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G Griffioen

Publications and source records attributed to G Griffioen.

At least 37 records · Page 2Linked to original sources

Superoxide dismutases in gastric and esophageal cancer and the prognostic impact in gastric cancer.

The oxidant-antioxidant balance is thought to be important in the initiation, promotion, and therapy resistance of cancer. In the present study, we assessed the expression of the antioxidants manganese superoxide dismutase (Mn-SOD) and copper/zinc superoxide dismutase in gastric and esophageal carcinomas and their relation with clinical outcome. Adenocarcinomas of the stomach (n = 81) as well as squamous cell carcinomas of the esophagus (n = 10) showed an enhanced immunohistochemical expression of Mn-SOD, which was accompanied by a significantly higher tissue level (P < or = 0.007) compared with their corresponding normal mucosa. In contrast, copper/zinc superoxide dismutase was found to be marginally lower in these malignant tissues in comparison with the normal tissues. The superoxide dismutase levels were not found to be associated with major clinicopathological features of the gastric cancer patients. Univariate analysis revealed, however, that a high Mn-SOD level in gastric carcinomas, a low level in the normal gastric mucosa, and a high ratio of these two levels in gastric cancer patients are indicative of a poor overall survival. Multivariate analysis, including all clinicopathological parameters, revealed that the Mn-SOD ratio in particular is an independent prognostic parameter in gastric cancer patients.

Adenocarcinoma↗

Chemoprevention of colorectal cancer by non-steroidal anti-inflammatory drugs.

AIM: To critically analyse the role of NSAIDs in colorectal cancer. METHODS: Update of the chemoprotective effect of NSAIDs on colorectal cancer. RESULTS AND CONCLUSION: Over the past 20 years exciting developments in clinical and basic research have opened up the possibility of NSAID-induced colorectal cancer chemoprevention. In particular, disclosure of the multistep genetic pathway of colorectal carcinogenesis and recognition of the impact of the COX-2 gene on this process have been of utmost importance. These findings have led to the possibility of colorectal cancer prevention by the administration of agents such as NSAIDs. Although it is accepted that these agents are potent inhibitors of colorectal carcinogenesis, their side effects in long-term use are of concern to clinicians dealing with colorectal cancer prevention. Moreover, neither the dose nor the duration of the medication, nor the most ideal compound with respect to protective effects against colorectal cancer, has been defined. Recently, selective COX-2 inhibitors have been developed which may show additional benefit compared to the classical NSAIDs. However, their efficacy and safety profiles need to be established firmly before large-scale use in colorectal cancer prevention can be considered. Based on the exciting developments it is anticipated that a more precise understanding of the molecular details of colorectal carcinogenesis will finally lead to the optimal chemopreventive regimen.

Anti-Inflammatory Agents, Non-Steroidal↗

[Genetics of colorectal cancer. I. Non-polyposis and polyposis forms of hereditary colorectal cancer].

About 5% of colorectal cancer cases are due to an autosomal dominant genetic predisposition with high penetrance. In this condition, the patient is carrier of a pathogenic gene mutation present in all body cells which can be transmitted to descendants, a so-called germ line mutation. The mutation is usually present in a tumour suppressor gene. Three subgroups of hereditary colorectal cancer can be distinguished on the basis of the clinical characteristics: (a) syndromes without polyposis (mostly hereditary non-polyposis colorectal carcinoma; HNPCC), (b) syndromes with adenomatous polyposis (mostly familial adenomatous polyposis; FAP) and (c) syndromes with hamartomatous polyposis. Recently, the main gene defects which underlie these syndromes were identified. Consequently, it is possible in approximately half the families with HNPCC or FAP in patients with colorectal cancer to demonstrate the causative gene defect and subsequently, by blood testing of healthy relatives to determine who is and is not a carrier of this hereditary condition. Thus, preventive measures can be directed toward family members with a demonstrable high risk of large bowel cancer.

Adenomatous Polyposis Coli↗

[Genetics of colorectal cancer. II. Hereditary background of sporadic and familial colorectal cancer].

