DNA flow cytometry of follicular non-Hodgkin's lymphoma

Proliferation activity in canine lymphomas

Forty five lymphomas, 14 of T cell origin, 28 of B cell and 3 with null-cell phenotype, were included in this study. Tumors were classified according to the updated Kiel classification system adapted to canine lymphomas. The percentage of Ki67+ cells and mitotic index (MI) were estimated in each specimen. Most of lymphomas (39 of 45) had high proliferation activity. Among them in 27 cases 50-70% of lymphoma cells expressed Ki67, the highest Ki67 expression (> 70% Ki67+ cells) was identified less frequently, in 12 cases. Moderate Ki67 expression (20-50% positive cells) was observed in 5 cases, only one tumor had low Ki67 expression (< 20% positive cells). Lower percentage of Ki67+ cells was usually accompanied with lower MI. The mean MI values in discussed groups differed significantly. Mean MI value was also significantly higher in T cell than in B cell lymphomas (4.30 vs. 3.33). Moreover, high positive correlation between the expression of Ki67 and MI was found (r = 0.668; P < or = 0.001). In T-cell tumors the correlation was very high (r = 0.83; P < or = 0.001) and in B-cell lymphomas the correlation was high (r = 0.61; P < or = 0.001). There were also differences between mean MI values in the lymphomas of different morphological subtypes, but in some of them high variations in the range of MI values were identified and wide overlaps of MI between individual cases from different subtypes were observed. Because of differences in the proliferation activity in single cases of the same subtype of lymphoma, the proliferation activity assessment may be helpful to chose appropriate scheme of treatment and should be commonly performed during routine histopathological diagnosis of canine lymphomas.

Association between the proliferative rate of neoplastic B cells, their maturation stage, and underlying cytogenetic abnormalities in B-cell chronic lymphoproliferative disorders: analysis of a series of 432 patients

Limited knowledge exists about the impact of specific genetic abnormalities on the proliferation of neoplastic B cells from chronic lymphoproliferative disorders (B-CLPDs). Here we analyze the impact of cytogenetic abnormalities on the proliferation of neoplastic B cells in 432 B-CLPD patients, grouped according to diagnosis and site of sampling, versus their normal counterparts. Overall, proliferation of neoplastic B cells highly varied among the different B-CLPD subtypes, the greatest numbers of proliferating cells being identified in diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma (BL). Compared with normal B cells, neoplastic B-CLPD cells showed significantly increased S + G2/M-phase values in mantle cell lymphoma (MCL), B-chronic lymphocytic leukemia (B-CLL), BL, and some DLBCL cases. Conversely, decreased proliferation was observed in follicular lymphoma, lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (LPL/WM), and some DLBCL patients; hairy cell leukemia, splenic marginal zone, and MALT-lymphoma patients showed S + G2/M phase values similar to normal mature B lymphocytes from LN. Interestingly, in B-CLL and MCL significantly higher percentages of S + G2/M cells were detected in BM versus PB and in LN versus BM and PB samples, respectively. In turn, presence of 14q32.3 gene rearrangements and DNA aneuploidy, was associated with a higher percentage of S + G2/M-phase cells among LPL/WM and B-CLL cases, respectively.

Grading of follicular lymphoma: comparison of routine histology with immunohistochemistry

CONTEXT

Follicular lymphoma (FL) grading is based on the average number of large transformed cells in 10 neoplastic follicles at x40 high-power field (x10-40 high-power field) examination (grade 1, 0-5 centroblasts per high-power field; grade 2, 6-15 centroblasts per high-power field; grade 3, >15 centroblasts per high-power field).

OBJECTIVE

Since there may be significant interobserver variability, we analyzed the usefulness of immunohistochemical stains in grading FLs more reliably.

DESIGN

Forty-three FLs initially graded by World Health Organization criteria (grade 1, 12; grade 2, 18; grade 3, 13) were reviewed and stained with CD3, CD20, Ki-67, CD30, CD68, PAX-5, and BCL-6. Retrospective review was performed for the average number of large cells, of large lymphoid cells, of large cells staining with CD3, CD20, BCL-6 (40 cases), and PAX-5, and of all cells staining with CD68, Ki-67, and CD30.

