Colorectal cancer and noncancer patients have similar labeling indices by microscopy and computed image analysis

A Monotonous Population of Elongated Cells (MPECs) in Colorectal Adenoma Indicates a High Risk of Metachronous Cancer

Accurate predictors for metachronous colorectal cancer (CRC) development after polypectomy are lacking. We evaluated the prognostic value of classical clinicopathologic features and a monotonous population of elongated cells (MPECs) in colorectal adenomas from 171 consecutively selected population-based patients with long-term follow-up. Quantitative image analysis, and univariate and multivariate regression analysis were applied. Ten of 171 adenomas (5.8%) developed metachronous CRC (defined as >24 mo interval and >5 cm from the index adenoma to the cancer). Median follow-up of adenomas with metachronous CRC was 68.4 and without cancer 149.7 months (range: 25 to 192 and 25 to 256, respectively). The most prognostic classical features were the localization of the marker adenoma as proximal (ie, in the cecum through transverse colon) versus distal from the transverse colon [P=0.0003, hazard ratio (HR)=8] and the number of polyps found during colonoscopy (<or=2 vs.>2, P=0.002, HR=6). Quantitative features of the MPECs included the longest nuclear axis and variance of the number of nuclei with 2 neighbors (higher and lower in cancer cases, respectively). Of the 171 adenomas, 50 (29%) had MPECs, of which 9 (18%) patients developed metachronous CRC at follow-up, contrasting 1/121 (0.8%) without MPECs (P=0.0003, HR=23). MPECs occurred in both low-grade and high-grade dysplasia, and in tubular and (tubulo) villous adenomas. MPECs had the strongest predictive value for metachronous CRC development. Adenomas proximally located had additional value but only if they were MPEC positive (which only occurred in 5 adenomas, 3 of which (60%) developed cancer). Having more than 2 polyps also had additional prognostic value but only in MPEC-negative adenomas [10 cases; 1 (10%) developed cancer]. Dysplasia grade and histologic growth pattern had no additional value. Thus, colorectal adenomas with subsequent metachronous cancer development can be identified more accurately with MPECs than with classical prognostic factors.

Digital image analysis for the evaluation of the inflammatory infiltrate in psoriasis

Traditionally the evaluation of the cellular infiltrate and protein expression in skin tissue sections is done by manual quantification. However, for reliable evaluation of histology in the development of new anti-psoriatic treatments there is a need for a more time-efficient and reproducible method. To test the use of digital image analysis (DIA) in this situation we compared the assessment of immunohistochemically stained skin sections with the more traditional manual quantification (MQ) and semi-quantitative analysis (SQA). The number of CD3+ T cells and the expression of E-selectin were evaluated in stained paired skin biopsies from 11 patients with chronic plaque psoriasis before and after initiation of anti-psoriasis therapy. We observed significant correlations between MQ and DIA for the number of T cells (epidermis: r=0.88, P< or =0.01, dermis r=0.87, P< or =0.01). Both DIA and MQ were equally effective in detecting reductions of T-cell numbers in active-treated patients. MQ took 20 h, compared to 6 h for DIA. We also observed significant correlations between SQA and DIA for the expression of E-selectin (r=0.88, P< or =0.01), although DIA was more sensitive than SQA to detect (early) changes. SQA took 10 h, compared to 4 h for DIA. In conclusion, the quantification of the inflammatory infiltrate in psoriatic lesional skin by DIA generated similar results as MQ and SQA in a reliable, reproducible and higher time efficient fashion.

Are dietary fiber-induced alterations in colonic epithelial cell proliferation predictive of fiber's effect on colon cancer?

Alterations in cell proliferation of the colon have been observed as a result of changes in amount and type of dietary fiber and in relation to risk of developing colon cancer. Although some human observational and intervention studies contribute to the database, most information results from experiments on rodents. Because of numerous contradictory reports linking dietary fiber, cell proliferation, and colon cancer, we undertook a critical review of existing methods in an attempt to explain the inconsistencies. Although there may be some individual types of dietary fiber that protect against chemically induced colon cancer, dietary fiber as a single entity does not appear to afford any consistent protection. Because of significant differences in experimental protocols among laboratories, it is not yet possible to state with certainty that increases in cell proliferation, induced by fiber consumption, are predictive of increased tumorigenesis. Much of what has been observed and interpreted as elevation of risk may simply be normal homeostatic changes in cell proliferation. Even though fermentation to short-chain fatty acids is a mechanistically attractive hypothesis to explain why fiber modulates cytokinetics, data do not consistently support short-chain fatty acids as biological intermediates in risk of colon cancer. The state of the art in this field has not yet progressed to the point where a clear effect of dietary fiber on cytokinetics and colon carcinogenesis can be assessed with any degree of certainty. Additional markers of apoptosis, differentiation, and cell-cell communication may be required for a more accurate analysis of the relation among fiber, cytokinetics, and colon cancer.

