Abstract GS4-07: Costs and effects in the first randomized trial comparing MRI breast cancer screening with mammography in women with a familial risk: FaMRIsc

Background: The large favorable stage shift, that MRI screening causes as compared with mammography has been published recently in Lancet Oncology as well as the disadvantage of more false-positive results with MRI. Here we want to present the first results of cost and effectiveness. Methods: In twelve Dutch hospitals, 1355 women aged 30-55 years with a cumulative lifetime risk (CLTR) of ≥20% without a BRCA1/2 mutation were randomized into two groups. From January 2011 until December 2017, women in the MRI-group received yearly MRI-screening, clinical breast examination (CBE), and mammography every other year; and in the Mx-group yearly mammography and CBE. We here present cost per group as well as per detected cancer in both groups, also by age group and breast density. Cost per life year gained can be presented in December. Results: After on average 4.3 screening rounds per woman, in the MRI-group (N=674) compared to the Mx-group (N=680) more breast cancers were detected (40 versus 15, p<0.002), invasive cancers were smaller (median size 9 versus 17 mm, p=0.01) and less often node positive (17% versus 63%, p=0.023) (Table). This resulted in lower cost for detection and treatment per tumor in the MRI-group compared to the Mx-group and lower mean treatment costs (MRI-group: €6,736; Mx-group: €10,128). In incident rounds fewer large or node positive cancers were detected with MRI, reducing the cost for adjuvant therapy, but there remained more false positive results and biopsies with MRI, increasing the cost for additional investigations. The total cost of MRI screening was nearly twice as high as for mammography-screening. Per detected cancer MRI screening was cheaper than mammography, especially above 50 yrs. and at density A-C (see Table). Cost per life year gained will be discussed. Conclusions MRI-screening advances the detection of breast cancer greatly, but with more additional investigastions. MRI-screening may be cost-effective in groups with sufficient tumor incidence, like women with familial risk.

This study was supported by funds of: the Dutch Governement ZonMw grant no. 200320002, The Dutch Cancer Society (DDHK 2009-4491), A Sisters Hope, Pink Ribbon, Stichting Coolsingel, J&T Rijke Stichting.

Table 1. Characteristics of participating women, detected breast cancers, and cost according to study armParticipantsMRI-arm n=674Mx-arm n=680p-valueMean age - yr ± SD44.7 ± 6.344.7 ± 6.3Premenopausal512 (76%)505 (74%)BI-RADS density categorya A(entirely fat) B (scattered densities) C (heterogeneously dense) D (extremely dense)88 (13%) 248 (37%) 237 (35%) 98 (15%)92 (14%) 229 (34%) 243 (36%) 102 (15%)Mean age at cancer detection49,6 ± 7.150,8 ± 4,60.88No cancer - no. (%) Invasive breast cancers - no. (%) DCIS - no. (%)634 (94%) 24 (4%) 16 (2%)666 (98%) 8 (1%) 7 (1%)0.0017Median size of invasive cancers9 mm (5-14)17 mm (13-22)0.01Node positive4/24 (17%)5/8 (63%)0.023Biopsy nr.14954< 0.0001Total screening cost in FaMRIsc€ 1,094,241€ 516,440Cost per detected cancer€ 32,340€ 42,384Cost per detected ca. BIRADS A-C€ 28,945€ 39,964aDetermined by radiologists, according to the fourth ACR BI-RADS edition

Citation Format: Madeleine MA Tilanus-Linthorst, H Amarens Geuzinge, Inge-Marie M Obdeijn, Emiel JT Rutgers, Ritse M Mann, Sepideh Saadatmand, Diderick BW de Roy van Zuidewijn, Robert AEM Tollenaar, Marc BI Lobbes, Margreet GEM Ausems, Martijne van 't Riet, Maartje J Hooning, Jelle Wesseling, Ingeborg Mares-Engelberts, Ernest JT Luiten, Jan C Oosterwijk, Eveline AM Heijnsdijk, Harry J de Koning. Costs and effects in the first randomized trial comparing MRI breast cancer screening with mammography in women with a familial risk: FaMRIsc [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr GS4-07.

Abstract P6-13-01: MRI breast cancer screening compared to mammography in women with a familial risk: A multicenter randomized controlled trial

Background: Screening guidelines for women with a family history of breast cancer without a known causative gene mutation differ per country. No randomized controlled trial has been performed to assess the optimal screening strategy for these women.

Methods: In twelve centers, 1355 women aged 30–55 years with a cumulative lifetime risk of ≥20% without a BRCA1/2 mutation were randomized into two arms. From January 2011 until December 2017, women in the MRI-arm received yearly MRI-screening, clinical breast examination (CBE), and mammography every other year; and in the Mx-arm yearly mammography and CBE. Outcomes were number and stage of detected breast cancers, sensitivity, specificity and positive predictive value, and stratified by screening round and by mammographic density.

Results: After on average 4.3 screening rounds per woman, in the MRI-arm (N=675) compared to the Mx-arm (N=680) more breast cancers were detected (41 versus 14, p<0.001), invasive cancers were smaller (median size 8 versus 17 mm, p=0.006) and less often node positive (20% versus 71.4%, p=0.019)(Table). In the MRI-arm, sensitivity was slightly higher (95.1% versus 92.9%, p=1), and specificity significantly lower (82% versus 90.1%, p<0.001), compared to the Mx-arm. After two rounds, specificity improved for both modalities (87.1% for MRI; 93.0% for Mx; p<0.001) and no ≥T2 tumors or interval cancers occurred in the MRI-arm. All tumors ≥T2 were in the two highest density categories. MRI detected more small invasive tumors than Mx across all density categories.

Conclusions: In real-life practice the MRI-arm detected more, relevantly smaller, and far more often node negative tumors, and also at low density in women with a familial risk for breast cancer.

