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PubMed1992

The natural history of intraepithelial neoplasia: relevance to the search for intermediate endpoint biomarkers.

The development of carcinomas, defined as invasive epithelial neoplasms, is preceded by a preinvasive stage termed intraepithelial neoplasia that typically lasts for years. Intraepithelial neoplasia is the target tissue for the action of chemopreventive agents and the site where biomarkers frequently develop. The term "dysplasia" refers to the morphological alterations that characterize intraepithelial neoplasia and, according to many authors, consists of seven basic changes that are the same for the majority of epithelia. These are increased nuclear size, abnormal nuclear shape, increased nuclear stain uptake, nuclear pleomorphism (increased variation in size, shape, and stain uptake), increased mitoses, abnormal mitoses, and disordered or absent differentiation. Clonal evolution appears to begin early in the neoplastic process during intraepithelial neoplasia. The use of intraepithelial neoplasia as an intermediate endpoint biomarker requires that effective chemopreventive agents cause it to regress. Two examples are the regression of dysplastic oral leukoplakia produced by beta-carotene and the regression of colonic polyps in familial polyposis patients following treatment with the nonsteroidal antiinflammatory drug sulindac. There is a critical need to identify and develop biomarkers that correlate with the appearance and regression of intraepithelial neoplasia.

Biomarkers↗
PubMed1993

Intraepithelial neoplasia, surrogate endpoint biomarkers, and cancer chemoprevention.

Neoplasia is a progression of molecular, cellular, and tissue changes starting with a critical cell mutation and advancing by clonal evolution, involving further multiple mutations and expanding mutated clones. This process is characterized by five general stages: latency, focal growth of normal-appearing but disorganized cells, abnormal-appearing cells (dysplasia), microinvasion, and finally, metastasis. The two driving forces of neoplastic progression in an epithelium are mutagenesis and mitogenesis. These forces frequently occur concurrently, produced by exposure of the epithelium to environmental and endogenous mutagens and mitogens. The major strategy of chemoprevention is to block the effects of both mutagens and mitogens during the early stages of predysplasia and dysplasia. Surrogate endpoint biomarkers (SEBs) are tissue, cellular, and molecular changes that correlate with the later development of cancer. Because of the savings in cost, labor, and time, SEBs are urgently needed to replace the use of cancer incidence reduction as the endpoint for chemopreventive agent clinical trials. The advent of computer-assisted cytometry allows each of the seven basic criteria of dysplasia to be individually assayed as an SEB. Since the dysplastic changes that characterize intraepithelial neoplasia are embodied in the causal pathway to invasive neoplasia, they are already validated as predictors of cancer incidence. More attention should be paid to the quality control of SEB assays, including control of variation in cell composition of tissue samples, assay protocol, instrumentation used, and observer performance. The dose-response relationship between a known chemopreventive agent and the SEB should also be evaluated. The Division of Cancer Prevention and Control, National Cancer Institute, has begun a program to test chemopreventive agents in short-term Phase II clinical trials using dysplasia-based SEBs. The SEBs are assayed, when possible, by computerized cytometry. Trials are being conducted for oral leukoplakia, cutaneous actinic keratosis, superficial bladder cancer, pulmonary metaplasia/dysplasia, cervical dysplasia (CIN III), and adenomatous colonic polyps.

Animals↗
PubMed1993

Oltipraz: a laboratory and clinical review.