Biomarkers of human colonic cell growth are influenced differently by a history of colonic neoplasia and the consumption of acarbose

The nutritional effects of butyrate on the colonic mucosa and studies of transformed cells suggest that butyrate has anti-colon cancer effects. If butyrate has antineoplastic effects, mucosal growth contrasts between normal subjects and those with a history of colonic neoplasia would parallel changes in growth characteristics caused by butyrate in a colon neoplasia population. To test this hypothesis, rectal biopsies from a survey of colonoscopy patients (n = 50) with and without a history of colonic neoplasia (controls) were compared. Similarly, rectal biopsies were compared from subjects (n = 44) with a colon neoplasia history in an acarbose-placebo crossover trial. Control subjects in the colonoscopy survey had higher bromodeoxyuridine (BrdU) uptake than subjects with a history of neoplasia (P = 0.05). The control subjects also had a higher correlation of BrdU and Ki-67 labeling (P = 0.003). Both findings were paralleled by acarbose use. Acarbose augmented BrdU uptake (P = 0.0001) and improved the correlation of BrdU and Ki-67 labeling (P = 0.013). Acarbose also augmented fecal butyrate (P = 0.0001), which was positively correlated with Ki-67 labeling (P = 0.003). p52 antigen had an earlier pattern of crypt distribution in subjects with a history of colon neoplasia but was not affected by acarbose use. Lewis-Y antigen was expressed earlier in the crypt with acarbose but had similar expression in the colonoscopy survey groups. The use of acarbose to enhance fecal butyrate concentration produced mucosal changes paralleling the findings in control subjects as opposed to those with neoplasia, supporting the concept of an antineoplastic role for butyrate.

Quantitative analysis of synovial membrane inflammation: a comparison between automated and conventional microscopic measurements

OBJECTIVE

The objective of this study was to quantify selected features of chronic synovial tissue inflammation by computerised image analysis and to validate the results by comparison with conventional microscopic measurements.

METHODS

Synovial biopsy samples were obtained from the knee joints of patients with chronic arthritis and prepared for immunohistochemical analysis using standard techniques. Following the development of special software, four parameters of chronic synovial inflammation were evaluated: intimal layer thickness, CD3+ cell infiltration, CD8+ cell infiltration and vascularity. Intimal layer thickness was expressed in microns. The intensity of CD3+ and CD8+ cell infiltration was expressed as the percentage area of the tissue section occupied by positively stained cells. Vascularity was expressed as the percentage area occupied by blood vessels. Conventional quantitative microscopic analysis was also undertaken and the results from both methods compared.

RESULTS

Seventy eight tissue sections were selected for study. Measurements of intimal layer thickness by both techniques correlated strongly: r = 0.85, p = 0.0006. Measurements of CD8+ cell infiltration, usually widely dispersed, also correlated well: r = 0.64, p = 0.005. Measurements of CD3+ cell infiltration, often densely aggregated, correlated less well: r = 0.55, p = 0.02. Measurements of vascularity demonstrated no statistically significant correlation: r = 0.41, p = 0.07. Proficiency in the use of computerised image analysis was readily acquired.

CONCLUSION

Computerised image analysis was successfully applied to the measurement of some features of synovial tissue inflammation. Further software development is required to validate measurement of blood vessels of variable size.

Rectal epithelial proliferation in persons with or without a history of adenoma and its association with diet and lifestyle habits

BACKGROUND

Rectal epithelial proliferation (REP) measurements are used as a biomarker of risk for colorectal neoplasia and response to chemoprevention. The authors evaluated REP in screenees with and without a history of adenoma and its association with demographic and adenoma characteristics, diet, and other lifestyle habits.

