Characteristics of Advanced- and Non Advanced Sporadic Polypoid Colorectal Adenomas: Correlation to KRAS Mutations

The malignant potential of colorectal adenomas highly correlates with their pathological characteristics, such as size, histology and grade of dysplasia. Currently, based on these parameters, adenomas are characterized as "non-advanced or advanced" and patient surveillance is adjusted accordingly. The aim of this study was to investigate the correlation between the KRAS mutations and characteristics of non-advanced and advanced colorectal adenomas for predicting the risk of increased malignant potential of adenomas that may influence the decision to offer follow-up endoscopic surveillance. We used a mutagenic polymerase chain reaction - restriction fragment length polymorphism method to determine KRAS mutations in 164 colorectal sporadic polypoid adenomas (51 non-advanced-, 113 advanced adenomas) and in 40 early colorectal carcinomas. The method of mutation detection was validated according to recommendation for KRAS mutation testing in colorectal carcinoma of the European Quality Assurance Program. The limit of detection of the assay was 3?% mutated DNA with a good reproducibility. Evaluation of pathological characteristics was performed according to European Guidelines for Quality Assurance in Colorectal Cancer Screening and Diagnosis. The morphological parameters of the adenoma such as size, histology, grade of dysplasia are highly correlated with one another: an increasing adenoma size raised the proportion of villous histology and degree of dysplasia (all p?相似文献   

Depressed adenoma of the duodenum in patients with familial adenomatous polyposis: endoscopic and immunohistochemical features.

BACKGROUND: Depressed neoplastic lesions of the colorectum have been specified in patients with familial adenomatous polyposis (FAP). The aim of this study was to characterize endoscopic, histologic, and immunohistochemical features of depressed adenoma of the duodenum in patients with FAP. METHODS: Duodenoscopy was performed on 25 patients with FAP, and the neoplastic nonampullary lesions were classified as polypoid or depressed adenomas. The grade of dysplasia, the proliferative activity determined by Ki-67 labeling index (LI), and the grade of p53 expression were compared between polypoid and depressed neoplasia. RESULTS: Ten subjects had depressed nonampullary adenoma, whereas polypoid adenoma was found in the remaining 15 subjects. Moderate dysplasia was more frequent in depressed adenoma than in polypoid adenoma (70% vs. 27%, P = 0.04). Whereas p53 expression was not different between the two adenoma groups, the LI was significantly higher in depressed adenoma than in polypoid adenoma (59.7 +/- 9.5 vs. 47.5 +/- 10.7, P < 0.01). CONCLUSIONS: Depressed adenoma of the duodenum is a distinctive phenotype of duodenal neoplasm in patients with FAP. The high proliferative activity of depressed adenoma suggests that there may be a need to survey FAP patients with such lesions intensively.     

68例大肠侧向发育性肿瘤内镜下腺管开口类型与病理的对比研究

目的：研究大肠侧向发育性肿瘤（tST）染色内镜下LST腺管开口类型和病理检查结果的对应关系,评估内镜下判定LST腺管开口类型对治疗和预后的临床意义。方法：所有68例病例均应用染色内镜技术检出LST,后进行内镜下IST切除,同时回收标本进行病理检查。结果：LST发生在直肠的28例,乙状结肠12例,降结肠6例,横结肠5例,升结肠9例,盲肠8例。病理分型和内镜肉眼所见对比分析,24例腺瘤型LST中,肉眼所见颗粒均一型占70．83％,结节混合型8．33％,平坦隆起型20．83％,假凹陷型为O％;37例绒毛管状腺瘤中肉眼见结节混合型占54．05％,颗粒均一型占43．24％,平坦隆起型2．7％,凹陷状为O％;7例黏膜内癌中颗粒均一型为28．57％,结节混合型71．43％,平坦隆起型和假凹陷型为0。内镜肉眼所见颗粒均一型的腺管开口分型依次为Ⅲ。．型占45．71％,IV型占37．14％,V。型占5．71％,结节混合型以Ⅳ为主占59．26％,平坦隆起型以Ⅲ,．型为主83．33％。内镜下病理分型腺瘤型的IST中腺管开151类型以Ⅲ。型为主占87．5％,绒毛管状腺瘤型的腺管开口以Ⅳ为主占72．97％,黏膜内癌以V．型开口为主占71．43％。结论：LST好发部位为左半结肠,腺管开口类型和病变的组织病理类型有一定关系,尤其是腺管开口V,型具有较高的癌变率。判定LST腺管开口类型对指导内镜下的病理活检部位和数量,治疗方案选择以及预后有一定的临床意义。     

