Proliferation in non-Hodgkin's lymphoma: a comparison of Ki-67 staining on fine needle aspiration and cryostat sections

Assessment of Ki-67 Proliferative Index in Cytological Samples of Nodal B-Cell Lymphomas

BACKGROUND

The Ki-67 proliferative index (PI) is part of the diagnosis of nodal B-cell lymphoma (nBCL), but its determination in cytological samples is not standardized. We aimed to establish an approach for the accurate determination of the Ki-67 PI in cytological slides to differentiate between indolent and aggressive nBCLs.

METHODS

Patients diagnosed with nBCL by fine-needle aspiration biopsy and subsequent excision biopsy were included. Cell suspensions were prepared from biopsy samples for CD3/Ki-67 double immunocytochemical staining and flow-cytometric verification of lymphoma B-cell counts. The Ki-67 PI was assessed by manual counting and eyeballing in cytology and eyeballing in histology. The cut-off values for the differentiation between aggressive and indolent lymphomas were determined for each method.

RESULTS

A strong correlation between manual and flow-cytometric counting of lymphoma B cells was confirmed (interclass correlation coefficient (IC coef.) = 0.78). The correlation of the Ki-67 PI determined in cytological and histological slides was also strong (IC coef. > 0.80). Histologically, 55 cases were classified as indolent and 31 as aggressive nBCLs. KI-67 PI cut-off values of 28.5%, 27.5%, and 35.5% were established for manual counting and eyeballing in cytology and eyeballing in histology, respectively, with high sensitivity and specificity.

CONCLUSIONS

The Ki-67 PI, assessed by manual counting and eyeballing in cytological samples, accurately differentiates between indolent and aggressive nBCLs.

Use of Monoclonal Antibody MIB-1 in Differential Diagnosis of Uterine Cervical Glandular Neoplasm

This study was undertaken to evaluate the significance of MIB-1 immunoreactivity in the discrimination of differential diagnosis of benign cervical lesion, endocervical glandular dysplasia, and endocervical adenocarcinoma on formalin-fixed, paraffinembedded tissue. Fifty-two cases were selected from the pathology files of Korea University Hospital from 1994 to 1998 and were composed of 25 cases of endocervical adenocarcinoma, including three cases in which squamous cell carcinoma coexists; six cases of endocervical glandular dysplasia associated with squamous cell carcinoma or cervical intraepithelial neoplasia (CIN); and 21 cases of chronic endocervicitis. Immunohistochemical staining for MIB-1 was performed after microwave treatment on formalin-fixed, paraffin-embedded tissue sections. MIB-1 expression was evaluated according to the labeling indexes. The labeling indexes were calculated for 52 specimens by means of image analysis (Quantification of Proliferation Index). The results are as follows; There was diffuse strong MIB-1 reactivity in endocervical adenocarcinoma (labeling index 37.6-61.4%, mean 54.9%), moderate spotty reactivity in endocervical glandular dysplasia (labeling index 27.9-42.6%, mean 35.1%), and minimal to focal reactivity in chronic endocervicitis (labeling index 0-24.4%, mean 5.2%). Significant differences in MIB-1 labeling indexes existed among the chronic endocervicitis group, the endocervical glandular dysplasia group, and endocervical adenocarcinoma group. In conclusion, MIB-1 immunostaining is of value in the differential diagnosis among benign cervical lesions, endocervical glandular dysplasia, and endocervical adenocarcinoma.

Amurensin G, a potent natural SIRT1 inhibitor, rescues doxorubicin responsiveness via down-regulation of multidrug resistance 1