RESULTS

By histologic review, 8 of 43 FLs had a significant grade change (4 cases upgraded and 4 cases downgraded). CD3 and CD30 stained only 0 to 3 large cells and 0 to 3 cells, respectively, in neoplastic follicles. CD68+ cells represented the large nonlymphoid cells. Increasing FL grades demonstrated increases in Ki-67+ cells. The original grade showed substantial agreement with CD20 and moderate agreement with PAX-5 and BCL-6. The original histologic grade agreed with immunohistochemical-based grade using 2 or more antibodies in 5 of 8 discordant cases (4 by CD20 or BCL-6 and PAX-5; 1 by CD20, PAX-5, and BCL-6).

CONCLUSIONS

Interobserver variability of histologic FL grading may be significant; we showed low-end "substantial agreement." Immunohistochemical stains (ie, CD20, PAX-5, and BCL-6) may more reliably determine the number of large transformed cells in neoplastic follicles; Ki-67 staining correlates with higher FL grades. Immunohistochemical stains may be evaluated in clinical trials of FL patients to determine prognostic significance.

Clinical and molecular prognostic factors in follicular lymphoma

The observed variability in the clinical course of follicular lymphoma (FL), along with the diverse range of therapeutic options available, necessitates accurate prognostic stratification of the individual patient. A number of clinical, laboratory, and pathologic parameters have been associated with both good and poor risk disease; in some instances these have been incorporated into readily calculable prognostic indices. With new insights into disease biology and the resulting identification of biomarkers that have arisen from the analysis of both the genome and the transcriptome, more accurate individualization of prognosis will be realized. At present the clinical application of such biomarkers, however, remains largely in its infancy. This review examines the clinical and molecular prognostic features that have been identified as of value in FL.

Low histologic grade follicular lymphoma with high proliferation index: morphologic and clinical features

Histologic grading has been used as a guide for clinical management in follicular lymphoma (FL). Proliferation index (PI) of FL generally correlates with tumor grade; however, in cases of discordance, it is not clear whether histologic grade or PI correlates with clinical aggressiveness. To objectively evaluate these cases, we determined PI by Ki-67 immunostaining in 142 cases of FL (48 grade 1, 71 grade 2, and 23 grade 3). A total of 24 cases FL with low histologic grade but high PI (LG-HPI) were identified, a frequency of 18%. On histologic examination, LG-HPI FL often exhibited blastoid features. Patients with LG-HPI FL had inferior disease-specific survival but a higher 5-year disease-free rate than low-grade FL with concordantly low PI (LG-LPI). However, transformation to diffuse large B-cell lymphoma was uncommon in LG-HPI cases (1 of 19; 5%) as compared with LG-LPI cases (27 of 74; 36%). In conclusion, LG-HPI FL appears to be a subgroup of FL with clinical behavior more akin to grade 3 FL. We propose that these LG-HPI FL cases should be classified separately from cases of low histologic grade FL with concordantly low PI.

Evaluation of the proliferative index as a prognostic factor in diffuse large cell lymphoma: correlation with the International Index

The reasons for differences in outcome between groups of patients with diffuse large cell lymphoma (DLCL) defined by clinical prognostic factors are largely unknown. Measures of cell proliferation may offer a biological explanation for these differences. This study tested the hypothesis that these survival differences between the groups defined by established prognostic factors were due to the proliferative index. The bromodeoxyuridine labeling index (LI), a measure of the S-phase fraction, was prospectively determined on fresh tumor specimens obtained at initial diagnosis in 80 patients with DLCL seen between 1986-1993 at a single institution. Patients were grouped using prognostic factors that were significant in a univariate analysis as well as the International Index (IPI). The LI in each of these groups was compared to determine whether the differences in outcome between the groups could be explained by differences in the LI. The median LI for all patients was 5.1% (range: 0.1-25%). When the predictive effect of the LI on response and survival was analyzed, the LI did not correlate with complete response or disease-free survival (DFS). There was a trend, however, for patients with a lower LI to have a poorer overall survival (p=0.06). When the patients were analyzed using the International Index (IPI), the mean LI for patients in the low-risk, low-intermediate, high-intermediate and high risk groups was 7.1%, 10.0%, 6.4% and 6.6% respectively (p=0.41). When analyzed separately, there was no significant difference in the LI for any of the patient groups defined by significant prognostic factors. The only difference in the LI was that the median LI in patients with T-cell DLCL was significantly lower than the LI in patients with B-cell DLCL (p=0.001) and these patients had an inferior complete response rate (p=0.001), disease-free survival (p=0.003) and overall survival (p=0.015). In this study, the LI, a measure of lymphoma cell proliferation, was not a significant prognostic factor for response, disease-free survival or overall survival. Furthermore, the LI did not explain the differences in outcome between patient groups defined by the IPI. However, a lower LI seen in patients with T-cell DLCL may account for their poorer response to therapy and inferior survival when compared to patients with B-cell DLCL.