Table 1Characteristics of participating women at baseline and of the detected breast cancers, according to study armParticipantsMRI-arm n=675Mx-arm n=680MRI-arm vs. Mx-arm p-valueMean age yr ± SD44.6 ± 6.244.7 ± 6.3 Premenopausal512 (76%)505 (74%) Previous Mx ≤ 2 yr536 (79 %)542 (80%) Previous Mx > 2 years ago23 ( 3%)29 ( 4%) Previous MRI ≤ 2 years ago62 ( 9%)81 (12%) Previous MRI > 2 years ago91 (14%)89 (13%) BI-RADS density category*   I (entirely fat)88 (13%)92 (14%) II (scattered densities)248 (37%)229 (34%) III (heterogeneously dense)238 (35%)243 (36%) IV (extremely dense)98 (15%)102 (15%) Mean age at cancer detection49,6 ± 7.049,8 ± 4,70.74No cancer – no. (%)634 (94%)666 (98%) Invasive breast cancers – no. (%)25 (4%)7 (1%)<0.001 (noBC/inv BC/DCIS)DCIS – no. (%)16 (2%)7 (1%) Median size of invasive cancers8 mm17 mm0.006T1a/b15 (60%)1 (14%) T1c7 (28%)4 (57%)0.078 (T1a-b/T1c/≥ T2)≥ T23 (12%)2 (29%) Node pos5 (20%)5 (71%)0.019 (N+/-)Node negative20 (80%)2 (29%) DCIS grade 15 (31%)2 (29%) DCIS grade 28 (50%)4 (57%)1 (dcis gr1,2,3)DCIS grade 33 (19%)1 (14%) *Determined by radiologists, according to the fourth ACR BI-RADS edition

Citation Format: Tilanus-Linthorst MM, Saadatmand S, Geuzinge AH, Rutgers EJ, Mann R, de Roy van Zuidewijn DB, Zonderland HM, Tollenaar RA, Lobbes MB, Ausems MG, van 't Riet M, Hooning MJ, Mares-Engelbert I, Luiten EJ, Heijnsdijk EA, Verhoef C, Karssemeijer N, Oosterwijk JC, Obdeijn I-M, de Koning HJ. MRI breast cancer screening compared to mammography in women with a familial risk: A multicenter randomized controlled trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-13-01.

Common germline polymorphisms associated with breast cancer-specific survival

INTRODUCTION

Previous studies have identified common germline variants nominally associated with breast cancer survival. These associations have not been widely replicated in further studies. The purpose of this study was to evaluate the association of previously reported SNPs with breast cancer-specific survival using data from a pooled analysis of eight breast cancer survival genome-wide association studies (GWAS) from the Breast Cancer Association Consortium.

METHODS

A literature review was conducted of all previously published associations between common germline variants and three survival outcomes: breast cancer-specific survival, overall survival and disease-free survival. All associations that reached the nominal significance level of P value <0.05 were included. Single nucleotide polymorphisms that had been previously reported as nominally associated with at least one survival outcome were evaluated in the pooled analysis of over 37,000 breast cancer cases for association with breast cancer-specific survival. Previous associations were evaluated using a one-sided test based on the reported direction of effect.

RESULTS

Fifty-six variants from 45 previous publications were evaluated in the meta-analysis. Fifty-four of these were evaluated in the full set of 37,954 breast cancer cases with 2,900 events and the two additional variants were evaluated in a reduced sample size of 30,000 samples in order to ensure independence from the previously published studies. Five variants reached nominal significance (P <0.05) in the pooled GWAS data compared to 2.8 expected under the null hypothesis. Seven additional variants were associated (P <0.05) with ER-positive disease.

CONCLUSIONS

Although no variants reached genome-wide significance (P <5 x 10(-8)), these results suggest that there is some evidence of association between candidate common germline variants and breast cancer prognosis. Larger studies from multinational collaborations are necessary to increase the power to detect associations, between common variants and prognosis, at more stringent significance levels.

Refined histopathological predictors of BRCA1 and BRCA2 mutation status: a large-scale analysis of breast cancer characteristics from the BCAC, CIMBA, and ENIGMA consortia

INTRODUCTION

The distribution of histopathological features of invasive breast tumors in BRCA1 or BRCA2 germline mutation carriers differs from that of individuals with no known mutation. Histopathological features thus have utility for mutation prediction, including statistical modeling to assess pathogenicity of BRCA1 or BRCA2 variants of uncertain clinical significance. We analyzed large pathology datasets accrued by the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) and the Breast Cancer Association Consortium (BCAC) to reassess histopathological predictors of BRCA1 and BRCA2 mutation status, and provide robust likelihood ratio (LR) estimates for statistical modeling.

METHODS

Selection criteria for study/center inclusion were estrogen receptor (ER) status or grade data available for invasive breast cancer diagnosed younger than 70 years. The dataset included 4,477 BRCA1 mutation carriers, 2,565 BRCA2 mutation carriers, and 47,565 BCAC breast cancer cases. Country-stratified estimates of the likelihood of mutation status by histopathological markers were derived using a Mantel-Haenszel approach.

RESULTS

ER-positive phenotype negatively predicted BRCA1 mutation status, irrespective of grade (LRs from 0.08 to 0.90). ER-negative grade 3 histopathology was more predictive of positive BRCA1 mutation status in women 50 years or older (LR = 4.13 (3.70 to 4.62)) versus younger than 50 years (LR = 3.16 (2.96 to 3.37)). For BRCA2, ER-positive grade 3 phenotype modestly predicted positive mutation status irrespective of age (LR = 1.7-fold), whereas ER-negative grade 3 features modestly predicted positive mutation status at 50 years or older (LR = 1.54 (1.27 to 1.88)). Triple-negative tumor status was highly predictive of BRCA1 mutation status for women younger than 50 years (LR = 3.73 (3.43 to 4.05)) and 50 years or older (LR = 4.41 (3.86 to 5.04)), and modestly predictive of positive BRCA2 mutation status in women 50 years or older (LR = 1.79 (1.42 to 2.24)).

CONCLUSIONS

These results refine likelihood-ratio estimates for predicting BRCA1 and BRCA2 mutation status by using commonly measured histopathological features. Age at diagnosis is an important variable for most analyses, and grade is more informative than ER status for BRCA2 mutation carrier prediction. The estimates will improve BRCA1 and BRCA2 variant classification and inform patient mutation testing and clinical management.

Abstract P3-02-09: Cost-effectiveness of screening with additional MRI for women with familial risk for breast cancer without a genetic predisposition

Background: To reduce mortality risk, women with a family history of breast cancer are often screened with mammography before 50 years of age. Additional Magnetic Resonance Imaging (MRI) can improve sensitivity. MRI screening is cost-effective for BRCA1/2 mutation carriers. However, for women with a family history of breast cancer without a proven mutation cost-effectiveness is not clear. We evaluated the cost-effectiveness of additional MRI for women with a familial risk in the largest prospective MRI screening study: the Dutch MRI Screening Study (MRISC).

