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

Lead article: The prognostic significance of proliferating cell nuclear antigen (pcna) in laryngeal cancer

Squamous cell carcinoma arising from upper aerodigestive tract carries with it a significant morbidity and mortality and, over the last few decades, its incidence has steadily increased. The management of patients requires thorough investigation to determine the local, regional, and distant extent of the disease, and treatment options include surgery, radiotherapy, chemotherapy, or combinations of these.Despite the large number of therapeutic and hsitopathologic studies in print, there is currently no morphologic or cytologic feature available which consistenly predicts outcome in patients with laryngeal carcinoma. The use of proliferating cell nuclear antigen (PCNA), a newly available marker of a cell's proliferative activity ( S-phase fraction), was evaluated in 25 cases of squamous cell carcinoma of the larynx. PCNA scores differed, statistically significantly as far as the localization of the lesion, pathological grade, clinical stage, presence of lymph node metastases and prognosis of the patients were concerned.These data suggest that PCNA is an indicator of the malignant potential of the larynx. PCNA can be used in decision making for treatment and assessing prognosis in carcinoma of the larynx.

A novel t(2;20)(q35;p12) in embryonal rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma of childhood, accounting for 5%-8% of all pediatric malignancies. RMS can be categorized into several subtypes, including embryonal RMS (ERMS), the botryoid and spindle cell variants of ERMS, and alveolar RMS (ARMS). The t(2;13)(q35;q14) and the variant t(1;13)(p36;q14) are seen in a majority of ARMS cases. In contrast, the embryonal subtype of rhabdomyosarcoma has not been associated with a recurring chromosomal translocation. We describe here a novel chromosomal t(2;20)(q35;p12) occurring in a case of childhood RMS with embryonal histology. It is notable that this translocation harbors breakpoints at or near the locus of the PAX3 gene, which is involved in the most common recurring translocation associated with ARMS.

Cell kinetics and apoptosis in laryngeal carcinoma patients

Cellular proliferation and apoptosis are both implicated in the process of carcinogenesis. The objective of this study was to access the prognostic significance of the expression of proliferating cell nuclear antigen (PCNA) and the apoptosis-related genes (bax, bcl-2, and p53) in laryngeal carcinoma patients. Thirty consecutive patients with stage I to IV squamous cell laryngeal carcinoma were treated in our department from 1992 to 1994. We immunohistochemically studied the expression of PCNA and bax, bcl-2, and p53 genes in their tumor specimens. Five healthy men were used as the control group. The staining results were correlated with clinicopathologic data. The PCNA protein expression was correlated with a significantly worse survival in those patients who were bax-negative (0% versus 42.86%, p = .0445). Similarly, the presence of PCNA led to an unfavorable clinical outcome in those patients who were bax-negative, bcl-2-negative, and p53-negative (0% versus 50%, p = .0278). Expression of bcl-2 protein was found to be an independent prognostic factor related to an unfavorable clinical outcome (p = .0262). The expression of bcl-2 protein appears to predict survival in laryngeal carcinoma patients. Furthermore, the combined study of proliferation markers and apoptosis-related genes helped us to identify a high-risk group of patients who may benefit from a more aggressive treatment protocol.

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.

Prognostic value of proliferating cell nuclear antigen immunostaining in pediatric rhabdomyosarcomas

BACKGROUND

The levels of proliferating cell nuclear antigen (PCNA) are almost negligible in long-term quiescent cells and increase dramatically during the cell cycle. Recently, the monoclonal antibodies to PCNA have been used to demonstrate the proliferative component of paraffin-embedded tumor tissues. It has been shown to be available as a simple histological marker of proliferative activity and the PCNA labeling index has been correlated with the prognosis of several malignant neoplasms.

METHODS

Formalin fixed, paraffin embedded tissue specimens of 29 primary pediatric rhabdomyosarcomas were immunostained by using an anti-PCNA monoclonal antibody (DAKO PCNA PC10). The relationship between the PCNA index and prognosis, clinicopathological features and survival were assessed retrospectively.

RESULTS

The mean PCNA index for the whole series was 54%. There was no correlation between PCNA index and any of the clinicopathological characteristics. However, patients having tumors with a high (> 54%) PCNA index demonstrated significantly lower survival rates than tumors with a low (< 54%) PCNA index (P = 0.01). Moreover, there were significantly more patients with relapse or progressive disease in the high PCNA index group (P = 0.005).

CONCLUSION

The PCNA labeling index can be a useful prognostic factor and a good indicator of recurrence and/or survival in patients with rhabdomyosarcoma.

Detection of proliferating cell nuclear antigen (PCNA) in peripheral blood mononuclear cells and sera of patients with malignant lymphoma

Proliferating cell nuclear antigen (PCNA) was detected in the peripheral blood mononuclear cells (PBMC) of patients with malignant lymphoma (ML). Twenty-one of 27 patients with ML had PCNA expressing PBMC (5.25+/-4.75% cells), which tended to increase in the advanced clinical stage of ML. PCNA in PBMC extracts was detected in 11 of 16 patients (54.5+/-41.9 ng/ml). The percentage of PCNA-positive cells correlated significantly with the concentration of PCNA in PBMC extracts (P < 0.005). Serum PCNA was detected in 6 of 16 patients (160.1+/-141.1 ng/ml), but did not correlate with the number of PCNA-positive cells. In some cases, the concentration of serum PCNA increased after chemotherapy while the percent PCNA-positive cells decreased. Our finding indicate that detection of PCNA in PBMC appears to help monitoring the extent of disease in ML and the serum PCNA level may be used in therapeutic studies of lymphoma patients.