Correlation of polypoid colorectal adenocarcinoma with pre-existing adenomatous polyps and KRAS mutation

Cetuximab is an anti-epidermal growth factor receptor that helps effectively treat patients with advanced colorectal adenocarcinoma without KRAS activating mutations. KRAS mutations are associated with 16% to 50% of isolated villous adenomas and approximately 30% of colorectal cancer. Correlation between the gross and histological subset of colorectal adenocarcinoma with KRAS mutation is unknown. Archived surgical resection specimens of colorectal adenocarcinoma (n = 42) and villous adenoma (n = 9) were collected. The gross appearance and histopathological features of these lesions were thoroughly reviewed, including the presence of a pre-existing adenomatous polyp. DNA was extracted from formalin-fixed, paraffin-embedded tissue sections and then subjected to TaqMan real-time polymerase chain reaction to detect the seven most common KRAS mutations. KRAS mutations were found in 13 of 42 cases (31%) of colorectal adenocarcinoma and 7 of 9 cases (78%) of villous adenoma. All 13 cases of colorectal carcinoma with a KRAS mutation showed a gross polypoid configuration, compared to no KRAS mutation in the colorectal carcinomas with ulcerative configuration. In addition, 13 of 17 of these cases (76%) had histological features of adenocarcinoma with a persistent preexisting adenomatous polyp with villous architecture. In summary, grossly polypoid colorectal adenocarcinomas with a persistent pre-existing adenomatous polyp with villous architecture are strongly associated with KRAS mutations.     

Classification of advanced colorectal carcinomas by tumor edge morphology: evidence for different pathogenesis and significance of polypoid and nonpolypoid tumors

BACKGROUND: Increasing evidence suggests that a substantial proportion of colorectal carcinomas develop without a preexisting polypoid adenomatous lesion, but it is difficult to detect the possible origin of advanced carcinomas. The purpose of this study was to test the validity and significance of a new histopathologic classification system based on the histologic analysis of the tumor edge. METHODS: One hundred eighty-six unselected cases of colorectal carcinoma were included. A new classification method to distinguish polypoid and nonpolypoid growth type was based on the presence or absence of elevation of tumor as compared with adjacent mucosa. Inter- and intraobserver agreement of classification was tested. Association with other clinicopathologic features including histopathologic characteristics of the tumors, presence or absence of lesional and concurrent adenoma, K-ras mutations, and prognosis was evaluated. RESULTS: Classification could be made in 75% of the tumors, and 25% were unclassifiable, mostly due to absence of tumor margin in sections. Of the classifiable carcinomas, 45% were classified as polypoid, of which 52% had lesional adenoma. Nonpolypoid tumors formed 48% of classifiable cases, and only 2% had lesional adenoma. Features of both polypoid and nonpolypoid carcinomas were present in 7% of cases. Concurrent extralesional adenomas were found more frequently in association with polypoid carcinomas. K-ras mutations were more common in polypoid (43%) than in nonpolypoid tumors (8%; P = 0.018). Nonpolypoid carcinomas were significantly (P = 0.03) more aggressive than polypoid carcinoma, with 38% and 20% recurrence rates, respectively. CONCLUSIONS: The authors' results indicate that advanced colorectal carcinomas can be classified according to growth pattern by observing the tumor edge. This classification has prognostic significance because nonpolypoid carcinomas appeared to have a worse prognosis than polypoid ones.     

Recurrences of adenomas of the large intestine

A retrospective mathematic-statistical evaluation of cases of adenoma of the large intestine--asymptomatic (group 1) or bleeding one (group 2)--showed the frequency and pattern of recurrence and malignant transformation following electrocoagulation to be identical in both groups. Such change in the histologic type as transformation of tubular polyps to a villous pattern proved to be an important factor of risk for relapse and neoplastic growth of solitary adenoma of the large intestine. Villous adenoma showed the highest rate of recurrence and malignant transformation. It is considered to be obligatory precancer.     