METHODS

Long term lifestyle habits were evaluated and proliferation assessed by in vitro bromodeoxyuridine labeling of rectal biopsies in 223 screenees, 132 of whom had adenomas removed > 3 years previously. Analyses included the total population, screenees with a previous history of adenomas and adenoma free screenees separately, and a subgroup of 55 matched adenoma cases and controls.

RESULTS

Crypt proliferation measurements were not elevated in screenees with a history of adenomas compared with adenoma free screenees (mean total labeling index [LI] of 4.8% and 4.9%, respectively). This was confirmed by the case-control analysis, in which the LI of the most superficial crypt compartment was lower in the adenoma cases (P=0.05). Moreover, their total LI correlated negatively with the number of adenomas removed previously (P < 0.01). Proliferation was more frequent in the most superficial crypt compartments of female adenoma free screenees than in female screenees with a history of adenomas (P=0.02), and in men age > 65 years compared with younger men (P=0.06). In the total population, negative Spearman rank correlations were found between total LI and long term dietary intake of calcium (correlation coefficient [r]=-0.15; P=0.02), LI of the two most superficial crypt compartments and intake of fiber (r=-0.18; P=0.01), water (r=-0.12; P=0.08), and carbohydrates (not significant). A positive correlation was found between LI of the most superficial crypt compartment and cigarette smoking (r=0.4; P=0.02).

CONCLUSIONS

REP measurements did not discriminate between screenees with a history of adenomas and adenoma free screenees. Long-term lifestyle habits, gender, and age were associated with REP levels and need to be considered when evaluating human intervention studies.

DNA content and cell proliferation in giant congenital melanocytic naevi (GCMN). An analysis by image cytometry

GCMN may be precursors of melanoma, and it has been suggested that the presence of atypical foci could increase the risk of malignant transformation. In order to better define atypical GCMN, we analyzed DNA content and proliferative activity in 21 samples of GCMN, with (n=13) or without (n=8) cytologic atypia. Six benign acquired naevi (AN) and 6 malignant melanoma (MM) were used as controls. DNA content was determined with the CAS 200 image analyzer, and DNA histograms were classified according to the Auer classification. The proliferative indices (PI) were measured after Ki 67 immunostaining using the CAS 200 system. All AN and GCMN without atypia showed class I histograms (normal DNA content) and low PI (mean 1.9 and 2.1). Atypical GCMN showed in 10 cases an abnormal DNA content (class III or IV histograms) with low PI (mean 2.7), and in 3 cases a normal DNA content (class I histograms) with higher PI (mean 16.2). All MM displayed abnormal DNA content and high PI (mean 32.6). In conclusion, abnormal DNA content seems to correlate with cytologic atypia in GCMN. Atypical GCMN exhibit an overall pattern of DNA content and cell proliferation intermediate between non-atypical naevi and MM.

Colonic retinoblastoma protein and proliferation in cancer and non-cancer patients

Both suppressor oncogene and proliferative activity are believed to indicate colon cancer risk. The retinoblastoma (Rb) gene is a suppressor oncogene affecting cell differentiation. Retinoblastoma gene inactivation is associated with tumour development. However, the relation of the Rb protein to cell proliferation and colon tumour formation is unknown. Retinoblastoma protein quantity was correlated with proliferative activity in flat, unaffected mucosa specimens from 36 cancer patients, 21 non-cancer control subjects and in 29 tumour tissue samples from cancer patients. Nuclear Rb protein was measured by using automated CAS-200 image analysis of monoclonal antibody labelled frozen sections from fresh, surgically removed tissue. All colon cells within 15 whole crypts were imaged. Proliferative activity was also measured by using analysis with Ki-67 monoclonal antibody. Retinoblastoma protein content correlated directly with proliferative activity in flat mucosa of non-cancer control subjects (r = 0.63; P < 0.001; n = 21). A significant correlation was also found in flat mucosa specimens of non-metastatic (Duke's stages A and B) cancer patients (r = 0.52; P < 0.01; n = 22). However, Rb protein did not correlate with proliferation in flat mucosa from metastatic (Duke's stages C and D) cancer patients (r = 0.03; NS; n = 14) or in cancer tissue (r = 0.068; NS; n = 29). Mucosal Rb protein in the colon normally increases as proliferation increases. Dissociation between Rb protein and colon proliferation may occur in flat mucosa in patients with a higher risk of metastatic tumour growth. Future studies comparing Rb protein quantity and proliferative activity may help identify high-risk colon cancer patients.