Oncological, surgical and functional results of the treatment of patients after hemipelvectomy due to metastases

BACKGROUND: Metastatic lesions localized in the pelvis cause pain, pathological fractures and decrease quality of patients life. Limited data are avaliable to compare the oncological, surgical and functional outcomes after different surgeries in patients with metastatic pelvic tumors. Most of the works presents the results of hemipelvectomy performed in patients with primary malignant bone tumors. The objectives of this study were to assess the outcome of patients after internal hemipelvectomy due to cancer metastases. METHODS: Over the period 2010–2015 at the Department of Orthopaedic Oncology in Brzozów, 34 patients with metastases to the pelvis were treated. This study group comprised of 21 men and 13 women. The mean age was 67 (range: 51–79) for men and 56 (range: 41–77) for women. The majority of the treated patients suffered from myeloma (12 patients) and breast cancer (8 patients). Following the Enneking system classification guidelines, tumours were found in zone I (5 cases), zone II (18 cases), zone III (4 cases). Tumour involvement of both zones (II and III) considered 7 patients. The following resections were accomplished: wide in 11 cases, marginal in 17 cases, and intralesional in 6 cases. 18 patients were postoperatively treated with 8 Gy single-dose radiotherapy. 25 patients underwent bone reconstruction using either Lumic prostheses (9 cases) or the Harrington technique (16 cases). The mean follow-up period was 2.1 years (range: 1.2–6 years). The analysis covered patients’ survival, number of local recurrences, functional results and effectiveness of surgical treatment, considering the type, number and reason of complications. RESULTS: Eight patients died. Overal survival calculated with Kaplan- Meier curve was 48.2% for 34 patients. Mean survival was 3.85 years. There were no statistically significant differences in overall survival depending on the type of metastasis resection. In this group, local tumour recurrences concerned 6 patients. The extent of tumour resection and the use of postoperative radiotherapy were statistically significantly related to local recurrences. Functional results were better in a group of patients without reconstruction. Postoperative VAS score was 2.7, Karnofsky status 71 and MSTS 23(86%). After Lumic prostheses implantation VAS score was 3.4, Karnofsky status 65 and MSTS 19(63%). The worst results were observed after Harrington procedure. We noticed 9 perioperative complications in 6 (18%) of patients. Most frequently, the problems included impaired wound healing due to infection (4 patients) and dislocation of Lumic prosthesis (2 patients). CONCLUSIONS: The frequency of local recurrences after hemipelvectomies is related to the radicality of tumour resection and the postoperative application of radiotherapy. Survival time depends on the type and stage of cancer and does not depend on the type of tumour resection. The best functional results were obtained in patients after type I resection followed by no reconstruction of the bone. Lumic prosthesis implantation gave better results than Harrington procedure.