Is Detection of Relapse by Surveillance Imaging Associated With Longer Survival in Patients With Rhabdomyosarcoma?

Background: We investigated whether surveillance imaging had an impact on post-relapse survival in patients with rhabdomyosarcoma (RMS). We hypothesized that relapse detected by imaging (group IM) would be associated with longer survival compared with relapse detected with a clinical sign or symptom (group SS). Materials and Methods: We performed an observational multi-institutional study in 127 patients with relapsed RMS comparing overall survival (OS) after relapse using Kaplan-Meier and Cox proportional hazards analyses. Results: Relapse was detected in 60 (47%) group IM and 67 (53%) SS patients. Median follow-up in survivors was 4 years (range 1.0 to 16.7 y). Four-year OS rates were similar between group IM (28%, 95% confidence interval [CI]: 14%-40%) and SS (21%, 95% CI: 11%-31%) (P=0.14). In multivariable analyses accounting for institution, age at diagnosis, time to relapse, risk group at diagnosis, and primary site, not receiving chemotherapy (hazard ratio [HR]: 6.8, 95% CI: 2.8-16.6), radiation (HR: 3, 95% CI: 1.7-5.3), or surgery (HR: 2.8, 95% CI: 1.6-4.8) after relapse were independently associated with poor OS. Conclusion: These results on whether surveillance imaging provides survival benefit in patients with relapsed RMS are inconclusive. Larger studies are needed to justify current surveillance recommendations. Chemotherapy, radiotherapy and surgery to treat recurrence prolong OS.