Oltipraz [5-(2-pyrazinyl)-4-methyl-1,2-dithiole-3-thione; RP 35972] is a synthetic, substituted 1,2-dithiole-3-thione previously used in humans as an antischistosomal agent. Cruciferous vegetables (e.g., Brussels sprouts, cabbage) contain several agents, including dithiolethiones, which appear to inhibit carcinogenesis; however, it is unclear which dietary compounds produce the protective effects. Animal studies have demonstrated that oltipraz is a potent inducer of Phase II detoxification enzymes, most notably glutathione-S-transferase (GST). Laboratory evaluations have shown that dietary concentrations of oltipraz produce marked inhibition of aflatoxin B1-induced hepatic tumorigenesis in rats. Levels of hepatic aflatoxin-DNA adducts, urinary aflatoxin-N7-guanine, and serum aflatoxin-albumin adducts decreased when biliary elimination of aflatoxin-glutathione conjugants increased, thus providing predictive biomarkers that measured a chemopreventive effect. In other animal experiments, oltipraz was found to inhibit chemically induced carcinogenesis in bladder, colon, breast, stomach, and skin cancer models. In addition, oltipraz has been shown to be non-mutagenic, a radioprotector, and a chemoprotective agent against carbon tetrachloride and acetaminophen toxicity. More recent studies in rats suggest that unsubstituted 1,2-dithiole-3-thiones may more effectively inhibit aflatoxin-induced hepatic tumorigenesis and induce electrophile detoxification enzymes. Multiple human clinical trials have been conducted using 1.0-4.5 gram doses of oltipraz over 1-3 days for the treatment of schistosomiasis. Phototoxicity has precluded its use in tropical areas. More recently, a 6 month Phase I trial was completed in which patients with resected colon polyps, or females with first degree relatives with breast cancer, were given oral daily doses of oltipraz at 125 mg or 250 mg. The maximum tolerated dose of oltipraz was < or = 125 mg daily. Grade I/II toxicities included photosensitivity/heat intolerance, GI and neurologic toxicity. Peak plasma concentrations were analyzed by HPLC with wide variability. In another Phase I study, a single oral dose of oltipraz was given to normal volunteers at dose levels of 125, 250, 375, and 500 mg. There was no significant difference in half-life (t1/2) between the four dose levels nor in clearance at the 125 and 250 mg levels. Peak oltipraz levels > or = 1.0 microgram/mL were achievable with marked interpatient variability. A series of small trials evaluating single oral doses of oltipraz for up to 28 days (dosing range 1 mg/kg-3 mg/kg/day) also showed a short t1/2 (4.1-5.3 hours), a sustained steady state without variation after a loading dose, and increased serum and urine concentrations with consumption of a high-fat diet.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed2003

Temporally and spectrally resolved fluorescence spectroscopy for the detection of high grade dysplasia in Barrett's esophagus.

BACKGROUND AND OBJECTIVES: Temporal and spectral fluorescence spectroscopy can identify adenomatous colonic polyps accurately. In this study, these techniques were examined as a potential means of improving the surveillance of high grade dysplasia (HGD) in Barrett's esophagus (BE). STUDY DESIGN/MATERIALS AND METHODS: Using excitation wavelengths of 337 and 400 nm, 148 fluorescence spectra, and 108 transient decay profiles (at 550 +/- 20 nm) were obtained endoscopically in 37 patients. Corresponding biopsies were collected and classified as carcinoma, HGD, or low risk tissue (LRT) [non-dysplastic BE, indefinite for dysplasia (IFD), and low grade dysplasia (LGD)]. Diagnostic algorithms were developed retrospectively using linear discriminant analysis (LDA) to separate LRT from HGD. RESULTS: LDA produced diagnostic algorithms based solely on spectral data. Moderate levels of sensitivity (Se) and specificity (Sp) were obtained for both 337 nm (Se = 74%, Sp = 67%) and 400 nm (Se = 74%, Sp = 85%) excitation. CONCLUSIONS: In the diagnosis of HGD in BE, steady-state fluorescence was more effective than time-resolved data, and excitation at 400 nm excitation was more effective than 337 nm. While fluorescence-targeted biopsy is approaching clinical usefulness, increased sensitivity to dysplastic changes-possibly through modification of system parameters-is needed to improve accuracy levels.

Adenocarcinoma↗
PubMed1991

Rhabdomyosarcoma associated with familial adenomatous polyposis.

We report a case of a 16 year old girl with orbital rhabdomyosarcoma who during chemotherapy developed bloody diarrhoea. On investigation she was found to have multiple colonic polyps. Cytogenetic analysis has shown a pattern typical of familial adenomatous polyposis. We present a review of the literature concerning the associations of familial adenomatous polyposis. The association of familial adenomatous polyposis with rhabdomyosarcoma has not been previously reported.

Adenomatous Polyposis Coli↗
PubMed1997

Colorectal carcinogenesis: historical review.