Prognostic value of lymphoma-specific S-phase fraction compared with that of other cell proliferation markers

The proliferation-associated antigens Ki67 (immunohistochemistry) and proliferative cell nuclear antigen (PCNA) (immunohistochemistry and immunoblotting) were analysed together with DNA synthesis (3H-thymidine incorporation) and cell-cycle distribution (tumour-specific S-phase fraction determined by flow cytometry) in lymph node suspensions from 63 patients with newly diagnosed B-Cell non-Hodgkin's lymphomas. Details of clinical parameters, treatment and patient outcome were available for all patients, and retrospectively analysed. Of the proliferation-associated parameters, only high S-phase fraction (p < 0.00001) and high PCNA expression by immunoblotting (p = 0.012) were predictive of a poor prognosis. Of the conventional parameters, high-grade malignancy, high International Prognostic Index (IPI) score, bulky disease and presence of B symptoms predicted a patient for poor survival. High S-phase fraction was predictive of a short survival for the low-grade lymphomas analysed separately (p < 0.00001), as well as for patients treated with an Adriamycin- and a non-Adriamycin-containing regimen (p < 0.005 for both groups). In a multivariate analysis, S-phase fraction (p = 0.00006), IPI score (p = 0.015) and B symptoms (p = 0.017) had independent prognostic values, but not histological grade.

Computer-assisted image analysis of small cell lymphoma of the thyroid gland. Comparison of nuclear parameters of small lymphocytes in lymphomas and Hashimoto's thyroiditis

The nuclear parameters of the small lymphocytes in nine cases of small cell lymphomas of the thyroid gland and 17 cases of Hashimoto's thyroiditis were assessed by computer-assisted image analysis. The nuclear area, maximal, minimal and averaged Ferret diameters, perimeter, regularity factor and elongation factor were gauged. Statistically, the nuclear area was ascertained to be the optimum descriptor discriminating between small neoplastic and reactive lymphocytes. Application of a novel variable, combining a nuclear area cut-off value of 14 microm2 with a nuclear averaged Ferret diameter cut-off value of 4.5 micron, allows for the distinction - with a high degree of sensitivity and specificity - between small neoplastic lymphocytes in thyroidal lymphomas and the reactive lymphocytes in Hashimoto's thyroiditis.

Tumour cell proliferation, but not apoptosis, predicts survival in B-cell non-Hodgkin's lymphomas

Tumour S-phase fraction, but not the apoptotic fraction, had prognostic value in 92 patients with B-cell non-Hodgkin's lymphoma (P < 0.0001 and P = 0.85 respectively). Multivariate analysis showed that S-phase fraction was the strongest prognostic indicator in all cases (P = 0.0003, relative risk 4.3; age: P = 0.16; grade: P = 0.81), as well as in the 63 primary biopsy cases (P = 0.0006, relative risk = 7.3; international prognostic index: P = 0.015, relative risk = 3.2; B symptoms: P = 0.017, relative risk = 3.3; bulkiness: P = 0.65; grade: P = 0.91).

Proliferation and apoptosis in malignant and normal cells in B-cell non-Hodgkin's lymphomas

We have examined apoptosis and proliferation in lymph node cell suspensions from patients with B-cell non-Hodgkin's lymphoma using flow cytometry. A method was developed which allowed estimation of the fractions of apoptotic cells and cells in the S-phase of the cell cycle simultaneously with tumour-characteristic light chain expression. Analysis of the tumour S-phase fraction and the tumour apoptotic fraction in lymph node cell suspensions from 95 B-cell non-Hodgkin's lymphoma (NHL) patients revealed a non-normal distribution for both parameters. The median fraction of apoptotic tumour cells was 1.1% (25 percentiles 0.5%, 2.7%). In the same samples, the median fraction of apoptotic normal cells was higher than for the tumour cells (1.9%; 25 percentiles 0.7%, 4.0%; P = 0.03). The median fraction of tumour cells in S-phase was 1.4% (25 percentiles 0.8%, 4.8%), the median fraction of normal cells in S-phase was significantly lower than for the tumour cells (1.0%; 25 percentiles 0.6%, 1.9%; P = 0.004). When the number of cases was plotted against the logarithm of the S-phase fraction of the tumour cells, a distribution with two Gaussian peaks was needed to fit the data. One peak was centred around an S-phase fraction of 0.9%; the other was centred around 7%. These peaks were separated by a valley at approximately 3%, indicating that the S-phase fraction in NHL can be classified as 'low' (< 3%) or 'high' (> 3%), independent of the median S-phase fraction. The apoptotic fractions were log-normally distributed. The median apoptotic fraction was higher (1.5%) in the 'high' S-phase group than in the 'low' S-phase group (0.8%; P = 0.02). However, there was no significant correlation between the two parameters (P > 0.05).

