Twelve-Month Metastatic State as a Landmark-Based Prognostic Stratifier in Metastatic Sarcoma.

Area of Science:

• Medical Oncology
• Sarcoma Research
• Clinical Prognostics

Background:

• Prognostic assessment in metastatic sarcoma is challenging.
• Baseline variables may not fully capture outcomes post-metastasis.
• Investigating the 12-month landmark for prognostic stratification.

Purpose of the Study:

• To evaluate the 12-month landmark for prognostic stratification of post-metastasis survival in sarcoma.
• To compare the prognostic value of the 12-month disease state versus institutional data.

Main Methods:

• Retrospective observational study using real-world clinical data from two sarcoma centers.
• Analysis of overall survival (OS) and post-metastasis survival (PMS).
• Landmark analysis at 12 months, classifying patients as oligometastatic or polymetastatic; Cox regression models used.

Main Results:

• 236 patients included; PMS showed numerical separation between institutions.
• Metastatic state at 12 months clearly stratified PMS; oligometastatic disease had a better outcome.
• Polymetastatic state at 12 months was the strongest independent predictor of inferior PMS (HR 3.09). High grade also significant (HR 5.16).

Conclusions:

• The 12-month metastatic state provides stronger prognostic stratification for post-metastasis survival in sarcoma than institutional comparison.
• A longitudinal, state-based prognostic framework is supported.
• Disease state at the 12-month landmark is more informative than crude center attribution for survival stratification.