PURPOSE: In view of the changing concept of colorectal carcinogenesis during the last 20 years, a historical review of colorectal carcinogenesis is presented. METHODS: The changing concept of colorectal carcinogenesis was presented in four different periods: 1) carcinogenesis based on surgical materials; 2) carcinogenesis based on polypectomy materials; 3) carcinogenesis based on nonpolypoid neoplasms; 4) carcinogenesis based on molecular biology. RESULTS: In the first period, large adenomas were thought to play the most important role as precursors to colorectal carcinomas; however, in the second period, smaller and nonpedunculated adenomas were found to have a much higher malignancy potential than previously thought. The discovery of nonpolypoid neoplasms, including flat and depressed adenomas/carcinomas, shed light on the new precursor of colorectal carcinomas that were not recognized in the past. Molecular biology clarified a lack of K-ras mutation in nonpolypoid, particularly depressed, neoplasms, suggesting the presence of a novel pathway of colorectal carcinogenesis, different from that in polypoid neoplasms. CONCLUSIONS: The concept referred to as the "adenoma-carcinoma sequence" changed because colonoscopic polypectomy specimens were studied, and rather small, nonpedunculated adenomas were found to play an important role as precursors of colorectal carcinomas. The discovery of nonpolypoid neoplasms provides us with new precursors of colorectal carcinomas. The genetic alterations in nonpolypoid neoplasms seem to differ from those in polypoid neoplasms, and genetic alterations in so-called de novo carcinomas need to be clarified.

Adenomatous Polyps↗
PubMed1990

Erythrocyte stearic acid desaturation in patients with colorectal carcinoma.

The erythrocyte stearic:oleic acid ratio (saturation index) was investigated as a means of differentiating between control subjects (n = 146) and patients with benign (n = 48) and malignant (n = 117) colorectal disease and patients undergoing postoperative follow-up after curative resection (n = 49). Erythrocyte fatty acid profiles were determined by gas liquid chromatography. Neither age, sex, Dukes' stage, nor degree of differentiation of the tumors had a significant effect on the erythrocyte saturation index. The erythrocyte saturation index was lower in patients with primary and recurrent colorectal cancer compared with control subjects and patients with inflammatory bowel disease or benign colonic polyps (P less than 0.0001). The erythrocyte saturation index was not found to be useful in the postoperative follow-up of these patients. Using both saturation index and age as a means of differentiating between patients with primary colorectal cancer and control subjects gave a sensitivity of 67 percent and a specificity of 81 percent.

Adult↗
PubMed1997

Thyroid neoplasia and familial adenomatous polyposis/Gardner's syndrome.

This study was conducted to clarify the actual morbidity and clinicopathologic features of thyroid neoplasia in patients with familial adenomatous polyposis. We analyzed the clinical records of 49 Japanese patients with familial adenomatous polyposis diagnosed at our institute. Six of these patients had thyroid neoplasias (3 carcinomas, 2 adenomas, and 1 of unknown histology). Among 17 patients (11 men and 6 women) who had been examined by thyroid ultrasonography or in whom postmortem examination was performed; we categorized 6 patients with thyroid tumor as the TT group, and the remaining 11 without thyroid tumor as the NTT group. The clinical features of the two groups were compared. Thyroid neoplasia was detected by physical examination in 2.3% of 43 patients so examined and was detected in 25% of 8 patients examined by thyroid ultrasonography, and in 44% of the 9 patients subjected to postmortem examination. There were no significant differences between the TT and NTT groups in gender; age at first admission, colectomy, and last follow-up visit; number of colonic polyps; or in presence of colorectal cancers, gastroduodenal adenomas, gastric fundic gland polyposis, retinal pigmented lesions, or extraintestinal tumors. The thyroid gland is frequently affected in patients with familial adenomatous polyposis, but there may be no association between thyroid neoplasia and other clinical manifestations.

Adenomatous Polyposis Coli↗
PubMed2003

Diagnosis and treatment of acromegaly complications.