About 15% of patients with colorectal cancer have a positive family history: 5% have hereditary colorectal cancer (hereditary non-polyposis colorectal carcinoma (HNPCC), familial adenomatous polyposis (FAP) or some other hereditary syndrome), while in 10% no clear hereditary pattern can be recognized ('familial colorectal cancer'). In sporadic and in familial intestinal cancer, a demonstrable hereditary predisposition may undoubtedly exist. HNPCC is often characterized by microsatellite instability, i.e. an increased number of short DNA sequences in the DNA indicating a disorder in DNA repair and a mutation in a DNA 'mismatch repair' (MMR) gene. Indicative of hereditary bowel cancer on the basis of such an MMR gene mutation are: (a) presence of bowel cancer in > or = 3 relatives, (b) early age at the time of the diagnosis of 'bowel cancer', (c) multiple primary bowel tumours, (d) uterine cancer in the family and (e) bowel and uterine cancer in a woman. Recent data demand a new subdivision of hereditary bowel cancer, based upon both the clinical picture and the results of DNA-tests. The genetic alterations in colonic adenomas and carcinomas are known to a large extent. In future these insights may be important in clinical practice, such as a more individual determination of the patient's prognosis and accordingly, of the treatment and follow-up.

Adenoma↗

[Periodic colonoscopic examinations of persons with a positive family history for colorectal cancer. Work Group 'Hereditary non-polyposis- colon-rectum cancers'].

Individuals with one first-degree relative with colorectal cancer diagnosed before age 45 years and those with two first-degree relatives with colorectal cancer run a significantly increased risk (relative risk: 4-6) of developing colorectal cancer. Based on calculation of the mortality due to colorectal cancer for the age group 50-70 years (which is higher than the mortality due to breast cancer) surveillance may be justified, e.g. by colonoscopy at 5-year intervals from the age of 45-50. The total number of people in the Netherlands in this high risk group is estimated at 10,000. The authors conclude that prospective studies are needed to assess the cost-effectiveness of such a programme.

Aged↗

Superoxide dismutases in the human colorectal cancer sequence.

PURPOSE: The oxidant-antioxidant balance within tissues is thought to contribute to the development and progression of cancer. Previous investigations have indicated changes in this balance during the colorectal oncogenic process that merit further investigation. The aim of the present study was to evaluate whether the human colorectal cancer sequence is accompanied by changes in the protein and activity levels of the antioxidant enzymes manganese- and copper/zinc-superoxide dismutase (Mn-SOD and Cu/Zn-SOD). PATIENTS AND METHODS: SOD levels were assessed in colorectal adenomas, carcinomas, and liver metastases and were compared with those in the corresponding normal tissues (n = 35 in each group). Mn- and Cu/Zn-SOD expression was first evaluated semiquantitatively by electrophoretic activity analysis, immunoblotting, and immunohistochemistry and was subsequently quantified by enzyme-linked immunosorbent assays (ELISAs) and spectrophotometric activity assays. RESULTS: The semiquantitative analyses showed enhanced Mn-SOD levels, primarily localized in (neoplastic) epithelial cells, in carcinomas, and in liver metastases as compared with adenomas and normal mucosa, whereas no consistent pattern was observed for Cu/Zn-SOD. Normal liver tissue expressed the highest levels of both SODs. The quantitative SOD analyses confirmed these observations and revealed that carcinomas and liver metastases expressed 2-4 times more Mn-SOD protein and enzymatic activity (0.0005 < P < 0.01) than did the normal mucosa. Adenomas expressed intermediate Mn-SOD levels, which increased significantly with the diameter and tended to increase with the grade of dysplasia and presence of a villous component. In contrast, adenomas, carcinomas, and the corresponding normal mucosa were found to have a similar Cu/Zn-SOD content, whereas liver metastases contained significantly (P < 0.02) more Cu/Zn-SOD as compared with these tissues. In addition, the Cu/Zn-SOD content was not related to any histopathological characteristic of the carcinomas or adenomas. CONCLUSIONS: Our study indicates that the development of neoplasia in the human colorectum is accompanied by major changes in the level and activity of Mn-SOD. This observation illustrates that Mn-SOD might have a functional role in human colorectal carcinogenesis.

Adenocarcinoma↗

Laparoscopically assisted bowel surgery for inflammatory bowel disease. The combined experiences of two academic centers.