The transition from a chemotherapy-responsive cancer to a chemotherapy-resistant one is accompanied by increased expression of multidrug resistance 1 (MDR1, p-glycoprotein), which plays an important role in the efflux from the target cell of many anticancer agents. We recently showed that a Forkhead box-containing protein of the O subfamily 1 (FoxO1) is a key regulator of MDR1 gene transcription. Because nuclear localization of FoxO1 is regulated by silent information regulator two ortholog 1 (SIRT1) deacetylase, we wondered whether SIRT1 dominates MDR1 gene expression in breast cancer cells. Overexpression of SIRT1 enhanced both FoxO reporter activity and nuclear levels of FoxO1. Protein expression of MDR1 and gene transcriptional activity were also up-regulated by SIRT1 overexpression. In addition, SIRT1 inhibition reduced both nuclear FoxO1 levels and MDR1 expression in doxorubicin-resistant breast cancer cells (MCF-7/ADR) cells. A potent SIRT1 inhibitor, amurensin G (from Vitis amurensis), was identified by screening plant extracts and bioassay-guided fractionation. The compound suppressed FoxO1 activity and MDR1 expression in MCF-7/ADR cells. Moreover, pretreatment of MCF-7/ADR cells with 1 μg/ml amurensin G for 24 h increased cellular uptake of doxorubicin and restored the responsiveness of MCF-7/ADR cells to doxorubicin. In xenograft studies, injection of 10 mg/kg i.p. amurensin G substantially restored the ability of doxorubicin to inhibit MCF-7/ADR-induced tumor growth. These results suggest that SIRT1 is a potential therapeutic target of MDR1-mediated chemoresistance and that it may be possible to develop amurensin G as a useful agent for chemoresistance reversal.

Classifying B-cell non-Hodgkin lymphoma by using MIB-1 proliferative index in fine-needle aspirates

BACKGROUND

MIB-1 proliferation index (PI) has proven helpful for diagnosis and prognosis in non-Hodgkin lymphomas (NHLs). However, validated cutoff values for use in fine-needle aspiration (FNA) samples are not available. We investigated MIB-1 immunocytochemistry as an ancillary technique for stratifying NHL and attempted to establish PI cutpoints in cytologic samples.

METHODS

B-cell NHL FNA cases with available cytospins (CS) MIB-1 immunocytochemistry results were included. Demographic, molecular, immunophenotyping and MIB-1 PI data were collected from cytologic reports. Cases were subtyped according to the current World Health Organization classification and separated into indolent, aggressive, and highly aggressive groups. Statistical analysis was performed with pairwise Wilcoxon rank sum test and linear discriminant analysis to suggest appropriate PI cutpoints.

RESULTS

Ninety-one NHL cases were subdivided in 56 (61.5%) indolent, 30 (33%) aggressive, and 5 (5.5%) highly aggressive lymphomas. The 3 groups had significantly different MIB-1 PIs from each other. Cutpoints were established for separating indolent (<38%), aggressive (> or =38% to < or =80.1%) and highly aggressive (>80.1%). The groups were adequately predicted in 76 cases (83.5%) using the cutpoints and 15 cases showed discrepant PIs.

CONCLUSIONS

MIB-1 immunohistochemistry on CS can help to stratify B-cell NHL and showed a significant increase in PI with tumor aggressiveness. Six misclassified cases had PIs close to the cutpoints. Discrepant MIB-1 PIs were related to dilution of positive cells by non-neoplastic lymphocytes and to the overlapping continuum of features between diffuse large B-cell lymphoma and Burkitt lymphoma. Validation of our approach in an unrelated, prospective dataset is required.

Ki-67 proliferative marker in lymph node aspirates of patients with non-Hodgkin's lymphoma

Proliferative activity of lymphoma cells was tested by immunocytochemical staining with Ki-67 monoclonal antibody in 63 aspirates of peripheral lymph nodes sampled from patients suffering from non-Hodgkin's lymphoma. Referring to the dominant cell population in nodal aspirates, a rising trend of Ki-67 proliferative marker was noted from the small cells (X = 13.20) and small cells with notched nucleus (X = 43.52) and large cells (X = 79.47) with histopathologic equivalents corresponding to aggressive lymphoma. Statistical testing of the difference in the Ki-67 proliferative marker against demographic and clinical-laboratory characteristics of the studied patients revealed the levels of significance for the performance status, bone marrow infiltration, and albumin serum value. Correlation of cytomorphological and immunocytochemical results was tested against International Prognostic Index (IPI). Statistically significant correlation of Ki-67 with cytomorphology and REAL-immunocytochemical classification of lymphoma was confirmed, but not with the IPI index. In order to determine the prognostic importance of Ki-67 marker, the patients were classified into those with low Ki-67 (<20% of proliferating cells), mean proliferation index Ki-67 (range 20-59%), and high proliferative index Ki-67 (positive in over 60% of lymphoma cells). Testing Ki-67 with survival we have found that the low proliferative index was associated with the longest survival, median about 36 mo; for proliferative marker values ranging between 20 and 59%, the median survival was 30.4 mo; and survival of patients with the high proliferative index was only 12.9 mo.

