Age-dependent rate of anaplastic transformation in low-grade astrocytoma

Abstract

Age and histologic grade are interrelated characteristics of diffuse fibrillary astrocytomas, because the peak age incidence rises with increasing grade. The relationship between age and grade may be explained if age determines the rate of anaplastic progression in astrocytomas. The authors tested this hypothesis by determining the interval between diagnosis of low-grade astrocytoma and progression to high-grade astrocytoma in patients of various ages. A two-way scatterplot of age at initial diagnosis versus interval to anaplastic progression demonstrated a strong negative correlation (n = 24; Pearson correlation coefficient = -0.83; Spearman correlation coefficient = -0.79; p< 0.001 for both values). It was concluded that the rate of anaplastic progression in low-grade astrocytoma is directly correlated with patient age.

Interstitial 125I radiosurgery of supratentorial de novo WHO Grade 2 astrocytoma and oligoastrocytoma in adults

“…Our finding supports preliminary data in the literature concerning an age-associated risk for malignant transformation. 30 Other studies of our group have stressed the independent negative influence of TP53 mutations. 31,32 The impact of any applied therapy on risk of malignant transformation remains unclear.…”

The management of incidental low-grade gliomas using magnetic resonance imaging: systematic review and optimal treatment paradigm

“…Considering evidence of an age-dependent increase in anaplastic transformation of incidental LGG, operative decisions may be made depending on the age of the patient at diagnosis. 4,32,33 For example, studies by Shafqat et al 33 demonstrated that patients older than 45 years of age have a mean time to dedifferentiation of 7.5 months after radiological diagnosis, compared with 44.2 months in patients younger than 45 years. However, the elderly population may benefit from active observation given that neurosurgery on elderly patients may have an increased risk for complications and poor outcomes.…”

Low-grade gliomas in adults

“…Definition of the timing of this phenomenon is equally elusive, as reported median intervals range from 2.1 to 10.1 years based upon studies published in the past 15 years. 23,76,82,88,127,132 Authors of several recent studies have examined histological upgrading in the context of extent of resection, reasoning that the risk of progression increases with tumor burden. In a study of hemispheric LGGs, greater preoperative tumor volume was significantly associated with shorter malignant progressionfree survival, 132 suggesting that tumors that are larger at presentation may have an inherently faster growth rate, and thus recur faster in the setting of a gross-total resection or continue to grow faster in the setting of a subtotal resection.…”