The Pituitary Society in conjunction with the European Neuroendocrine Association held a consensus workshop to develop guidelines for diagnosis and treatment of the co-morbid complications of acromegaly. Fifty nine pituitary specialists (endocrinologists, neurosurgeons and cardiologists) assessed the current published literature on acromegaly complications in light of recent advances in maintaining tight therapeutic control of GH hypersecretion. The impact of elevated GH levels on cardiovascular disease, hypertension, diabetes, sleep apnea, colon polyps, bone disease, reproductive disorders, and neuropsychologic complications were considered. Guidelines are proposed for effective management of these complications in the context of overall acromegaly control. When appropriate, requirements for prospective evidence-based studies and surveillance database development are enunciated. Effective management of co-morbid acromegaly complications will lead to improved morbidity and mortality in acromegaly.

Acromegaly↗
PubMed2006

The use of preoperative endoscopic tattooing in laparoscopic colorectal cancer surgery for endoscopically advanced tumors: a prospective comparative clinical study.

BACKGROUND: Endoscopic India ink marking techniques are often used for the intraoperative location of colonic polyps and early stage neoplasms. The aim of this study was to compare how effective this technique is compared with conventional localization methods, as well as its influence on the results of colorectal laparoscopy (LSCRC) for endoscopically advanced tumors. METHODS: From January 2003 to January 2005, 47 patients with colorectal carcinomas were included in the study. In one group, lesions were localized preoperatively by endoscopic India ink tattooing (n = 21; tattooed group, TG), while conventional methods were used in the others (n = 26; non-tattooed group, NTG). Patients' perioperative clinical and pathoanatomical data were prospectively collected. RESULTS: Both groups were comparable in age, sex distribution, American Society of Anesthesiologists (ASA) score, body mass index (BMI), technique performed, tumor size and proportion of patients who had previous abdominal surgery. Three patients presented ink spillage without clinical repercussions. Visualization of the correct resection site was higher in the TG (100% vs. 80.8%, P = 0.03). Operative time (147.3 +/- 46.2 vs. 187.0 +/- 52.7 minutes, P = 0.02) and blood loss (99.3 +/- 82.8 vs. 163.6 +/- 96.6 cc, P = 0.03) were lower in the TG. There were no differences between groups regarding peristalsis, introduction of oral intake, hospital stay or intra- and postoperative complication rates. No differences were observed amongst pathoanatomical data studied. CONCLUSIONS: Preoperative endoscopic tattooing is a safe and effective technique for intraoperative localization of advanced colorectal neoplasms, improving the operative results of LSCRC.

Aged↗
PubMed2001

Laparoscopic autopsies.

BACKGROUND: In recent years, autopsy consent rates have fallen nationwide. In our institution they have declined from 15% to 7% in 10 years. We perceived that family reluctance to grant permission for autopsy was related to the invasiveness of the open procedure, so we began to do autopsies by needle biopsy, with an increase in consents to 25% during the first year. However, the procedure is inherently inaccurate, so we recently have introduced minimally invasive laparoscopic autopsy. METHODS: From July through October 1999, needle biopsy was performed on 25 patients who died at our institution, which was followed by laparoscopic evaluation. Consent for full conventional autopsy had been granted in nine cases, and these then were performed. Data from these autopsies were compared with those from the laparoscopic procedures. RESULTS: Of the patients for whom consent was obtained for open autopsy, there was complete agreement as to cause of death between the laparoscopic and conventional procedures. In one case, a liver hemangioma was missed by laparoscopy, and in two other cases, colon polyps were not discovered. Biopsies of internal organs were accurately performed on the pancreas, kidneys, and adrenals, all of which had been troublesome for needle biopsy alone. CONCLUSIONS: Laparoscopic autopsy is much more acceptable to the families of patients than the conventional form, resulting in a higher consent rate. On the basis of our study group, this procedure provides accurate data concerning the cause of death. In addition, performing these autopsies gives surgical residents invaluable training in laparoscopic skills.

Adult↗
PubMed2000

Colonoscopy in octogenarians and older patients.