Giant Brunner's gland adenoma as an unusual cause of anaemia: report of a case

BACKGROUND: Brunner's gland adenoma (BGA) is a rare benign duodenal tumour proliferating from Brunner's glands. Here, we present a giant BGA leading to anaemia, with its clinical, endoscopic, radiological, surgical and pathological findings. CASE REPORT.: A 48-year-old Turkish man complained of a six months history of vague epigastric discomfort, loss of appetite and nausea after meals without vomiting. The physical examination had no unremarkable finding. Laboratory findings, including liver function tests, were within normal limits except a hypochromic, microcytic anaemia. The upper gastrointestinal endoscopic examination revealed a lobulated, red, polypoid tumour with a smooth surface covered with normal mucosa. The tumour was located on the anterior surface of duodenal bulb and had a wide base measuring 3.5 × 4 cm in size. Endoscopic ultrasonography revealed a submucosal polypoid mass located at the anterior surface of duodenal bulb. The endoscopic excision was tried but was not successful. The patient was operated and transduodenal polypectomy was done. The postoperative period was uneventful and the pathologic diagnosis was assessed as Brunner's gland adenoma. During the follow-up period, the endoscopic examination was normal at 12th month postoperatively. CONCLUSIONS: BGA is a rare benign cause of anaemia that can be treated with excellent results.     

Predictors of metachronous colorectal neoplasms in sporadic adenoma patients

Our objective was to assess the overall risk of subsequent colorectal neoplasms (cancer or adenoma) in relation with the various characteristics of the index lesion in a cohort of patients who underwent endoscopic polypectomies of colorectal adenomas. A total of 1086 patients with adenomas of the large bowel were reported between 1979 and 1999 at the National Cancer Institute of Milan during a screening program for colorectal carcinoma. Data on patients who had colonoscopic examinations and treatments were collected prospectively. The relation between colorectal cancer (CRC) and adenoma features was assessed by computing the hazard ratio (HR) values and corresponding confidence intervals (95% CI) according to Cox proportional hazard models. Of the 1086 eligible patients (487 females, 579 males), 736 had single adenomas (67.7%) and 350 had multiple adenomas (32.3%). Histologic examination revealed 772 cases of tubular adenoma (73%), 205 cases of tubulovillous adenoma and 80 cases of villous adenoma (7.5%). Severe dysplasia was found in 3.3% of the cases. During the 11393 person-years of follow-up, with an average time of surveillance of 10.5 years, colorectal carcinomas developed in 10 patients (0.8%) and a new adenoma in 323 patients (29%). Multivariate analysis showed that male gender (HR 1.6; 95% CI 1.3-2.0), multiple polyps (HR 1.6; 95% CI 1.3-2.0), polyps larger than 2 cm (HR 1.5; 95% CI 1.1-2.1), tubulovillous and villous histology (HR 1.3; 95% CI 1.0-1.6 and HR 1.8; 95% CI 1.2-2.6, respectively) at index polypectomy were statistically significant risk factors for developing metachronous adenomatous polyps. The standardized incidence rates (SIR) for CRC was 0.52 (95% CI 0.25-0.95). The SIR was increased in subjects with severe dysplasia (2.8; 95% CI 0.34-1.02). Some features of large bowel adenomas are strongly correlated with an increased risk of metachronous adenomas and colorectal cancer. However, the endoscopic polypectomy is able to reduce by 50% the incidence of CRC in patients with large bowel adenomas.     

Colorectal adenomas: clinical and morphological aspects. A review of 166 polyps from 124 Dutch patients

In a series of 124 consecutive Dutch patients the clinical and morphological features of 166 endoscopically removed colorectal adenomatous polyps were reviewed. The most frequent clinical symptom was manifest blood loss with the stools (51%), but no specific adenoma symptom seemed to exist. Barium enema X-ray examination was done in 108 patients, whereas all patients were colonoscoped. The routinely performed barium examinations detected 71% of the polyps that were found during endoscopy, but not all X-ray examinations were air contrast barium enemas. A good correlation between the localization of the adenomas after both diagnostic modalities was found, indicating that more than 80% were located in the left part of the colon. Nineteen percent of the patients had had a metachronous (pre)neoplastic lesion removed from their large bowel previously, while 40% of the patients had a synchronous polypoid lesion at the moment of polypectomy. Sixty-two percent of the adenomas were tubular, whereas 38% were villous adenomas. There was a strong correlation between size and villous architecture (r = 0.38; p less than 0.001). The epithelial dysplasia was mild in 21%, moderate in 70% and severe in 9% of the adenomas. The degree of dysplasia correlated well with the villous type of mucosal growth (r = 0.24; p less than 0.005). These findings indicate that, 1) there are no colorectal adenoma specific symptoms, 2) to detect colorectal adenomas colonoscopy is the investigation of choice, 3) after the detection of a colorectal adenoma the whole colon should be investigated, 4) colorectal adenoma patients should be kept under surveillance, and 5) determination of the diameter and of the degree of epithelial cell dysplasia may be helpful in assessing the biological behavior of an adenomatous polyp.     

