Assessment of cell proliferation in colorectal carcinomas using the monoclonal antibody Ki-67. Correlation with pathohistologic criteria and influence of irradiation

Utility of synthetic MRI in predicting the Ki-67 status of oestrogen receptor-positive breast cancer: a feasibility study

AIM

To evaluate the utility of synthetic magnetic resonance imaging (MRI) of the breast in predicting the Ki-67 status in patients with oestrogen receptor (ER)-positive breast cancer.

MATERIALS AND METHODS

Forty-nine patients with 50 histopathologically proven breast cancers who underwent additional synthetic MRI were enrolled in the present study. Using synthetic MRI images, T1 and T2 relaxation times and their standard deviations (SD) in the breast lesions before (T1-Pre, T2-Pre, PD-Pre, SD of T1-Pre, SD of T2-Pre, SD of PD-Pre) and after (T1-Gd, T2-Gd, PD-Gd, SD of T1-Gd, SD of T2-Gd, SD of PD-Gd) contrast agent injection were obtained. These quantitative values were compared between the low Ki-67 expression (<14%) lesions (low-proliferation group: n=23) and high Ki-67 expression (≥14%) lesions (high-proliferation group: n=27).

RESULTS

The univariate analysis showed that the SD of T1-Gd (p<0.001) and T2-Gd (p=0.042) were significantly higher in the high-proliferation group than in the low-proliferation group. Multivariate analysis further showed that the SD of T1-Gd was a significant and independent predictor of Ki-67 expression, with an area under the receiver operating characteristic (AUROC) curve of 0.885. The sensitivity, specificity, and accuracy of the SD of T1-Gd with an optimal cut-off value of 98.5 were 77.8%, 87%, and 82%, respectively.

CONCLUSION

The SD of T1-Gd obtained from synthetic MRI was useful to predict Ki-67 status.

An MRI-based Radiomics Classifier for Preoperative Prediction of Ki-67 Status in Breast Cancer

RATIONALE AND OBJECTIVES

This study aims to investigate the value of a magnetic resonance imaging-based radiomics classifier for preoperatively predicting the Ki-67 status in patients with breast cancer.

MATERIALS AND METHODS

We chronologically divided 318 patients with clinicopathologically confirmed breast cancer into a training dataset (n = 200) and a validation dataset (n = 118). Radiomics features were extracted from T2-weighted (T2W) and contrast-enhanced T1-weighted (T1+C) images of breast cancer. Radiomics feature selection and radiomics classifiers were generated using the least absolute shrinkage and selection operator regression analysis method. The correlation between the radiomics classifiers and the Ki-67 status in patients with breast cancer was explored. The predictive performances of the radiomics classifiers for the Ki-67 status were evaluated with receiver operating characteristic curves in the training dataset and validated in the validation dataset.

RESULTS

Through the radiomics feature selection, 16 and 14 features based on T2W and T1+C images, respectively, were selected to constitute the radiomics classifiers. The radiomics classifier based on T2W images was significantly correlated with the Ki-67 status in both the training and the validation datasets (both P < .0001). The radiomics classifier based on T1+C images was significantly correlated with the Ki-67 status in the training dataset (P < .0001) but not in the validation dataset (P = .083). The T2W image-based radiomics classifier exhibited good discrimination for Ki-67 status, with areas under the receiver operating characteristic curves of 0.762 (95% confidence interval: 0.685, 0.838) and 0.740 (95% confidence interval: 0.645, 0.836) in the training and validation datasets, respectively.

CONCLUSIONS

The T2W image-based radiomics classifier was a significant predictor of Ki-67 status in patients with breast cancer. Thus, it may serve as a noninvasive approach to facilitate the preoperative prediction of Ki-67 status in clinical practice.

Growth Fraction of Colorectal Carcinoma (Ki67): A Comparative Study

We studied the growth fraction of55 resected colorectal adenocarcinomas by means of a three-step immunoperoxidase technique (avidin-biotin-peroxidase) using the monoclonal antibody Ki67 directed against a cell proliferation-associated nuclear antigen.

The percentage of Ki67-positive cells was evaluated independently by two observers, and a Ki67 score was obtained for each case.

No correlation was observed between Ki67 staining and patient's age and sex, tumor size and localization or grading and staging according to Dukes’ method (modified by Astler-Coller and Turnbull).

The growth fraction showed extreme heterogeneity in the cases examined, within each grade of differentiation.

Immunohistochemical Expression of p53 and Ki67 in Colorectal Adenomas and Prediction of Malignancy and Development of New Polyps

The aim of this study was to investigate the immunohistochemical expression of p53 and Ki67 in colorectal adenomas in order to clarify their significance as indicators of malignancy and development of new polyps. Seventy-eight polyps were removed from 51 patients and examined. Twenty-nine patients (56.9%) had adenomas with low-grade atypia (13 of them developed new polyps at 3-year follow-up) and 22 (43.1%) had adenomas with high-grade atypia (6 of them developed new polyps at 3-year follow-up). We tested the association between p53 and Ki67 expression and various clinicopathological variables, and regression analysis was performed to identify the risk factors for malignancy and development of new adenomas. A significant correlation between the grade of atypia and p53 immunoreactivity was observed. Ki67 expression was not related to atypia and no correlation was found between p53 and Ki67 immunoreactivity. Regression analysis showed that size (p=0.0002) and p53 staining (p=0.0111) were the selected factors related to malignant transformation, whereas the number of synchronous primary polyps emerged as the only predictive factor of development of new adenomas, although without statistical significance. The expression of biological markers may be in future added to the currently examined features of polyps; however, further studies are needed to better define their predictive value.

Remnant Liver Ischemia as a Prognostic Factor for Cancer-Specific Survival After Resection of Colorectal Liver Metastases

IMPORTANCE

Ischemia-reperfusion injury during hepatic resection has been shown to accelerate progression of liver cancer. However, the prognostic relevance of remnant liver ischemia (RLI) after resection of colorectal liver metastases (CLMs) is unknown to date.

OBJECTIVES

To assess the prognostic influence of RLI after resection of CLMs and to identify correlates of greater extent of RLI.

DESIGN, SETTING, AND PARTICIPANTS

This study was a retrospective analysis at The University of Texas MD Anderson Cancer Center based on prospectively collected data. The study identified 202 patients who underwent curative resection of CLMs between January 1, 2008, and December 31, 2014, and had enhanced computed tomographic images obtained within 30 days after surgery.

MAIN OUTCOMES AND MEASURES

Remnant liver ischemia was defined as reduced or absent contrast enhancement during the portal phase. Postoperative RLI was classified as grade 0 (none), 1 (marginal), 2 (partial), 3 (segmental), or 4 (necrotic) as previously defined. Experienced members of the surgical team retrospectively performed imaging assessments. Team members were masked to the postoperative outcomes. Survival after resection was stratified by RLI grade. Predictors of RLI grade 2 or higher and survival were identified.

RESULTS

Among 202 patients (median [range] age, 56 [27-87] years; 84 female), the RLI grades were as follows: grade 0 (105 patients), grade 1 (47 patients), grade 2 (45 patients), grade 3 (5 patients), and grade 4 (0 patients). Recurrence-free survival (RFS) and cancer-specific survival (CSS) rates after hepatic resection were worse in patients with RLI grade 2 or higher vs grade 1 or lower (RFS at 3 years, 6.4% [3 of 50] vs 39.2% [60 of 152]; P < .001 and CSS at 5 years, 20.7% [10 of 50] vs 63.7% [97 of 152]; P < .001). A largest metastasis at least 3 cm (OR, 2.74; 95% CI, 1.35-5.70; P = .005), multiple CLMs (OR, 2.51; 95% CI, 1.25-5.24; P = .009), and nonanatomic resection (odds ratio [OR], 3.29; 95% CI, 1.52-7.63; P = .002) were associated with RLI grade 2 or higher. A largest metastasis at least 3 cm (hazard ratio [HR], 1.70; 95% CI, 1.01-2.88; P = .045), mutant RAS (HR, 2.15; 95% CI, 1.27-3.64; P = .005), and RLI grade 2 or higher (HR, 2.90; 95% CI, 1.69-4.84; P < .001) were associated with worse CSS.

CONCLUSIONS AND RELEVANCE

In this study, remnant liver ischemia grade 2 or higher was associated with worse CSS after resection of CLMs. High-quality anatomic surgery to minimize RLI after resection is essential.

A food-based approach that targets interleukin-6, a key regulator of chronic intestinal inflammation and colon carcinogenesis

Studies have shown a causal link between high-calorie diet (HCD) and colon cancer. However, molecular mechanisms are not fully elucidated. To understand etiology of HCD-induced colon carcinogenesis, we screened 10 pathways linked to elevated colonic cell proliferation and chronic inflammation in an HCD-consuming human-relevant pig model. We observed elevated colonic mucosal interleukin-6 (IL-6) expression in HCD-consuming pigs compared to standard diet controls (SD, P=.04), and IL-6 strongly correlated with Ki-67 proliferative index and zone, early biomarkers of colon cancer risk (r=0.604 and 0.743 and P=.017 and .002, respectively). Liquid chromatography-tandem mass spectrometry-based proteomic analysis and Ingenuity Pathway Analysis showed that HCD consumption altered IL-6 signaling pathway proteins (PI3KR4, IL-1α, Mapk10, Akt3, PIK3CG, PIK3R5, Map2k2). Furthermore, these proteins also correlated with Ki-67 proliferative index/zone. Anti-IL-6 therapeutics are available for treating colon cancer; however, they are expensive and induce negative side effects. Thus, whole foods could be a better way to combat low-grade chronic colonic inflammation and colon cancer. Whole plant foods have been shown to decrease chronic diseases due to the potential of anti-inflammatory dietary compounds acting synergistically. We observed that supplementation of HCD with anthocyanin-containing purple-fleshed potatoes (10% w/w), even after baking, suppressed HCD-induced IL-6 expression (P=.03) and the IL-6-related proteins IL-1α and Map2k1 (P≤.1). Our results highlight the importance of IL-6 signaling in diet-linked induction/prevention of colonic inflammation/cancer and demonstrate the potential of a food-based approach to target IL-6 signaling.

