High Ki-67 Score Research Articles

Relevance of Ki-67 antigen expression and K- ras mutation in colorectal liver metastases

Aims The liver is a frequent site of metastases from colorectal cancer. While these lesions are potentially amenable to surgical resection, they are usually very aggressive, and recurrence is frequent. Mutations of the proto-oncogene K- ras are thought to impart a strong growth signal to tumour cells and are closely associated with the development of malignancies of the colon and rectum. Hepatic metastases from colorectal cancer have notably elevated proliferative rates. The present study was performed to investigate the relationship between proliferation or K- ras mutation and prognosis following curative resection of colorectal liver metastases. Methods Colorectal liver metastases from 41 patients undergoing curative hepatic resection were examined for proliferation status and presence of K- ras mutations. The proliferative activity was assessed by Ki-67 immunohistochemistry. DNA from the same tissue samples was screened for point mutations in codon 12 of the K- ras gene using a novel microplate-based allelic-specific hybridization assay. Ki-67 scores and K- ras status were then related with patient survival as determined through retrospective analysis. Results Median survival was 40 months. Patients with high Ki-67 scores (≥50%) had significantly shorter median survival compared with those with low scores (30 vs 44 months, log-rank P=0.02). A high Ki-67 score was an independent negative prognostic factor by multivariate regression analysis (relative risk=3.04, P=0.036). K-ras point mutations were detected in 6/41 patients (15%), but mutational status did not correlate with Ki-67 score or survival. Conclusions These findings suggest that the tumour proliferative index is a useful predictor of aggressive tumour behaviour and an indicator of patient survival. The presence of K- ras mutations does not appear to correlate with tumour proliferation status or patient survival.

Ductal carcinomas of the prostate: a clinicopathological and immunohistochemical study.

To confirm the expression of prostate specific antigen (PSA) and prostatic acid phosphatase (PAP) in ductal carcinomas of the prostate, and to analyse p53, Ki67, oestrogen (ER) and androgen (AR) receptors in these tumours. Paraffin-embedded samples from 12 patients with ductal carcinoma of the prostate were assessed for pattern, mitotic count and the presence of a microacinar carcinoma component. There were six pure ductal and six mixed microacinar and ductal carcinomas. Sections were stained immunohistochemically for the expression of PSA, PAP, Ki67, p53, AR and ER. Clinical data were obtained from case notes. Six of the ductal tumours had a papillary pattern whilst the others had a cribriform appearance. The mitotic rates in the ductal areas were high in the tumours from eight of the 12 patients. PSA and PAP immunohistochemistry were positive in all the cases. No ER immunoreactivity was found in any of the patients. Ten of the ductal tumours showed strong reactivity with AR, the other two were weakly positive; two of the tumours were strongly positive for p53 protein. All the ductal carcinomas expressed Ki67, three having > 25% nuclear marking. One patient who was strongly positive for p53 and had a high Ki67 score survived only one year after diagnosis. Survival ranged from 1 to 13 years after diagnosis. This study confirms the expression of PSA and PAP in ductal carcinomas of the prostate. The percentage of tumours expressing p53 was similar to that published for high-grade microacinar carcinomas. The results for Ki67 suggest that ductal tumours have higher scores than microacinar tumours, but further studies are required to ascertain if this is significantly different. As half the patients with ductal tumours had co-existent microacinar tumours, we advise transrectal prostatic biopsies in patients diagnosed with pure ductal carcinomas on transurethral resection specimens, to exclude high-grade microacinar carcinomas. The presence of AR and the lack of ER in all the ductal carcinomas confirms that these tumours are prostatic in origin and should be treated with antiandrogen therapy.

P53 is a persistent and predictive marker in advanced ovarian carcinomas: multivariate analysis including comparison with Ki67 immunoreactivity.

p53 mutation and p53 protein overexpression are common findings in ovarian carcinomas. In order to evaluate the prognostic significance of the p53 status and its role in metastasis, we examined 104 ovarian carcinomas, among them 83 cases with follow-up data, and 40 pairs of primary tumors and metastases, by p53 immunohistochemistry and temperature-gradient gel electrophoresis. Comparison of primary tumors and their metastases revealed identical results in 88%-90% of the cases, indicating that, in most cases, mutant p53 occurs prior to metastatic spread and remains clonally conserved. With respect to all tumors, moderate/high p53 expression was significantly more prevalent in serous-papillary types, carcinomas with high grade, and high Ki67 scores, but was not associated with age, stage, or hormone receptor status. Kaplan-Meier analysis of 83 cases, followed-up for 9-96 months, demonstrated that moderate/high p53 overexpression in the group of 66 stage T3/M1 tumors was associated significantly (P = 0.0028 and P = 0.0105) with shorter overall and recurrence-free survival. Multivariate analysis revealed that advanced clinical stage and p53 positivity were the only independent predictive variables. No significance was seen in regard to second-look results and outcome of 50 patients receiving platinum-based chemotherapy. These observations show that p52 immunohistochemistry is an independent prognostic indicator at the given cut-off level, but does not reliably predict chemotherapy response.

