Papillary tumor of the pineal region: a patient-level meta-analysis and multivariate evaluation of prognostic factors

Introduction: Papillary tumor of the pineal region (PTPR) clinical course and biological behavior are still under investigation. The optimal therapeutic approach is yet to be defined. We performed a comprehensive patient-level meta-analysis with all PTPR cases reported thus far to elucidate clinical and treatment features regarding this tumor and identify prognostic factors.

Methods: A WebOfSciences, Medline and EMBASE search for case series/reports on PTPR (January/2003-June/2017) was performed. Only PTPR cases with individual-level data were included. Data addressing PTPR’s clinical presentation, imaging, treatment and histological features were registered and factors associated with the primary outcome of 36-month survival were identified through Cox regression models.

Results: Initial search yielded 1054 results, of which 154 remained after screening for relevance. A total 71 studies were included, 60 case reports and 11 case series comprising 175 patients (mean age 33.4 ± 15.4 years, 53.2% male). Headache was the most frequent symptom (82.9%) and 88.6% presented with hydrocephalus. Mean tumor size and volume were 2.9 ± 1.0 cm and 8.3 ± 7.1 cm³. Surgery was performed on 82.0% and gross total resection (GTR) was achieved on 71.4%. The Glasgow outcome scale was available on 76 cases and its median was 2 (quartiles 1–5). A total 56.8% recurred on a median 28 months (quartiles 11–45). The 36-month survival rate was 83.5%. General mean 36-month survival was 33.6 ± 0.7 months. After multivariate analysis adjusted for age, tumor size (per each additional centimeter, HR 1.99, 95% CI 1.12–3.53, p = 0.019) and surgical treatment (HR 0.16, 95% CI 0.06–0.46, p = 0.001) were associated with 36-month survival.

Conclusion: Our results provided information regarding the clinical course and management of PTPR. Tumor size and surgical resection were associated with PTPR survival. We did not find significant benefit on GTR or adjuvant treatment for PTPR, although clinical trials are warranted to overcome the inherent limitations of this study design.