Nocturnal urinary 6-sulfatoxymelatonin and proliferating cell nuclear antigen-immunopositive tumor cells show strong positive correlations in patients with gastrointestinal and lung cancer

The hormone melatonin plays a key role in coordinating neuroendocrine signals involved in the control of biological rhythms and also appears to be involved in the regulation of cellular proliferation. In this study on patients with gastrointestinal and lung cancer the nocturnal urinary excretion of 6-sulfatoxymelatonin (aMT6s) reflecting pineal melatonin production as well as immunohistochemically detectable proliferating cell nuclear antigen (PCNA) and melatonin were measured in corresponding tumor specimens (6 colorectal, 8 stomach, and 12 lung cancers). Strong positive correlations were detected between aMT6s and PCNA for the different types of tumors analysed (1 > or = Rs > or = 0.736, P < 0.01-0.0001). These findings provide support to the concept of an involvement of the pineal gland in malignancy and suggest that aMT6s-measurements may be considered as a non-invasive tool to estimate tumor cell proliferation. Negative correlations found between urinary aMT6s and melatonin in tumor cells (-0.735 > or = Rs > or = -0.928, P < 0.01-0.0025) could be interpreted as an effort of the pineal gland to secrete melatonin to compensate for the decrease in the number of melatonin-immunopositive cells within tumor tissue where it may possess important regulatory functions.

Flow cytometric evaluation of proliferating cell nuclear antigen expression in human hematopoietic malignancies

Cell proliferation is a strong prognostic factor in various malignancies including non-Hodgkin's lymphoma's (NHL). Several methods to evaluate tumour proliferation are available based on immunohistochemical and flow cytometric techniques, but none has been widely accepted for multicenter studies. In the present study 51 samples from patients with haematological disorders were analysed for the expression of proliferating cell nuclear antigen (PCNA) by a previously described flow cytometric approach. S-phase specific PCNA (PCNA-S) as well as growth fraction-associated PCNA (PCNA-tot) expression were evaluated. The mean value for PCNA-S was 9.0% and for PCNA-tot 17,4%. PCNA-S and PCNA-tot correlated strongly to each other (r(s) = 0.969, p < 0.001) and to the S-phase fraction determined by DNA histogram analysis (r(s) = 0.927 and 0.934 respectively, p < 0.001). In 23 cases with NHL in vivo iododeoxyuridine (IdUrd) labelling was performed to assess the labelling index (IdUrd-LI, i.e. S-phase fraction), S-phase duration time (Ts) and potential tumour doubling time (Tpot). IdUrd-Li correlated significantly to both PCNA-S and PCNA-tot (r(s) = 0.704 and 0.622 respectively, p < 0.001 and 0.02). In conclusion, especially the PCNA-S seemed to be a candidate for future larger studies of proliferation related aspects of haematological malignancies.

Proliferating cell nuclear antigen (PCNA) in non-Hodgkin's lymphomas: correlation with working formulation and Kiel classification in formalin-fixed paraffin-embedded material

PCNA is a 36-KD proliferating cell nuclear antigen associated with the cell cycle. The immunocytochemical detection of PCNA represents a useful tool for the study of tumor proliferation activity. This study documents the detection of PCNA, using antibody PC 10 in formalin-fixed, paraffin-embedded tissue, and correlates the proliferative activity of the non-Hodgkin's lymphomas (NHL) with histological grading assessed by the International Working Formulation (WF) and Kiel classification. In 92 cases of NHLs we found a strong correlation between the PCNA index and lymphoma grading. Statistically significant differences were also found between the proliferative index (PI) in low and high grade lymphomas according to the Kiel classification (t = 9.519; p < 0.001) and between low, intermediate and high grade lymphomas according to the WF classification (F = 79.01; p < 0.001). In the Kiel classification the mean of low grade lymphomas was 39.5% and of high grade 75.7%. In the WF the average of low grade lymphomas was 29.7%, intermediate 53.1% and high 75.1%. Although the differences among the groups had been significant, we found variations inside each histological subgroup in both classifications. The intermediate lymphomas were the most heterogeneous group, with PI inside the same histologic subtypes coincident with low and high grade lymphomas. Since PCNA may be used as a marker of cell proliferation in clinical studies to estimate the biological aggressiveness of lymphomas, its determination in intermediate grade NHL could be very useful to evaluate individual cases in this group and determine prognosis and probably the appropriate therapy.

Expression of proliferating cell nuclear antigen (PCNA) and Ki-67 in soft tissue sarcoma. Is prognostic significance histotype-specific?