Materials & Methods: Between 1999 and 2007 a total of 1597 women (8370 women years at risk) between 25–70 years, with an estimated cumulative lifetime risk of 15–50% for breast cancer participated in the MRISC. Women were screened with clinical breast examination (CBE) every six months and annual mammography and MRI. We calculated the costs per detected breast cancer. In addition, MRISC data were incorporated into a micro simulation screening analysis model: MISCAN. This model simulates screening programs with different screening modalities and time intervals. Different screening schemes were evaluated and the cost per life-year gained (CLYG) estimated.

Results: Forty-seven breast cancers, including 9 Ductal Carcinoma in Situ, were detected. Screening with additional MRI leads to a cost per detected breast cancer treated of €101,962. In increasing age-cohorts the cost decreased, probably due to the higher breast cancer incidence. The cost per detected and treated breast cancer in age group 40–50 years doubled in the age group &gt;60 years. We will demonstrate these results more extensively.

With MISCAN modeling we predicted that screening with this scheme from age 35 to 60 years reduces breast cancer mortality by 30% at a CLYG of €119,945 (3.5% discounting), compared to 21% estimated mortality reduction at €45,707 CLYG with mammography and CBE alone.

Conclusion: Screening with MRI may improve survival for women with familial risk for breast cancer, but is expensive. However, it may be cost-effective for a select group. We will discuss subgroups that may benefit from MRI screening and in which age category MRI was most effective in our study.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-02-09.

[Genetic research with stored human tissue: a coding procedure with optimal use of information and protection of privacy]

To answer research questions concerning the course of disease and the optimal treatment of hereditary breast cancer, genetic typing together with the clinical and tumour characteristics of breast cancer patients are an important source of information. Part of the incidence of breast cancer can be explained by BRCA1 and BRCA2 germline mutations, which with current techniques can be retrospectively analysed in stored, paraffin-embedded tissue samples. In view of the implications of BRCA1- or BRCA2-carrier status for patients and other family members and the lack of clear legal regulations regarding the procedures to be followed when analysis is performed on historical material and no individual informed consent can be asked from the patients, an appropriate procedure for coding such data or rendering it anonymous is of great importance. By using the coding procedure described in this article, it becomes possible to follow and to work out in greater detail the guidelines of the code for 'Proper secondary use of human tissue' of the Federation of Biomedical Scientific Societies and to use these valuable databases again in the future.

MRI screening for breast cancer in women with familial or genetic predisposition: design of the Dutch National Study (MRISC)

Mammography screening of women aged 50-70 years for breast cancer has proven to be effective in reducing breast cancer mortality. There is no consensus about the value of breast cancer screening in women aged 40-49 years. Five to ten per cent of all breast cancers are hereditary. One of the options to reduce the risk of breast cancer mortality for women with a familial or genetic predisposition is intensive surveillance. However, the effectiveness of mammography screening for breast cancer in these women, who are mainly younger than 50 years, is unproven. MRI might increase the effectiveness of screening in women with a familial or genetic predisposition. This paper describes the design of the Dutch national study for Magnetic Resonance Imaging (MRI) screening in women with a familial or genetic predisposition. The aims of this study are to investigate: the value of regular surveillance in women with a familial or genetic predisposition for breast cancer, the efficacy of MRI as compared to mammography, cost-effectiveness of regular screening and quality of life during surveillance. Included are women with a lifetime risk of familial breast cancer of 15% or more or BRCA1/2 mutation carriers, who visit one of the Dutch family cancer clinics. The aim is to include 2,500 women. The study started on 1 November 1999. On 1 January 2002, more than 1,700 women, including 210 proven carriers of a BRCA1 or BRCA2 mutation, were included in the study.

Clinical and pathological features of BRCA1 associated carcinomas in a hospital-based sample of Dutch breast cancer patients

Thus far, studies investigating the differences in tumour characteristics between breast cancer in BRCA1-carriers and other patients, have focused on highly selected groups of patients, potentially limiting the conclusions that can be drawn. Previously, we had identified 10 patients with BRCA1 germline mutations in a hospital-based series of 642 breast cancer patients not selected for age or family history. The aim of this analysis is to investigate the clinical and pathological features of these BRCA1 associated carcinomas as compared to other breast cancers in this representative sample. Tumours from patients with BRCA1 germline mutations (n = 10) were compared to an age-matched sample of other patients (n = 50) from the same cohort. The following characteristics were considered: axillary nodal status and tumour size, histologic parameters (tumour type, histologic grade, mitotic rate, tubule formation, nuclear grade, CIS and lymphangio invasion) and expression of several proteins (oestrogen and progesterone receptors, cyclin D1, p53, HER2/neu, E-cadherin). In BRCA1 associated tumours receptors for oestrogen and progesterone were expressed less frequently (respectively, P = 0.001 and P = 0.002) than in controls, which is in line with findings from other studies. Other differences were also in accordance with findings from other studies, although not statistically significant. We conclude that the features of BRCA1 associated tumours detected in a hospital-based series of breast cancer patients not selected for family history of age at diagnosis are similar to tumours in cases selected for family history or age at diagnosis.

Mechanisms of oncogenesis in colon versus rectal cancer

Observations support the theory that development of left- and right-sided colorectal cancers may involve different mechanisms. This study investigated different genes involved in oncogenesis of colon and rectal cancers and analysed their prognostic value. The study group comprised 35 colon and 42 rectal cancers. Rectal cancer patients had been treated with standardized surgery performed by an experienced rectal cancer surgeon. Mutation analysis was performed for p53 in eight colon cancers and for APC and p53 in 22 rectal cancers. MLH1, MSH2, Bcl-2, p53, E-cadherin and beta-catenin were investigated by immunohistochemistry in all colorectal tumours. APC mutation analysis of the MCR showed truncating mutations in 18 of 22 rectal tumours (82%), but the presence of an APC mutation was not related to nuclear beta-catenin expression (p=0.75). Rectal cancers showed significantly more nuclear beta-catenin than colon cancers (65% versus 40%, p=0.04). p53 mutation analysis corresponded well with p53 immunohistochemistry (p<0.001). Rectal cancers showed significantly more immunohistochemical expression of p53 than colon cancers (64% versus 29%, p=0.003). In rectal cancers, a significant correlation was found between positive p53 expression and worse disease-free survival (p=0.008), but not in colon cancers. Cox regression showed that p53-expression (p=0.03) was an independent predictor for disease-free survival in rectal cancers. This study concluded that rectal cancer may involve more nuclear beta-catenin in the APC/beta-catenin pathway than colon cancer and/or nuclear beta-catenin may have another role in rectal cancer independently of APC. The p53-pathway seems to be more important in rectal cancer, in which it also has independent prognostic value. When prognostic markers are investigated in larger series, differences in biological behaviour between colon and rectal cancer should be considered.