Ki67--An unsuitable marker of gastric cancer prognosis unmasks intratumoral heterogeneity

Background and Objectives

Due to contradictious findings of previous studies regarding Ki67's value in gastric cancer (GC), we reevaluated the expression of Ki67 in whole tissue sections (WTS) and tissue microarrays (TMAs) of GC testing the following hypotheses: does Ki67 show intratumoral heterogeneity; are TMAs representative in the determination of the Ki67 proliferation index (PI); is the Ki67 PI subject to an intralaboratory variability; and is the Ki67 PI related to clinico‐pathological patient characteristics and/or prognostically relevant in GC.

Methods

Corresponding WTS and TMAs samples from 315 GCs were stained immunohistochemically. The Ki67 PI evaluated on WTS was correlated with the Ki67 PI evaluated on TMAs, sample age, clinico‐pathological characteristics, and patient survival.

Results

The overall amount of Ki67‐positive tumor cells did not depend on sample age. Three distinct, partly heterogeneous Ki67 expression patterns were observed. The mean Ki67 PI evaluated on TMAs differed on average minus 16.9% from the Ki67 PI evaluated on WTS. Ki67 in WTS correlated significantly with the Laurén phenotype and tumor grade, but not with patient survival.

Conclusion

TMAs carry the risk of a systematic underestimation of the Ki67 PI. Ki67 has no prognostic value in GC but might be a potential indicator of intratumoral heterogeneity. J. Surg. Oncol. 2016;113:46–54. © 2015 The Authors. Journal of Surgical Oncology published by Wiley Periodicals, Inc.

High Ki67 expression is an independent good prognostic marker in colorectal cancer

AIMS

To correlate Ki67 expression with outcome in colorectal cancer (CRC).

METHODS

Ki67 labelling index (Ki67LI) was analysed by immunohistochemistry on a tissue microarray containing 1800 CRCs. The results were compared with clinicopathological and molecular parameters.

RESULTS

Ki67LI was considered low in 26.3%, moderate in 56.7% and high in 17.0% of 1653 interpretable CRCs. High Ki67 expression was associated with low tumour stage (p<0.0001) and nodal status (p=0.0315), but not with tumour grade (p=0.8639), histological tumour type (p=0.1542) or tumour localisation, and was an independent prognosticator of favourable survival (p=0.0121). High Ki67 expression was also significantly associated with high-level nuclear β-catenin and p53 expression (p<0.0001 and p=0.0095, respectively).

CONCLUSIONS

In summary, our data show that high Ki67 expression in CRCs is associated with good clinical outcome. Ki67, p53 and β-catenin overexpression seem to be linked to CRC, and indicate a cellular state of high proliferative activity. Finally, our findings strongly argue for a clinical utility of Ki67 immunostaining as an independent prognostic biomarker in CRC.

Transforming growth factor beta 1 and metalloproteinase-9 overexpression in colorectal cancer (CC) and adenoma

BACKGROUND AND AIMS

Although the role of transforming growth factor beta (TGFbeta) 1 and metalloproteinase-9 (MMP-9) is well documented in colorectal cancer (CC), there is a little evidence supporting its role in early carcinogenesis. The aim of the study was to determine the pattern of immunohistochemical expression of TGFbeta1, MMP-9, and Ki-67 in CC and adenomatous polyps.

PATIENT/METHODS

The study group comprised 50 patients with colorectal polyps and 33 patients with CC. Endoscopically removed polyps and CC biopsies had been evaluated with histopatologic examination and immunohistochemistry. The biopsies from 30 healthy objects served as a control group. For all antibodies labeling indices (LI) had been calculated.

RESULTS

Among 62 adenomas, 33 high-grade dysplasia (HGD) and 29 low-grade dysplasia (LGD) had been detected. Mean TGFbeta1, MMP-9, and Ki-67 LI in CC were significantly higher (p < 0.01, 0.01, and 0.01, respectively) than in HGD polyps. Mean TGFbeta1, MMP-9, and Ki-67 LI in HGD polyps were significantly higher than in LGD polyps (p < 0.01, 0.01, and 0.01, respectively). There had been no statistical difference in TGFbeta1, MMP-9, and Ki-67 LI between LGD and the control group (p > 0.05, 0.05, and 0.05, respectively). There was a positive correlation between TGFbeta1 and MMP-9 (r = 0.898), Ki-67 and MMP-9 (r = 0.938), and TGFbeta1 and Ki-67 (r = 0.913). We did not observe any correlation between TGFbeta1, MMP-9, Ki-67 LI and the clinical parameters evaluated.

CONCLUSION

The increased expression of TGFbeta1, MMP-9 observed in colorectal adenomas seems to be related to the grade of dysplasia. We assume that overexpression of TGFbeta1, MMP-9 represent an early event in colorectal carcinogenesis and may possibly have the prognostic value.

Antitumor efficacy of capecitabine and celecoxib in irradiated and lead-shielded, contralateral human BxPC-3 pancreatic cancer xenografts: clinical implications of abscopal effects

PURPOSE

X-ray therapy (XRT) remains one of the major modalities used to treat patients diagnosed with locally advanced pancreatic adenocarcinoma. However, the effect of XRT on metastatic tumors outside the field of irradiation (abscopal effect) remains largely unknown. In the current study, we examined the effect of XRT alone and in combination with capecitabine and/or celecoxib in both irradiated and lead-shielded contralateral BxPC-3 pancreatic cancer xenografts. This chemoradiation regimen was chosen based on our molecular analysis of pancreatic adenocarcinoma.

EXPERIMENTAL DESIGN

Athymic mice were injected bilaterally with BxPC-3 cells and treatment was initiated 28 days postimplant. During XRT (2 Gy for 5 consecutive days, administered on days 0 and 24), one flank was irradiated whereas the rest of the body (including the contralateral tumor) was lead shielded. Capecitabine (350 mg/kg) was administered on days 0 to 13 and 24 to 37. Celecoxib was initiated in the diet at 100 ppm (equivalent to 20 mg/kg/d p.o.) and administered throughout the study.

RESULTS

In irradiated xenografts, capecitabine and XRT showed synergistic anitiumor efficacy (P=0.008), which was further improved with the addition of celecoxib (P<0.001). In contralateral shielded xenografts, abscopal effects were observed. Whereas monotherapy with XRT showed significant reduction in tumor area in irradiated xenografts, growth was promoted by 23% (P<0.001) in contralateral lead-shielded tumors in the same animals relative to untreated tumors. Interestingly, synergistic antiproliferative efficacy occurred in these contralateral tumors when capecitabine was administered (P<0.001), despite being outside the irradiated field. The addition of celecoxib further inhibited tumor growth (P<0.001). This trimodal combination most effectively stabilized disease in both shielded and irradiated tumors; however, tumor eradication was not observed. There were no significant changes in thymidine phosphorylase, dihydropyrimidine dehydrogenase, or cyclooxygenase-2 mRNA levels in irradiated or lead-shielded tumors, suggesting that efficacy cannot be predicted solely from these previously identified indicators of response. Immunohistochemistry examining the proliferation marker Ki-67 showed concordance with tumor response in both irradiated and contralateral shielded xenografts.

CONCLUSIONS

These results have implications in the rational design of treatment paradigms for pancreatic cancer where metastatic disease remains the primary cause of patient morbidity and abscopal effects in tumors outside the field of irradiation may affect tumor response.

Increased proliferation activity measured by immunoreactive Ki67 is associated with survival improvement in rectal/recto sigmoid cancer

AIM: To assess the expression of Ki67 as prognosticator in rectal/recto sigmoid cancer.

METHODS: Samples from 146 patients with rectal and recto sigmoid cancer were studied for expression of Ki67 and its prognostic significance in comparison with clinico-pathological predictors of survival. Formalin-fixed, paraffin-embedded tissues from 6 (4.1%) patients with T1, 26 (17.8%) with T2, 94 (64.4%) with T3, and 20 (13.7%) with T4 tumors were studied. Ki67 expression was determined immunohistochemically. Samples were divided according to mean value into high (>40%) and low (≤40%) expression. Areas of extensive proliferation (>50%) were defined as ‘hot spot’ areas.

RESULTS: Hot spot areas were present in samples regardless of histopathological grade. Lower TNM and Dukes stage and higher expression of Ki67 and presence of Ki67 hot spot areas in histopathological samples were associated with better survival, whereas no association was observed with histopathological grade (P = 0.78). In Cox multivariate regression analysis, significant prognostic factors were Dukes stage (P<0.001), presence of lymph node metastases (P = 0.015), age (P = 0.035) and presence of Ki67 hot spot areas (P = 0.044).