Immunophenotyping of lymphoproliferative disorders: state of the art

Immunophenotyping was introduced into diagnostic pathology over 30 years ago to assist in the diagnosis and classification of lymphoproliferative disorders. Today the role of immunophenotyping has been expanded beyond this to include the detection of markers of prognosis, determination of disease phenotypes associated with specific chromosomal abnormalities, detection of targets for immunotherapy and to monitor residual disease. Immunoperoxidase detection methods remain the most popular in histopathology, whilst flow cytometry is most commonly applied for haematological samples. The range of monoclonal antibodies available, including those which work in routinely performed tissue specimens, continues to increase. This is in part a result of gene expression studies identifying precise genetic signatures for certain lymphoproliferative disorders and the generation of new protein markers to gene products of upregulated genes. This review summarises the current status and applications of immunophenotyping in the assessment of many of the lymphoid malignancies.

The Value of Fluorescence In Situ Hybridization and Polymerase Chain Reaction in the Diagnosis of B-Cell Non-Hodgkin Lymphoma by Fine-Needle Aspiration

Context.—Molecular genetic analyses have been predicted to improve the diagnostic accuracy of fine-needle aspiration of B-cell non-Hodgkin lymphoma.

Objective.—To determine the value of routine molecular genetic assays, polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH), in the diagnosis of B-cell non-Hodgkin lymphoma by fine-needle aspiration (FNA).

Design.—A multiparametric method, including cytology, flow cytometry, PCR, and FISH, was prospectively evaluated in the diagnosis of B-cell non-Hodgkin lymphoma by FNA. Aspirates from 30 consecutive patients with suspected hematolymphoid malignancies were collected. All aspirates were triaged through a uniform program including cell-size analysis, B- and T-cell clonality studies, flow cytometric immunophenotyping, and bcl-1 and bcl-2 gene rearrangements by PCR and FISH. After completion of FNA evaluations, FNA results were compared with diagnoses from prior or subsequent surgical biopsies.

Results.—Monoclonal B-cell populations were detected in 18 of 20 B-cell non-Hodgkin lymphomas by flow cytometry and PCR. bcl-1 gene rearrangement was detected in 2 of 2 cases of mantle cell lymphoma. bcl-2 rearrangement was detected in 5 cases including 4 of 4 low-grade follicular lymphomas and 1 transformed follicular lymphoma. By incorporating the results of molecular genetic and ancillary diagnostics, a definitive classification was reached in 12 cases of B-cell non-Hodgkin lymphoma by FNA, including all cases of low-grade follicular lymphoma (4/4) and mantle cell lymphoma (2/2) and approximately 50% of small lymphocytic lymphoma (2/4) and large B-cell lymphoma (4/8). Ten of the 12 cases with a final classification reached by FNA had either prior or follow-up surgical biopsies, and all 10 cases showed agreement between the diagnoses rendered on FNA and surgical biopsies.

Conclusions.—With proper handling and management of specimens, FNA can routinely provide samples adequate for molecular genetic studies, in addition to cytomorphology and flow cytometry, making it possible to consistently render accurate and definitive diagnoses in a subset of B-cell non-Hodgkin lymphomas. By incorporating FISH and PCR methods, FNA may assume an expanded role for the primary diagnosis of B-cell non-Hodgkin lymphoma.

Apoptotic and proliferation indexes in canine lymphoma

Proliferative and apoptotic fractions of tumors were evaluated in 41 dogs with lymphoma for prediction of response to chemotherapy. All dogs had advanced clinical stage tumors, were untreated prior to study, and received identical induction-remission chemotherapy. Tumor cell proliferation was determined in all pretreatment biopsy specimens and in 18 specimens collected at the time of clinical relapse from remission. Quantitative measures included mitotic index and immunoreactivities for proliferating cell nuclear antigen (PCNA) and Ki-67. Apoptotic index was evaluated from 40 dogs pretreatment and from 16 dogs at the time of first relapse. Pretreatment tumor values for Ki-67, PCNA, and apoptosis were compared with posttreatment values. The median first relapse-free interval (RFI) and overall survival (OS) time were 174 days and 445 days, respectively. Of the proliferation markers, only the results of the Ki-67 analysis were predictive for duration of the first RFI but not OS. Pretreatment apoptotic index was also predictive of the duration of first RFI but not OS. No significant predictive value for comparison of the pretreatment and postrelapse values was demonstrated. Ki-67 labeling index and apoptotic indexes were combined to form both a proliferation/apoptotic ratio (PAR) and a sum, or turnover index. Only the PAR was predictive for duration of first RFI on multivariate analysis. Other variables that were evaluated for their influence on treatment outcome included patient age, weight, gender, clinical stage, clinical substage, and tumor immunophenotype. Of these variables, only immunophenotype was found to be of value for predicting duration of first RFI and OS.