BACKGROUND: Laparoscopic bowel surgery was evaluated in 44 consecutive patients who underwent surgery for inflammatory bowel disease (IBD). We studied feasibility, results, and final outcome. METHODS: At two academic institutes, 44 laparoscopically assisted colectomies and laparoscopic ileostomies or colostomies were attempted. All patients had histologically proven IBD and no prior surgery for IBD. Loop ileostomy (n = 4), end colostomy (n = 1), ileocecal resection (n = 26) and (procto)colectomy (n = 13) were performed. All resections were laparoscopically assisted with extracorporal resection and anastomosis. RESULTS: Only in two patients (ileocecal resection in both) was conversion to open surgery necessary. Two patients with laparoscopic ileocolic resection had intra-abdominal abscesses, which were drained percutaneously in both. One patient in the laparoscopically assisted colectomy group had a subphrenic abscess that was drained percutaneously, and one patient had a generalized candidiasis. CONCLUSIONS: Laparoscopically assisted colectomies can be performed safely in treating IBD. The laparoscopic method with use of a small vertical umbilical or Pfannenstiel's incision seems acceptable with regard to operating time and overall costs, also allowing superior cosmesis to be maintained.

Adolescent↗

Mesalazine-induced apoptosis of colorectal cancer: on the verge of a new chemopreventive era?

BACKGROUND: It is an accepted fact that non-steroidal anti-inflammatory drugs (NSAIDs) are potent inhibitors of colorectal carcinogenesis. However, the major disadvantages of NSAIDs are gastrointestinal and renal toxicity. We conducted a prospective pilot study on the effects of the safe salicylic acid derivative, mesalazine, on apoptosis and proliferation of tumour cells and on normal tissue in colorectal cancer patients. METHODS: Patients with colorectal cancer were asked to take mesalazine enemas for 14 days. Biopsies from malignant and normal tissue were taken prior to and after this treatment. Apoptosis was scored on haematoxylin/eosin-stained tissue sections, and cell proliferation was assessed by the proliferation marker Ki-67. RESULTS: Ten out of 14 patients completed the study. The apoptotic score increased significantly in the tumour samples (pre-treatment 14.6 +/- 1.3 vs. post-treatment 19.4 +/- 0.8; P < 0.03). The apoptotic index in the normal mucosa was unchanged (pre-treatment 3.1 +/- 0.4 vs. post-treatment 2.9 +/- 0.3; N.S.). The cell proliferation in malignant tissue, according to the Ki-67 score, was hardly affected by mesalazine (pre-treatment 522 +/- 38 vs. post-treatment 493 +/- 39; N.S.). There was no effect on the Ki-67 index of normal mucosa (pre-treatment 24.2 +/- 2.0 vs. post-treatment 28.3 +/- 2.0; N.S.). CONCLUSIONS: This pilot study conducted in patients with colorectal cancer clearly shows that mesalazine selectively induces apoptosis of tumour cells. On the basis of these findings, which need to be confirmed in larger studies, it may be speculated that 5-ASA could be useful in the chemoprevention of colorectal cancer.

Aged↗

Azathioprine: an update on clinical efficacy and safety in inflammatory bowel disease.

BACKGROUND: The approval of azathioprine (AZA) for the long-term therapy of patients with Crohn's disease in The Netherlands. METHODS: Review and update of the literature on clinical efficacy and safety of AZA in inflammatory bowel disease. RESULTS: AZA and its metabolite 6-mercaptopurine (6-MP) are effective in the treatment of active Crohn's disease. However, the onset of the clinical response is delayed, requiring combination with other active medication in the early phase of treatment. Maintenance therapy with AZA/6-MP is also effective in the prevention of relapses in patients with Crohn's disease in remission. Indications for AZA/6-MP therapy further include refractory, fistulizing and steroid-dependent Crohn's disease. It is not known whether or when AZA/6-MP can be withdrawn in patients in long-term remission, but most clinicians discontinue therapy after 3-5 years. Although fewer data are available, AZA/6-PM appears to be effective also in the therapy of patients with ulcerative colitis. Side effects of AZA/6-MP occur in about 15% of patients and include skin rash, pancreatitis and hepatitis, dose-related neutropenia and thrombocytopenia, and risk of increased occurrence and severity of infections. Recent data suggest that the risk of malignancy, other than colorectal cancer, is not increased. Safety in pregnancy has not been studied extensively, but no increased prevalence of birth defects has been reported. CONCLUSIONS: AZA/6-MP therapy is efficacious in patients with active Crohn's disease, but the drug is especially valuable in the long-term treatment of patients with Crohn's disease and ulcerative colitis. Drug-related side effects are frequent and require discontinuation or dose-reduction of the AZA/6-MP therapy. Due to an increased risk of infections secondary to myelosuppression, careful follow-up is mandatory. Insufficient data are available on safety in pregnancy and on the risk of malignancies, but the limited data available in patients with inflammatory bowel disease appear to be reassuring.