Adenomatous lesions of the large bowel: an autopsy survey.

A comprehensive autopsy survey of the large bowel showed that adenomas were very common lesions occurring in about one-half of the 518 cases studied. The great majority were small adenomatous polyps (tubular adenomas), 86.7% measuring less than 10 mm in diameter. Adenomas with a more complex tubulovillous pattern were larger with a mean diameter of 19.0 mm. There was no apparent incresae in mean size of adenomas with age. Nineteen clinically unsuspected cancers were discovered. Fourteen (8 in situ and 6 invasive) cancers had areas of residual benign adenoma. Five invasive cancers had no residual benign component. No in situ carcinomas or small (less than 10 mm) invasive cancers not containing residual adenoma were found. The results suggest that, although adenomas of the large bowel are very common, the vast majority are simple adenomatous polyps which do not undergo progressive growth and malignant change. Conversely, it appears that cancers may arise from benign adenomas which have the characteristics of large size and a more complex villous architecture.     

Nup88 expression in normal mucosa, adenoma, primary adenocarcinoma and lymph node metastasis in the colorectum.

OBJECTIVES: It was the aim of this study to investigate Nup88 expression in normal colorectal mucosa, adenoma, adenocarcinoma and lymph node metastasis, as well as the relationship between Nup88 expression and clinicopathological features. METHODS: Nup88 expression was examined by immunohistochemistry in 84 normal mucosa samples, 32 adenomas, 181 primary adenocarcinomas, and 18 lymph node metastases from colorectal tumour patients. RESULTS: Nup88 expression was observed in normal epithelial and tumour cells. The frequency of strong Nup88 expression was increased from normal mucosa or adenoma to primary tumour and lymph node metastasis (p < 0.0001). There was no significant difference in the expression between normal mucosa and adenoma (p = 0.41). The frequency of strong Nup88 expression was higher in ulcerated tumours (40%) than in polypoid/large fungating tumours (23%; p = 0.048). The frequency of strong Nup88 expression was significantly different among tumours with good (21%), moderate (42%) and poor differentiation (48%; p = 0.01). Nup88 expression was not related to the patients' gender, age, tumour location, size, histological type, invasive depth, lymph node status and Dukes stage (p > 0.05). CONCLUSION: Our results suggest that Nup88 may play a role during the development, aggressiveness and differentiation of colorectal tumours.     

Clinicopathological features of elevated lesions of the duodenal bulb

We present here our findings on patients with an elevated lesion of the duodenal bulb. All these patients were treated in our clinics between the years 1984 and 1988. These lesions were present in 36 of 8,802 patients who underwent upper gastrointestinal pan-endoscopy. Two patients had a duodenal carcinoma, 2 an adenoma, and 1 a Brunner's gland adenoma. There were 15 with a hyperplastic polyp, 3 with a heterogenic gastric mucosa, 3 with Brunner's gland hyperplasia, 6 with duodenitis, and 4 with regenerative mucosa. Among these 36 lesions, only 69% (25 lesions) were evident on the upper gastrointestinal X-ray series. Adenoma and Brunner's gland adenoma were of a pedunculated form of the gross type and had an irregular surface mucosa. Both duodenal carcinomas were detected by endoscopic biopsy and were resected. Histologically, these lesions were limited to the submucosal layer and were of the non-pedunculated polypoid form, but there were no other characteristic endoscopic features, in comparison with other elevated lesions. Thus, upper gastrointestinal endoscopy with routine observations of the duodenal bulb plus endoscopic biopsy will lead to a definite diagnosis of these elevated lesions and to the early detection and treatment of this rare malignant lesion.     

Nucleotide excision repair gene polymorphisms and risk of advanced colorectal adenoma: XPC polymorphisms modify smoking-related risk.

