Main Session
Sep
27
PQA 02 - Pediatric Cancer, Sarcoma and Cutaneous Tumors, Medical Education & Professional Development, and Health Services Research
2299 - Detecting Local and Metastatic Recurrences after Treatment of Soft Tissue Sarcomas: Periodicity and Duration of Surveillance
Presenter(s)
Emmanuel Jnr Amoateng, MD, MBA - University of Rochester Medical Center, Rochester, NY
E. J. B. Amoateng1, D. Huang1, G. Ge2, S. Bandyopadhyay1, H. Yang3, S. Mcdowell1, A. Victor4, and L. S. Constine5; 1University of Rochester Medical Center, Rochester, NY, 2Providence Portland Medical Center, Portland, OR, 3Department of Biostatistics and Computational Biology,University of Rochester Medical Center, Rochester, NY, 4University of Rochester School of Medicine and Dentistry, Rochester, NY, 5Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY
Purpose/Objective(s):
For Soft Tissue Sarcomas (STS), time interval for risk of local recurrence (LR) and metastatic disease (MD) is ill-defined and periodicity and duration of surveillance approaches requires definition. Whether extremity vs. other sites (e.g. abdominal, chest, H&N) should be considered differently is unclear.Materials/Methods:
Retrospective review identified adults (=18 yrs) with STS (excluding rhabdomyosarcoma, Ewings) at one institution (1/2010–9/2022). Demographics, tumor characteristics, treatment, surveillance imaging, and outcomes were studied. Primary aims: (1) time to LR and MD; (2) detection method; (3) interval when recurrences ceased. Analyses included Kaplan-Meier curves, Cox regression, and competing risk analysis.Results:
Of 112 patients (66 extremity, 46 others), 19 (17%) were nonwhite, 33 (40%) Grade 3, 40 (36%) >10cm. Treatment: 12 (10%) No RT, 87 (78%) Perioperative RT, 13 (11%) Definitive RT. 39 (34%) developed MD (extremity 31.8%, other 39.1%) and 14 (12%) developed LR (extremity 10.6%, other 15.2%). Median follow-up was 46.8 months (Range: 0.1-198.3). Nonwhites had higher 5-yr recurrence risk compared to whites (70.8% vs 38.1%, p<0.05). Tumor site (extremity vs other) was not associated with recurrence risk (p=0.45), whereas Grade 3 vs Grades 1-2 more likely to have MD (41% vs. 19.2%, p=0.042); Of LR 71.4% were image-detected (CT 28.6%, PET 28.6%, MRI 14.3%) and 28.6% clinically. Timing: 57.1% <2 yrs, 14.3% 2-5 yrs, 28.6% 5-10 years, 0% >10 yrs. Of MD, 92.3% were image-detected (CT 64.1%, PET 23.1%, MRI 5.1%) and 7.7% clinically. Timing: 79.5% <2 yrs, 10.2% 2-5 yrs, and 7.6% 5-10 yrs, 2.6% >10 yrs. 5-yr cumulative recurrence incidence was 77.0% with chemotherapy (ChT) versus 24.8% without (p<0.05). Hazard rates (HR) revealed distinct patterns by risk group: ChT patients (high-risk) had annual MD HR of 0.445 (Yr 1), 0.420 (Yr 2), 0.108 (Yr 3), 0.159 (Yr 4), 0.266 (Yr 5) and 0 thereafter. Non-ChT: 0.162 (Yr 1), 0.042 (Yr 2), 0.024 (Yr 3), approaching 0 by Yr 4.Conclusion:
This study demonstrates recurrence patterns in STS are strongly associated with treatment modalities (such as addition of ChT) and patient demographics but not tumor site. Higher recurrence rates with ChT likely reflect selection of high-risk disease rather than treatment failure. Surveillance imaging predominantly detected both LR and MD. Concentration of MD within 2 years (79.5%) supports intensive early surveillance. HR analysis demonstrates that high-risk patients maintain elevated MD risk through Yr 3, supporting intensive CT surveillance for 3 yrs before de-escalation. Lower-risk patients demonstrate near-zero hazard by Yr 3, suggesting earlier de-escalation may be appropriate. With 100% (local) and 97.4% (distant) recurrences occurring within 10 yrs, routine imaging may be safely discontinued thereafter. Findings support risk-stratified, time-limited surveillance protocols applicable across tumor sites.