Abnormal patterns of proliferation characterize the behavior of many tumors. Proliferating cell nuclear antigen (PCNA) and Ki-67 are two cell cycle antigens which are expressed in proliferative states. Our study examines the prognostic value of these cell-cycle antigens in soft tissue sarcoma (STS). Paraffin-embedded primary tumor tissues from 185 patients (1980-92) were stained with the anti-PCNA antibody PC-10; 182 of these were stained with the antibody MIB-1 for Ki-67. Using PCNA (< or = 50; > 50%) and Ki-67 (< or = 10; > 10%) indices, we examined and compared metastasis-free survival (MFS) in a mixed-histotype group, as well as after subdivision into MFH and non-MFH groups. Fifty-seven patients developed metastases. The median follow-up for survivors was 6 (2-13) years. In the mixed series, the 2-year MFS for a PCNA index < or = 50 was 76%, and for an index > 50 56%. Survival predicted by Ki-67 index was comparable. PCNA index (but not Ki-67) strongly correlated with the incidence of metastasis in MFH tumors and predicted 2-year MFS of 81 vs 48%. In contrast, Ki-67 index (but not PCNA) strongly correlated with metastasis in non-MFH tumors and predicted 2-year MFS survival of 90 vs 45%. No correlation existed between PCNA and Ki-67 indices in the mixed histotype, MFH or non-MFH groups. In combination, a high PCNA and Ki-67 index correlated with poor survival, a high PCNA and lower Ki-67 index (or vice versa) with an intermediate survival, and low PCNA and Ki-67 indices with the best survival. The pattern of PCNA and Ki-67 expression raises the possibility of histotype specificity.

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.

p53 protein, PCNA staining, and DNA content in follicular neoplasms of the thyroid gland

Forty-nine follicular adenomas and 11 follicular carcinomas of the thyroid were investigated by immunohistochemistry for the expression of p53 protein and proliferating cell nuclear antigen (PCNA). The DNA ploidy and the S-phase fraction (SPF) of the neoplasms were analysed by flow cytometry. Twelve adenomas (24 per cent) and six carcinomas (55 per cent) were DNA non-diploid (P = 0.07). The carcinomas had a higher proliferation rate than the adenomas when assessed either by SPF size (median 9.9 per cent vs. 2.9 per cent, P = 0.0003) or by PCNA staining intensity (P < 0.0001). Some scattered nuclei in two (4 per cent) adenomas and in three (27 per cent) carcinomas stained positively for p53 (P = 0.04). The two adenomas with positive staining for p53 were subserially sectioned, but no signs of invasion were found; both patients are alive and well 6 and 7 years after surgery. One of the two adenomas showing positive p53 nuclear staining was DNA aneuploid, and both were positive in PCNA staining, but their SPFs were low (2.1 and 3.3 per cent). We conclude that p53 protein expression is not confined to follicular carcinomas; scattered p53-positive cells may also be present in histologically and clinically benign follicular adenomas. Because both follicular adenomas and carcinomas may be DNA aneuploid and their SPF and PCNA staining distributions overlap, the distinction between follicular adenoma and carcinoma should still be based on histological criteria.

Proliferating cell nuclear antigen (PCNA) in high-grade malignant fibrous histiocytoma: prognostic value in 48 patients

Grading based on histopathologic features is used to predict survival in soft-tissue sarcoma. However, variations in clinical behavior between tumors of the same grade motivate a search for additional factors that correlate with prognosis. Proliferating cell nuclear antigen (PCNA) is expressed in proliferating cells during the G1, S and G2-phases. To evaluate a prognostic implication of PCNA, the tumors of 48 patients with malignant fibrous histiocytomas (13 grade III, 35 grade IV) with a minimum follow-up of 2 years were immunohistochemically studied. We used PC10, a monoclonal antibody (MAb) directed against PCNA, which allows cell proliferation in formalin-fixed, paraffin-embedded tumor tissue to be evaluated. We applied a semiquantitative PCNA grading scheme to all stained nuclei of an entire slide. The 3-year metastasis-free survival rate was 0.87 for patients in grade A (low PLNA rate), and 0.14 for patients in grade C (high PLNA). Our findings show that immunohistochemical evaluation of cell kinetics in soft-tissue sarcomas by PCNA might be a useful adjunct to conventional tumor grading.

Proliferation profile of benign and premalignant cervical epithelium as established by PCNA staining pattern

Since immunohistochemical detection of proliferating cell nuclear antigen (PCNA) is closely related to the cell cycle, this method can be used to visualize proliferative activity in paraffin sections of benign and premalignant cervical lesions. This was done in two types of benign lesions, immature and mature metaplasia, and the three types of CIN (I, II, and III). PCNA staining was assessed as heavy, faint, or negative nuclei in the deep, middle, and superficial layers of the epithelium. In the analysis of variance, significant differences between the three layers and between the five groups were found. The PCNA values can be helpful to distinguish immature metaplasia from CIN I. The values for PCNA-positive (heavy+faint) for an individual lesion at the three layers constitute its proliferation profile. The PCNA profiles of the CIN lesions differ fundamentally from the metaplasia profiles. It is conceivable that for an individual CIN lesion, PCNA staining might be prognostically more valuable than its CIN grade.