CONCLUSION: Proliferative activity as measured by Ki67 in rectal cancer is associated with survival improvement compared with patients with low Ki67. Areas of prognostically significant increased proliferation were found independently of histopathological tumor grade.

Surgical treatment for anomalous arrangement of the pancreaticobiliary duct with nondilatation of the common bile duct

BACKGROUND/PURPOSE

For anomalous arrangement of the pancreaticobiliary duct (AAPBD) with nondilatation of the common bile duct (CBD), the optimal surgical procedure remains controversial. The authors investigated which procedure would be most effective for AAPBD with nondilatation of the CBD.

METHODS

The authors encountered 60 children with AAPBD in our institution between 1979 and 2002. Six of the 60 were classified as the nondilated type (CBD diameter; less than 8 mm), whereas the other 54 were classified as the dilated type (CBD diameter; more than 9 mm). Amylase levels in serum, CBD, and gallbladder were examined. Cellular activity of the resected gallbladder was examined for the incidence of hyperplasia and Ki-67 labeling index (Ki-67 LI).

RESULTS

The amylase level in the nondilated type was elevated as in the dilated type. Epithelial hyperplasia of the gallbladder was present in 4 of the 6 with the nondilated type (67%). 10 of the 20 with the dilated type (50%), and none of the 6 controls (0%). The Ki-67 LI of the dilated type was significantly higher than that of control.

CONCLUSIONS

A free reflux of pancreatic juice into the biliary system was found regardless of dilatation, and cellular proliferative activity of the gallbladder mucosa was increased in both the nondilated and dilated type. Therefore, excision of the extrahepatic bile duct including cholecystectomy is recommended for AAPBD with nondilatation of the CBD.

High-level mRNA quantification of proliferation marker pKi-67 is correlated with favorable prognosis in colorectal carcinoma

PURPOSE

The present study retrospectively examines the expression of pKi-67 mRNA and protein in colorectal carcinoma and their correlation to the outcome of patients.

METHODS

Immunohistochemistry and quantitative RT-PCR were used to analyze the expression of pKi-67 in 43 archival specimens of patients with curatively resected primary colorectal carcinoma, who were not treated with neo-adjuvant therapy.

RESULTS

We determined a median pKi-67 (MIB-1) labeling index of 31.3% (range 10.3-66.4%), and a mean mRNA level of 0.1769 (DeltaC(T): range 0.01-0.69); indices and levels did not correlate. High pKi-67 mRNA DeltaC(T) values were associated with a significantly favorable prognosis, while pKi-67 labeling indices were not correlated to prognostic outcome. A multivariate analysis of clinical and biological factors indicated that tumor stage (UICC) and pKi-67 mRNA expression level were independent prognostic factors.

CONCLUSION

Quantitatively determined pKi-67 mRNA can be a good and new prognostic indicator for primary resected colorectal carcinoma.

High intrinsic apoptosis, but not radiation-induced apoptosis, predicts better survival in rectal carcinoma patients

PURPOSE

An important feature of malignant tumors is the disturbance in the balance between proliferation and cell death. We evaluated the relevance of intrinsic and radiation-induced apoptosis and proliferation for prognosis in rectal cancer patients.

METHODS AND MATERIALS

Patients were selected from a study that randomized for preoperative radiotherapy (RT). Apoptosis and proliferation were scored using specific antibodies in immunohistochemistry. The number of positive cells per square millimeter of carcinoma cells was determined in 98 randomly selected tumors, of which 45 had been irradiated. For the survival analyses, a cohort of 104 patients without positive circumferential resection margins was selected.

RESULTS

In nonirradiated patients, high levels of intrinsic apoptosis correlated with better local control (p = 0.04) and better cancer-specific survival (p = 0.02). RT increased the median amount of apoptosis from 10.8 to 21.5 cells/mm(2) (p = 0.004), but this was not predictive for survival. The amount of proliferative cells was not altered after RT and had no influence on prognosis.

CONCLUSIONS

Intrinsic apoptosis correlated with both local control and cancer-specific survival, but proliferation was not predictive for prognosis. However, although RT increased apoptosis, its prognostic value was lost after RT. This is possibly because in rectal cancer, the proliferative status of tumors is always high and the aggressiveness of the tumor is determined by the number of "spontaneous" apoptotic tumor cells.

Colorectal carcinomas with high MIB-1 labelling indices but low pKi67 mRNA levels correlate with better prognostic outcome

AIMS

Antibodies specific to the proliferation-associated protein pKi67 (e.g. Ki67, MIB-1) are routinely used in oncology to assess the proliferation index of tumour cells. In untransformed cells the amount of pKi67 present at any time of the cell cycle is strictly regulated. To achieve a better understanding of expression and regulation of this protein in tumour cells, we investigated both pKi67 mRNA and protein expression in routinely fixed and embedded tissue of colorectal carcinoma.

METHODS AND RESULTS

We determined a median pKi67 specific in-situ hybridization labelling index of 42% (9-79%) and a median Ki67 index (MIB-1 labelling index) of 59% (26-94%) in 47 resected colorectal adenocarcinomas of different stages and grades. In 32 cases expression of pKi67 mRNA and protein correlated well but we observed a significant difference between both values in 15 tumours. In these cases more than 30% of the cells expressed the protein but not the mRNA of pKi67, possibly due to cell cycle arrest. Patients belonging to this group had a significantly (P < 0.012) better prognosis.

CONCLUSIONS

Tumours with a high pKi67 protein level but low mRNA expression are likely to proliferate more slowly than calculated on the basis of their Ki67 staining index, which possibly explains the patients' improved outcome.

Incidence of apoptosis increases with age in colorectal cancer

The incidence of cancer increases with advancing age, but the biological behavior of cancer is known to be less aggressive in elderly people. Thus, the proliferative activity and extent of apoptosis of cancer cells were assessed in samples from 163 cases of colorectal cancer focusing on the age of patients, using Ki-67 labeling index (LI) and apoptotic index (AI) by terminal deoxynucleotidyl transferase (TdT)-mediated d-UTP nick end labeling method and staining for activated caspase-3. The Ki-67 LI of colorectal cancer ranged from 2.33 to 80.4% (mean 32.2%), while the AI ranged from 0.00 to 14.8% (mean 3.57%). Concerning the aging effect, linear and positive correlations were found for the Ki-67 LI of cancer with age (p<0.05) and the AI of cancer with age (p<0.05). However, in normal colorectal mucosa, aging of patients revealed a significant correlation only with the AI but not with the Ki-67 LI. The AI in earlier stages of cancers (stages 0 and 1) revealed a significant difference between younger cases (age<65) and more elderly cases (age>/=65) (p<0.05), however, the Ki-67 LI did not exhibit a significant difference. Therefore, an increased frequency of apoptosis in colorectal cancer tissues, especially in the earlier stages, may possibly explain the slower growth of colorectal cancers in the elderly. Next, the expressions of several regulatory molecules for the proliferation/apoptosis of tumor cells were determined. The results demonstrated a tendency for stronger and more frequent expressions of c-myc, Bak and Bax despite a rather weaker expression of Bcl-2 in cancer tissues from the elderly compared with those from the younger patients. The potential roles of these regulatory molecules on age-change in the proliferation/apoptosis of colorectal cancers are discussed.

Cell proliferation in colorectal adenocarcinomas: comparison between Ki-67 immunostaining and bromodeoxyuridine uptake detected by immunohistochemistry and flow cytometry

We compared three different means of assaying tumor proliferative activity in 30 human colorectal adenocarcinomas labeled in vivo with bromodeoxyuridine (BrdUrd). The labeling indices (LI) of BrdUrd obtained both by flow cytometry (FCM) and immunohistochemistry (IH) were also compared with the labeling index of Ki-67. These methods were then related to tumor ploidy and pathological features. Flow cytometry was performed in accordance with Begg's method after intravenous infusion of BrdUrd four hours before surgery. Immunohistology was carried out on paraffin-embedded sections with monoclonal antibodies against BrdUrd and Ki-67. A positive correlation was found between BrdUrd LI obtained by both FMC and IH (p<0.0001), a finding that complies with the literature. However, we report on a correlation between Ki-67 LI and BrdUrd LIs in colorectal tumors (p=0.012). The results were valid for all tumors when they were subdivided into diploid and aneuploid groups. The labeling indices were significantly higher in the aneuploid tumor group than in the diploid group (p=0.047). No relationship between proliferation parameters and tumor stage or grade was found. To our knowledge, this is the first report on a positive correlation between tumor proliferation indices in BrdUrd LIs and Ki-67 in colorectal carcinomas. This finding validates the value of Ki-67 immunostaining, which, however, should be confirmed in a larger series under the same technical conditions.

Assessment of proliferative activity in colorectal carcinomas by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR)

The monoclonal antibody Ki-67 and the isospecific monoclonal antibody MIB-1 are routinely used in oncology to assess the proliferation index of tumor cells. A more objective and sensitive method is the determination of the of Ki-67 protein-specific mRNA by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). In 25 resected colorectal adenocarcinomas of different stages and grades we determined between 0.2 and 4.4 amol (10(-18) mol) Ki-67 protein-specific mRNA per microgram total RNA (median = 0.88 amol). The corresponding Ki-67 indices (expressing the percentage of Ki-67/MIB-I positive tumor cells) ranged from 41 to 81% (median = 61%). We found a good correlation between Ki-67 index and mRNA expression (r = 0.75), a significant correlation between both data and tumor stage (primary tumor, regional nodes, metastasis [pTNM] staging classification) (p < 0.001), but not between both data and tumor grade. Both Ki-67 indices (p = 0.05) and mRNA levels (p = 0.014) correlated significantly to the patients' survival. These results demonstrate that the Ki-67 protein-specific quantitative RT-PCR is a useful method for the characterization of tumor cell proliferation.

