base mutations in the estrogen receptor gene (ESR). Three patients with a family history of cancer were carrying a Gly160Cys germline substitution. This alteration was also detected in eight (four females and four males) of 729 controls (366 female, 363 males), indicating that the substitution probably represents a polymorphism. However, in the 229 female controls in whom family history of cancer was known, one of two who had a sister with breast cancer was carrying the variant allele. Hence, a possible clinical significance of the glycine into cysteine cannot be completely ruled out and should be further investigated. Somatic mutations were not detected in any of the tumours studied, and the present data do not provide support for somatic ESR base mutations as an important mechanism for hormonal therapy resistance in estrogen receptor-positive breast carcinomas.

Adult↗
PubMed1997

Combined modality treatment including intraoperative radiotherapy in locally advanced and recurrent rectal cancer.

BACKGROUND: Treatment of locally advanced and recurrent rectal cancer usually has a high local recurrence rate and poor survival. Promising results have been reported by combined external radiotherapy, extensive surgery and intraoperative radiotherapy (IORT). METHODS: One hundred fifteen patients with locally advanced rectal cancers fixed to the pelvic wall or locally recurrent rectal cancers underwent preoperative external radiotherapy with 46-50 Gy. Six to 8 weeks later radical pelvic surgery was attempted, and was combined with intraoperative electron beam radiotherapy (15-20 Gy) in 66 patients. The patients were followed closely to evaluate complication rate, local and distant recurrence rate and survival. RESULTS: Surgery with no macroscopic tumour remaining was obtained in 65% of the patients with no postoperative deaths. Pelvic infection was the major complication (21%). Although the observation time is short (3-60 months), the local recurrence rate seems low (22%) and survival seems promising (about 60% at 4 years) in patients with complete tumour resection, in contrast to patients with residual tumour (none living at 4 years). CONCLUSIONS: The combined modality treatment with preoperative external radiotherapy and extensive pelvic surgery with IORT is sufficiently promising to start a randomized trial on the clinical value of IORT as a boost treatment in the multidisciplinary approach to this disease.

Adult↗
PubMed1997

Randomized controlled trial of postoperative radiotherapy and short-term time-scheduled 5-fluorouracil against surgery alone in the treatment of Dukes B and C rectal cancer. Norwegian Adjuvant Rectal Cancer Project Group.

BACKGROUND: The purpose of the present study was to investigate whether a 1-month regimen of postoperative radiotherapy combined with 5-fluorouracil could reduce the local recurrence rate and improve survival in patients with Dukes B and C rectal cancer. METHODS: One hundred and forty-four patients were randomized to surgery alone or surgery combined with postoperative radiotherapy (46 Gy) and bolus 5-fluorouracil 30 min before six of the radiotherapy fractions. One hundred and thirty-six patients were eligible. RESULTS: The adjuvant treatment was well tolerated. After an observation time of 4-8 years, patients in the adjuvant treatment group had a cumulative local recurrence rate of 12 per cent compared with 30 per cent in the group that had surgery only (P = 0.01). The 5-year recurrence-free and overall survival rate was 64 per cent in the adjuvant group compared with 46 per cent (P = 0.01) and 50 per cent (P = 0.05) respectively in the surgery group. The adjusted relative risk of recurrence and death for the adjuvant group was 0.48 (95 per cent confidence interval 0.28-0.82) and 0.56 (0.33-0.94) respectively. CONCLUSION: The 1-month postoperative combination regimen improved treatment results in patients with Dukes B and C rectal cancer, in terms of local recurrence rate, recurrence-free survival and overall survival, without serious side-effects.

Adult↗
PubMed1996

[Chemotherapy in colorectal cancer. Recommendations of the Norwegian Gastrointestinal Cancer Group].

The scientific documentation for fluorouracil-based chemotherapy in patients with colorectal cancer has increased during recent years, both for the adjuvant primary situation and in recurrent and metastatic disease. In the case of operable colorectal cancer (stage Dukes B and C), the patients should be included in the ongoing randomized trial on use of fluorouracil and levamisol. In advanced disease, fluorouracil combined with calcium folinate may have palliative effects in terms of relief of symptoms, improved quality of life, delay of onset of symptoms and probably also prolonged survival in 40-50% of the patients, without serious toxicity. In many cases, however, the patient should not be given chemotherapy.

Chemotherapy, Adjuvant↗
PubMed1996

[Treatment of fixed, primarily non-resected rectal cancer. Recommendations from Norwegian Gastrointestinal Cancer Group].