Azathioprine↗

Treatment of mesenteric desmoid tumours with the anti-oestrogenic agent toremifene: case histories and an overview of the literature.

Desmoid tumours are histologically benign but due to their infiltration and compression of surrounding structures potentially life-threatening fibromatous lesions of unknown aetiology. The annual incidence rate is 2-4 per million people. The mesenteric variant constitutes about 10% of all desmoid tumours, although in familial adenomatous polyposis (FAP) patients this may be up to 70%. Due to the small number of patients with mesenteric desmoids the therapy is mainly empirical. This report describes the rationale as well as the value of the short- and long-term treatment (up to 6 years) with the anti-oestrogenic agent toremifene in combination with sulindac in two patients suffering from such a mesenteric desmoid tumour. These patients did not respond to sulindac alone and previous treatment with tamoxifen together with this non-steroidal anti-inflammatory drug had also failed. An overview of the literature on the management of these dismal tumours is presented.

Adult↗

Familial adenomatous polyposis: from bedside to bench and vice versa. A tribute to the somatic cell geneticist P. Meera Khan.

Familial adenomatous polyposis (FAP) is characterized by the presence of numerous adenomatous polyps in the colorectum, as well as an autosomal dominant mode of inheritance. This syndrome will inevitably lead to colorectal cancer when left untreated, and it is estimated that 1% of all colorectal cancer cases are due to it. Over the past 20 years molecular genetic studies on FAP patients have laid down the basis for the elucidation of the genetic phenomena that ultimately result in the development of colorectal cancer. Professor P. Meera Khan was one of the leading authorities in the world of molecular genetics of colorectal cancer in general and of FAP in particular. His scientific contributions from the pre-DNA era up to the recent implementation of molecular genetic research in daily clinical practice have helped revolutionize our approach and management of FAP patients and their relatives.

Adenomatous Polyposis Coli↗

[Unconventional imaging techniques in inflammatory bowel diseases].

In patients with inflammatory bowel disease (IBD), radiologic examinations are important for diagnosis and treatment. With conventional X-ray examinations, mucosal abnormalities, ulcers and fistulas can be visualised, but no information on the extramural extension of the disease can be obtained. Newer radiologic modalities (ultrasound, CT and MRI) offer new diagnostic possibilities. With ultrasound IBD can be diagnosed with good confidence and it can differentiate between Crohn's disease and ulcerative colitis. CT and MRI are indicated not so much to diagnose the disease but rather to determine the severity and spread of disease activity (transmural and extramural inflammation) and to detect complications such as fistulas and abscesses.

Colitis, Ulcerative↗

A cost-effectiveness analysis of colorectal screening of hereditary nonpolyposis colorectal carcinoma gene carriers.

BACKGROUND: It has been estimated that the prevalence of carriers of a mutated mismatch repair (MMR) gene among the general population in Western countries is between 5 and 50 per 10,000. These carriers have a risk of >85% of developing colorectal carcinoma (CRC) and therefore need careful follow-up. The objective of this study was to analyze the cost-effectiveness of CRC surveillance of carriers of a mutated MMR gene. METHODS: The authors constructed a model to estimate the potential health effects (life expectancy) and healthcare costs of two strategies: 1) surveillance, with colonoscopy every 2-3 years, and 2) no CRC surveillance. Estimates of the lifetime risk of developing CRC and the stage distribution of CRC for symptomatic patients were derived from the Dutch hereditary nonpolyposis colorectal carcinoma (HNPCC) registry. The CRC stage specific relative survival rates and the effectiveness of surveillance in preventing or detecting cancer early were based on Finnish studies. The costs of surveillance and treatment were derived from recent American studies. RESULTS: The results showed that 1) surveillance of gene carriers led to an increase in life expectancy of 7 years, and 2) the costs of surveillance under a wide range of assumptions are less than the costs of no CRC surveillance. CONCLUSIONS: CRC surveillance of HNPCC gene carriers appears to be effective and considerably less costly than no CRC surveillance and therefore deserves to be supported by governmental agencies and health insurance organizations.