OBJECTIVES: Nucleotide excision repair enzymes remove bulky damage caused by environmental agents, including carcinogenic polycyclic aromatic hydrocarbons found in cigarette smoke, a risk factor for colorectal adenoma. Among participants randomized to the screening arm of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, we studied the risk of advanced colorectal adenoma in relation to cigarette smoking and selected single nucleotide polymorphisms (SNP) in the nucleotide excision repair pathway.METHODS: Cases (n = 772) were subjects with left-sided advanced adenoma (>1 cm in size, high-grade dysplasia, or villous characteristics). Controls (n = 777) were screen-negative for left-sided polyps by sigmoidoscopy. DNA was extracted from blood samples and 15 common nonsynonymous SNPs in seven-nucleotide excision repair genes [XPC, RAD23B (hHR23B), CSB (ERCC6), XPD (ERCC2), CCNH, XPF (ERCC4), and XPG (ERCC5)] were genotyped.RESULTS: None of the studied SNPs were independently associated with advanced adenoma risk. Smoking was related to adenoma risk and XPC polymorphisms (R492H, A499V, K939Q) modified these effects (P(interaction) from 0.03-0.003). Although the three XPC variants were in linkage disequilibrium, a multivariate logistic regression tended to show independent protective effects for XPC 499V (P(trend) = 0.06), a finding supported by haplotype analysis (covariate-adjusted global permutation P = 0.03).CONCLUSIONS: Examining a spectrum of polymorphic variants in nucleotide excision repair genes, we found evidence that smoking-associated risks for advanced colorectal adenoma are modified by polymorphisms in XPC, particularly haplotypes containing XPC 499V.     

结肠肿瘤性病变单克隆抗体MC3的表达及其与异型粘液分泌的关系

本文应用抗人结肠癌单克隆抗体MC_3对32例结肠腺病性息肉。11例绒毛状腺病,18例结肠腺瘤伴不典型增生和36例结肠腺癌组织进行了PAP免疫组织化学染色,并同时采用醛复红—阿辛蓝(AF/AB)复合染色法,观察了结肠癌异型粘液分泌与MC_3表达的关系。结果表明,MC_3主要为结肠肿瘤的标记癌组织MC_3表达有三种类型即腺腔型腔缘型和细胞型、前两型表达亦见于结肠腺瘤,其中腺瘸性息肉和绒毛状腺瘤MC_3表达的阳性率存在差异。本文还观察到癌组织MC_3表达的类型与强度癌细胞分泌非硫酸粘液有一定关系。 本文提示MC_3与结肠肿瘤细胞的分泌有关,并可将其用于结肠癌细胞生物学特性研究及结肠肿瘤的辅助诊断。     

28例低位直肠绒毛状腺瘤癌变局部切除治疗经验

目的：探讨合理选择治疗低位直肠绒毛状腺瘤癌变的手术方式。方法：回顾性分析我院28例经局部切除治疗的低位直肠绒毛状腺瘤癌变的临床资料，并加以讨论。结果：经肛局部切除(transanal excision，TE术)20例．经骶局部切除(Kraske术)8例。术后病理高、中分化腺癌27例，低分化腺癌1例；肿瘤浸润粘膜层13例，浸润粘膜下层12例，浸润肌层3例。术后复发4例，转移2例，5年生存率78.6％(22／28)。结论：直肠绒毛状腺瘤癌变恶性程度低，对于病变位于低位直肠的患者，只要符合适应证，则局部切除术既可以达到根治术的疗效，又能保留正常排便功能，提高患者生存质量。     

Prevalence of proximal adenomas after an adenoma is found on flexible sigmoidoscopy

BACKGROUND: Adenomatous polyps are a precursor of colorectal cancer and a frequent finding on screening flexible sigmoidoscopy (FS). Performance of colonoscopy when a diminutive (<6mm) adenoma is found on FS has been the subject of considerable debate. METHODS: We retrospectively reviewed the data from our colorectal cancer screening program for patients with adenoma(s) found on FS. Patients were divided into three groups based on FS findings: (1) an adenoma <6mm in size, (2) multiple non-advanced adenomas or an adenoma 6-10mm in size, or (3) advanced adenoma defined as an adenoma >10mm or with villous histology or high-grade dysplasia or cancer. A comparison of the proximal findings was then made. RESULTS: 5291 FS reports were reviewed with 606 (12%) patients having at least one adenoma. Colonoscopy reports were available in 550 patients. Of the 258 patients with a diminutive distal adenoma, 69 (27%) had a proximal adenoma and 13 (5%) had an advanced proximal adenoma on colonoscopy. Of the 164 patients with an adenoma 6-10mm or multiple non-advanced adenomas, 59 (36%) had a proximal adenoma and 13 (8%) had an advanced proximal adenoma. Of the 128 patients with a distal advanced adenoma, 58 (45%) had a proximal adenoma and 15 (12%) had an advanced proximal adenoma. The increase in proximal adenomas across the three groups was significant (P=0.001), and there was a trend for increased prevalence of advanced adenomas (P=0.061). CONCLUSIONS: The prevalence of proximal adenomas increased significantly with more advanced lesions found distally at FS, and there was a trend towards a higher prevalence of advanced proximal adenomas. Based on current guidelines, flexible sigmoidoscopy is a screening option that can be used to identify average-risk patients at increased risk of proximal neoplasia.     