In most cases (70%), fixed rectal cancers are primarily non-resectable, and of the ones that are resected, local recurrence will occur in 50-70%. The same trend, but less pronounced, is also seen for partly fixed or tethered tumours. High-dose irradiation (45-60 Gy) has been reported to yield resectability rates up to 70%, with 17% local recurrences and a 5-year disease-free survival of up to 60-70%. Combined chemotherapy and sequential radiation therapy, hyperthermia or addition of intra-operative radiotherapy, have shown promising results, but no randomized studies have been published comparing the different treatment modalities. Surgery should be performed 4-6 weeks after preoperative treatment. Resectability can only be determined by exploratory laparotomy and serious attempts to remove the tumour-bearing segment by anatomic dissection.

Combined Modality Therapy↗
PubMed1996

Evaluation of digitally guided fine needle aspiration cytology versus fine needle core biopsy for the diagnosis of recurrent rectal cancer.

The clinical value of transrectally digitally guided fine needle aspiration cytology (FNAC) was compared with fine needle core biopsy (FNCB), FNAC was performed with a 21G and FNCB with a 18G needle. No prophylactic antibiotic was given. In the first part of the study 100 patients (20 primary/80 recurrences, 17 benign/83 cancers) were studied by both techniques. In 93% a definite diagnoses was given in FNAC specimen versus 96% of the FNCB cases. There were no false positive cancer diagnoses. The sensitivity of the FNAC was 88% versus 68% of the FNCB specimens. This difference was statistically significant. In a second part of the study 142 specimens of recurrent cases were examined by FNAC including 78 of the patients of the first part. The negative predictive value was around 60% for FNAC versus around 40% for FNCB. Both techniques were without any major complications. For the diagnosis of a palpable recurrent pelvic tumour a digitally guided puncture may be tried before proceeding to CT or US guided examination. In our hands FNAC seems preferable to FNCB.

Aged↗
PubMed1995

Field homogeneity of bevelled intraoperative electron beam cones: the influence of virtual focus surface distance.

Field flatness of bevelled intraoperative electron therapy cones were evaluated from dose profiles, taken at dmax, both in the longitudinal plane (long axis direction) and the transversal plane (short axis direction), and were found to depend strongly on the setting of the x-ray collimators. Dose gradients in the longitudinal plane of 10-12% were found for collimator settings of 5 mm larger than the cone diameter for low energies, while the dose gradient were smaller for higher energies, both decreasing with larger collimator setting. The dose increase, relative to the central dose, of the hot spots observed in the profile of the transversal plane were in the range of 5-10% for high energies and large collimator settings, decreasing to less than 3% for low electron beam energies and smaller collimator setting. A decrease in virtual focus to surface distance (VFSD) was found to accompany the increasing dose gradient in the longitudinal plane with decreasing collimator setting, this due to increased scatter of electrons at collimator level. Increasing scatter with smaller collimator setting is also indicated by the increase in photon contamination ranging from 1-2.5% for low energies and 3.5-5% for high energies.

Humans↗
PubMed1994

Evaluation of deoxyribonucleic acid ploidy and S-phase fraction as prognostic parameters in advanced epithelial ovarian carcinoma: a prospective study.

OBJECTIVE: Our goal was to study the prognostic value of deoxyribonucleic acid ploidy and S-phase fraction in advanced ovarian carcinoma. STUDY DESIGN: Prognostic factors for corrected survival were evaluated in a prospective study including 169 patients with stage III and IV ovarian cancer treated between 1985 and 1990. RESULTS: A total of 79% of the tumors were deoxyribonucleic acid aneuploid. Deoxyribonucleic acid aneuploidy was associated with grade of differentiation. S-phase fraction could be calculated in all deoxyribonucleic acid euploid tumors and 76% of the deoxyribonucleic acid aneuploid tumors. By multivariate analysis deoxyribonucleic acid ploidy, histologic type and grade, age, International Federation of Gynecology and Obstetrics stage, and amount of residual tumor were independent prognostic variables for corrected survival. On the basis of Cox regression a relative risk for the individual patient could be calculated. CONCLUSION: Deoxyribonucleic acid ploidy gives additive prognostic information and is a useful parameter for dividing patients with advanced ovarian cancer into risk groups for treatment decisions.

Adult↗
PubMed1994

Host markers and prognosis in recurrent rectal carcinomas treated with radiotherapy.

The value of blood tests as prognostic factors in patients with recurrent rectal carcinomas treated with radiotherapy was studied in one retrospective (n = 114, 1976-1984) and one prospective (n = 100, 1985-1989) group of patients. The retrospective group was used for validation of the results from the prospective group. In univariate survival analyses, 19 of totally 38 variables significantly correlated to the survival. Of 13 significant blood parameters, lactate dehydrogenase (LD), erythrocyte sedimentation rate (ESR), alpha 1-, alpha 2-globulin, fibrinogen, carcinoembryonic antigen (CEA), C-reactive protein (CRP), haptoglobin, granulocytosis and thrombocytosis were the most important ones (p < or = 0.01). In the multivariate analyses (Cox regression) of the prospective group, LD, alpha 1-globulin, diagnosed liver metastases and CEA were found to be significant predictors of survival. A prognostic index was derived from the prospective group including ESR, LD and relapse-free interval. This clearly separated the patients in the retrospective group into one low- and one high-risk group.

