Prediction of disease-free survival after therapy in Wilms' tumor using nuclear morphometric techniques

A morphological study of the effect of chlorambucil during the S and G2 phases of the cell cycle of synchronized HEp-2 cancer cell populations using computerized morphometry

Chlorambucil, a bisalkylating agent, used extensively in the treatment of autoimmune and neoplastic diseases, is known to affect DNA synthesis. However recent studies have revealed that it also affects the synthesis of other nuclear protein constituents, especially histones. Since histones play a major role in both the structural and functional integrity of chromatin, we have analyzed the morphological effects of this agent, using low dose conditions and synchronized populations of HEp-2 cancer cells in the S and G2 phases of the cell cycle. Analyses at the light and electron microscopy levels were undertaken using synchronous image analysis techniques. Computerized morphometry was used so as to evaluate various nuclear and cytological morphological parameters. It was found that chlorambucil affects the organization of chromatin, as well as other cellular parameters in a manner characteristic of decreased tumor aggressiveness. A finding of significance in this study was that chlorambucil exerted its influence on all these morphological parameters only when treatment was initiated at the beginning of the S phase and not during the second half of the S phase or the G2 phase.

Nuclear morphometry predicts disease-free interval for clinically localized adenocarcinoma of the prostate treated with definitive radiation therapy

Men treated for prostate cancer often have unexpected outcomes despite predictive models based on stage, grade and prostate-specific antigen (PSA). Previous results have indicated that nuclear morphometry can predict patient outcome in urologic malignancies. Application of this analytical method in prostate cancer treated with radiation therapy is limited. We have evaluated the predictive ability of nuclear morphometry in such patients. Histologic sections from 23 men with clinically localized adenocarcinoma of the prostate treated with radiation therapy were studied. Nuclear morphometric parameters were assessed using a previously described and validated system. Univariate and multivariate logistic regression analyses and a Cox proportional hazards model were used to assess the ability of nuclear morphometric parameters to predict recurrence and disease-free interval. Ten patients had no recurrence with median follow-up of 47. 5 months, while 13 had recurrence. Gleason grade was not predictive of treatment outcome. Pre-treatment PSA data, available for only 11 patients, were predictive of treatment outcome. Several nuclear morphometric parameters predicted recurrence, including upper quartile of suboptimal circle fit and upper quartile of feret-diameter ratio. A prognostic factor score incorporating these 2 parameters was derived, which predicted disease-free interval (p = 0.0014). Int. J. Cancer (Pred. Oncol.) 84:594-597, 1999.

Nuclear morphometry and prognosis in favorable histology Wilms' tumor: A prospective reevaluation

PURPOSE

This study was designed to evaluate the ability of a previously published nuclear morphometry discriminant function to predict disease-free survival in patients with Wilms' tumor.

PATIENTS AND METHODS

We identified 218 patients with stage I-IV Wilms' tumor of favorable histology who were entered onto the National Wilms' Tumor Study (NWTS) between January 1, 1990 and April 15, 1994. The nuclear morphometry score was calculated for each patient as follows: MV(f) = (0.02 x AGE) + (1.17 x SNRF) + (90.6 x LEFD) - 94, with AGE denoting age at diagnosis in months, SNRF the skewness of the nuclear roundness factor, and LEFD the lowest value of nuclear ellipticity as measured by the feret diameter method. Relative risks of relapse were estimated for the total score and for each of its components. Sensitivity and specificity were determined for the criterion of "MV(f) is greater than -0.35" as a predictor of relapse.

RESULTS

By contrast with previously published results, neither the SNRF nor the LEFD made any contribution to the prediction of disease-free survival. Sensitivity and specificity of the criterion of "MV(f) is greater than -0.35" were 71% and 56%, respectively.

CONCLUSION

Re-evaluation of a published nuclear morphometry score showed that it did not predict disease-free survival in patients with Wilms' tumor. The earlier study very likely overestimated the predictive power of nuclear morphometry by using the same data set both to develop the score and to evaluate its properties. Because of the huge number of combinations of nuclear morphometry measurements that may enter into the multivariate discriminant function, use of appropriate statistical methods is essential to estimate accurately the sensitivity and specificity.

Nuclear morphometry adds significant prognostic information to stage and grade for renal cell carcinoma

OBJECTIVES

Identification of patients with a high probability of recurrence after nephrectomy for renal cell carcinoma (RCC) is required for adjuvant studies of new therapies. Nuclear morphometry predicts prognosis for prostate, bladder, and Wilms' tumors and in RCC according to previous small pilot studies.

