Factors influencing overall survival specific to adult low-grade astrocytoma: a population-based study

Abstract

Aims: We report a population-based overall survival and prognostic factor analysis specific to adult patients diagnosed with low-grade astrocytoma (LGA).

Materials and methods: All histologically confirmed cases of LGA diagnosed between 1992 and 1996 in the province of Ontario, Canada, were identified from the Ontario Cancer Registry and reviewed.

Results: In total, 182 patients were identified; the mean age was 50 years and the mean survival time was 4.1 years (standard deviation = 5.1 years). Fifty-four per cent of patients had a surgical excision and 46% were biopsied alone. Both univariate and multivariate analyses showed that patients aged <30 years were significantly more likely to undergo an excision as compared with a biopsy alone (odds ratio = 4.26, 95% confidence interval 1.54-11.77). For the entire cohort, we observed a significant relationship between decreasing survival as a function of increasing age at diagnosis. In the biopsy sub-group, relative to patient's age <30 years, the hazard of dying increased significantly according to age when stratified by decade. However, in those patients having had a primary surgical excision, the hazard of dying relative to patient's age <30 years was similar for those aged 30-49 years and then significantly greater as patient age surpassed 50 years.

Conclusions: Age is a significant prognostic factor for LGA. Our analysis suggests that in those patients amenable to a primary tumour excision, a survival benefit may be confined to those under age 50 years.