Genetic cancer syndromes and large-scale gene expression analysis: applications in surgical oncology

The last decade of the 20th century was characterized by an explosion in genetic discoveries. The Human Genome Project and technical advances have made it possible to unravel many genetic abnormalities underlying cancer. Many genes responsible for inherited cancer syndromes have been identified and diagnostic tests are readily available. The clinical implications of these tests are currently under debate. Large-scale gene expression analysis enables simultaneous monitoring of expression of thousands of genes, in vitro and in vivo. The identification of high risk patients and drug responsiveness, can be studied within the framework of complex molecular networks. This article will focus on the possibilities for surgical oncology.

Prospective study of primary anastomosis following sigmoid resection for suspected acute complicated diverticular disease

BACKGROUND

A primary anastomosis after resection of the sigmoid colon for suspected acute complicated diverticular disease has the advantage of saving the patient a secondary operation for restoring bowel continuity. Fear of anastomotic leakage often deters surgeons from making a primary anastomosis.

METHODS

A series of 45 patients who underwent primary anastomosis was studied prospectively to evaluate the feasibility of a primary anastomosis following acute sigmoid resection. Acute Physiology and Chronic Health Evaluation (APACHE) II score, Mannheim Peritonitis Index (MPI) and Hughes' peritonitis classification were used to classify patients and to detect factors predictive of postoperative outcome. Death, anastomotic leakage and septic complications were main outcome measures.

RESULTS

Neither anastomotic leakage (four of 45 patients) nor death (three of 45) was related to a higher MPI, APACHE II or Hughes' score. More postoperative septic complications were seen in patients with a MPI over 16. Death, anastomotic leakage, reintervention and wound infection were observed more frequently in patients who presented with colonic obstruction than in those with abscess or perforation.

CONCLUSION

Primary anastomosis is safe and effective in non-obstructed cases of complicated diverticular disease. Colonic obstruction seems to be a risk factor for the development of postoperative complications.

Caspase-3 activity as a prognostic factor in colorectal carcinoma

Several techniques to determine apoptotic frequencies in tumors have been described. In this study, we report that biochemical detection of enzymatic caspase-3 activity is a simple and quantitative technique to measure apoptosis in colorectal tumor cells. The relevance of the level of apoptosis in colorectal cancer for the clinical course remains unclear. Therefore, we studied the correlation between caspase-3 activity and prognosis of the disease in relation to different factors known to be involved in apoptosis induction. High caspase-3 activity significantly correlated with a higher risk of recurrence and was preferentially found in tumors of the right side of the colon. No correlation was detected between high caspase-3 activity and altered protein expression of p53, beta-catenin, or proteins of mismatched repair genes. This indicates that high caspase-3 activity has no evident correlation with the genetic Wnt-signaling or the mismatch repair mutational pathways. The caspase-3 activity significantly correlated with CD57(+) tumor infiltrating cells. Therefore, high caspase-3 activity in right-sided tumors might be induced by a specific lymphocytic reaction.

Primary pheochromocytoma extending into the right atrium: report of a case and review of the literature

Pheochromocytoma rarely extends locally into the vena cava or the right atrium. We report a case of malignant pheochromocytoma with growth into the inferior vena cava, extending into the right atrium, address clinical aspects of this tumour and review the literature on this malignancy. Pre-operative work-up of this tumour should include measurements of urinary vanillyl mandelic acid and cathecholamine excretion, MRI and spiral CT of the abdomen and thorax. After the diagnosis is made the patient should be treated with catecholamine alpha-receptor blockade and if necessary with subsequent beta-receptor blockade. An aggressive surgical approach is always warranted, even in cases with very large localized tumours, because surgery has been shown to lead to relief of symptoms and to prolong survival in cases otherwise deemed irresectable. The optimal surgical exposure is obtained via a transsternal midline thoraco-laparotomy. If feasible, a combination of cardiopulmonary bypass, hypothermia, cardiac arrest and exsanguination procedures should be used. In case of local of tumour remnants after surgery or distant metastases treatment options are secondary surgery, tumour embolization, or treatment with radioactive labelled drugs, including(131)I-MIBG.

Operative treatment of acute complications of diverticular disease: primary or secondary anastomosis after sigmoid resection

OBJECTIVE

To assess the comparative effects of two surgical regimens on the outcome of acute complicated diverticular disease.

DESIGN

Retrospective study.

SETTING

Teaching hospital, The Netherlands.

SUBJECTS

60 patients who presented with acute complicated diverticular disease.

INTERVENTIONS

28 patient were treated by sigmoid resection and a Hartmann operation, and 32 by resection with primary anastomosis and defunctioning stoma.

MAIN OUTCOME MEASURES

Morbidity and mortality.

RESULTS

The severity of peritonitis and the amount of faecal contamination were similar in the 2 groups. 12 patients died (7 in the Hartmann group and 5 in the primary anastomosis group). There were 3 radiological leaks with no clinical implications in the primary anastomosis group. 6 patients in the Hartmann group and 5 in the primary anastomosis group required reoperations for intra-abdominal abscess or infection. 7 and 3 patients, respectively, developed dysfunction of their stomas, and 9/21 and 3/27, respectively, required a permanent stoma (p = 0.02, 95% confidence interval of difference 0.07 to 0.56). 3 patients in the Hartmann group developed anastomotic leaks after closure of their stomas, 1 of whom required reoperation but died. No patient developed an anastomotic leak after closure of the stoma in the primary anastomosis group.

CONCLUSION

Both regimens are accepted treatments for patients with acute complicated diverticular disease, but because of the higher morbidity after the Hartmann procedure we prefer primary anastomosis with covering stoma.