Family history of colorectal cancer: A determinant of advanced adenoma stage or adenoma multiplicity?

A family history of colorectal cancer may increase colorectal cancer risk by influencing adenoma growth or enhancing the formation of new lesions. Data of men from the prospective Health Professionals Follow‐Up Study who underwent an endoscopy between 1986 and 2004 were used to evaluate whether a family history of colorectal cancer is associated with adenoma multiplicity or advanced adenoma stage (≥1 cm, histology with villous component or carcinoma in situ). 21.4% of the 3,881 adenoma patients and 13.9% of the 24,959 adenoma‐free men had a first‐degree relative with colorectal cancer. Thousand four hundred and ninety‐six men were classified as having advanced and 1,507 as having nonadvanced adenomas. Six hundred and twenty‐two men had multiple and 1,985 had single adenomas in the distal colon and rectum. A family history of colorectal cancer was similarly associated with advanced and nonadvanced adenomas [multivariable odds ratio (OR) (95% confidence interval): advanced vs. nonadvanced, 0.98 (0.82–1.17), advanced vs. adenoma‐free: 1.67 (1.47–1.91), nonadvanced vs. adenoma‐free: 1.70 (1.49–1.94)], although potential differences according to adenoma location were seen. A family history of colorectal cancer was more strongly associated with multiple distally located adenomas [odds ratio (95% confidence interval): multiple vs. single, 1.35 (1.09–1.68), multiple vs. no distally located adenomas: 2.02 (1.67–2.44), single vs. no distally located adenomas: 1.49 (1.32–1.68)]. The number of adenomas was also positively associated with a family history of colorectal cancer. Our findings suggest that at the population level, heritable factors may be more important in earlier stages of adenoma formation than at stages of adenoma advancement for at least distally located adenomas. © 2009 UICC     

An analysis of immunocomplexes for the detection of the early stages of colon cancer

A radioimmunoassay was developed for the detection of the early stages of colon cancer by analysis of immune complexes (IC) with a specific polyclonal antibody. Human colon cancer cells were grown in a capillary culture system to provide unaltered antigens for the development of a specific antibody. The antibody was labeled with iodine 125 (125I) and used to analyze the antigen component of IC removed from whole serum. The assay was positive in 50% and 88% of known Dukes' A and Dukes' B colon cancer patients, respectively. It was also positive for only 25% of Dukes' C and 14% of Dukes' D patients, possibly because of the decreased quantity of specific IC found in the late stages of colon cancer. A blind study of patients referred for colonoscopy compared pathology diagnosis with the test results. The assay was positive for one patient with a polypoid adenocarcinoma (Dukes' B) and one with a villous adenoma and negative for 38 patients with benign polyps and 43 with no polyps. The assay was negative for all patients with stomach cancer and inflammatory bowel diseases and positive for about 10% of the patients with pancreas or breast cancer. The results of this preliminary investigation suggest that this radioimmunoassay may be useful for the detection of the early stages of colon cancer.     

CEA levels in patients with colorectal polyps.

Preoperative plasma CEA levels were measured in 93 selected patients with histologically defined colorectal adenomata removed at fibroptic colonoscopy in order to determine whether CEA levels are elevated in patients with colonic polyps, or vary with different histologic patterns. None of the patients had inflammatory bowel disease, previous history of carcinoma, or evidence of liver disease. Fifteen percent of the patients had elevated CEA levels (greater than or equal to 2.5 ng/ml; Hansen method), and two-thirds of these were between 2.5 and 4.0 ng/ml. Increased association of elevated CEA levels was noted with old age, villous adenomas (2- to 4-fold), and increased tumor size (greater than 2.3-cm diameter; 2-fold), but not with foci of dysplasia or carcinoma in situ as such. One-half (7/14) of the patients with elevated CEA levels showed the following: two patients had villous tumors with carcinoma in situ, one had a villous adenoma, two had mixed villous and tubular adenomas (with a high proportion of villous pattern), and two were subsequently shown to have carcinoma elsewhere in the colon. It is uncertain that the polyps were the source of the elevated circulating CEA levels; other factors including smoking and patient selection need to be considered. This preliminary study suggests that patients with colorectal adenomata and elevated circulating CEA may be at higher risk for the development of carcinoma. Further follow-up studies of the malignant potential of the polyp-bearing colon are essential.