Adult↗

Cosmesis and body image after laparoscopic-assisted and open ileocolic resection for Crohn's disease.

BACKGROUND: The objectives of this study were to evaluate body image, cosmetic results, and quality of life in patients with Crohn's disease of the terminal ileum who had either laparoscopic-assisted or open ileocolic resection, and to determine how patients experienced the pre- and postoperative periods after both procedures. METHODS: Thirty-four patients participated: 11 patients after open resection (OR), 11 patients after laparoscopic-assisted resection (LR), and 12 patients without resection (WR). Retrospectively, the patients filled out several questionnaires pertaining to body image, hospital experiences, and quality of life. One-way analysis of variance, Student's t-tests, and Pearson's correlation were used for statistical analysis. RESULTS: The cosmetic score was significantly higher in the LR than in the OR group (p < 0.01). Body image correlated strongly with cosmesis and with quality of life. The hospital experiences of the laparoscopic and open groups were similar. CONCLUSIONS: Laparoscopic surgery was associated with better cosmesis than open surgery. Patients do not experience laparoscopic surgery any differently from open surgery.

Adolescent↗

Activity of Crohn's disease assessed by measurement of superior mesenteric artery flow with Doppler ultrasound.

PURPOSE: To investigate the value of superior mesenteric artery (SMA) Doppler flow measurements as a marker for disease activity in patients with Crohn's disease. MATERIALS AND METHODS: Duplex Doppler sonographic measurements of SMA bloodflow volume were obtained in 90 patients with suspected or known Crohn's disease in three separate studies. The first study was a pilot study to ascertain the value of Doppler measurements in patients with proven active or inactive disease and to check our performance. In two following studies prospectively a correlation was sought between the independent assessment of Doppler flow measurements and our standard of reference based on clinical history, physical examination, laboratory values, endoscopy, surgery and/or follow-up and prospectively a correlation was sought between Doppler studies and the results of enteroclysis. RESULTS: In all but two patients (study II) adequate measurements of SMA flow were obtained. In the active patient groups the Doppler SMA flow was significantly increased (P < 0.05) compared to the inactive patient groups and the control groups. CONCLUSION: These studies show that SMA Doppler flow measurements can be used as a parameter to assess disease activity in patients with Crohn's disease.

Adolescent↗

Laparoscopic-assisted bowel resections in inflammatory bowel disease: state of the art.

The objectives of this paper are to review the rational, the present results and future of laparoscopic-assisted bowel surgery in patients with inflammatory bowel disease (IBD). Only a few centres in the world report on laparoscopic bowel resection in IBD that include stoma surgery, ileocolic resection, left, right and (sub)total colectomy for Crohn's disease, and subtotal or restorative total proctocolectomy (ileal pouch anal procedures). The combined series report conversion rates between 2.5% and 22.2%. Ileocolic resection, stoma creation, stricturoplasty and segmental small bowel resection are associated with an acceptable length of surgery, but laparoscopic(-assisted) total colectomy or restorative proctocolectomy still demand up to 4-6 hours of operative time. The few randomised studies addressing laparoscopic-assisted (segmental) bowel surgery versus conventional surgery demonstrated significantly less pain, a quicker return to self-care and a shorter hospital stay. The results of the series reporting on laparoscopic-assisted (ileo)colectomy in IBD are similar to those from these randomised studies. Laparoscopic-assisted subtotal colectomy and restorative proctocolectomy have no benefit compared with conventional surgery other than superior cosmesis. Morbidity of laparoscopic (ileo)colectomy in IBD is low, that of laparoscopic-assisted subtotal colectomy and restorative proctocolectomy remains to be seen. The various laparoscopic bowel resections done in IBD are all feasible. The first series describing laparoscopic surgery for IBD indicate that laparoscopic-assisted segmental (ileo)colectomy is safe and is the preferred approach provided it is done in a centre specialised in the treatment of IBD and by skilled laparoscopic surgeons beyond the learning curve. Until now, laparoscopic-assisted subtotal colectomy and restorative proctocolectomy do not have the same short-term benefits as seen in other laparoscopic colorectal procedures. Patients with inflammatory bowel disease (IBD) have a high life-time risk of having abdominal surgery and reoperations. The proposed advantages of laparoscopic surgery in this group of young patients might be higher than in patients with other colorectal diseases. Minimal physiologic insult in patients who already are under significant physiologic stress, less adhesion formation and superior cosmesis are important benefits over time. In a time where patient's demands will increase, the future of laparoscopic colonic surgery in IBD looks assured.

