Clinicopathological features, prognostic factors, and survival outcomes in giant cell tumors of bone: a retrospective study at the Instituto Nacional de Cancerología, Mexico.

INTRODUCTION: giant cell tumor of bone (GCTB) is a locally aggressive bone neoplasm that predominantly affects young adults. It most frequently involves the distal femur and proximal tibia. Despite its benign classification, GCTB carries a significant risk of local recurrence and pulmonary metastasis. Surgical resection remains the cornerstone of treatment, often complemented by local adjuvants. Denosumab has emerged as a therapeutic option, although its impact on recurrence rates remains controversial. Evidence regarding early predictors of recurrence remains limited.

MATERIAL AND METHODS: this retrospective cohort study included 97 patients with confirmed GCTB treated at the INCan in Mexico City between 2010 and 2023. Inclusion required a minimum follow-up of six months. Clinical, demographic, and treatment-related variables were analyzed to identify prognostic factors for local and distant recurrence. Kaplan-Meier survival analysis and log-rank tests were used to assess recurrence-free and overall survival.

RESULTS: the median patient age was 30 years, with a median tumor size of 8.8 cm. The femur (28%) and tibia (22%) were the most commonly affected sites. Campanacci grade III was present in 77% of cases. Recurrence occurred in 22% of patients, with local relapse in 15% and pulmonary metastases in 8%. Tumors located in the lower extremities and those treated initially at outside institutions showed significantly higher recurrence rates. Denosumab use was not associated with recurrence.

CONCLUSIONS: treatment at high-volume centers and early identification of high-risk features are critical for reducing recurrence in GCTB. Denosumab remains a valuable adjunct in selected cases within a multimodal approach.