Breast conservation without axillary dissection: the role of axillary radiotherapy

Breast cancer is a heterogeneous disease. Many women who are given adjuvant cytotoxic chemotherapy for breast cancer receive no benefit from this treatment because established micrometastases are resistant to the chemotherapy. Integrated analysis of genetic alterations that i) disregulate the cell division process, resulting in faster cell proliferation, ii) affect physiologically cell death mechanisms that cause slower rates of cell loss and iii) enhance drug resistance, may be useful for defining the biology of response of breast carcinoma to adjuvant treatment. Immunohistochemistry with antibodies recognizing ER, PgR, Ki-67, HER-2/neu, ~53, bcl-2, encoded products was performed on 156 primary high risk breast carcinoma (Premenopausal patients: T> 1 cm, G2-3, NO1, any ER/PgR status; Postmenopausal: T> 1 cm, G2-3, NO-l, ER-/PgR-) who received four cycles of adjuvant HD EC (Epirubicin 120 mg/m’ iv. on day 1, Cyclophosphamide 600 mg/m2 i.v. on day 1) with or without Lonidamine between March 1991 and December 1993. Graphical correspondence analysis of multivariate relationship showed that a p53-, bcl-2+, HER-Uneu-phenotype with nuclear grade 2 and low Ki-67 score characterizes most lobular carcinomas (ILC) while ductal carcinomas (IDC) were frequently identified by a bc12-, p53+, HER-2/ neu-phenotype with nuclear grade 3 and high Ki-67 score. Separate multivatiate analysis (Cox model) demonstrated an independent prognostic role of ~53, nodal status and Ki-67 score in predicting short-term (36 months) disease-free-survival in the IDC group whereas only bcl-2 emerged as significant predictive parameter in the ILC group. Multiparametric analysis conducted on several biopathological parameters might be useful for distinguishing different biological behaviours of breast carcinoma in the adjuvant setting. Our findings suggest that bcl-2 and ~53 may play an important role in ILC and IDC respectively.

Correlation between the lymphocytic infiltration of tumors and the proliferative activity of cancer cells from surgically treated esophageal carcinoma.

To evaluate the correlation among the biological behavior of cancer cells, the local immune response of the host, and survival of patients with esophageal carcinoma, we investigated the proliferative activity of cancer cells by immunostaining with the Ki-67 monoclonal antibody in 95 cases of surgically resected esophageal squamous cell carcinoma and compared them with the extent of lymphocytic infiltration of the tumor (LI) in the same specimens. The mean Ki-67 score of 43 tumors with low-grade LI was 46.7% and it was not different from that of 52 tumors with high-grade LI (49.4%, p = 0.441). A significant correlation between the Ki-67 score and the clinicopathological characteristics of tumors (depth of tumor invasion, lymph node metastasis, and stage) was detected. However, in the same stage, the survival of patients with a low Ki-67 score was not different from that of patients with a high Ki-67 score. On the other hand, even no significant correlation between the extent of LI and the clinicopathological characteristics of tumors was found; the 5-year survival rate of 17 patients with high-grade LI (13.9%) was significantly better than that of 15 patients with low-grade LI (0%, p = 0.07) in stage III. These facts indicate that proliferative activity might correlate with the tumor progression, however, when the survival is compared in the same stage, the local immune response such as the extent of lymphocytic infiltration of the tumor might be the better prognostic factor than proliferative activity in patients with esophageal cancer.

