Low tumor cell content predicts favorable prognosis in germinoma patients
Abstract Background Germinoma preferentially occurs in pediatric and young adult age groups. Although they are responsive to treatment with chemotherapy and radiation, the treatment may cause long-term sequelae in their later lives. Here, we searched for clinical and histopathological features to predict the prognosis of germinoma and affect treatment response. Methods A total of 114 germinoma cases were included in the analysis. We investigated the association between clinical factors, tumor cell content, and progression-free survival (PFS). Results The tumor cell content was widely distributed from <5% to 90% in the specimens, with a median value of 50%. Female patients showed higher tumor cell content in the specimens (p=0.002). Cases with lesions at atypical sites showed shorter PFS than those with lesions at other sites (p=0.03). Patients with a higher tumor cell content (≥50%) showed shorter PFS than those with a lower tumor cell content (<50 %) (p=0.03). In multivariate analysis, tumor cell content was the only statistically significant prognostic factor (p=0.04). Among the seven cases treated with local radiation and chemotherapy, all three cases that recurred (two outside of the radiation field, one unknown) had tumor cell content of ≥50% in the original specimen, whereas all four cases without recurrence had tumor cell contents of <50%. Conclusions We found that tumor cell content significantly affected the prognosis of germinomas. Although validation of these results using an independent and larger cohort is necessary, this potentially opens the possibility of leveraging this pathological factor in future clinical trials when stratifying the treatment intensity.