Immunohistochemical expression of bcl-2 and p53 oncoproteins: correlation with Ki67 proliferation index and prognostic histopathologic parameters in colorectal neoplasia

The bcl-2 oncogene plays an important role in carcinogenesis by inhibiting cell death (apoptosis). It was initially discovered in follicular B cell lymphoma with t(14,18) and subsequently found in other malignant and premalignant lesions. Alteration of the normal controls of cell proliferation is also a significant factor in the multistep process of tumorigenesis. The proliferative activity of a given lesion is commonly evaluated by MIB 1, a monoclonal antibody to Ki67 proliferation antigen. Mutation of the p53 gene is considered the most common genetic aberration in colorectal cancer. Immunohistochemical (IHC) staining expression of bcl-2, Ki67, and p53 was retrospectively investigated in a series of 52 colorectal carcinomas and 56 adenomas. The aim of the study was twofold: (i) to investigate any correlation between MIB 1, p53, and bcl-2 immunostaining expression in colonic adenomas and carcinomas and (ii) to identify any relation between these markers and several histopathologic parameters including tumor size, pathologic stage, lymph node metastasis, angiolymphatic invasion, tumor grade, and differentiation in colon carcinomas. bcl-2 was consistently higher in adenomas than in carcinomas. There were 44 of 56 (78.6%) adenomas and 27 of 52 (51.9%) carcinomas positive for bcl-2 (P = 0.004). The mean Ki67 labeling index (LI) was 30.05 +/- 7.6 and 38.12 +/- 11.01 in adenomas and carcinomas, respectively (P = 0.0001). p53 was significantly higher in carcinomas (35 of 52 [67.3%]) than in adenomas (18 of 56 [32.1%]) (P = 0.0004). Expression of bcl-2 in carcinoma was associated with a lower p53 levels and lower mean Ki67 LI and with favorable histopathologic parameters. Higher p53 and Ki67 values were associated with prognostically poor histopathologic features (differentiation and Duke's stage). We conclude that, in contrast to p53 and Ki67, bcl-2 oncoprotein expression is probably an early step in the process of colon carcinogenesis, and its expression may be associated with favorable pathologic parameters. Furthermore, an inverse relation exists between p53 and Ki67, and bcl-2 IHC expression in colonic neoplasia. Evaluation of bcl-2, p53, and Ki67 IHC expression in colonic carcinoma may be of value in predicting the clinical course in these patients.

Immunogold labelling of PCNA and Ki-67 antigen at the ultrastructural level in laryngeal squamous cell carcinoma and its correlation with lymph node metastasis and histological grade

Streptavidin-gold was used for the immunolocalization of PCNA and Ki-67 antigen at the ultrastructural level with a postembedding technique in biopsies of 15 patients with laryngeal squamous cell carcinoma. Positive immunoelectron staining was obtained in 9 cases for PCNA (60%) and in 8 cases for Ki-67 (53%). PCNA was predominantly found in heterochromatin of the nucleus of laryngeal carcinoma cells in a granular pattern. Positivity for PCNA was not found in nucleoli. In 4 cases, positive staining was observed both in nucleus and cytoplasm. In the cytoplasm, it was found to be present on the endoplasmic reticulum and on ribosomes throughout the cytoplasm. Ki-67 antigen was localized in the nucleus where it was associated with heterochromatin and euchromatin. It was also observed in nucleoli in all cases. Cytoplasmic localization of Ki-67 antigen was similar to that of PCNA. All 8 cases that were positive for Ki-67 were also positive for PCNA. Control incubations did not result in labelling with steptavidin-gold particles for both antigens. A significant correlation between PCNA and Ki-67 expression in association with pathological characteristics such as nodal status and histological grade was not found. Our data indicate that Ki-67 antigen staining correlates with PCNA labelling, whereas a relationship between proliferation markers and tumour progression was not found.

Correlation of bcl-2 oncoprotein immunohistochemical expression with proliferation index and histopathologic parameters in colorectal neoplasia

Thebcl-2oncogene plays an important role in carcinogenesis by inhibiting cell death (apoptosis). It was initially discovered in follicular B cell lymphoma with t(14,18), and subsequently found in other malignant and premalignant lesions. Alteration of the normal controls of cell proliferation is also a significant factor in the multistep process of tumorigenesis. The proliferative activity of a given lesion is commonly valuated by MIB1, a monoclonal antibody to Ki67 proliferation antigen. Immuno-histochemical (IHC) staining expression of bcl-2 and Ki67 was retrospectively investigated in a series of 52 colorectal carcinomas and 56 adenomas according to the avidin-biotin-complex method. The aim of the study was twofold: 1) to investigate any correlation between MIB1 and bcl-2 immunostaining expression in colonic adenomas and carcinomas, 2) to identify any relationship between either marker and several histopathologic parameters including tumor size, pathologic stage, lymph node metastasis, angio-lymphatic invasion, tumor grade and differentiation in colon carcinomas. Bcl-2 was consistently higher in adenomas than in carcinomas. There were 44/56 (78.6%) adenomas, and 27/52 (51.9%) carcinomas positive for bcl-2 (p=0.004). The mean Ki67 labeling index (LI) was 30.05+/-7.6 and 38.12+/-11.01 in adenomas and carcinomas, respectively (p=0.0001). Expression of bcl-2 in carcinoma was significantly associated with a lower mean Ki67 LI and with favorable histopathologic parameters. We conclude that bcl-2 oncoprotein expression is probably an early step in the process of colon carcinogenesis, and its expression may be associated with a favorable clinical course. Furthermore, an inverse relationship exists between bcl-2 and Ki67 in colonic neoplasia. Evaluation of bcl-2 and Ki67 IHC expression in colonic carcinoma should be performed prospectively to determine if their expression is of value in predicting the clinical course in these patients.

Cellular activity in the gallbladder of children with anomalous arrangement of the pancreaticobiliary duct

BACKGROUND/PURPOSE

Anomalous arrangement of the pancreaticobiliary duct (AAPBD) is closely related to congenital biliary dilatation and frequently associated with biliary tract malignancy. To examine the mechanism of biliary tract carcinogenesis in patients with AAPBD, we investigated histologically the early changes in cell proliferative kinetics of the gallbladder mucosa of children with AAPBD.

METHODS

Twenty-three specimens of gallbladder were obtained from 23 children with AAPBD, and six control specimens were obtained from pediatric patients. All specimens were fixed routinely and paraffin embedded and examined histologically with H&E staining and immunohistochemically with monoclonal antibody Ki-67(MIB-1), which reacts with a human nuclear antigen associated with cell proliferation. Ki-67 labeling index (Ki-67 LI) was obtained by counting the numbers of Ki-67-positive cells per 1,000 gallbladder epithelial cells.

RESULTS

Significant differences in Ki-67 LI were noted between children with and without AAPBD. Furthermore, Ki-67 LI and the incidence of epithelial hyperplasia of gallbladder were significantly higher in children with AAPBD in whom the major pancreatic duct joined the common bile duct (P-C type) than in those in whom the common bile duct joined the major pancreatic duct (C-P type).

CONCLUSIONS

Cellular proliferative activity was increased in children with AAPBD, especially those with the P-C-type anomaly. These results suggest that the early mucosal changes of the gallbladder occurred in early childhood of patients with AAPBD and might be associated with gallbladder cancer. Early diagnosis and early surgical division of the biliary tract and pancreatic duct is recommended for children with AAPBD.

Clear cell change in colorectal adenomas: its incidence and histological characteristics

AIMS

The aim of our investigation was to clarify the histological characteristics and biological significance of clear cell change in colorectal adenomas. METHODS ANID RESULTS: We found three cases (0.086%) of tubular adenomas with clear cell change in a review of 3486 cases of colorectal adenoma. These three cases occurred in male patients and were located in the left-sided colon. To investigate the nature and biological significance of the clear cells, we conducted histochemical staining (periodic acid-Schiff (PAS) with or without diastase digestion, alcian blue pH 2.5) and immunohistochemical staining (using antibodies against carcinoembryonic antigen (CEA), alpha-fetoprotein, p53 protein and Ki67 antigen) and also mitotic counts. Histologically, the changed area was characterized by pyknotic and randomly arranged nuclei with PAS-negative clear and vacuolated cytoplasm. Immunoreactivity for CEA was diffuse and strong in the clear cells, but not in the tumour cells in the ordinary portion of the adenomas. The Ki67 labelling index and the mitotic activity were both higher in the clear cell portion than in the ordinary portion.

CONCLUSIONS

This is the first study to indicate the incidence of clear cell change among colorectal adenomas. It has confirmed high proliferative activity within the clear cell portion of colorectal adenomas.

