Post operative infection and increased survival in osteosarcoma patients: Are they associated?

Background: Despite neo-adjuvant chemotherapy osteosarcomas having significant mortality, recent studies have shown survival advantages following infections for some tumour types. This study investigates the effect of post-operative infection in patients treated for osteosarcoma using endoprosthetic replacement and neo-adjuvant chemotherapy. Material and Methods: A consecutive series of 547 patients underwent surgery between 1981 and 2001 for osteosarcoma. Patients were excluded from the study if over 60 years old at diagnosis (n = 14) as they would not routinely receive chemotherapy. Studies showed that 70% of deep infections occur within one year from reconstruction. Therefore landmark analysis was performed; all patients infected after 12 months of reconstruction were excluded (15 patients, 2.7%) and those who died within 12 months from diagnosis due to metastases were excluded (105 patients, 19.2%), leaving 412 patients. Any survival advantage of early infection was analysed by Kaplan-Meier survival analysis from this landmark point. Results: Overall population survival was 65% at 10 years after landmarking. There were 41 patients (10%) who developed an infection within one year of implantation. These patients had significantly better survival (p = 0.017). The 10-year survival for patients with osteosarcoma with infection was 84.5% compared to 62.3% in the non-infected group after landmarking. There was no significant difference in the percentage post-chemotherapy specimen necrosis between the two groups (p = 0.36). Infection was an independent prognostic factor on cox regression analysis. Conclusions: There was evidence for increased survival after deep post-operative infection in osteosarcoma patients, in keeping with other research. The authors feel this warrants further investigation.