The pathologist and the clinical oncologist: a new effective partnership in assessing tumor prognosis

Genetic staging of unresectable or metastatic neuroblastoma in infants: a Pediatric Oncology Group study

BACKGROUND

Current staging systems for unresectable or metastatic neuroblastoma do not reliably predict responses to chemotherapy in infants under 1 year of age. Previous studies have indicated that the DNA content, or ploidy, of malignant neuroblasts can discriminate between good and poor responders in this group of patients, but the clinical utility of ploidy assessment has remained in question.

PURPOSE

We tested, in a prospective nonrandomized study, the hypothesis that neuroblast ploidy could be used as the sole guide for treatment selection in infants with unresectable or metastatic tumors and could differentiate between those who would respond to our previous standard regimen and those who would benefit from an immediate switch to another therapy.

METHODS

One hundred seventy-seven infants were enrolled in this trial. Five of these infants were subsequently excluded (two ineligible, two lacking ploidy information, and one protocol violation); therefore, 172 patients were included in the study. One hundred thirty infants with hyperdiploid tumors (DNA index > 1.0; better prognosis in retrospective studies) were treated with a well-tolerated regimen of cyclophosphamide (150 mg/m2 per day orally or intravenously on days 1-7) and doxorubicin (35 mg/m2 intravenously on day 8). Forty-two infants with diploid tumors (DNA index = 1.0; worse prognosis in retrospective studies) received cisplatin (90 mg/m2 intravenously on day 1) and teniposide (100 mg/ m2 intravenously on day 3) after an initial course of cyclophosphamide plus doxorubicin. Statistical end points were response and long-term survival. In addition, we assessed within each ploidy group (i.e., patients with hyperdiploid tumors and those with diploid tumors) the prognostic significance of NMYC gene copy number, tumor stage, and other variables commonly measured in this disease.

RESULTS

Of the 127 assessable infants with hyperdiploid tumors, 115 (91%) had complete responses--85 after receiving five courses of cyclophosphamide plus doxorubicin and 30 after receiving further therapy including cisplatin plus teniposide. The 3-year survival estimate for the entire hyperdiploid group was 94% (95% confidence interval [CI] = 89%-98%). Nineteen (46%) of 41 assessable infants with diploid tumors were complete responders. The overall 3-year survival estimate for this group was 55% (95% CI = 39%-70%). Prognostic factor analysis indicated that NMYC gene amplification and an elevated serum lactate dehydrogenase level were statistically significant markers of higher risk disease within the diploid group (two-sided P values of .005 and .003, respectively). Only NMYC was predictive in the hyperdiploid group (P = .003).

CONCLUSION

Use of a prognostic staging system based on tumor cell ploidy, augmented with the NMYC gene copy number and serum level of lactate dehydrogenase, would very likely improve the treatment of infants with unresectable or metastatic neuroblastoma. Patients with diploid tumors characterized by an amplified NMYC locus represent a particularly unfavorable risk group that may benefit from innovative new therapies.

Histologic grading of breast carcinoma. A reproducibility study

BACKGROUND

A concern with the histologic grading of breast cancer is that tumor grading is a subjective evaluation that may have problems with reproducibility.

METHODS

A single slide from 10 invasive breast cancers was submitted to 25 pathologists who practice in six separate groups. Pathologists graded the tumors using a modified Bloom-Richardson (B-R) scheme, and the results were compared.

RESULTS

In 8 of the 10 cases, there was greater than 87% agreement by the pathologists as to the final combined B-R grade, with complete agreement in 2 cases. Only one case had any discrepant opinions that ranged from low to high grade, and this involved only 3 of the 25 pathologists. With respect to B-R score, the pathologists tended to score the tumors as either one of two adjacent scores. Due to this clustering, the B-R scheme appears reproducible into five groups: very low and very high grade tumors and B-R score "5,6," "6,7," and "7,8" tumors. This clustering was especially noticeable in two cases with split decisions, in which the discrepancy in final combined grade was largely due to the tumors being given B-R scores that straddled and were then condensed into two B-R grades. A consensus from each pathology group tended to merge with the majority opinion of all 25 pathologists and was correct for outliers.

CONCLUSIONS

This study indicates that reproducibility of grading breast cancers can be achieved when a histologic grading scheme with specified guidelines is used. Pathologists must be aware of the limits of reproducibility, with appropriate guidelines being followed to help optimize agreement, and there should be an awareness of how pathologists group in their evaluations. Also, it may be advisable to better correlate or link reproducibility data with prognostic data in the design of grading schemes.

Prognostic significance of the expression of c-fos, c-jun and c-erbB-1 oncogene products in human squamous cell lung carcinomas

The expression of the oncogenes c-fos, c-jun, c-myc, c-erbB-1 and c-erbB-2 at the protein level was analyzed in squamous cell lung carcinomas of 121 patients by means of immunohistochemistry. Patients with overexpression of proteins encoded by the oncogenes c-fos, c-jun and c-erbB-1 had significantly shorter survival times than these without overexpression of these oncogene products (c-fos: p = 0.009; c-jun: p = 0.029; c-erbB-1: p = 0.018). No significant correlations were found between the expression of c-myc and c-erbB-2 products and the survival of the patients. In addition to the univariate analyses (Kaplan-Meier-estimates) multivariate analyses (Cox-regression-model) revealed that protein expression of the oncogenes c-fos, c-jun and c-erbB-1 are significant prognostic factors in addition to staging.

Expression of mitoses per thousand cells and cell density in breast carcinomas: a proposal

A method of standardizing mitotic counts is described. This provisional approach, which expresses mitoses as a percentage of breast cancer cells present, holds the promise of facilitating interlaboratory agreement as well as providing a measure of tumor cellularity, probably an independent prognostic indicator in its own right. We suggest that this approach or one similar to it will maximize the evaluation and quantitation of proliferative activity from routinely available histologic material. Furthermore, the method is accomplished with little added effort beyond the customary histologic evaluation.

How malignant is malignant? A brief review of the microscopic assessment of human neoplasms, and the prediction of whether they will metastasize and kill

This review examines ways in which histopathologists can attempt to predict the degree of malignancy from the microscopic examination of surgically removed samples of human neoplasms. These include mitotic counts, measurement of DNA content, analysis of DNA turnover, measurement of proliferation antigens, measurement of nucleolar organizing areas, counting nucleoli, morphometry of nuclei, identification of genetic change, measurement of lysis of basement membrane, and measurement of invasion in vitro. The latter two are not currently of practical value. Of the rest none is uniformly capable of predicting the degree of malignancy of a human neoplasm. After further refinement and control measurement of several such parameters may however contribute more to the prediction of malignancy than present subjective assessments.