Value of Ki67 immunostain in identification of malignancy in serous effusions

The distinction between malignant and benign serous effusions continues to be a challenging and a frequent problem to cytopathologists. Recently, immunostains employing various antibodies have improved the diagnostic accuracy of malignant effusions. We investigated the usefulness of Ki67 (MIB1) antigen immunostaining in the evaluation and diagnosis of malignant serous effusions. Cell block sections from a total of 54 cases of serous effusions cytologically diagnosed as malignant (28), suspicious (6), and benign (20) were immunostained with MIB1 monoclonal antibody to the Ki67 nuclear proliferation antigen according to the avidin-biotin immunoperoxidase method. The patients were 30 women and 24 men with an average age of 58 yr. Ki67 (MIB1) immunostain labeling index (LI) values were higher than 20% in 23 of 28 (82%) cytologically malignant, in 3 of 6 (50%) suspicious, and in 1 of 20 (5%) benign/reactive. Further investigation revealed histologic, radiologic, and/or clinical evidence of malignancy in the 3 suspicious (but not in the benign/reactive) cases with Ki67 LI values higher than 20%. Correlation between Ki67 LI (> 20%) and cytologic effusion type (benign, suspicious, or malignant) was statistically significant (P < 0.0001). Ki67 immunostaining has value as an adjunct testing to cytomorphology and other immunostains in distinguishing benign from malignant effusions. The addition of Ki67 immunostaining to conventional cytology appears more sensitive than cytomorphology alone and may assist in arriving at accurate diagnoses in suspicious cases with inconclusive cytomorphologic features.

MUC-1 expression as a predictor of the curative endoscopic treatment of submucosally invasive colorectal carcinoma

PURPOSE

This study was undertaken to clarify the clinical significance of MUC-1 expression in the endoscopic treatment of colorectal carcinoma with submucosal invasion.

METHODS

One hundred eighty-four colorectal carcinomas with submucosal invasion were examined. The depth of submucosal invasion was classified as scanty or massive. The histologic subclassification at the deepest invasive portion was defined as well-differentiated, moderately well-differentiated, moderately to poorly differentiated, poorly differentiated, or mucinous adenocarcinoma. MUC-1 expression was examined immunohistochemically at the deepest invasive portion. In addition, the Ki67 labeling index was also examined immunohistochemically.

RESULTS

Lymph node metastases were detected in 28 (15.2 percent) of 184 lesions. Lesions with both scanty submucosal invasion and well-differentiated or moderately well-differentiated adenocarcinomas had no lymph node metastases. MUC-1 expression was detected in 88 (47.8 percent) of 184 lesions and correlated significantly with the presence of lymph node metastases. The Ki67 labeling index also correlated significantly with lymph node metastases. Furthermore, lesions with both MUC-1-negative and low Ki67 labeling index showed no lymph node metastases, even in lesions with massive submucosal invasion. Multivariate analysis indicated that MUC-1 expression was one of the most important risk factors for lymph node metastases and histologic grade among the clinicopathologic factors usually examined.

CONCLUSION

MUC-1 expression is one of the accurate predictors of the presence of lymph node metastases among the clinicopathologic factors commonly used. Combined analysis of MUC-1 expression and Ki67 labeling index may be a useful indicator of lymph node metastases and may broaden the indications for the curative endoscopic treatment of carcinoma with massive submucosal invasion.

A comparative study of nucleolar organizer region, proliferating cell nuclear antigen and epidermal growth factor receptor staining in colon tumours

Several studies have reported that proliferating cell nuclear antigen (PCNA), nucleolar organizer regions (NOR) and epidermal growth factor receptor (EGF-R) are cellular proliferation parameters in malignant tumours. However, the correlation of EGF-R with PCNA and NOR has not been reported in colon tumours. To clarify this, we investigated the correlation of the expression of EGF-R with PCNA and NOR in colonic epithelial tumours. Using immunohistochemical staining and one-step silver staining techniques, the expressions of EGF-R-, PCNA- and NOR-associated protein were studied in paraffin sections from five normal mucosae, 10 adenomas with mild atypia, 16 adenomas with moderate atypia, 32 adenomas with severe atypia including carcinoma in situ and 47 with invasive colon carcinomas. Significant differences were found among the respective degrees of atypia in Ag-NOR counts, PCNA labelling index (LI), and the expression of EGF-R. However, there were no significant differences among the Ag-NOR counts of the severe atypia and invasive carcinoma. There was a significant positive correlation between Ag-NOR counts and PCNA LI (P < 0.001). The Ag-NOR counts and PCNA LI in EGF-R-positive cases were higher than in EGF-R-negative cases (P < 0.001). These results indicate that each of the parameters increased significantly with the increase in atypia and the progression of cancer. Epidermal growth factor receptor provokes an exacerbation of protein synthesis and the cell cycle in colonic epithelial tumours.

Natural history of colorectal carcinoma: can the tumor volume doubling time be predicted by radiologic findings or immunohistochemical variables?

BACKGROUND AND OBJECTIVES

The factors influencing the growth rate of colorectal carcinoma have not been determined. The aim of this study was to clarify the relationship between the doubling time (DT), morphology, and proliferating cell nuclear antigen, Ki-67 and p53 immunohistochemistry in colorectal carcinoma.

METHODS

Thirty-three patients (37 lesions) were studied retrospectively. The DT was calculated and correlated with the initial and final tumor size, morphologic shape, and immunohistochemical results.

RESULTS

The DT ranged from 2.4 to 48.0 months (mean: 12.0 months). The mean DT of the early-stage carcinomas was significantly longer than that of the advanced carcinomas. In the latter group, both slowly growing and rapidly growing tumors were observed. The DT showed no correlation with the initial or final size and shape of the tumors on radiographs, or with the immunohistochemical results.

CONCLUSIONS

Our data revealed that it is not possible to evaluate the growth rate of colorectal carcinomas based on their morphological shape, cellular proliferative activity, or tumor suppressor gene activity.

Ki-67 expression in relation to clinicopathological variables and prognosis in colorectal adenocarcinomas

Ki-67 is a protein associated with cell proliferation which is expressed in all phases of the cell cycle except Go. In the present study, Ki-67 expression in 255 human colorectal adenocarcinomas was examined using immunohistochemistry with the monoclonal antibody MIB-1. One hundred and fifty-seven (62%) cases had more than 50% positive tumour cells and 98 (38%) cases less than 50%. The tumours showed a wide range of Ki-67 expression, from 13% to 90%, which indicated a variation in proliferative activity. There was no significant relationship between Ki-67 expression and sex, age, tumour location, Dukes' stage, growth pattern, differentiation, DNA content, S-phase fraction or survival (p > 0.05). In conclusion, the proliferative activity as measured by Ki-67 antibody was not related to clinicopathology and prognosis in colorectal cancer.

Ki-67, p53, and Bcl-2 expression of serrated adenomas of the colon

To investigate epithelial cell proliferation and oncoprotein expression of the serrated adenoma, a term that has been used synonymously with mixed hyperplastic and adenomatous polyp, immunohistochemical staining using polyclonal antibodies against Ki-67 and p53, and a Bcl-2 monoclonal antibody, was performed and the results compared with those in hyperplastic polyps and tubular adenomas. A total of 20 serrated adenomas all characterized by a serrated glandular pattern, contained immature goblet cells, upper crypt zone mitotic figures, and a few nucleoli within the epithelial cells. Twenty hyperplastic polyps and 20 tubular adenomas (all with low-grade dysplasia) were examined, and lesions that contained separate areas of hyperplastic and adenomatous glands were excluded. The Ki-67-positive rate in the middle zone of the crypts in serrated adenomas was significantly higher than in hyperplastic polyps but lower than in tubular adenomas; a similar tendency was also noted for the upper zone. Both serrated adenomas and hyperplastic polyps demonstrated Bcl-2-positive reactivity that was essentially limited to the lower crypt zone, while in contrast, involvement in tubular adenomas often extended to the middle zone. No p53 overexpression was found in any category. These results suggest that serrated adenomas may be committed to independent growth.

Determination of proliferative activity in colorectal carcinoma using monoclonal antibody Ki67

PURPOSE

In the search for a prognostic discriminant, Ki67 immunoreactivity of colorectal carcinoma was used to see whether this marker correlated with clinical and pathologic parameters and the ultimate prognosis of the patient.

METHODS

Fresh specimens from 30 surgically resected adenocarcinomas were obtained and frozen in liquid nitrogen. Slides were immunohistochemically stained with Ki67. Ten randomly chosen fields were examined, and 1,000 nuclei per specimen were counted. The percent positive stained nuclei determined the Ki67 score. Correlation was made with the parameters of Dukes stage, location within the colon, size of malignancy, gender, age, and survival.

RESULTS

There was a positive correlation of the Ki67 score for patients with metastatic disease, but no correlation was found to Dukes B and C cases. There was no correlation between Ki67 immunoreactivity and size or location of lesion, patient's age, patient's gender, or whether patient died of disease or developed a recurrence compared with those who survived five years disease-free.

CONCLUSION

Ki67 immunoreactivity could not be correlated with clinical and pathologic parameters except for metastatic disease in this study and was of limited use as a prognostic discriminant.

Proliferating cell nuclear antigen expression and its relationship to malignancy potential in invasive colorectal carcinomas

PURPOSE

Cellular proliferative activity is a useful indicator of biologic aggressiveness in colorectal carcinoma. Immunohistochemical analysis of proliferating cell nuclear antigen (PCNA) has important advantages of maintaining tissue architecture and technical simplicity. The aim of this study was to investigate the correlation between proliferative activity and malignancy potential in colorectal carcinomas to determine whether proliferative index of cancer cells has prognostic significance using immunohistochemical technique.