Clinicopathological analysis of follicular lymphoma with a polyploid karyotype

The prognostic significance of specific cytogenetic abnormalities in follicular lymphoma (FL) is an area of ongoing research. A small percentage of FL are characterized by a polyploid karyotype. Several studies have analyzed ploidy level to determine its role as an independent prognostic factor in non-Hodgkins lymphoma, with equivocal results, mostly using DNA flow cytometry to ascertain ploidy status. We have performed cytogenetic analyses on 180 cases of FL with a t(14;18) diagnosed between 1980 and 1995. Cases were divided into a polyploid group (20 cases) and a non-polyploid group (160 cases), polyploidy defined as a modal chromosome number of 58 or greater. Each group included examples of the 3 subtypes of FL, [Working Formulation]: 1) follicular small cleaved cell (FSC), 2) follicular mixed, small and large cell (FM), and 3) follicular large cell (FLC). The median follow-up time was 38.5 months. The histological subclassification of the polyploid group revealed much less FSC (30% vs 66%, p < 0.004) and much more FLC (25% vs 4%, p < 0.003) than the non-polyploid group, implying histological progression may occur in parallel with the development of polyploidy. Recognized clinical prognostic factors were evenly distributed between the two groups and no survival difference was detected. We show that polyploidy as determined by classical cytogenetics is present in different frequencies across the subtypes of FL with a t(14;18), but is not an independent prognostic factor for survival in FL.

Cell proliferation, bcl-2, c-myc, p53 and apoptosis as indicators of different aggressiveness in small lymphocytic lymphoma (SLL)

Cell proliferation activity, by MIB1 mAb, expression of bcl-2, c-myc and p53 gene proteins and apoptotic index (AI) were assessed in 54 cases of SLL and compared to the morphological subtypes of this disorder, defined by Lennert on the basis of amount and distribution of small and larger activated lymphocytes as diffuse, tumor-forming and pseudofollicular subtypes (DS, TFS, PFS). MIB1 scores showed significant differences between DS, PFS and TFS (5.5%, 16.61% and 24.14%, respectively; p < 0.0001). Worth noting, the MIB1 score did not differ significantly when comparing DS with the diffuse areas of PFS, or TFS with the pseudofollicles of PFS. The mean bcl-2 gene protein score was displayed to a high extent in all subtypes, but less extensively by larger activated lymphocytes that, conversely, expressed c-myc. MIB1 score correlated negatively with bcl-2 and positively with c-myc protein scores. These findings suggest that lymphocytes protected from apoptosis by bcl-2 would be exponed to cell activation and growth acceleration provided by c-myc. This condition would account for a different aggressiveness of morphologically activated subtypes, such as TFS and PFS with larger pseudofollicles. The survival analysis, performed in 23 cases, showed a trend of association of cell proliferation and c-myc expression with a more aggressive progression of the disease. Overexpression of p53 and apoptosis were found only in a minority of cases, unrelated to the subtypes. In conclusion, cell growth fraction, bcl-2 and c-myc assessment may be of help in predicting the aggressiveness of different subtypes of SLL. This approach should be most conveniently applied to PFS, which represents a continuum between DS and TFS, in order to distinguish, in this heterogeneous subtype, more indolent from more aggressive disorders.

Biological heterogeneity of diffuse mixed small and large cell non-Hodgkin's lymphomas assessed by DNA flow cytometry and Ki67

