Excess mortality after craniopharyngioma treatment: are we making progress?

Purpose Craniopharyngioma is associated with an increased risk of mortality even after surgical, radiotherapeutic and hormone supplementations. Previous studies using different designs showed a possible trend of decreasing mortality in recent years. This review summarises studies reporting standardised mortality ratio (SMR) after craniopharyngioma treatment, as well as the bias and confounding in these studies to plan further researches. Methods PubMed and Embase was searched for manuscripts published before October 2018 using medical subject heading terms (craniopharyngioma or hypopituitarism and mortality). Results Eight studies reported SMR after craniopharyngioma treatment, with a total of 2802 patients. The subgroup meta-analysis using random effects model was conducted to pool the SMR, which was 6.2 (95% CI 4.1-9.4) before 2010 and 2.9 (95% CI 2.2-3.8) after 2010 (subgroup test p<0.01), respectively. Misclassification (one study) and selection bias (six studies) either inflated or deflated the result. The trend of increasing survival rate over the time was observed in studies without reporting SMR. Female patients, childhood-onset disease, hydrocephalus, tumour recurrence, body mass index and panhypopituitarism were identified as the important risk factors for excess mortality. Conclusions Though bias and confounding existed across studies, the decreasing SMR and increasing survival rate over the time was in favour of a real signal. It is necessary to launch studies to further investigate the morality and risk factors after multidisciplinary treatment of craniopharyngioma in a hospital-based manner, using the modern statistical method to adjust for bias and confounding.