METHODS

Proliferation index at the invasive tumor margin of 86 paraffin sections of advanced colorectal carcinomas was assessed by immunohistochemical study using a mouse monoclonal antibody to PCNA (PC-10) and was compared with conventional clinicopathologic factors and other possible prognostic parameters, including p53 overexpression, tissue carcinoembryonic antigen immunoreactivity pattern, and flow cytometric DNA ploidy. In addition, recurrence and survival were analyzed in accordance with degree of PCNA expression.

RESULTS

PCNA labeling index (PCNA-LI) increased significantly as the Astler-Coller stage advanced (P = 0.0001). Strong correlations were observed between PCNA-LI and various pathologic parameters, including histologic differentiation (P = 0.0027), lymphatic invasion (P = 0.0001), vascular invasion (P = 0.0001), lymph node metastasis (P = 0.0001), and liver metastasis (P = 0.0036). Mean PCNA-LI was also significantly higher in tumors with DNA aneuploidy (P = 0.0006) and negative and cytoplasmic patterns of carcinoembryonic antigen immunoreactivity (P = 0.01). Linear relationships were demonstrated between PCNA-LI and clinical outcomes; recurrence rate was significantly greater in the group with higher than the mean PCNA-LI, who underwent curative resection (P < 0.01), and four-year survival rates for both overall and curative cases with higher than the mean PCNA-LI were significantly poorer than those with lower than mean PCNA-LI (P < 0.005 and P < 0.01, respectively).

CONCLUSION

Evaluation of PCNA-LI at the invasive tumor margin in colorectal carcinomas is suggested to be valuable in predicting those people with a higher potential for metastasis and recurrence after surgery; thus, the evaluation is helpful in planning reasonable adjuvant therapy, even in the earlier stages.

Ki-67 index in fine needle aspiration cytology specimens from primary and recurrent rectal cancer

A Ki-67 index was determined in 63 fine needle aspiration cytology (FNAC) specimens from patients with rectal cancer, 21 with primary cancers and 42 with local recurrences. Seventeen of the patients had received external irradiation before the examination. In primary cancers, in recurrences as well as in the post-irradiation cases, the mean percentage of Ki-67 positive cells was about 55% with a wide variation. The percentage of Ki-67 positive cells was independent of the length of the recurrence-free period. In conclusion, the Ki-67 antigen may well be studied in FNAC specimens. The presence of antigen did not correlate with development of recurrence, length of recurrence-free period or irradiation prior to the analysis.

Complete reversion and prevention of rectal adenomas in colectomized patients with familial adenomatous polyposis by rectal low-dose sulindac maintenance treatment. Advantages of a low-dose nonsteroidal anti-inflammatory drug regimen in reversing adenomas exceeding 33 months

PURPOSE

This nonrandomized, controlled Phase II pilot study aims at the lowest effective dose of rectally applied sulindac to achieve and maintain adenoma reversion in colectomized patients with familial adenomatous polyposis (FAP).

METHODS

The study group (n = 15) underwent proctoscopic and laboratory follow-up for polyp reversion every 6 to 12 weeks. Polyp reversion was followed by dose reduction in predefined steps. Proliferating cell nuclear antigen/cyclin (PCNA) and KI-67 proliferation indices (PI) were performed by point counting. Prostaglandin (PG)E2 and PGF2 alpha were quantified by time-resolved competitive fluorescence immunoassay.

RESULTS

All patients responded to therapy within 6 to 24 weeks. Sixty and 87 percent of patients achieved complete adenoma reversion after 48 weeks at 53 and 67 mg of sulindac per day per patient on average, respectively. Reversion was evident compared with the control group. Dose reduction by one-sixth to one-eighth of the usual oral dose was significant (Mann's trend test, P < 0.05). PCNA and KI-67 PIs of adenomatous and flat mucosa were significantly reduced (Wilcoxon's test, P < 0.05). Correlation of PCNA and KI-67 PIs indicate similar reaction of different tissue structures (Spearman's rank correlation test, P < 0.01). Nonsteroidal anti-inflammatory drug-induced redifferentiation from high-grade to low-grade dysplasia occurred in all but two patients. Tissue-PGE2 levels were greatly reduced. Unwanted, curable side effects were rare (gastritis, n = 2), and laboratory controls are within detection limits.

CONCLUSIONS

Low-dose rectal sulindac maintenance therapy is highly effective in achieving complete adenoma reversion without relapse in 87 percent of patients after 33 months. Rectal FAP phenotype should be crucial for the surgical decision. Colectomy with ileorectal anastomosis and regular chemoprevention might proceed to be a promising alternative to pouch procedures. Chemoprevention with lower incidence of FAP-related tumors via dysplasia reversion may be possible in the future.

Evidence for quiescent S- and G2-phase cells in human colorectal carcinomas: a flow cytometric study with the Ki-67 antibody

The expression of certain antigens specific for proliferating cells can be determined simultaneously with cell cycle distribution by means of two-dimensional flow cytometry. In this way, a tumour's growth potential is characterized more precisely than with any one parameter alone. Here we describe such simultaneous measurements of DNA content and labelling with the Ki-67 antibody that distinguishes between cycling and non-cycling cells. Having overcome a number of technical problems we were able to analyse material from 29 biopsies of human colorectal tumours. In a number of cases, Ki-67 negative cells were found with a DNA-content of G0/1 only, whereas all cells with an S- or G2-phase DNA-content were Ki-67 positive. There were other cases in which cells with an S- and G2-phase DNA-content had obviously become quiescent (Ki-67 negative), sometimes even outnumbering the proliferating (Ki- 67 positive) cells in the respective compartments of the cycle. Generally, however, when Ki-67 negative and positive subpopulations were analysed separately it was found that the former had a significantly lower (S + G2)-phase fraction than the latter. There was evidence for a correlation between Ki-67 index and (S + G2)-phase fraction at least in the subgroup of aneuploid tumours. Neither of the two parameters was correlated with stage according to Duke's classification or tumour size. However, a positive correlation was found between the fraction of unlabelled S- and G2-phase cells and tumour size as reflected in the T category.

Rectal cancer: the influence of tumor proliferation on response to preoperative irradiation

PURPOSE

Regression of rectal carcinoma after preoperative irradiation is variable, likely reflecting differences in the physical and biologic properties of these tumors. This study examines the association between the pathologic response of rectal cancer after irradiation and its pretreatment proliferative state as assayed by the activity of the proliferative dependent antigens (Ki-67, PCNA) and mitotic counts.

METHODS AND MATERIALS

One hundred and twenty-two patients with locally advanced rectal cancer received preoperative irradiation followed by surgery. Pretreatment tumor biopsies were scored for the extent of Ki-67 and PCNA immunostaining and the number of mitoses per 10 high-powered fields. Postirradiation surgical specimens were examined for extent of residual disease.

RESULTS

The tumors of 38 of 122 patients (31%) exhibited marked pathologic downstaging (no residual tumor or cancer confined to the rectal wall) after preoperative irradiation. Two features were associated with the likelihood of marked pathologic regression after preoperative irradiation: tumor proliferative activity and lesion size. When stratified by lesion size, marked tumor regression occurred most frequently in smaller tumors with high Ki-67, PCNA, and mitotic activity compared to larger tumors with lower Ki-67, PCNA, and mitotic activity. Intermediate downstaging rates were seen for small or large tumors with moderate Ki-67, PCNA, and mitotic activity.

CONCLUSION

Tumor Ki-67, PCNA, and mitotic activity predicts the likelihood of response to irradiation, which may aid in formulating treatment policies for patients with rectal cancer.

A comparison of cellular proliferation markers in squamous cell carcinoma of the head and neck

Head and neck squamous cell carcinoma has a relatively good prognosis but treatment may be at the expense of function and quality of life. Various host and tumour parameters have been studied in an attempt to predict the course of the disease but without success. It has been hoped that laboratory based methods, particularly those based on molecular biology, may prove more useful. Cell kinetic parameters are studied in this paper. The present study includes 75 patients with a proven squamous cell carcinoma of the head and neck at various sites and undergoing various forms of treatment. The patient's mean age was 62 years and the median survival rate 45 months. Immunohistochemical techniques using Ki67 and PCNA were compared with flow cytometric analysis which included the BRDU labelling index, the duration of S phase, ploidy and potential doubling time. The median PCNA index was 560 and the Ki67 index 298. These indices varied between 980 and 150 for PCNA and 808 and 110 for Ki67. The BRDU labelling index measured by flow cytometry was 8.9 with a range from 25 to 1.6 and the duration of S phase was 14.8 hours. The PCNA index failed to correlate with any host or tumour factors and this failure was also seen in Ki67 indices and also in the flow cytometric parameters. There was a strong correlation between PCNA and Ki67 expression (p < 0.0001). Neither PCNA nor Ki67 values were significantly different between irradiated and nonirradiated tissues nor in sites or in patients who later developed lymph node metastases.(ABSTRACT TRUNCATED AT 250 WORDS)

An evaluation of five different methods for estimating proliferation in human colorectal adenocarcinomas

Five different methods of determining cell proliferation have been compared in samples taken from a group of 125 human colorectal tumours labelled in vivo with iododeoxy-uridine (IUdR). The labelling index (LI) was obtained immunocytochemically using monoclonal antibodies against proliferating cell nuclear antigen (PCNA), the Ki67 antigen and IUdR (IUdRimm). Incorporation of IUdR was also determined flow cytometrically (IUdRfcm) and PCNA expression was measured in both formalin- and methanol-fixed tissue (PCNAf and PCNAm respectively). There was significant variation in the results obtained both within and between the different assays. Paired analysis of the data showed that the correlation between the different methods of determining the LI was poor. However, the IUdRfcm LI was significantly correlated with both IUdRimm (r = 0.39; n = 78; P < 0.001 by Spearman's test) and Ki67 LIs (r = 0.32; n = 87; P < 0.001). The IUdRimm LI was also significantly related to the Ki67 LI (r = 0.44; n = 60; P < 0.001). The median IUdRfcm and IUdRimm LIs were significantly higher in the aneuploid vs. the diploid tumours (17.4% vs. 6.2% for IUdRfcm; 23.2% vs. 18.9 for the IUdRimm; P < 0.001 and P = 0.014 respectively by Mann-Whitney U-test) but none of the other proliferative indices showed this relationship. Finally, none of the LIs showed a significant association with the clinical characteristics of the tumours such as stage, grade, age, sex or fixity. The findings of this investigation highlight the need for carefully controlled studies when assessing the value of proliferation markers in solid human tumours.