The cell proliferative activity of the clinico-pathologically heterogeneous non-Hodgkin's lymphomas (NHL) included in the intermediate grade F category of the Working Formulation (WF) was investigated. S-phase fraction with flow cytometry on cell suspensions, and Ki67 on frozen tissue sections were performed in 42 F NHL. An avidin-biotin immunocomplex method was used and 1000 cells from 10 representative fields were counted. DNA content, S-phase and Ki67 were also detected in 194 NHL covering the whole spectrum of the WF. DNA content anomalies were found in 52 of 194 NHL. Their incidence, like that of S-phase fraction and Ki67 positive cells, progressively increased from low- to high-grade. A linear correlation was found between Ki67 and S-phase (r = .59). Using the median value of proliferating cells obtained with both procedures as a cut off, two very different groups of lymphomas could be distinguished within a series of 42 F-intermediate NHL: with low and high proliferative cell activity (p < .0001) that were termed F(low) and F(high), respectively. A intermediate group was placed between them. It differed significantly from the others if Ki67 was used but only from the F(high) group if the S-phase fraction analysis was applied. No significant differences were seen when comparing F(low) with the single categories of low-grade NHL and F(high) with H high-grade NHL; no significant differences were found between F(high) and G, and between G and H categories. The existence of distinct groups of NHL in the F category, as defined by biological parameters assessing the cell proliferative activity, indicates that this category includes biologically heterogeneous lymphoma subtypes with different grades of aggressiveness. The results also indicate that the G intermediate category displays proliferation indices similar to those of H high grade category.

S-phase fraction by the labeling index as a predictive factor for progression and survival in low grade non-Hodgkin's lymphoma

BACKGROUND

The purpose of this study was to learn if the bromodeoxyuridine labeling index (LI), a measure of the S-phase fraction, is an independent prognostic factor for overall survival (OS) for patients with newly diagnosed low grade non-Hodgkin's lymphoma (NHL). In addition, the ability of the LI to predict time to progression (TTP) in a group of patients observed without therapy after initial diagnosis was determined.

METHODS

Patients eligible for this study had biopsy proven low grade NHL, adequate tissue to perform the LI, and were previously untreated. The bromodeoxyuridine LI was performed on fresh biopsy samples using a slide-based immunofluorescence procedure.

RESULTS

One-hundred twelve patients were followed prospectively for OS, and 50 of these patients who initially were observed without therapy were eligible for an analysis of TTP. The LI (< or = 1% vs. > 1%) and presence of "B" symptoms were significant univariate prognostic factors for survival (P values of 0.004 and < 0.001, respectively). In a multivariate analysis, the LI and symptoms retained independent prognostic significance, whereas disease stage, histologic subtype, and age did not. In the group who were observed after diagnosis, the LI was not an independent predictor of TTP.

CONCLUSIONS

The LI at initial diagnosis is an independent prognostic factor for OS of patients with low grade NHL, but it does not help choose patients for observation without therapy. Measurements of the LI should be considered as part of the on-study evaluation of patients entering cooperative group trials evaluating new therapies for this group of lymphomas.

Cell kinetic analysis of non-Hodgkin's lymphomas using in vivo iododeoxyuridine incorporation and flow cytometry

The aim of this study was to analyse dynamic cell proliferation parameters in non-Hodgkin's lymphomas. Sixty-one patients with newly diagnosed or with recurrent disease were given iododeoxyuridine (IdUrd) intravenously near 4 h prior to tumour biopsy. After staining with an IdUrd reactive antibody and propidium iodide, S-phase fraction (SPF), labelling index (LI), S-phase duration time (Ts) and potential tumour doubling time (Tpot) were determined by flow cytometry. Thirty-eight samples, 15 low grade (LGM) and 23 high grade (HGM) malignant lymphomas, were possible to evaluate. Twenty-three cases were excluded due to aneuploidy, insufficient amount of material or technical problems. Tpot values varied between 0.8-32.9 days (mean 7.0 days). HGM lymphomas had shorter mean Tpot times than LGM lymphomas (4.8 versus 10.4 days, p = 0.05). For Ts the range was 4.2-20.1 h (mean 9.1 h), and a difference between the two histological groups was demonstrated with a longer mean Ts for HGM compared with LGM cases (10.0 versus 7.8 h, p = 0.04). Tpot showed a negative correlation with SPF (P = 0.003), and Ts demonstrated a positive correlation to SPF (p = 0.02). The clinical significance of the dynamic cell proliferation parameters studied remains to be clarified, but the interrelationships between Ts/SPF and Ts/morphologic subtype might be factors of interest for future prognostic studies in malignant lymphomas.