Prognostic Factors Including Proliferation Markers Ki-67, bax, and bcl-2 in Temporal Bone Paraganglioma

Valuable criteria with which to predict the clinical behavior of the temporal bone paraganglioma or the response to treatment are lacking. The analysis of markers of cell proliferation is a possibility to estimate the prognosis. Extensive patient data on 40 temporal bone paragangliomas were gathered over the years and correlated with the data obtained by staining histologic sections with bcl-2, bax, and MIB I markers of cellular proliferation. The immunohistochemistry was in all cases negative for bcl-2, positive for bax, and for Ki-67 positive in 20% of tumors. The scores for Ki-67 did not correlate with the majority of clinical parameters, except for treatment modality, preoperative hearing loss, and cranial nerve involvement. The tendency toward poorer hearing and a higher incidence of preoperative lower cranial nerve palsies was demonstrated in patients with higher Ki-67 scores. Furthermore, the higher rate of subtotal tumor removals in these patients reveals technical difficulties in accomplishing a radical removal, although the incidence of residual tumors was thus not affected. In view of the present information obtained with proliferation markers, the site of tumor origin still remains the most predictive variable for the course of the disease.

Correlation of growth fraction by Ki-67 and proliferating cell nuclear antigen (PCNA) immunohistochemistry with histopathological parameters and prognosis in primary breast carcinomas.

The immunoreactivity for Ki-67 and PCNA was investigated in 487 patients with primary breast carcinomas using MIB-1 (Immunotech, France) and PC-10 (DAKO, Denmark) as primary antibodies. Formalin-fixed and paraffin-embedded tissue sections were used. The immunoreactivity for Ki-67 and PCNA was found to be independent of the length of fixation if the sections were pretreated in a microwave oven in citrate buffer and distilled water, respectively. The immunostaining was evaluated semiquantitatively. High Ki-67 score (more than 1% positive tumour cells) and PCNA over-expression (more than 25% positive tumour cells) were correlated with clinicopathological parameters such as large tumour size, high histological grade (poor differentiation), and absence of steroid hormone receptors, which are parameters of an aggressive phenotype of the tumour. In univariate analysis of survival data, both Ki-67 and PCNA were parameters of a poor overall survival in both lymph node-positive and -negative patients. In multivariate anlaysis using a Cox model stratified by nodal status, Ki-67 and PCNA failed to be of prognostic significance whereas classical histopathological parameters such as tumour size and histological grade turned out to be of independent prognostic significance in both lymph node-positive and -negative patients, while progesterone receptors were of independent prognostic significance only in lymph node-positive patients.

C-erbB-2/neu Oncogene and Ki-67 analysis in the assessment of palatal salivary gland neoplasms

To evaluate the role of the Ki-67 proliferation antigen and c-erbB-2/neu oncogene expression in the clinical assessment of salivary gland tumors, we followed up 71 patients with minor salivary tumors of the palate. All benign neoplasms ( n = 18) showed low Ki-67 scores (<12%), whereas 26% (14 of 53) of malignant neoplasms manifested high Ki-67 scores (>12%). A significant statistical difference between Ki-67 scores for benign and malignant neoplasms was observed ( p <0.001). Ki-67 index also correlated significantly with malignant tumor grade ( p = 0.04) and patient survival ( p = 0.02). Only 1 of the 18 benign tumors had c-erbB-2/neu oncogene overexpression. A significant difference between c-erbB-2/neu overexpression in benign and malignant tumors was observed ( p = 0.01). Overexpression of c-erbB-2/neu oncogene was noted in 38% (16 of 42) of malignant tumors and was significantly associated with aggressive tumor behavior ( p <0.001). Multivariate analysis of significant factors revealed that gender, tumor stage, and c-erbB-2/neu oncogene overexpression were jointly predictive of survival. Our data indicate that although the Ki-67 proliferating antigen and c-erbB-2/neu oncogene expression may reflect certain intrinsic biologic properties of these neoplasms, only c-erbB-2/neu overexpression is significantly associated with their biologic aggression.(OTOLARYNGOL HEAD NECK SURG 1995;112:391-8.)

C‐erbB‐2/neu Oncogene and Ki‐67 Analysis in the assessment of palatal salivary gland neoplasms