Proliferating cell nuclear antigen expression at the invasive tumor margin predicts malignant potential of colorectal carcinomas

BACKGROUND

Proliferative activity may be a useful measure of malignant potential for a variety of tumors. Colorectal carcinomas contain multiple cell populations with different biologic properties. The invasive tumor margin is thought to represent the area with the highest metastatic potential.

METHODS

Cell proliferation at the invasive tumor margin of 49 specimens of advanced colorectal carcinoma was assessed by immunohistochemical staining of proliferating cell nuclear antigen (PCNA) and compared with clinicopathologic findings.

RESULTS

Colorectal carcinomas showed a wide range of PCNA labeling indexes (LI), reflecting variation in proliferative activity. The PCNA LI of tumors showing venous invasion (mean, 51.7% +/- 16.2%) was significantly higher than that of tumors without venous invasion (mean, 36.7% +/- 18.2%; P < 0.01). A strong association was observed between the PCNA LI and the metastatic potential of colorectal carcinoma; the PCNA LI of tumors showing lymph node metastasis (mean, 50.5% +/- 17%) was significantly higher than that of tumors without nodal involvement (mean, 39.8% +/- 18.5%; P < 0.05). In addition, the PCNA LI of tumors metastatic to liver (mean, 55.2% +/- 15.7%) was significantly higher than that of tumors without liver metastasis (mean, 41.0% +/- 17.6%; P < 0.01). Correlation with histologic features at the invasive tumor margin showed that a higher PCNA LI was associated with less differentiated tumors (P < 0.05).

CONCLUSION

Evaluation of the PCNA LI at the invasive tumor margin may help identify colorectal carcinomas that have a higher malignant potential.

Has the cellular proliferation marker Ki67 any clinical relevance in squamous cell carcinoma of the head and neck?

Over the years many laboratory factors have been studied with a view to predicting the course of head and neck cancer. The lack of success prompted the application of various measures of cell kinetics to this topic. The present study includes 79 patients with a proven squamous cell carcinoma of the head and neck at various sites and having various treatments. Ki67 staining was carried out using the avidin-biotin complex method and counts recorded per 1000 tumour cells. The patients' mean age was 61 years and the 5 year survival was 54% (95% CI, 29-73%). The median Ki67 index was 278 representing the number of cells stained positively per 1000 tumour cells. The minimum staining was 82 and the maximum 808 with a lower quartile of 95 and an upper quartile of 452. The Ki67 index failed to correlate with any host or tumour factors. In addition, median Ki67 values were not significantly different between irradiated tissue and non-irradiated tissue, between sites nor between patients who did and did not later develop lymph-node metastases. Of particular relevance is that Ki67 value did not correlate with survival. Data was further analysed using Cox's proportional hazards model for survival. Ki67 had no significant effect on survival. It is concluded that Ki67 index is of no value in predicting the course of squamous cell carcinoma of the head and neck.

Transient increases of growth fraction during fractionated radiation therapy for cervical carcinoma. Ki-67 and PC10 immunostaining

BACKGROUND

The Ki-67 and PC10 indexes are consistent with the growth and S-phase fractions, respectively.

METHODS

Eighty-three biopsy specimens from 18 patients with cervical squamous cell carcinoma were examined before and during fractionated radiation therapy (RT), using an immunohistochemical method.

RESULTS

The 18 patients were divided into two groups according to the Ki-67 index before RT; those with values of less than 42% (Group A; n = 11) and those with values of 42% or more (Group B; n = 7). The Ki-67 index in Group A increased approximately twofold at radiation doses of 5.4-9 Gy compared with values before RT. The Ki-67 index in Group B, which increased slightly at doses of 5.4-9 Gy, decreased by approximately one-fifth at a dose of 27 Gy, compared with the value before RT. The PC10 indexes in both groups showed little change to doses of 5.4-9 Gy. The mitotic indexes were less than 1% before RT and decreased to a minimum with doses of 18-27 Gy. There was no correlation between the Ki-67 and PC10 indexes before or during RT.

CONCLUSION

In cancer tissues with a low growth fraction before RT, radiation doses of 5.4-9 Gy produced increases in the numbers of cycling cancer cells in the G1 or G2 phases. This transient increase possibly was attributable to the combined effects of the recruitment phenomenon and G1 or G2 block.

Ki-67 antigen expression and growth pattern of basal cell carcinomas

The expression and location of the Ki-67 antigen was investigated in 62 basal cell carcinomas (BCC) using immunostaining techniques (PAP and APAAP) on cryostat sections. The tumor samples were classified into three groups according to microarchitecture (nodular, superficial or fibrosing). The Ki-67 growth fraction displayed great variation between tumors belonging to the same group (nodular type, 7-67%; superficial type, 18-49%; fibrosing type 4-33%). In nodular and superficial BCC formations Ki-67 reactivity was confined either to the nuclei of three to five rows of peripheral cells, or Ki-67-positive nuclei were scattered in the central as well as in the peripheral parts of the tumor strands. The staining patterns varied in an individual tumor. Areas with a high Ki-67 labelling index often occurred adjacent to rather quiescent strands, suggesting that an individual tumor is not in a uniform state of proliferation. So far there are no experimental findings on the regulation of proliferative activity in BCCs. In view of the fact that BCCs are rather slow-growing tumors, the large Ki-67 growth fractions indicate a prolonged duration of the cell cycle or a considerable continuous loss of cells. As the microarchitecture of BCCs is much more complex than would be expected from the location of their Ki-67-positive cells, the growth pattern is probably determined to a high degree by the adjacent connective connective tissue (physical properties and texture of collagen and elastic fibres, enzyme activity of fibroblasts).

Evaluation of Ki-67 monoclonal antibody as prognostic indicator for prostatic carcinoma

Prostate tissue containing either primary adenocarcinoma (45 patients) or benign hyperplasia (15 patients) was immunostained with the monoclonal antibody Ki-67, which recognises a human nuclear antigen expressed by human cycling cells. The percentage of cells staining positive was considered a measure of proliferation. This derived Ki-67 index was higher for carcinomas than for hyperplastic glands. Within the group of carcinomas, Ki-67 indices in patients with metastatic disease were significantly higher than in those without and there was a trend towards increasing Ki-67 indices with increasing Gleason grade. When patients with prostate cancer were prospectively followed up, the Ki-67 index did not predict either disease progression or hormone responsiveness. Ki-67 immunostaining may define a group of patients with prostate cancer of poor prognosis.

Expression of the histone H3 gene in benign, semi-malignant and malignant lesions of the head and neck: a reliable proliferation marker

To search for a reliable proliferation marker in epithelial head and neck lesions, we have analysed the expression of the histone H3 gene by in situ hybridisation and compared this with the immunoreactivity of the widely used monoclonal antibody Ki-67. In many lesions, the Ki-67 staining failed to delineate proliferation. In contrast, the H3 hybridisation signals were in accordance with the histopathology of the biopsies: in hyperplastic epithelia, significant H3 mRNA levels were only seen in areas with inflammation. Dysplastic cells showed distinctly elevated H3 expression. Benign and semi-malignant tumours, i.e. basal cell carcinomas, showed moderate H3 signals at the periphery. In squamous cell carcinomas, H3 expression was always high at the expanding zone of the tumour and was most extensive in undifferentiated carcinomas. Thus, the expression of the histone H3 gene closely reflected the dynamics of neoplastic growth within and around head and neck tumours.

Production of matrix metalloproteinase-2 and metalloproteinase-3 related to malignant behavior of esophageal carcinoma. A clinicopathologic study

BACKGROUND

Matrix metalloproteinases (MMP) are a gene family of zinc enzymes capable of degrading almost all of the extracellular matrix macromolecules in vivo. Their enzymic activities are believed to be responsible for tumor invasion and metastasis.

METHODS

In this study, using peroxidase-antiperoxidase method, monospecific antisera against MMP-1 (tissue collagenase), MMP-2 (type IV collagenase/72-kilodalton [KD] gelatinase), and MMP-3 (stromelysin) were applied to 29 squamous cell carcinomas and normal epithelium of the esophagus to identify cells synthesizing and secreting these enzymes.