Low-grade lymphoma: clinical and prognostic studies in a series of 143 patients from a single institution

Clinical and prognostic studies were carried out in a series of 143 patients with low-grade (small-lymphocytic, follicular small cleaved cell, follicular mixed small- and large-cell) lymphoma. After treatment with alkylating agents (21.5% cases), combination chemotherapy (73.3%) or other therapies (5.2%), complete response (CR) was obtained in 40.7% of cases and partial response (PR) in 43.7%. The stage of the disease was the most important factor for response. With a median follow-up of 6.5 years, 48.0% (95% Cl: 37.5-58.5) of patients were alive 10 years after diagnosis. Among the initial parameters, advanced stage. B-symptoms, poor performance status, nodal involvement > 3 sites, extranodal involvement > or = 2 sites, WBC count > or = 10 x 10(9)/L, leukemic expression, high serum LDH levels, and bone marrow infiltration were all related to survival; treatment modality, however, had no influence on survival. In the multivariate analysis, stage (p = 0.008) and age (p = 0.053) were the most important prognostic factors. When considering response to therapy, both CR (p < 0.001) and PR (p = 0.003) emerged as the most important predictive variables, with only the absence of B-symptoms retaining its prognostic significance (p = 0.014) among the other parameters. In addition, in CR patients the duration of the response (< or = 1 year vs. > 1 year) was the most significant parameter for survival (p < 0.001). Finally, the initial stage (p = 0.011) and the histologic subtype (those patients with follicular mixed lymphoma relapsing less frequently than the others) (p = 0.052) were the only significant factors for relapse.

Prognosis in low grade non-Hodgkin's lymphoma: relevance of the number of sites involved, absolute lymphocyte count and serum immunoglobulin level

Eighty-eight patients with low grade non-Hodgkin's lymphoma were followed for a median period of 63 months. Sixty-eight per cent of the group were centrocytic/centroblastic B cell lymphomas by the updated Kiel classification. Fifty-one (58 per cent) of the patients were stage IV by the Ann Arbor classification. In 18 of these patients the bone marrow was the only site of extranodal involvement. Univariate survival analysis showed that the sum of involved sites was more discriminatory than Ann Arbor stage. Analysis by site of involvement showed that the liver and other intraabdominal sites were associated with worse survival than involvement of peripheral lymph nodes. Bone marrow and spleen involvement were not significantly associated with short survival. Increasing age at presentation was strongly associated with shorter survival and was also inversely correlated with serum albumin. Both low absolute lymphocyte count (< 1.0 x 10(9)/l), low serum IgG level (< 10 g/l) and low total immunoglobulins on presentation were significantly associated with short survival. Multivariate analysis showed that age, serum albumin and number of involved sites gave the best survival prediction. The sum of involved sites, immunoglobulin level and absolute lymphocyte count may be useful objective markers of prognosis in low-grade non-Hodgkin's lymphoma.

Nucleolar organiser regions and survival in patients with non-Hodgkin's lymphomas classified by the working formulation

AIMS

To correlate the numbers of silver staining nuclear organiser regions (AgNORs) in non-Hodgkin's lymphoma classified by the working formulation with survival, the first complete remission, and the length of remission.

METHODS

Sixty one patients were included in the study. Paraffin wax sections were stained using silver solution to visualise nucleolar organiser regions. The AgNORs were counted in 150 nuclei of each specimen. Data were examined using the Kruskal-Wallis test, multivariate discriminant analysis, and Cox's regression test. Curves were calculated by the method of Kaplan and Meier.

RESULTS

Most patients who were alive had low grade lymphoma (p < 0.01). The first complete remission was obtained more frequently in the low and intermediate grade groups (p < 0.05). The longest survival was found in the low grade group (p < 0.001). The mean number of AgNORs differed significantly in all three groups (p < 0.001). This was also true for area of nuclei (p < 0.001) and length of remission (p < 0.05). In a multivariate analysis the numbers of AgNORs were highly predictive for survival, remission, and the length of remission.

CONCLUSIONS

The numbers of AgNORs correlated with survival, remission, and the length of remission in patients with non-Hodgkin's lymphoma.

Prognostic significance of serum lactic dehydrogenase levels and fraction of S-phase cells in non-Hodgkin lymphomas

Sixty-four untreated patients with non-Hodgkin lymphomas (NHL) were analyzed with respect to fraction of S-phase cells in tumor material and serum lactic dehydrogenase (LD) levels. A significant correlation between the two variables was found in the low-grade (LGM) (r = 0.44, p < 0.01), but not in the high-grade (HGM) lymphomas. Shorter survival times were found for patients with tumors showing a high fraction of S-phase cells (> 4%) (p < 0.001) as well as for patients with elevated LD values (> or = 7.5 mukat/l) (p < 0.001). A multivariate analysis showed clinical stage (p < 0.001), S-phase fraction (p = 0.002) and age (p = 0.002) to be independent prognostic factors. For serum LD a borderline value (p = 0.05) was found, whereas morphology and B-symptoms were non-significant. LD level, but not fraction of S-phase cells, added prognostic information for LGM lymphomas (p < 0.001). For HGM lymphomas, the clinical stage was the strongest factor for prediction of prognosis. We conclude that the fraction of S-phase cells describes the biological behavior in a more reliable way than morphology (HGM vs LGM) and better identifies lymphomas with poor or good prognosis. The strong additional prognostic information obtained by serum LD within LGM lymphomas is assumed to be due to an association with the tumor burden.