Anastomosis, Surgical↗

Superoxide dismutases in relation to the overall survival of colorectal cancer patients.

Reactive oxygen metabolites are implicated in the initiation and promotion of cancer. In addition, oxidant scavengers, such as manganese--(Mn-SOD) and copper/zinc--superoxide dismutase (Cu/Zn-SOD), are thought to contribute to colorectal cancer treatment response. In the present study, the prognostic significance of the Mn- and Cu/Zn-SOD antigen content of normal mucosa and carcinomas of 163 patients with colorectal cancer was evaluated in comparison with major clinicopathological parameters, with respect to the 5-year overall survival. The Mn-SOD content of carcinomas was found to be significantly higher than that of normal mucosa, whereas there was no difference in the Cu/Zn-SOD content between the normal mucosa and carcinomas. No association was demonstrable between the Mn-SOD and Cu/Zn-SOD content of the tissues and the assessed clinicopathological parameters (gender, age, localization, differentiation grade, diameter and Dukes' stage), with the exception of the Cu/Zn-SOD and the differentiation grade of the carcinomas. Univariate analysis showed that a high Mn-SOD content of carcinomas was associated with a poor 5-year overall survival of the patients with colorectal cancer. Multivariate analysis including all clinicopathological parameters revealed that this Mn-SOD parameter was prognostically independent. The Mn- and Cu/Zn-SOD content of normal mucosa and the Cu/Zn-SOD content of carcinomas were not associated with the overall survival of the patients. In conclusion, this study demonstrates that for patients with colorectal cancer the Mn-SOD content of colorectal carcinomas has a significant prognostic value that is independent from major clinicopathological parameters, including Dukes' stage.

Aged↗

Extracolonic manifestations of familial adenomatous polyposis: desmoid tumours, and upper gastrointestinal adenomas and carcinomas.

It is well known that patients with familial adenomatous polyposis (FAP) are at considerable risk of developing extracolonic manifestations of the disease. Particularly, desmoid tumours of the abdominal cavity, and duodenal adenomas and carcinomas are the most serious ones. It is estimated that some 10% of the FAP patients will develop desmoids, whereas 50-90% of the FAP patients will get duodenal adenomas predominantly concentrated on or around the major papilla. Desmoid tumours and duodenal carcinomas are major causes of death in those patients in whom a prophylactic (procto)colectomy has been performed. Desmoids are histologically benign tumours, composed of mature fibroblasts. They usually grow slowly but they can become quite large and may compress or infiltrate surrounding viscera, which might cause significant morbidity as well as mortality. Successful treatment of these tumours is extremely difficult as surgical therapy often requires the removal of considerable lengths of small bowel. Moreover, surgical therapy may lead to uncontrollable bleeding and is seldom radical. Chemotherapy with cytoxic agents seems promising but so far the data are too few for firm conclusions to be drawn. The same holds true for drug regimens which interfere with the metabolic and hormonal metabolism of the tumour. Although various lines of evidence suggest that the adenoma-carcinoma sequence, which is generally accepted for colorectal adenomas, also applies for the duodenal adenomas in FAP patients, it is not clear whether we should screen these patients for upper gastrointestinal adenomas or not. As these polyps are usually small, sessile, multiple and difficult to remove, the benefit of endoscopic surveillance would be the early detection of cancer rather than eradication of the polyps. In addition, evidence that screening and early treatment leads to improvement of the prognosis is not available. Although the role of (procto)colectomy in the treatment of large-bowel polyps is well established in FAP patients, the treatment of their duodenal counterparts is still open for debate. The risk of the development of periampullary cancer is not high enough to warrant an aggressive prophylactic surgical approach, i.e. a Whipple's procedure, immediately after the discovery of duodenal adenomas. The considerable morbidity and mortality rates of this procedure must be weighted against a putative benefit of screening.

Adenoma↗