RESULTS

Immunoreactivity of MMP-1, -2, and -3 was observed in small cancer nests of the deeply invasive or marginal portion of the tumor. Among the 29 patients studied, the presence of at least one MMP was observed in 17 (58.6%). All three enzymes were observed in six (20.6%) patients, MMP-2 and -3 in five (17.2%) patients, only MMP-2 in three (10.3%) patients, and MMP-3 alone in three (10.3%) patients. There was a good correlation among histologic stage and tumor invasion, lymph node metastasis, and MMP expression. In particular, expression of MMP-2 and -3 was closely related to lymph node metastasis and vascular invasion.

CONCLUSIONS

These results suggest that MMP, especially MMP-2 and -3, play an important role in tumor invasion and metastasis and that analysis of MMP-2 and -3 production is useful for evaluation of malignant potential in esophageal carcinoma.

Ki-67-determined growth fraction versus standard staging and grading parameters in colorectal carcinoma. A multivariate analysis

BACKGROUND

The antibody Ki-67 binds to nuclei in all cell cycle phases except GO and can be used to measure growth fraction. Because proliferative activity has been linked to prognosis in neoplasia, the authors analyzed 100 cases of colorectal carcinoma, each with 3 or more years of follow-up, using Ki-67 immunostaining.

METHODS

The Ki-67-positive nuclear area and total nuclear area of carcinoma cells in 20 microscopic fields were measured by computed morphometry. A Ki-67 score (percent positive nuclear area x 100) was calculated. The following characteristics also were recorded for each case: patient age and sex, tumor site and size, modified Dukes' stage, spread beyond bowel wall, lymph node status, tumor grade, histologic type, extramural venous spread, tumor growth pattern, fibrosis, lymphocytic infiltration, and mitotic rate.

RESULTS

Ki-67 scores ranged from 1 to 90 (mean, 34.6). Ki-67 scores were higher in Stage A disease (versus Stage B, C, and D disease) but were not associated with survival. Survival curves differed by stage, lymph node metastases, infiltrative growth pattern, lymphocytic infiltration, fibrosis, extramural venous spread, and tumor grade in a univariate analysis. The infiltrative growth pattern (P = 0.04) and lymphocytic infiltration (P = 0.003) were features associated independently with survival after adjusting for modified Dukes' stage. Furthermore, the lack of a significant lymphocytic infiltrate was associated with a death rate 3.4 times greater than that occurring in patients with Stage B disease with a significant infiltrate.

CONCLUSIONS

The authors conclude that proliferative activity in colorectal carcinoma as measured by Ki-67 immunostaining was not associated with prognosis.

Prognostic markers of colorectal cancer: an evaluation of DNA content, epidermal growth factor receptor, and Ki-67

Between January 1989 and August 1991, 62 patients undergoing resection for colorectal adenocarcinoma were assessed in a prospective fashion on the basis of various tumor characteristics that are thought to indicate prognosis. Parameters measured included epidermal growth factor receptor (EGFr) expression, a cell membrane receptor known to be overexpressed in a variety of tumors, Ki-67, a monoclonal antibody marker of cell proliferation, as well as flow cytometry and standard histologic examination. Statistical analysis included chi square with Yates correction when appropriate, Wilcoxon W, and multivariate logistic regression. EGFr positive tumors were associated with worse Dukes' stage (27% of EGFr negative tumors were Dukes' C or D vs. 58% of EGFr positive tumors, P = 0.03), as well as more aneuploid characteristics by flow cytometry (48% EGFr negative = aneuploid vs. 82% EGFr positive = aneuploid, P = 0.01). Lymphatic invasion was more frequent in EGFr positive tumors (P = 0.03). These factors proved to be independent of each other by multivariate analysis. Ki-67 did not correlate with any of the measured parameters and was of extremely limited use in the evaluation of the study population. Multivariate analysis indicated that aneuploid tumors were associated with worse Dukes' stage than diploid tumors. Histologic parameters such as lymphatic and vascular invasion as well as histologic grade are compared to the other parameters involved with prognosis.

Comparison of proliferation rates assessed using "multiblock" and conventional tissue blocks of lung carcinoma

AIMS

To compare the proliferative rates, assessed immunohistochemically, of human lung tumours using conventional paraffin wax blocks and the multitumour tissue block (MTTB) technique.

METHODS

A multiblock containing 20 lung tumours (eight adenocarcinomas, five squamous cell, five small cell and two carcinoid tumours) was constructed. Sections were also cut from the original blocks of formalin fixed, paraffin wax embedded tissue used to construct the multiblock. Sections were stained with the monoclonal antibody PC10, which recognises a proliferating cell nuclear antigen, using the three stage immunoperoxidase technique.

RESULTS

The proliferation rates of the lung tumours obtained using both techniques were, overall, significantly different (p = 0.05), although most cases showed good correlation. Some tumours displayed a high degree of intratumoral variation in PC10 staining. The degree of PC10 staining was in keeping with the known proliferative state of particular histological subtypes--that is, carcinoid tumours showed little staining and small cell carcinomas showed extensive positivity.

CONCLUSION

The MTTB technique is a less suitable means of assessing proliferation rate in lung carcinomas than conventional tissue blocks. It should be restricted to qualitative antibody studies or quantitative studies using tumours with little intratumoral variation.

Cell cycle dependent expression and stability of the nuclear protein detected by Ki-67 antibody in HL-60 cells

The expression and stability of the proliferation-associated nuclear antigen detected by Ki-67 antibody have been investigated in human promyelocytic leukaemic HL-60 cells in relation to their progression through the cell cycle. Expression of this antigen was minimal in late G1 and early S phase cells. The antigen accumulated in the cells predominantly during S phase, and its rate of increase per cell accelerated during the second half of this phase. The accumulation of Ki-67 antigen during S exceeded the increase in DNA content, and thus the Ki-67/DNA ratio rose 80% from late G1 to G2 + M. This antigen rapidly disappeared from post-mitotic cells. The half-life of this protein estimated in post-mitotic cells during stathmokinesis induced by vinblastine appeared to be shorter than 1 h. This rapid turnover should be compared with the relatively long (6-8 h) duration of G1 of the studied cells. In cells in which de novo protein synthesis was inhibited by 0.1 microgram/ml cycloheximide, the half-life of the Ki-67 antigen was also found to be about 1 h regardless of the cell position in the cell cycle. Thus, the data suggest that variations in the level of this protein during the cell cycle are a consequence of its different synthesis rate rather than phase-specific changes in the rate of its degradation. Because the late G1 and very early S phase cells express the antigen at levels only slightly above background, it is possible that, when using Ki-67 antibody as a marker of the cell growth fraction, some late G1 cells can be erroneously classified as non-cycling cells.

Morphometry and cell proliferation in endoscopic biopsies: evaluation of a technique

A simple method for the quantification of intestinal epithelial cell proliferation in humans was evaluated. Endoscopic biopsy specimens were stained and microdissected, and the number of mitoses per gland or crypt was determined, as was the area of these units. The technique could readily be applied to tissue from the stomach, small intestine colon, and rectum. The number of mitoses and the size of the proliferative compartments increased caudally from the stomach to the cecum in humans. There was a good correlation between area and mitoses per gland or per crypt (r = 0.89; P less than 0.001), confirming the general equivalence between proliferative rate and compartment size. The method was validated by comparing microdissection-derived data with data previously obtained as part of an autoradiography-based study in the dog. This showed that similar differences in proliferation and crypt cell mass could be obtained but in less than one sixth of the time taken to score autoradiographs. It is concluded that this method for the estimation of gastrointestinal epithelial proliferation correlates well with other well-established techniques, confers speed as well as accuracy, has an all encompassing denominator, and can thus avoid many of the problems associated with the quantification of tissue sections.

Ki 67 immunostaining in melanocytic skin tumors. Correlation with histologic parameters

A total of 145 melanocytic tumors (nevus, 38; primary malignant melanoma, 72; metastatic malignant melanoma, 35) were stained with Ki 67 monoclonal antibody using a three-step immunoperoxidase technique. For each case, mean numerical density and maximum numerical density of Ki 67 positive nuclei (number per mm3) were quantitatively evaluated using interactive image analysis. Maximum numerical densities revealed highly significant differences. Within the group of primary malignant melanomas, there was a significant correlation between proliferative activity and maximum tumor thickness. Further, a 'Ki 67-prognostic index' was assessed in each case of primary malignant melanoma, calculating the product of the Breslow index and maximum numerical density/1000 (103 +/- 12; range 1-694). In a prospective, short-term evaluation of primary malignant melanomas, there was a significant difference concerning 'Ki 67-prognostic index' between disease-free survival and occurrence of metastases. After a follow-up time of 24 months, only 63% of the patients with a 'Ki 67-prognostic index' greater than 25 were disease-free, whereas no patient with a 'Ki 67-prognostic index' less than 25 was found to have metastases. We conclude: assessment of the maximum numerical density of Ki 67 reflects the degree of malignancy in melanocytic skin tumors; within primary malignant melanomas, maximum numerical density of Ki 67 positive cells correlates with well-established prognostic parameters (tumor thickness, level of invasion, mitotic rate); assessment of the 'Ki 67-prognostic index' may be of additional prognostic value for patients with primary malignant melanoma.