Adult↗
PubMed1993

Flow cytometric DNA analysis as prognostic factor in human breast carcinoma.

Fresh tumour tissue from 198 primary invasive breast carcinomas was analysed by DNA flow cytometry. 108 tumours were non-diploid. A significantly higher proportion of non-diploid tumours was found among node-positive patients, patients with oestrogen receptor negative tumours and among patients with ductal carcinomas. The survival of patients with diploid and non-diploid tumours was not significantly different (p = 0.1). Totally, 145 tumours were analyzed with respect to S-phase fraction (SPF). The distribution of SPF was different in diploid and non-diploid tumours. A low SPF group, defined as the lower SPF quartile (< or = 4.6% in diploid and < or = 8.5% in non-diploid tumours), was associated with highly differentiated tumours and oestrogen receptor positive tumours. Histological grading revealed a highly significant correlation to SPF. 57% of ductal carcinomas grade I (8 out of 14), 30% of ductal carcinomas grade II (20 out of 67) and 5% of ductal carcinomas grade III (2 out of 37) had a low SPF. Patients within the low SPF group had a significantly longer survival than had patients within the high SPF group (p = 0.006). In a multivariate analysis the SPF was found to be an additional prognostic factor next to node status and ER status.

Aged↗
PubMed1993

Chemoradiotherapy of anal carcinoma: tumour response and acute toxicity.

This study was performed to evaluate local tumour control and toxicity of chemoradiotherapy given to patients with primary or recurrent carcinoma of the anal canal. A total of 117 patients were admitted to the Norwegian Radium Hospital during the period of 1983-1989, of which 106 received a combination of radiotherapy (50 Gy to the pelvis) and chemotherapy (mitomycin C + 5-fluorouracil). Sixty-five percent of the patients with primary carcinomas presented with advanced tumours (T3 or T4). Good local tumor control was obtained as only 25% of the patients with advanced tumours (T3 and T4) and 7% of those with smaller tumours (T1 and T2) had a local relapse after treatment. Recurrent tumours following primary surgery did not respond as well; 50% of these patients still had carcinoma 1 month following therapy. All patients experienced acute toxicity (dermatitis/mucositis, diarrhoea and general fatigue), and 50% needed as split course. There was, however, no therapy-related mortality. Survival data seem promising, but further follow-up is necessary to make conclusions. Eight percent of the patients had serious anal insufficiency after treatment. We conclude that the present regimen provides good local tumour control and well-preserved anal function, but has considerable acute toxicity.

Adult↗
PubMed1993

Amplification of c-erbB-2, int-2 and c-myc genes in node-negative breast carcinomas. Relationship to prognosis.

Primary tumours from 100 Norwegian node-negative breast carcinoma patients were examined for c-erbB-2, int-2, and c-myc proto-oncogene amplification. c-erbB-2, int-2, and c-myc amplification was found in 12.1% (12 of 99), 8.6% (8 of 93), and 1.1% (1 of 89) of the samples respectively. All the c-erbB-2 amplified tumours were of the ductal type, and all the int-2 amplified tumours were oestrogen receptor positive. No other significant or borderline significant associations between gene amplification and clinical or histopathological parameters were found. Relapse occurred more frequently in patients with c-erbB-2 gene amplification (relapse in 33.3% of the patients with c-erbB-2 amplification compared to 20.7% in the non-amplified group), but the difference was not statistically significant, int-2 amplification was not associated with increased risk of relapse, whereas the prognostic value of the c-myc amplification could not be evaluated.

Adult↗
PubMed1993

Postirradiation changes in the pelvic wall. Findings on MR.

MR images of 45 patients who had received radiation therapy for carcinoma of the anus or recurrent carcinoma of the rectum were reviewed with regard to postirradiation changes of the pelvic wall. High signal intensity in bone marrow on T1-weighted images due to fatty replacement was almost always observed. Presacral edema occurred in 7 of 36 patients who were examined 4 to 6 weeks after the end of irradiation and was more frequent at later studies. The pelvic wall muscles showed high signal intensity on T2-weighted images compatible with edema. This finding was most frequent on studies performed more than 6 weeks after the end of irradiation. The changes subsided more than a year after radiation therapy. To avoid an erroneous diagnosis of tumor infiltration into the pelvic wall, it is important to be familiar with the normal postirradiation changes of the presacral space and the muscles.

Adult↗