Long lasting p53-specific T cell memory responses in the absence of anti-p53 antibodies in patients with resected primary colorectal cancer

Colorectal carcinoma is commonly associated with mutation and overexpression of p53, making this antigen a potential target for immune intervention. We analyzed humoral and proliferative immunity against p53 in the blood of patients with resected primary colorectal cancer. The majority of these patients displayed anti-p53 T helper (Th) immunity in the absence of measurable p53 specific antibody levels. The Th responses were long-lasting since they could be detected up to several years after resection of the primary tumor. In a number of cases the Th responses were highly sensitive, reflected by the recognition of naturally processed p53 protein. Our data argue that boosting of these responses in patients with minimal residual disease through p53-specific vaccination, may be employed for improving the chance of disease-free survival of these patients.

[From gene to disease; from BRCA1 or BRCA2 to breast cancer]

Hereditary breast cancer is a heterogeneous syndrome, both phenotypically and genetically. It affects about 5% of all breast cancer patients. The presence of ovarian cancer or breast cancer in males defines important subtypes. BRCA1 and BRCA2 are involved in all hereditary breast cancer syndromes in varying degrees. Both genes confer strongly elevated breast and ovarian cancer risks in mutation carriers, but these risks may be subject to modifying effects by other factors (genetic and/or environmental) at the individual level. In the Netherlands, DNA testing is offered under the national health insurance programme and has led to the identification of over 500 families with either a BRCA1 or BRCA2 mutation. The results of the test are being used widely by Dutch women in the decision for or against prophylactic surgery.

Prevalence of BRCA1 in a hospital-based population of Dutch breast cancer patients

The prevalence of disease-related BRCA1 mutations was investigated in 642 Dutch breast cancer patients not selected for family history or age at diagnosis. They were tested for germline mutations in the BRCA1 gene using an assay which detects small deletions and insertions (DSDI), as well as the two major genomic founder deletions present in the Dutch population. Data on family history and bilateral breast cancer were obtained retrospectively. Ten protein truncating mutations were detected and one in-frame deletion with an unknown relation to disease risk. Four patients carried the Dutch founder deletion of exon 22. Based on these results the estimated prevalence of breast cancer in the general population in the Netherlands attributable to BRCA1 mutations is 2.1%. Under 40 years-of-age and under 50 years-of-age this prevalence is 9.5% and 6. 4%, respectively. All mutation carriers were under 50 years-of-age at diagnosis of the first breast cancer, and five did not have any relative with breast cancer. The proportions of bilateral breast cancer in the mutation carriers and non-carriers did not differ from each other. These data indicate that in the general Dutch breast cancer population the great majority of BRCA1 mutations will be found in women diagnosed under 50 years-of-age.

Increased local cytostatic drug exposure by isolated hepatic perfusion: a phase I clinical and pharmacologic evaluation of treatment with high dose melphalan in patients with colorectal cancer confined to the liver

A phase I dose-escalation study was performed to determine whether isolated hepatic perfusion (IHP) with melphalan (L-PAM) allows exposure of the liver to much higher drug concentrations than clinically achievable after systemic administration and leads to higher tumour concentrations of L-PAM. Twenty-four patients with colorectal cancer confined to the liver were treated with L-PAM dosages escalating from 0.5 to 4.0 mg kg(-1). During all IHP procedures, leakage of perfusate was monitored. Duration of IHP was aimed at 60 min, but was shortened in eight cases as a result of leakage from the isolated circuit. From these, three patients developed WHO grade 3-4 leukopenia and two patients died due to sepsis. A reversible elevation of liver enzymes and bilirubin was seen in the majority of patients. Only one patient was treated with 4.0 mg kg(-1) L-PAM, who died 8 days after IHP as a result of multiple-organ failure. A statistically significant correlation was found between the dose of L-PAM, peak L-PAM concentrations in perfusate (R = 0.86, P< or =0.001), perfusate area under the concentration-time curve (AUC; R = 0.82, P<0.001), tumour tissue concentrations of L-PAM (R = 0.83, P = 0.011) and patient survival (R = 0.52, P = 0.02). The peak L-PAM concentration and AUC of L-PAM in perfusate at dose level 3.0 mg kg(-1) (n = 5) were respectively 35- and 13-fold higher than in the systemic circulation, and respectively 30- and 5-fold higher than reported for high dose oral L-PAM (80-157 mg m(-2)) and autologous bone marrow transplantation. Median survival after IHP (n = 21) was 19 months and the overall response rate was 29% (17 assessable patients; one complete and four partial remissions). Thus, the maximally tolerated dose of L-PAM delivered via IHP is approximately 3.0 mg kg(-1), leading to high L-PAM concentrations at the target side. Because of the complexity of this treatment modality, IHP has at present no place in routine clinical practice.

Absence of genetic alteration at codon 531 of the human c-src gene in 479 advanced colorectal cancers from Japanese and Caucasian patients

Activation of c-src, a cellular human gene homologous in sequence to the v-src gene of Rous sarcoma virus, had been thought to play an important role in the progression of several types of human cancers, without having undergone any genetic changes. However, recently truncating mutations at codon 531 of the c-src gene were reported in 12% of the advanced colon cancers, and it was also demonstrated that this change was activating, transforming, tumorigenic, and metastasis promoting. To investigate whether the codon 531-specific mutation could be involved in the carcinogenesis of colorectal cancer in the Japanese and Caucasian populations, we examined a total of 479 advanced colorectal cancers from 421 Japanese patients (46 of them with liver or lung metastases) and from 58 Caucasian patients (11 of them with liver metastases). Using the PCR-RFLP assay and additional single-strand conformation polymorphism analysis, we detected no genetic alteration in any of the advanced colorectal cancers. Our results suggest that the codon 531-specific mutational activation of c-src is unlikely to play a significant role in the malignant progression of colorectal cancers among most Japanese and Caucasian patients.

Acute-phase response patterns in isolated hepatic perfusion with tumour necrosis factor alpha (TNF-alpha) and melphalan in patients with colorectal liver metastases

BACKGROUND

In this study, we have evaluated hepatotoxicity, secondary cytokine production and hepatic acute-phase response (APR) in patients who underwent isolated hepatic perfusion (IHP) with tumour necrosis factor (TNF) alpha and melphalan for irresectable colorectal liver metastases.