To evaluate the role of the Ki-67 proliferation antigen and c-erbB-2/neu oncogene expression in the clinical assessment of salivary gland tumors, we followed up 71 patients with minor salivary tumors of the palate. All benign neoplasms (n = 18) showed low Ki-67 scores (< 12%), whereas 26% (14 of 53) of malignant neoplasms manifested high Ki-67 scores (> 12%). A significant statistical difference between Ki-67 scores for benign and malignant neoplasms was observed (p < 0.001). Ki-67 index also correlated significantly with malignant tumor grade (p = 0.04) and patient survival (p = 0.02). Only 1 of the 18 benign tumors had c-erbB-2/neu oncogene overexpression. A significant difference between c-erbB-2/neu overexpression in benign and malignant tumors was observed (p = 0.01). Overexpression of c-erbB-2/neu oncogene was noted in 38% (16 of 42) of malignant tumors and was significantly associated with aggressive tumor behavior (p < 0.001). Multivariate analysis of significant factors revealed that gender, tumor stage, and c-erbB-2/neu oncogene overexpression were jointly predictive of survival. Our data indicate that although the Ki-67 proliferating antigen and c-erbB-2/neu oncogene expression may reflect certain intrinsic biologic properties of these neoplasms, only c-erbB-2/neu overexpression is significantly associated with their biologic aggression.

HLA-DR positive epidermal Langerhans' cells in liver cirrhosis and immunosuppressed liver transplanted patients.

The monoclonal Ki-67-specific MIB-1 and p53 protein-specific DO-1 antibodies were used to identify proliferating cell fractions on microwave-pretreated paraffin sections of 7 cutaneous Bowen's disease specimens. A high Ki-67 score was characteristic of all cases examined, and significant p53-positivity was seen in 4 cases. In the peritumoral, histologically normal epidermis, Ki-67- and p53-positive cells were frequently present, in one case with very high scores (89% as well as 82%, respectively). These findings indicate an increase in the proliferative activity of the Bowen cells (high Ki-67 score) and that p53 mutations are frequently found in this disease. The p53 expression was not related to the Ki-67 score. The expression of Ki-67 and p53 in morphologically normal epidermal cells is also discussed. The histologically normal epidermal cells expressing p53 and Ki-67 antigens may correspond to pre-malignant clones.

Prognostic significance of Ki67 labelling in resected non small cell lung cancer

One hundred and eleven tissue samples of primary non small cell lung cancer obtained from patients undergoing radical surgery for resectable disease were investigated for the presence and distribution of Ki67 related antigen using an immunohistochemical technique, as a marker of the proliferative activity of the tumour. No correlation was seen between Ki67 expression and clinico-pathological variables (sex, age, histology, grading and pTNM stage) but disease-free survival was significantly lower in patients with higher Ki67 score (> 25% positive cells) at diagnosis ( P < 0.03). Growth fraction evaluated by Ki67 labelling may provide a complementary prognostic parameter in non small cell lung cancer.

Pathological and clinical associations of Ki-67 defined growth fractions in human prostatic carcinoma.

Estimation of the growth fraction of 153 prostatic carcinoma specimens employing Ki-67 immunostaining was undertaken and its relationship to various clinical parameters investigated. In prostate specimens, the percentage of tumour nuclei expressing Ki-67 antigen was measured and assigned a Ki-67 score. It was observed that high Ki-67 scores were associated with the poorly differentiated tumours, the correlation of this proliferation marker with histological grade was found to be significant (P less than 0.001). No relationship was observed between the Ki-67 score of the primary tumour with either the patient's age or with the primary tumor stage (T category). The metastatic status of the patient at diagnosis and the Ki-67 score of the tumour were correlated (P less than 0.05), higher Ki-67 scores being associated with M1 disease. Life-table analysis of 86 patients who subsequently received androgen withdrawal therapy, was undertaken with reference to the various Ki-67 scores of their primary tumors. A statistically significant difference in survival times was observed in patients whose Ki-67 values were less than 1% (P less than 0.0001) when compared to those patients whose tumours expressed 1% and over Ki-67 positivity, the former having longer survival times. When patients were subdivided according to their metastatic status and similar life-table analyses were carried out, no statistical difference was found between survival times and Ki-67 scores in M0 staged patients. In the M1 population of patients, however, those patients whose tumours were negative for Ki-67 expression had significantly longer survival times than those patients whose tumours exhibited positive Ki-67 staining (P less than 0.01). Comparing M1 staged patients whose prostate tumor cells exhibited less than 1% Ki-67 positive nuclei with M1 staged patients whose prostate tumour cells contained 1% and higher Ki-67 stained nuclei, a significantly longer survival time was found in the former group of patients (P approximately 0.0001).

