Significance of the neutrophil-to-lymphocyte ratio in predicting the response to neoadjuvant chemotherapy in extremity osteosarcoma: a multicentre retrospective study

Background At present, no predictive factor has been validated for the early efficacy of neoadjuvant chemotherapy (NACT) in osteosarcoma. The purpose of this study was to investigate the significance of the neutrophil-to-lymphocyte ratio (NLR) in predicting the response to NACT in extremity osteosarcoma. Methods Pathological complete response (pCR) was used to assess the efficacy of NACT. Receiver operating characteristic (ROC) curves and the Youden index (sensitivity + specificity-1) were used to determine the optimal cut-off values of the NLR. Univariate and multivariate analyses using logistic regression models were conducted to confirm the independent factors affecting the efficacy of NACT. Results The optimal NLR cut-off value was 2.36 (sensitivity, 80.0%; specificity, 71.3%). Univariate analysis revealed that patients with a smaller tumour volume, lower stage, lower NLR and lower PLR were more likely to achieve pCR. Multivariate analyses confirmed that the NLR before treatment was an independent risk factor for pCR. Compared to patients with a high NLR, those with a low NLR showed a more than 2-fold higher likelihood of achieving pCR (OR 2.82, 95% CI 1.36-5.17, p = 0.02). Conclusion The NLR is a novel and effective predictive factor for the response to NACT in extremity osteosarcoma patients. Patients with a higher NLR showed a lower percentage of pCR after NACT.

Early response monitoring of neoadjuvant chemotherapy using [18F]FDG PET can predict the clinical outcome of extremity osteosarcoma

Background To propose a personalized therapeutic approach in osteosarcoma treatment, we assessed whether sequential [18F]FDG PET/CT (PET/CT) could predict the outcome of patients with osteosarcoma of the extremities after one cycle and two cycles of neoadjuvant chemotherapy. Methods A total of 73 patients with AJCC stage II extremity osteosarcoma treated with 2 cycles of neoadjuvant chemotherapy, surgery, and adjuvant chemotherapy were retrospectively analyzed in this study. All patients underwent PET/CT before (PET0), after 1 cycle (PET1), and after the completion of neoadjuvant chemotherapy (PET2), respectively. Maximum standardized uptake value (SUVmax) (corrected for body weight) and the % changes of SUVmax were calculated, and histological responses were evaluated after surgery. Receiver-operating characteristic (ROC) curve analyses and the Cox proportional hazards models were used to analyze whether imaging and clinicopathologic parameters could predict event-free survival (EFS). Results A total of 36 patients (49.3%) exhibited a poor histologic response and 17 patients (23.3%) showed events (metastasis in 15 and local recurrence in 2). SUVmax on PET2 (SUV2), the percentage change of SUVmax between PET0 and PET1 (Δ%SUV01), and between PET0 and PET2 (Δ%SUV02) most accurately predicted events using the ROC curve analysis. SUV2 (relative risk, 8.86; 95% CI, 2.25–34.93), Δ%SUV01 (relative risk, 5.97; 95% CI, 1.47–24.25), and Δ%SUV02 (relative risk, 6.00; 95% CI, 1.16–30.91) were independent predicting factors for EFS with multivariate analysis. Patients with SUV2 over 5.9 or Δ%SUV01 over − 39.8% or Δ%SUV02 over − 54.1% showed worse EFS rates than others (p < 0.05). Conclusions PET evaluation after 1 cycle of presurgical chemotherapy can predict the clinical outcome of extremity osteosarcoma. [18F]FDG PET, which shows a potential role in the early evaluation of the modification of timing of local control, can be a useful modality for early response monitoring of neoadjuvant chemotherapy.

Functional outcome of surgical treatment of adults with extremity osteosarcoma after megaprosthetic reconstruction—single-center experience

Background Osteosarcoma is the most common primary malignant bone tumor in adults and is usually located in the long bones. Standard treatment consists of perioperative chemotherapy and radical surgical resection. Limb-sparing surgery using a variety of reconstructive techniques remains the gold standard. Methods In our study, we retrospectively analyzed 90 adult patients operated at our institution between 2000 and 2017 for extremity osteosarcoma that underwent limb-sparing reconstruction with the megaprosthesis. Sixty-one patients underwent resection and reconstruction of the distal femur, 9 patients—proximal femur, 7 patients—proximal tibia, 5 patients—total femoral resection and reconstruction, 5 patients—proximal humeral resection, and 3 patients—other types of resection with endoprosthetic reconstruction. The median follow-up time was 41 months, median overall survival was 86 months (3–225 months), and progression-free survival was 81 months (1–86 months). Functional assessment was made on 48 out of 56 living patients, after endoprosthetic reconstruction. The assessment was made according to MSTS functional scale. Results In 14 cases (15%), the endoprosthesis had to be explanted, or amputation was performed for local recurrence or septic complication. Due to a mechanical failure of the implant, we had to perform a revision in 5 patients (5%). Eighteen out of 74 patients with endoprosthesis died of the disease. The median MSTS score was 84% (53–100%), and the best result of 85% was achieved in patients after distal femoral resection with endoprosthetic reconstruction. Conclusion Careful planning of the treatment of patients with extremity osteosarcoma that is performed at the referral centers gives the possibility of long-term survival with a good and excellent functional result.