DESIGN

An extracorporeal veno-venous bypass was used to shunt blood from the lower body and intestines to the heart. Inflow catheters were placed in the hepatic artery and portal vein, and an outflow catheter in the inferior caval vein. The liver was perfused for 60 min with 0.4 mg of TNF-alpha plus 1 mg kg-1 melphalan (IHPTM group, n = 6) or 1 mg kg-1 melphalan (IHPM group, n = 3). The liver was washed with macrodex before restoring vascular continuity.

RESULTS

After the washout procedure, a TNF-alpha peak (169 +/- 38 pg mL-1) was demonstrated in the IHPTM group only. Both groups demonstrated peak levels of interleukin 6 (IL-6) in the perfusate as well as systemically. These were significantly higher in the IHPTM group. Acute-phase protein (APP) levels followed a similar pattern as has been demonstrated after major surgery, with no significant differences between both groups. The addition of TNF-alpha to the perfusate did not lead to a significant difference in APP levels and the time course between groups.

CONCLUSIONS

IHP with TNF and melphalan is followed by a transient systemic peak of TNF directly after liver washout. Secondary IL-6 induction was seen in the present study after IHP with and without TNF, which was highest when TNF was added. This phenomenon cannot be extrapolated to APP induction, which appeared unaffected by the addition of TNF, presumably because the surgical procedure itself already causes maximal stimulation of APP production.

Molecular detection of minimal residual disease in colorectal and breast cancer

Recent developments in the field of molecular biology enable us to detect tumour cells at a submicroscopical level. In colorectal and breast cancer the most important prognostic factor is dissemination of malignant cells to locoregional lymph nodes. An important issue is whether molecular 'super'-staging augments the accuracy by which the prognosis of individual patients can be assessed. Over the past few years numerous studies have reported the use of different PCR-based techniques in various types of cancer. The reported incidence of micrometastases and specificity of different assays varies tremendously. This clearly indicates the need for uniformity in protocols. For colorectal cancer the use of molecular techniques may improve staging and guide clinical decisions. For breast cancer there is still need to prove the clinical implication of finding occult metastatic disease. Nevertheless, PCR-based techniques are a powerful tool in the staging of common solid tumours and are likely to find their way into the daily practice of diagnostic histopathologists in the near future.

Micrometastases and survival in stage II colorectal cancer

BACKGROUND

Standard treatment of colorectal cancer includes adjuvant chemotherapy for patients with stage III disease (defined by the presence of lymph-node metastases), but not for patients with stage II tumors (who have no lymph-node metastases). However, 20 percent of patients with stage II tumors die of recurrent disease. We investigated whether the detection of micrometastases can be used to identify patients with stage II disease who are at high risk for recurrence.

METHODS

We analyzed 192 lymph nodes from 26 consecutive patients with stage II colorectal cancer, using a carcinoembryonic antigen-specific nested reverse-transcriptase polymerase chain reaction. Five-year follow-up information was obtained on all patients. Observed and adjusted survival rates were assessed in the patients with and the patients without micrometastases.

RESULTS

Micrometastases were detected in one or more lymph nodes from 14 of 26 patients (54 percent). The adjusted five-year survival rate (for which only cancer-related deaths were considered) was 50 percent in this group, whereas in the 12 patients without micrometastases, the survival rate was 91 percent (P=0.02 by the log-rank test). The observed five-year survival rates were 36 percent and 75 percent, respectively (P=0.03). The groups were similar with respect to age, sex, tumor side (location in relation to the flexura lienalis), degree of tumor differentiation (grade), and diameter of the primary tumor.

CONCLUSIONS

Molecular detection of micrometastases is a prognostic tool in stage II colorectal cancer.

Immunohistochemical detection of p53 and Bcl-2 in colorectal carcinoma: no evidence for prognostic significance

To evaluate the prognostic significance of immunohistochemically detected p53 and Bcl-2 proteins in colorectal cancer, tissue sections from 238 paraffin-embedded colorectal carcinomas were immunostained for p53 (MAb DO-7 and CM-1 antiserum) and Bcl-2 (MAb Bcl-2:124). Staining patterns were assessed semiquantitatively and correlated with each other and with sex, age, tumour site, Dukes' classification, tumour differentiation, mucinous characteristics, lymphocyte and eosinophilic granulocyte infiltration, and patient survival. In our series, 35% of carcinomas showed no nuclear staining and 34% (DO-7) to 40% (CM-1) showed staining in over 30% of tumour cell nuclei. A majority of carcinomas that had been immunostained with CM-1 showed cytoplasmic staining, but this was not observed with DO-7. With respect to Bcl-2, 51% of tumours were completely negative, 32% displayed weak and 15% moderate staining; only 3% showed strong positive staining. No evidence was found for reciprocity between Bcl-2 expression and nuclear p53 accumulation. From 13 cases containing tumour-associated adenoma, four were Bcl-2 negative in premalignant and malignant cells, in another four cases these cells showed similar staining intensities and in the remaining cases only the malignant colorectal cells were Bcl-2 negative. Therefore, our data indicate that Bcl-2 is dispensable in the progression towards carcinoma. Except for an association between nuclear p53 accumulation and mucinous tumours (P = 0.01), no significant correlation was found between the clinicopathological parameters mentioned above and immunostaining pattern of (nuclear or cytoplasmic) p53 or Bcl-2.

Isolated hepatic perfusion with tumor necrosis factor alpha and melphalan: experimental studies in pigs and phase I data from humans

We report our experience with isolated hepatic perfusion (IHP) with tumor necrosis factor (TNF) and melphalan in an experimental pig study and of a phase I study in humans. IHP was performed with inflow catheters in the hepatic artery and portal vein and an outflow catheter in eh caval vein. An extracorporeal venovenous bypass was used. IHP consisted of a 60-min perfusion with hyperthermia (> 41 degrees C). For the pig protocol rhTNF alpha 50 micrograms/kg alone (n = 5) or rhTNF alpha 50 micrograms/kg plus melphalan 1 mg/kg (n = 3) were added. In two control pigs no drugs were added. In the phase I study, patients received melphalan 1 mg/kg with 0.4 mg rhTNF alpha (n = 8) or 0.8 mg rhTNF alpha (n = 1). After the perfusion the liver was washed with Macrodex before vascular continuity was restored. All pigs but one survived the procedure. Systemic leakage was less than 0.02%. Transient, mild liver toxicity was seen in all pigs, including controls, as demonstrated by liver enzyme assays and histology. There was no significant hemodynamic, cardiopulmonary hematological, or renal toxicity. In the phase I clinical study there was leakage in one patient (cumulative leakage 20%). There were three perioperative deaths (one possibly drug-related). All patients demonstrated significant hepatotoxicity. Survival ranged from 6 to 26 months (median 10.3 months). All patients demonstrated a tumor response (partial response 5/6, 1/6 stable disease) with a median duration of 18 weeks. In contrast to our pig program, many problems were encountered in the phase I study. By using both the hepatic artery and portal vein for IHP we encountered more toxicity than expected based on data from the pig program, resulting in fatal coagulative disturbances in one patient who received the second rhTNF alpha dose. Furthermore, local control after one IHP with TNF alpha and melphalan is only temporary.