Assessment of cell proliferation by Ki-67 staining and flow cytometry in fine needle aspirates (FNAs) of reactive lymphadenitis and non-Hodgkin's lymphomas

This study was undertaken to assess cell proliferation in FNAs from a series of 57 non-Hodgkin's lymphomas (NHL) and 11 cases of reactive lymphadenitis using Ki-67 staining and flow cytometry (FCM). The results were compared and correlated to the cytomorphological subgrouping according to Kiel classification. The mean percentages of Ki-67 positivity were 16.6% and 61.1% for low and high grade lymphomas, respectively (P < 0.001). The mean S-phase fraction (SPF) determined by FCM was 4.61% for low grade and 12.9% for high grade lymphomas (P < 0.001). The figures for Ki-67 positivity and S-phase fraction in reactive lymphadenitis were 16.8% and 40%, respectively. We observed a strong correlation in low grade lymphomas between Ki-67 and SPF. A good correlation was also found in reactive lymphadenitis. In high grade lymphomas, however, with highly scattered Ki-67 and S-phase values, this correlation was lost. In some cases this discrepancy can be explained by a rich admixture of non-neoplastic, non-proliferating cells in aspirates from diploid tumours. In addition, the existence of a minor aneuploid tumour cell population of high proliferation such as that in Ki-1 lymphomas will not be accurately analysed by FCM but is easily assessed by Ki-67 staining. However, the main reason seems to be a high variability between the fraction of cells in S-phase and the total number of cells in G1, S and G2 in individual tumours.

The relevance of cytological studies and Ki-67 reactivity to the clinical course of chronic lymphocytic leukemia

The aim of the study was to investigate whether the growth fraction and cytology of peripheral blood and lymphoid tissues relate to response to treatment in CLL. Growth fraction was assessed using the monoclonal antibody Ki-67. Peripheral blood (PB) films and lymph node and spleen touch imprints or aspirates were examined in 35 patients (pts) with CLL: smouldering CLL (4 pts) (no therapy), progressive CLL but responsive to chlorambucil and cyclophosphamide (15 pts) and resistant CLL (16 pts). Cytological studies of lymphoid tissues showed that pts with resistant CLL had an increased proportion of prolymphocytes and blasts and the highest Ki-67 expression (mean 6,6%). PB morphology was not different between the groups of resistant and responsive CLL. However, the cases with resistant CLL showed a higher percentage of Ki-67 positive PB cells (p<0,05). Four pts with indolent CLL had typical CLL morphology in the PB and the lowest numbers of prolymphocytes and blasts with Ki-67 positive cells in lymphoid tissues.

Growth fractions in canine non-Hodgkin's lymphomas as determined in situ by the expression of the Ki-67 antigen

The proportion of proliferating cells in non-Hodgkin's lymphomas (NHLs) as determined in situ by the expression of the Ki-67 antigen, has prognostic value in human oncology, and is strongly related to the different grades of malignancy. The evaluation of the Ki-67 index in canine NHLs may be useful in assessing the individual variability of the growth fraction in the different sub-types of lymphoma, and also the validity of the classification in terms of grade of malignancy. The growth fraction was evaluated in 92 canine NHLs, previously classified according to the Kiel classification (as adapted to the canine species), by determining the expression of the Ki-67 antigen with the MIB1 antibody on (1) paraffin-wax tissue sections in all 92 cases, and (2) fine-needle aspirates or tumour imprints in 30 cases. The labelling appeared satisfactory in 88% of the cases, with good concordance between the histological and cytological data. A highly significant correlation (P < 0.001) was established between the proportion of Ki-67+ cells and the classification into low-grade (Ki-67 index < 21%) and high-grade malignancy (Ki-67 index > 21% and usually > 29%). In the low-grade lymphoma group, a macronucleolated medium-sized-cell lymphoma not found in man had the lowest proliferation index. In the high-grade malignancy group, the number of Ki-67+ cells seemed to be proportional to cell size, whatever the phenotype, with the rare exceptions of some unclassifiable small-cell Burkitt-type or plasmacytoid lymphomas, which were highly proliferating. The classification of lymphomas into low-grade and high-grade appears to correlate well with their proliferative index. The existence of individual variations, within given categories of canine NHL, suggests that, as in human medicine, prognosis may be assisted by determining the growth fraction at initial diagnosis, and by fine-needle aspiration at relapses.