METHODS

To validate this finding, we studied an additional 101 patients who underwent nephrectomy for Stage pT1 to pT3 RCC at our institution from 1977 to 1993 for whom data regarding recurrence or disease-free survival of greater than 60 months were available. Patient records and pathology specimens were reviewed. Of the 101 patients, 66 (65%) did not experience recurrence with greater than 60 months of follow-up, and 35 (35%) had RCC recurrence with a median time to recurrence of 17 months. Nuclear shape descriptors were tested as predictors of disease recurrence after accounting for stage and grade in proportional hazards regression models.

RESULTS

Range of ellipticity (hazards ratio 3.39, P = 0.014) was confirmed to be a significant predictor of recurrence. A prognostic model using stage, grade, and range of ellipticity identified three distinct groups: low, moderate, and high recurrence risk groups, with recurrence rates of 4%, 37%, and 63%, respectively, at 5 years of follow-up. Morphometry significantly (P = 0.018) improved prognostication on the basis of stage and grade alone in this multivariate model.

CONCLUSIONS

Nuclear morphometry is valid and accurate in predicting relapse in early-stage RCC. The model can select patients with RCC for adjuvant therapies.

New developments in the pathology of Wilms tumor

Wilms tumor (WT) is an embryonal renal neoplasm that has proven to be an exceptionally productive model for the study of tumor pathogenesis and therapy. It also provides a striking demonstration of what can be achieved through the collaborative study of rare tumors, as well as the importance of incorporating formal pathological review into the design of therapeutic cancer trials. As a result of the National Wilms Tumor Study, a majority of children are now cured of their WT with less intense and prolonged therapy than was customary at the middle of the 20th century. The presence of extreme polyploidy (anaplasia) identifies a small subset of WT which have a grim prognosis in the context of present therapy, and which will require innovative therapeutic intensification. Recent evidence suggests that anaplasia is a marker of resistance to adjuvant therapy, rather than increased aggressiveness. Stage I anaplastic WT and advanced-stage WT with anaplasia limited to a portion of the primary tumor seem to fare as well as nonanaplastic WT and do not require therapeutic intensification. New neoplastic entities formerly confused with WT have been identified, and refinements of staging criteria have been achieved. New insight into the pathogenesis has significant implications for clinical management. Despite these achievements, much remains to be learned from this tumor model, before we have achieved the ultimate goal of curing every child with WT, while exposing that child to the minimum possible adverse sequelae of therapy. Adverse effects of therapy are far more significant for the young child cured of cancer than for the elderly patient, and their avoidance is therefore the most important goal beyond the cure itself.

Nuclear morphometric analysis of metastasis in Wilms' tumor after multimodal therapy: comparison with primary tumor

OBJECTIVES

The outlook for children with Wilms' tumor has improved with the use of multimodal therapy, and survival rates now exceed 85%. Yet, 15% of children with tumors with favorable histologic findings continue to recur unpredictably. We previously reported that nuclear morphometry (the distribution of nuclear roundness factor [NRF], lowest values for ellipticity, and age) when combined in a multivariate analysis accurately predicted response to therapy for patients with histologically favorable Wilms' tumors.

METHODS

To investigate further the nuclear shape changes associated with disease recurrence, we analyzed histologic sections taken from primary tumors and postmultimodal therapy metastatic lesions for 7 children who had a recurrence with initially histologically favorable primary tumors.

RESULTS

Mean NRF was significantly lower (P = 0.0001) in the metastatic lesion (35 +/- 5) group when compared with the primary tumor group (50 +/- 5). The percent coefficient of variation for NRF was also significantly lower (P = 0.006) in the metastatic lesion when compared with the primary tumor. Nuclear area was increased (P = 0.02), although the nuclear perimeter was unchanged (P = 0.1).

CONCLUSIONS

(1) Nuclei in metastatic lesions from Wilms' tumors with favorable histologic findings after multimodal therapy are more round and exhibit less variable distribution, suggesting clonal homogeneity within the metastatic lesion. (2) Nuclei in the metastatic lesions have greater area than in the primary tumors yet have an unchanged perimeter, which may be due to internal nuclear expansion secondary to increased cellular deoxyribonucleic acid (DNA) ploidy. Although the results of this study are promising, we are currently extending this hypothesis to a larger group of patients.