p53 protein overexpression is common and independent of human papillomavirus infection in squamous cell carcinoma of the vulva

BACKGROUND

Human papillomavirus (HPV) infection and p53 abnormalities might both play a role in the carcinogenesis of subtypes of squamous cell carcinoma of the vulva. In this study, the authors investigated the prevalence of and the relationship between p53 overexpression and HPV infection in patients with vulvar carcinoma.

METHODS

Immunohistochemical methods for the detection of p53 protein and consensus primer polymerase chain reaction (PCR) were used, followed by direct sequencing of the PCR product for the evaluation of HPV subtype infection. Sixty-six patients with squamous cell carcinoma of the vulva were available for this study.

RESULTS

DO7, an anti-p53 monoclonal antibody, showed p53 overexpression in 35 carcinomas (53%). Consensus primer PCR showed HPV infection in 12 carcinomas (18%). No significant association was observed between p53 overexpression or HPV infection and tumor subtype. Approximately 57% of the HPV negative carcinomas and 33% of the HPV positive carcinomas had p53 overexpression. With regard to the patients with DO7 positivity in > or =50% of the nuclei only, significantly more HPV negative carcinomas were DO7 positive compared with HPV positive carcinomas (41% vs. 0%, respectively; P = 0.018). No relation was found between either HPV infection or p53 overexpression and disease free survival.

CONCLUSIONS

p53 overexpression is common in both HPV positive and HPV negative carcinomas of the vulva. These findings indicate that these two both play a role in the pathogenesis of vulvar carcinoma, but do not influence disease free survival.

Analysis of the variety in surgeons' decision strategies for the management of left colonic emergencies

OBJECTIVES

The aim of this study is to analyze surgeons' decision strategies about the optimal treatment for acute sigmoid resection for different patients. In particular, the authors wished to determine the predominant accepted treatment choice among surgeons, to determine the importance of patient characteristics for surgeons' evaluations of the appropriateness of treatments, and to identify the variety in decision strategies.

METHODS

A survey was carried out among all surgical members of the Netherlands Society of Gastro Intestinal Surgery, who evaluated 16 patient cases. Approximately 70% of the members completed the survey.

RESULTS

Overall, the predominant accepted strategy is resection, delayed anastomosis, and colostomy (Hartmann procedure). Consensus in terms of preferred treatment, however, was low. The most important factors influencing surgeons' evaluations of the appropriateness of treatments were the age of a patient, the degree of peritonitis, and the degree of fecal contamination. Further analysis showed that the variety in surgeons' decision strategies could not be explained by differences in experience, but was shown to be related to the evaluation of the appropriateness of treatment for 60-year-old patients and patients with a local peritonitis. Except for these factors, surgeons did not differ fundamentally in the evaluation of the factors that make a treatment more appropriate. Surgeons agreed about the optimal treatment for older patients in poor condition, although there is no epidemiologic literature to support this consensus position.

CONCLUSIONS

This study showed that lack of consensus in surgeons' choice of treatment could be explained partly by disagreement of the appropriateness of treatments for some, rather than all, patients.

p53 protein overexpression, a frequent observation in squamous cell carcinoma of the vulva and in various synchronous vulvar epithelia, has no value as a prognostic parameter

In this study we have investigated the prevalence of p53 overexpression in various vulvar lesions and its significance as a prognostic parameter in patients with vulvar carcinoma. Overexpression of p53 was studied in 66 patients with squamous cell carcinoma of the vulva and in the following synchronous epithelial lesions: intraepithelial neoplasia grade I (VIN I) (n = 33), VIN II (n = 11), VIN III (n = 16), lichen sclerosus (n = 30), squamous cell hyperplasia (n = 37), normal vulvar skin of patients with vulvar carcinoma (n = 55), and in 18 samples of normal skin from healthy controls. Survival curves of the p53-positive and p53-negative patients were compared using the log-rank test. The use of DO7, and anti-p53 monoclonal antibody, showed p53 overexpression in 35 (53%) specimens of carcinoma, in eight (27%) of lichen sclerosus, in five (14%) of squamous cell hyperplasia, in six (18%) of VIN I, in two (18%) of VIN II, in two (13%) of VIN III, and in seven (13%) specimens of normal vulvar skin. Staining of normal skin from healthy controls showed no p53 positive specimens. No relationship between expression of p53 and disease-free survival in patients with vulvar carcinoma was present. In malignant, synchronous premalignant and non-neoplastic epithelial disorders of the vulva, p53 overexpression is a frequent observation, indicating that the latter two groups have characteristics of premalignant lesions. In addition, p53 overexpression was not a useful prognostic parameter for patients with vulvar carcinoma.

Evidence of clonal divergence in colorectal carcinoma

BACKGROUND

The aim of this study was to investigate the generation of DNA ploidy diversity in different stages of colorectal carcinoma development.

METHODS

DNA flow cytometry was performed on tissue samples from 20 colorectal adenomas, 38 colorectal carcinomas, 30 lymph node metastases, and 70 hematogenous metastases.

RESULTS

DNA aneuploidy was detected in 30% of the adenomas, 82% of the primary colorectal tumors, 57% of the lymph node metastases, 92% of the liver metastases, and 100% of the other distant hematogenous metastases. Multiple DNA tumor stemlines were found in 10%, 39%, 29%, 24%, and 40%, respectively. Sixty-two percent of the DNA tumor stemlines detected in the lymph node or liver metastases were also present in the primary tumors. In primary carcinomas and lymph node metastases, the DNA index distribution had a bimodal shape with a minimum at the 1.2-1.4 region. In the hematogenous metastases, a higher percentage of hypertetraploid stemlines was found.