Value of Ki-67 immunostaining in preoperative biopsies of carcinomas of the lung

In lung carcinomas, the proliferative activity, as detected by Ki-67 antigen immunostaining of surgical specimens, is a valuable factor predicting clinical evolution and response to treatment. We investigated whether bronchial endoscopic and fine-needle aspiration (FNA) biopsies of lung carcinoma can provide a reliable estimation of the tumor proliferative fraction (TPF). In 66 resectable lung carcinomas, sections of preoperative bronchial or FNA biopsies and the corresponding surgical specimens were stained in parallel for Ki-67 using MIB-1 monoclonal. The mean TPF was 44.7% in the surgical specimens, 40.3% in bronchial biopsies, and 26.3% in FNAs. When the scores of biopsy and resected specimen of each individual tumor were compared, a significant correlation between the TPFs of preoperative and postoperative specimens was found (r = .79). In both biopsy and surgical specimens, a high TPF was associated with squamous cell carcinoma histological type and high-grade (poorly differentiated) tumors. In addition, a significantly (P < .05) lower disease-free interval was found in patients affected by highly proliferating tumors (irrespective of the tumor stage). We conclude that the proliferative activity of lung cancer can be reliably assessed in bronchial or FNA biopsies. This information could help to select chemotherapy protocols in nonresectable lung carcinomas.

Proliferating cell nuclear antigen (PCNA) as a prognostic factor in non-Hodgkin's lymphoma

The prognostic value of immunoperoxidase staining for proliferating cell nuclear antigen (PCNA) was studied in a series of 140 non-Hodgkin's lymphomas with median follow-up of 9 years. Lymphomas where > 50% of cells showed positive staining for PCNA had inferior 5-year survival as compared with those with less than 50% of positive cells (57% vs 41%, P = 0.008). The presence of > 50% of positively staining cells for PCNA was strongly associated with a larger than the median size of the SPF (median, 8.3%), and high histological grade of malignancy (P < 0.0001 for both). Lymphomas with both a large percentage (> 50%) of PCNA positive cells and a larger than the median SPF had inferior outcome as compared with lymphomas where either one or both of these factors were small. Although PCNA staining was not an independent prognostic factor in a multivariate analysis, it appears to be supplementary to the SPF even if determined from old paraffin-embedded tissue material.

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.

Measuring proliferation in routine fine needle aspirates. Immunocytochemical detection of bromodeoxyuridine incorporation and Ki-67 expression in breast aspirates

Two simple quantitative means of measuring tumour proliferation which can be applied to cytological material are described. One method involves immunocytochemical staining of cytological smears prepared from breast aspirates with the monoclonal antibody Ki-67. The other method involves incubation of aspirated material with 5-Bromo-2-deoxyuridine (BrdU). Direct measurement of the S phase of the cell cycle is feasible in breast fine needle aspirates by Bromodeoxyuridine incorporation and subsequent immunocytochemical detection. The proliferation indices obtained correlate with those derived from Ki-67 staining. This technique is suitable for routine use in the assessment of tumour proliferation.

Ki-67 staining in histological subtypes of breast carcinoma and fine needle aspiration smears

Thirty four cases of invasive breast carcinoma were analysed for heterogeneity of Ki-67 reactivity in a tumour, and proliferative activity in various histological subtypes was compared. The growth factions determined in areas of central and peripheral tumour were the same. Mucinous and lobular carcinoma showed lower Ki-67 activity than ductal carcinomas. When ductal carcinomas were subdivided according to their dominant growth pattern, the carcinomas with a solid or comedo growth pattern showed the highest proliferative activity. These results largely confirm data from previous cell kinetic studies on the incorporation of radioactively labelled thymidine. A correlation between the growth fraction determined by Ki-67 in fine needle aspiration smears and cryostat sections of corresponding tumours was shown, implying that the immunostaining of cytological smears gives a reliable impression of the growth fraction of a tumour and may therefore be used in prospective studies.