INTRODUCTION: Colonoscopy in the elderly has been considered by many to be risky because of mechanical bowel preparation and dehydration, electrolyte disturbances, conscious sedation, and hypoxic complications. We hypothesized that colonoscopy in octogenarians and older patients is a safe procedure. MATERIALS AND METHODS: A retrospective review of 803 patients who underwent colonoscopy from January 1997 to October 1997 was performed. The patients were grouped by age: group A (17-49 years) had 166 patients (20%); group B (50-79 years) had 534 patients (67%); and group C (80 years and older) had 103 patients (13%). Results were considered significant at p value less than 0.05 unless otherwise noted. RESULTS: Blood in the stool (84%) and history of colonic vascular disease (5.8%) were the most common indication in group C (84%). Colonoscopy was used in group A (18%) more often than in the other groups to rule out inflammatory bowel disease. History of colon polyps was a more common indication in group B (20%) than in the other groups. Group A had a significantly higher incidence of normal examinations (84%) and diagnosis of inflammatory bowel disease (14%). Group B had a higher incidence of polyps than the other groups. Group C had the highest incidence of vascular disease (15%). Diverticular disease and carcinoma were more common in groups B (37%) and C (52%). The amount of sedation in the groups did not significantly differ. Completion of the colonoscopy to the cecum or anastomotic sites did not differ among the groups (p > 0.05), nor did complication rates among groups (p > 0.05). CONCLUSIONS: Colonoscopy is safe in octogenarians and older patients. Age does not, by itself, confer an increased risk to the procedure.

Adolescent↗
PubMed2001

A prospective analysis of 13,580 colonoscopies. Reevaluation of credentialing guidelines.

BACKGROUND: The aims of this study were to assess the safety and efficacy of surgeons performing colonoscopy, and to use the results to reevaluate currently available credentialing guidelines. METHODS: A prospective outcomes study was designed to include all members of the Society of American Gastrointestinal Endoscopic Surgeons (SAGES). End points were related to the efficacy and safety of colonoscopy. Credentialing guidelines were reviewed. RESULTS: Between April 1998 and September 1999 13,580 colonoscopies were prospectively entered into a database. The most common indications were rectal bleeding, colonic polyps, and change in bowel habits. The colonoscopy was normal or revealed only diverticulosis or nonspecific inflammation in 8,473 (62.4%), lower gastrointestinal bleeding in 4 (0.03%), polyps in 4,645 (34.2%), and tumors in 458 (3.4%) patients. The most common biopsy methods for polyps or tumors were the snare (n = 1,728; 34%), the hot (n = 1,600; 31%), and the cold (n = 1,340; 22%) procedures. The colonoscopy was complete in 12,495 cases (92%), requiring a mean procedure time of 22.7 min (range, 1-170 min). Intraprocedural complications included arrhythmia (n = 14; 0.1%), bradycardia (n = 115; 0.8%), hypotension (n = 171; 1.2%), and hypoxia (n = 806; 5.6%). Postprocedural complications were seen in 27 patients (0.2%). Bleeding (n = 10; 0.07%) was managed by observation alone (n = 9; 0.06%) and repeat colonoscopy with transfusion (n = 1; 0.01%). Perforation (n = 10; 0.07%) was treated successfully by observation with conservative management (n = 5; 0.05%) and surgery (n = 5; 0.05%); severe abdominal pain (n = 4; 0.03%) was managed by observation and conservative therapy; and bronchospasm (n = 2; 0.015%) was managed by observation and supportive care. One single mortality (0.007%) was that of a 70-year-old man with a massive lower gastrointestinal hemorrhage who had a cardiac arrest in the recovery room following colonoscopy. The complication rate was not significantly associated statistically with either the level of experience or the number of prior or annual colonoscopies. However, prior colonoscopic experience did have an impact on the completion rate (p < 0.001) and was inversely proportional to the time to completion (p < 0.001). Similarly, the number of annual colonoscopies affected the completion rate and was inversely correlated with the time to completion (p < 0.001). CONCLUSIONS: This large prospective outcomes study showed that colonoscopy performed by surgeons can be rapidly and successfully done with acceptably low morbidity and mortality. There was no association between experience and complications. However, a minimum of 50 prior colonoscopies and 100 annual colonoscopies were associated with a significant improvement in the rate of completion. There was also a significant correlation between both prior and ongoing annual experience and the time required for the examination. No minimum number of cases can be mandated for credentialing to perform "safe" colonoscopies.

Clinical Competence↗
PubMed2006

Anal canal carcinoma with Pagetoid spread: report of a case.