CONCLUSIONS

The emergence of DNA aneuploidy as well as clonal divergence seems to take place during the transition from adenoma to carcinoma. The DNA aneuploid stemlines formed during this phase remain relatively stable over time, although ongoing clonal evolution at distant metastatic tumor sites cannot be completely ruled out.

Liver and tumour tissue concentrations of TNF-alpha in cancer patients treated with TNF-alpha and melphalan by isolated liver perfusion

In this study we determined the level of tumour necrosis factor alpha (TNF-alpha) in liver and tumour tissue samples obtained from patients with colorectal metastases confined to the liver, who were treated with isolated liver perfusion with TNF-alpha and melphalan. We adapted a standard enzyme-linked immunosorbent assay kit for the quantification of TNF-alpha in serum to measure the amount of this cytokine in solid tissue. For this purpose, we developed a buffer that lysed the tissues without affecting the TNF-alpha present. The minimum detection level was about 2 pg of TNF-alpha per mg tissue. Using this technique, we found a significant increase in the TNF-alpha level after perfusion in the liver tissue of all evaluable patients, which may explain the transient liver toxicity we observed in all patients. In tumour tissue, a significant TNF-alpha increase was observed in one out of five patients. The level of TNF-alpha in all liver tissue samples and some of the tumours after treatment by isolated liver perfusion was much higher than the peak serum concentrations obtained after systemic administration of the maximum tolerated dose of TNF-alpha. Furthermore, we demonstrated that the level of TNF-alpha in the liver tissue samples was about seven to eight times higher than in tumour tissue. We concluded that regional liver treatment resulted in a relatively high local level of TNF-alpha, but also that this cytokine did not preferentially accumulate in tumour tissue.

Antibodies against p53 are associated with poor prognosis of colorectal cancer

Mutation of the p53 gene is a common event in colorectal cancer. This alteration can result in cellular accumulation of p53 and may also induce p53 antibodies. Accumulation of p53 in tumour cells has been associated with poor prognosis of colorectal cancer. We tested preoperative sera from 255 patients with colorectal cancer by enzyme-linked immunosorbent assay (ELISA). A total of 70.2% had reactivity that was higher than the 'low' control serum. Employing a cut-off level of 10% of the 'high' control sample, 25.5% of the patients were positive for p53 antibodies. The presence of p53 antibodies correlated with the following prognostic factors: histological differentiation grade, shape of the tumour, and tumour invasion into blood vessels. Patients with p53 antibodies were shown to have decreased survival and decreased disease-free survival. Specifically for patients with cancer stage A and B1 the presence of p53 antibodies selected a subgroup with poor prognosis.

[Surgical strategy in acute or elective sigmoid resection in The Netherlands; survey based on a marketing model]

OBJECTIVE

To gain insight into the operative strategies used by Dutch surgeons for complicated diverticulitis and sigmoid carcinoma, and into the influence of patient risk factors and surgeon's experience on the preferred operative strategy.

DESIGN

Descriptive.

METHOD

A questionnaire was sent to all 148 members of the Dutch Society of Gastrointestinal Surgery, concerning 32 fictitious patients with sigmoid pathology. It was based on conjoint-analysis, a model used in marketing research. This model analyses qualities that make a product preferable to another product of the same product group. The operative choices were: resection with Hartmann's procedure, resection with primary anastomosis after on-table lavage, or with primary anastomosis only, or no primary resection but diverting stoma only, or some personal technique. The survey focused on experience of the surgeons with the operative procedures, and on treatment choices in four fictitious cases frequently encountered in general surgery.

RESULTS

There was little agreement concerning the preferred surgical option for treatment of complicated diverticular disease or sigmoid carcinoma. With the exception of one fictitious young, electively operated 'ideal' patient (resection with primary anastomosis) there is hardly any consensus among the surgeons with respect to preferred treatment.

CONCLUSIONS

Reasons to depart from the conceptually optimal treatment (resection and anastomosis) in complicated cases (from the point of view of the surgeon or the patient), and absence of agreement on responsible other treatment could be differences in appraisal of the importance of several risk factors, or differences in acquired decision making strategies. The literature offers no answer to the question which techniques should be preferred under various circumstances.

Scalp cooling has no place in the prevention of alopecia in adjuvant chemotherapy for breast cancer

35 patients were studied to determine the effectiveness of scalp hypothermia in the prevention of alopecia caused by adjuvant chemotherapy for breast cancer. Scalp hypothermia was induced by the newly developed Theracool cooling machine. The chemotherapeutic regimen consisted of one perioperative course of doxorubicin 50 mg/m2, cyclophosphamide 600 mg/m2 and 5-fluorouracil 600 mg/m2 (EORTC protocol 10854). Only 4 (11%) patients showed acceptable hair preservation (no or minor alopecia). 12 patients (34%) had moderate alopecia, all requiring a wig. 19 patients (54%) had complete alopecia. No scalp metastases were observed after scalp cooling. These results and a review of the literature suggest that scalp hypothermia to prevent alopecia may only be effective in a cytotoxic regimen containing an anthracycline as the sole alopecia-inducing agent. With current adjuvant chemotherapy for breast cancer, in which a combination of cyclophosphamide and an anthracycline is often used, there is no place for scalp hypothermia.

External radiotherapy and extrahepatic bile duct cancer

The hospital records of patients with extrahepatic bile duct cancer who where treated surgically between 1968 and 1983 were reviewed. Of 55 patients, 16 (29%) received radiotherapy after surgery. The total dose given ranged from 40 to 60 Gy. Median follow-up time for analysis was 4.0 months and lasted until January 1988. The overall median survival was 4 months (range 0-36), that of the irradiated patients was 16 months (range 2-36), and that of the 39 patients who were not irradiated was 3 months (range 0-32). When the 13 post operative deaths were excluded the median survival was 4 months. Radiotherapy did not cause any severe complications. No firm conclusion about the role of radiotherapy can be drawn from these data because the patients were not randomly chosen to receive radiotherapy and selection was therefore biased. We conclude that most patients with extrahepatic bile duct cancer still die of locoregional disease. Effective adjuvant treatments are needed and should be evaluated in prospective randomized trials.