Inl. J. Radiation Oncolo~

Bid. Phgs..

1976, Vol.

1. p. 813.

Pergamon Press.

Printed in the U.S.A.

THE CASE FOR SUBCLASSIFICATION MALIGNANT GLIOMAS SIMON

KRAMER,

OF THE

M.D.

Medicine, Thomas Jefferson University Hospital, Philadelphia,PA 19107,U.S.A.

Department of Radiation Therapy and Nuclear

Dr. Earle, in his erudite and comprehensive editorial,’ describes the diScuSes inherent in grading or otherwise subdividing malignant gliomas on the basis of a surgical specimen which may be inadequate in amount or not representative of the true nature of the gliomatous tumor under study. He refers to Dr. Rubinstein’s work3 and recommends adoption of the classification described in the AFIP fascicle number six until the World Health Organization’s classification is universally used. For the practicing neuro-oncologist there remains the need to decide on therapy and to be able to give the patient and family some indication of prognosis based on past experience. At present, the established degree of malignancy of the glioma remains the single most important predictor. Most physicians concerned with the treatment of malignant brain tumors recognize that any separation of gliomas into rigid groups is somewhat arbitrary and only broadly indicates the biologic behavior and outcome of a tumor in any specific patient. Nonetheless, with all its imperfections the grading of malignant tumors

into Grade III and Grade IV tumors has shown good correlation with outcome in at least two published series.2*4 Aggressive radiation therapy can lead to approximately 20% five year survival in patients with Grade III gliomas, while essentially no five year survivals were found in Grade IV tumors. Thus, in reporting treatment results in patients with malignant gliomas the proportion of relatively more or less highly malignant tumors must be known if any comparison of effectiveness of therapy is to be made. Few clinicians would be competent or willing to dispute the fine points leading to the pathologic stratification of the gliomas with Dr. Earle and his colleagues, nor do many of us care whether this stratification is made by a grading system of by whatever nomenclature the neuro-pathologists can agree upon. What matters, as Dr. Earle so rightly points out, is that there be an agreed system of pathologic classification of the gliomas, which relates to prognosis at least as well as the Kemohan grading system and allows us to compare the results of therapeutic studies in appropriate categories.

REFERENCES 1. Earle, K.: The proper nomenclature for glioblastoma multiforme. ht. I. Radiat. Oncol. Biol. Phys. 1: 805-808, 1976. 2. Kramer, S.: Radiation therapy in the management of malignant gliomas. In Seventh National Cancer Conference Proceedings. Philadelphia, Lippincott, 1973, pp. 823-826.

3. Rubinstein, L.J.: Tumors of the Central Nervous System. Second Series. Fascicle 6. Armed Forces Institute of Pathology, Washington, DC, 1972. 4. Sheline, G.E.: Radiation therapy of primary tumors. Semin. Oncol. 11(l): 29-42, 1975.

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The case for subclassification of the malignant gliomas.

Inl. J. Radiation Oncolo~ Bid. Phgs.. 1976, Vol. 1. p. 813. Pergamon Press. Printed in the U.S.A. THE CASE FOR SUBCLASSIFICATION MALIGNANT GLIOM...
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