A 70-year-old man with a history of colon polyps was found to have a semipedunculated polyp in the anal canal. The patient was asymptomatic. The lesion was 14 mm in diameter and located 5 mm from the dentate line. Histological examination of biopsy specimens revealed well-differentiated adenocarcinoma of the anal canal. During transanal local excision of the tumor, an abnormality of the perianal skin was recognized. Although intraoperative frozen section of the perianal skin did not show malignancy, permanent sections of the perineal skin revealed Paget's cells in the epidermis. Pathological examination of the anal canal carcinoma revealed submucosally invasive well-differentiated adenocarcinoma with a positive distal surgical margin. Thus, we performed additional wide local excision of the perianal skin including the distal margin of the previous local excision. Pathological examination revealed continuance within the epidermis between the anal canal adenocarcinoma and Paget's cells in the perianal skin lesion. Scattered Paget's cells also formed some glandular structures. Thus, we concluded that the perianal skin lesion was Pagetoid spread of anal canal adenocarcinoma. This report shows that the perianal skin should be examined carefully in patients with anal canal carcinoma.

Adenocarcinoma↗
PubMed1999

Histopathologic criteria for local excision of colorectal cancer: multivariate analysis.

BACKGROUND: Local treatment of colorectal cancer, including endoscopic removal of colonic polyps and transanal resection of rectal tumors, has become widely accepted. However, risk factors predicting the presence of lymph node metastasis have not been fully investigated. To determine the criteria for local excision of colorectal cancer, histopathologic factors independently predicting the lymph node metastasis were investigated. METHODS: We performed a retrospective histopathologic study on 335 patients who underwent resection of colorectal cancer and dissection of regional lymph nodes between 1982 and 1996. Features of node-positive tumors (n = 150) were compared with those of node-negative tumors (n = 185), with special reference to the histopathologic findings of the resected tumor. Multivariate analysis was done using the stepwise logistic regression test. RESULTS: Node-positive tumors, when compared with node-negative tumors, were characterized by tumor larger than 6 cm (42% vs. 22%), serosal invasion (88% vs. 56%), lymphatic invasion (32% vs. 5%), venous invasion (9% vs. 2%), and histology other than well-differentiated (66% vs. 29%). Multivariate analysis showed that factors independently associated with lymph node metastasis were serosal invasion, lymphatic invasion, and histologic type. When these three risk factors were negative, lymph node metastasis was rare (5%). When one, two, or three factors were positive, the frequency of lymph node metastasis was 38%, 66%, and 85%, respectively. CONCLUSIONS: In colorectal cancer, factors independently associated with lymph node metastasis are serosal invasion, lymphatic invasion, and histologic type. When these three parameters are favorable, local treatment of colorectal cancer does not require additional lymph node dissection.

Colorectal Neoplasms↗
PubMed2005

A comparison of the phenotype and genotype in adenomatous polyposis patients with and without a family history.

OBJECTIVES: Adenomatous polyposis of the colon is often secondary to an inherited mutation in adenomatous polyposis coli (APC) gene, however, approximately one third of patients have no family history of the disease. We studied the phenotype and genotype of adenomatous polyposis in patients without a family history. METHODS: A cohort of 57 unrelated adenomatous polyposis patients were evaluated. Seventeen patients with no family history were compared with 40 patients who had a positive family history of the disease. Family history and medical records were collected and analyzed. Germline APC and Mut Y homologue (MYH) testing was undertaken. RESULTS: Patients without a family history were diagnosed with polyposis at an older age (41 years vs. 32 years) and presenting more frequently with symptoms (76 vs 20, P < 0.05). The number of colonic polyps and frequency of extracolonic manifestation associated with adenomatous polyposis did not differ between the two groups. APC mutations were detected less frequently among patients without a family history of the disease (4 out of 17 vs 25 out of 40, P=0.007), even among those with greater than 100 colorectal adenomas (4 out of 12 versus 21 out of 29, P=0.03). One homozygous MYH mutation carrier (G382D) was detected among the six patients without a family history and without a germline APC mutation who were tested. CONCLUSIONS: Adenomatous polyposis patients without a family history are usually diagnosed with symptoms, and at a later age. Phenotypically, they are similar to those with a family history. However, germline APC mutations are detected far less frequently in patients without a family history. A small percentage of these cases may be secondary to biallelic germline MYH mutations.

Adenomatous Polyposis Coli↗