Growth fraction in centrocytic and follicular center cell lymphomas: assessment in paraffin sections with a proliferating cell nuclear antigen antibody and morphometric correlates

Measurement of growth fraction is an important way to provide an objective assessment of non-Hodgkin's lymphomas; however, many of the techniques used require fresh tissue and/or special instrumentation. Recently, antibodies to the proliferating cell nuclear antigen (PCNA)/cyclin reactive in paraffin-embedded sections have become available. To investigate the utility of one such antibody in the study of follicular center cell (FCC) lymphomas and cleaved cell lymphomas of centrocytic type (CC), paraffin sections from 40 cases that had been characterized in two previous morphometric studies were stained with a PCNA antibody. Strong correlations were found between PCNA staining in formalin- and B5-fixed tissues, between the overall proportion of PCNA-positive cells and the proportion in the area of greatest staining, and between strong and total staining. Proliferating cell nuclear antigen staining was significantly stronger in the noncleaved FCC lymphomas than in the cleaved cell lymphomas. The FCC lymphomas showed moderate to strong correlations between PCNA staining and morphometric features of transformation, but only nuclear area correlated with PCNA staining in the CC group. Proliferating cell nuclear antigen staining was not significantly different between CC lymphomas with and without the characteristic bcl-1/PRAD 1 gene rearrangement. In summary, PCNA staining of either B5- or formalin-fixed, paraffin-embedded tissue sections is a simple aid in the objective categorization of FCC lymphomas and may offer additional potentially prognostic information in some FCC subsets and in CC lymphomas. The findings further support the distinction between CC and true FCC lymphomas.

Hodgkin's disease and the malignant lymphomas

The unanticipated finding of a subcutaneous swelling, typically an enlarged lymph node in the neck, is legitimate cause for concern. After excluding benign or reactive conditions, this sign should initiate a series of investigations to characterize the neoplasm and, in the case of a lymphoma, lead to prompt treatment aimed at cure. The classic description of such cervical adenopathy is that by Thomas Hodgkin, who clearly recorded both the clinical behavior and the macroscopic findings evident at dissection. Subsequent histologic study revealed the multinucleate giant cells that characterize the tumor that now bears his name and linked it to those of Greenfield, Sternberg, and Reed. Initial debate centered on whether this entity was inflammatory or malignant, with the issue further clouded by the frequent coexistence of tuberculosis. Although a number of features exist in favor of both concepts, current consensus places it among the neoplastic processes. Hodgkin's disease was separated from other malignant lymphomas as agreement on diagnostic criteria emerged. The next major step forward was the demonstration, first by Vera Peters and then by Henry Kaplan, that adequate doses of radiotherapy were curative when delivered to treatment fields that encompassed the tumor. A further milestone was the introduction by Vincent DeVita, Jr., and his colleagues of combination chemotherapy that was effective in late stage of disseminated disease. The established cornerstones of managing these patients are accurate diagnosis; precise anatomic staging, modified as appropriate by associated factors known to have prognostic value; and selection of irradiation, chemotherapy, or whatever combination will result in the best possible patient survival. However, success is not universal, and death due to resistant or relapsing disease is encountered all too frequently. It is here that the benefits of a multidisciplinary approach are evident, because a substantial level of expertise coupled with sound judgment is needed to salvage these individuals, often by means of investigational programs. Some of the latter are limited by profound myelosuppression, and safety may center on the use of cytokines in the form of interleukins and growth factors, with or without bone marrow transplantation. In such situations, benefit must be balanced against risks in well-structured clinical trials that embody informed consent. Herein lies one of the major goals for the next decade. The non-Hodgkin's lymphomas can conveniently be considered in two broad categories. Some follow an indolent clinical course, in which the lymph node retains a follicular pattern with small component cells, and others are aggressive tumors, in which primitive blasts have diffusely effaced the glandular architecture.(ABSTRACT TRUNCATED AT 400 WORDS)

Correlations between apoptotic and proliferative indices in malignant non-Hodgkin's lymphomas