The relevance of the DNA index and proliferation rate in the grading of benign and malignant soft tissue tumors

The relevance of the DNA index (DI) to malignancy grading and the relationships between mitotic score, Ki-67 score, and the proportion of cells in the G1-phase (G1PF) of the cell cycle, as proliferative indicators, were investigated in benign (n = 8) and malignant (n = 46) soft tissue sarcomas. Although DI was not found to be related to the histology of the sarcomas, it was associated with malignancy grade, i.e., 14%, 25%, 42%, and 86% of benign, Grade 1, Grade 2, and Grade 3, respectively had a DI greater than 1. The relevance of aneuploidy in benign tumors is discussed and the literature reviewed. A subgroup of the malignant tumors (n = 13) had both a low mitotic score and a low Ki-67 value. However, a distinct correlation between Ki-67 and the mitotic score could not be shown. For malignant tumours G1PF was related to DI, i.e., low G1PF occurred in tumors with diploid DNA content. Low Ki-67 scores were observed in 59% of diploid tumors and in 20% of aneuploid tumors. However, it appeared that G1PF and Ki-67 were not correlated. In conclusion, (1) benign and Grade 1 tumors were predominantly diploid with high G1PF and low Ki-67 values, (2) most of Grade 3 tumors were aneuploid (86%) with low G1PF and high Ki-67 values, and (3) the group of Grade 2 tumors could be divided into two subgroups either with the characteristics displayed by benign and Grade 1 tumors (DI = 1, low Ki-67 scores, and high G1PF) or with the characteristics exhibited by Grade 3 tumors (DI greater than 1, high Ki-67 scores, and low G1PF). Hence, supplementary to the grading of soft tissue tumors, DI, G1PF, and Ki-67 score could be useful as prognostic parameters in soft tissue tumors.

Evaluation of cell proliferation in breast carcinoma. Comparison of Ki-67 immunohistochemical study, DNA flow cytometric analysis, and mitotic count

Growth kinetics of 102 breast carcinomas were studied by immunohistochemical analysis with the monoclonal antibody Ki-67, which reacts with a nuclear antigen in proliferating cells. The results were correlated with ploidy and S-phase fraction (SPF) analyzed by DNA flow cytometric study and with mitotic count analyzed by light microscopic study. The proportion of Ki-67-positive cells (Ki-67 score) in breast carcinomas varied from 0.6% to 80% (median, 6.3%). Ki-67 scores were significantly higher in the DNA aneuploid than in the DNA diploid tumors. Ki-67 scores correlated significantly with tumor SPF in DNA aneuploid tumors. In DNA diploid tumors SPF showed no correlation with Ki-67 score. High Ki-67 scores were associated with high mitotic counts (P less than 0.0001) and histologic grade (P less than 0.0001). Nuclear pleomorphism, tubule formation, or lymph node status were not correlated with Ki-67 score. In conclusion, Ki-67 immunostaining correlates with other measures of cell proliferation (SPF, mitotic count) supporting its clinical significance.

P53 expression in breast cancer

Immunohistochemical evaluation of 200 primary breast cancers with the anti-p53 mouse monoclonal antibody (MAb) PAb421 showed positivity in nuclei of malignant cells in 31 cases (15.5%). PAb421+ cases were significantly more frequently epidermal growth factor receptor (EGF-R)-positive (67.7%; p less than 0.001) and estrogen receptor (ER)-negative (73.3%; p less than 0.001); they displayed surface histocompatibility class-1 (80.6%; p less than 0.01) and 11 (74.2%; p less than 0.05) antigens. Low values for progesterone receptor (mean 67.20 +/- 25.2 fmol/mg; p less than 0.05) and a high number of cells positive for the proliferation-associated antigen Ki-67 (log mean 6.88 +/- 0.33; p less than 0.01) were found in PAb421+ tumors as well as a high number of grade-3 infiltrating duct carcinomas (70%; p = 0.01). Of the 200 cases of mammary carcinoma, 88 were further analyzed using another human specific anti-p53 MAb PAb1801, and 40 (45.5%) were found positive. This MAb stained all the PAb421+ cases and was significantly associated with negative ER status (39.5%; p less than 0.05) and high Ki-67 scores (log mean 6.93 +/- 0.24; p = 0.001). Analysis of PAb1801+/Pab421- cases for HLA antigens, EGF-R and ER showed a phenotype similar to that of the p53-ve/ER+ carcinomas, except for the high Ki-67 score. No differences in age of the patient, number of involved nodes, tumor size, ploidy or labelling index scores were evident between p53+ and carcinomas. We concluded that p53 in mammary carcinomas is associated with ER-negative, growth factor receptor-positive, high-grade tumors, and is a promising new parameter to evaluate the cellular biology and prognosis of breast cancer.