Cell production versus cell loss rates were estimated, across the boundaries of histological classification, in 50 cases of malignant non-Hodgkin's lymphomas by use of mitotic indices, percentage of Ki-67+ cells and percentage of PC10+ cells as proliferative indices, and the relative number of apoptotic bodies (apoptotic indices, AIs) as parameters. Regression analysis revealed significant (P < 0.01) positive correlations between the AIs and the proliferative indices; among the immunohistochemically assessed proliferative indices; and between these, the mitotic indices and the AIs on the one hand and histological malignancy grades on the other hand. The cellular protein BCL-2, which counteracts apoptosis, was significantly (P < 0.01) more often expressed in lymphomas with low than in those with high AIs. Multivariate analysis of data showed that of all parameters tested in this series, only the AIs correlated significantly (P < 0.05) with overall lethality. The correlation between BCL-2 positivity of lymphoma cells and overall survival did not quite attain significance (P = 0.08). Results of the present study suggest that high AIs and lack of BCL-2 expression may be adverse prognostic factors, independent of histological grade.

Prognosis of lymphoma from a fine-needle aspirate

The prognostic value of S-phase fraction (SPF) determined by flow cytometry from a fine-needle aspirate was investigated in a prospective series of 52 non-Hodgkin lymphomas. The aspirates were drawn either at diagnosis (n = 16) or at lymphoma recurrence (n = 36). Patients with lymphoma with a large SPF (> 10%, n = 24) had only a 21% 3-year survival rate corrected for intercurrent deaths as calculated from the date of aspiration, whereas a smaller SPF was associated with a 71% 3-year survival rate (n = 28, P = 0.0009). SPF size also correlated with Working Formulation grading (P = 0.002). In a multivariate analysis the relative risk of death from lymphomas with a large SPF was 4.01 (1.60-10.1), whereas histological grading, age, and sex had no additional independent prognostic value. SPF determined from a fine needle aspirate had unexpectedly good prognostic value, and the result suggests that the method is of clinical importance.

AgNORs predictive value of prognosis in non-Hodgkin's lymphoma: comparison with flow cytometric cell cycle analysis

Paraffin-embedded histopathologic specimens, taken before the commencement of therapy from 14 low-grade and 21 high-grade malignant lymphoma patients, and 9 normal lymph nodes were utilized to analyze six cell DNA-related parameters. The flow cytometry technique was used to determine cell-cycle G0/G1, S and G2/M phases, and silver staining to enumerate nuclear organized regions (AgNORs); nucleus surface area was determined by an image-analyzing system. The six parameters and natural logarithm of cell proportion in the S-phase (LS) were determined according to the histologic tumor type and achievement of the first complete remission (CR). All parameters except cell proportion in G1/M cycle phase differed significantly with respect to histologic cell type, but were not related to the achievement of first CR. Inasmuch as the parameters significantly correlated with each other, multivariate discriminant analysis and proportional hazard regression were applied to estimate their discriminant/predictive values with respect to tumor malignancy. AgNORs proved to be far superior in all three clinical parameters, S-phase was significantly predictive for the achievement of first CR, and LS for tumor histology type. The statistical model applied narrowed down the analysis of seven parameters to two with respect to tumor histology type (AgNORs and LS) and achievement of first CR (AgNORs and S), but only to one for overall patient survival (AgNORs). Only the model for tumor histology type discrimination was statistically significant (R2 = 0.904, p < 0.001). It appears that AgNORs may be of utmost predictive importance for the clinical outcome in NHL.

'Aggressive' low grade lymphocytic lymphomas can be identified by flow cytometric S-phase determinations

Forty-five patients with low grade non-Hodgkin's lymphomas were studied with respect to the fraction of S-phase cells in fresh tumour material by flow cytometric analysis. Patients with stage I lymphomas were treated with radiotherapy, patients with stage II-IV lymphomas with Prednimustine (Sterecyt). Patients with lymphocytic lymphomas of CLL type were only treated if they had symptoms. Median S-phase fraction in the samples was 2.0 per cent. A significantly shorter survival was found for patients with lymphocytic lymphomas with S-phase fractions > 2.0 per cent compared with cases showing lower S-phase fractions. No significant difference in survival was found in the subgroups of immunocytic or follicular and follicular/diffuse centroblastic/centrocytic lymphomas. In a Cox multivariate analysis, in which also age, constitutional symptoms, stage and morphology were included, the fraction of S-phase cells was found to be a statistically significant, prognostic parameter for low grade lymphomas, mainly due to the result in the subgroup of lymphocytic lymphomas.