Purpose of the study: Diagnosis and treatment of primary malignant tumors of the pelvis raise difficult problems. The purpose of this retrospective study was to analyze the functional and cancerological results observed after surgical treatment in a single center.

Material and methods: Between 1973 and 2002, 24 patients (16 men and 8 women) underwent surgery in our unit for histological proven malignant tumors. A posterior approach was used for curettages and sacrectomies of the apex. A combined anterior and posterior approach was used for total sacrectomy and hemisacrectomy. Oncological results were assessed in terms of local recurrence, presence of metastasis and patient status at last follow-up. Overall survival and disease-free survival were calculated with the Kaplan-Meier method.

Results: Mean age was 53.38 years. Mean follow-up in our series was 54 months. Mean time to diagnosis was 16 months. Pain was the predominant symptom. Sixteen patients presented neurological manifestations and the digital rectal examination was positive in all. Chondroma was the most frequent histological type (18/24). None of the patients had metastatic disease at diagnosis. A posterior approach was used for 15 patients and a combined approach for the others. There was a clear correlation between type of resection and volume of blood loss (p=0.0002). Wide dissection was wide in five patients, marginal in five and oncologically insufficient in 14. Mean operative time was 1.34 hours for posterior approaches and 9 hours for combined approaches. The postoperative period was uneventful for ten patients. Infection was the most frequent complication. Adjuvant radiotherapy, delivered in 16 patients, effectively retarded the occurrence of local recurrence. Functional disorders were correlated with the level of the neurological sacrifice. At least one S3 root had to be preserved to limit the urological and digestive incapacity. At last follow-up, local recurrence was present in 12 patients. Mean time to first recurrence was 32 months. There was a strong correlation between quality of the resection and time to local recurrence. There was a significant difference between patients with a wide resection and those with an oncologically insufficient resection (p=0.0312). Five patients had metastases. Five-year actuarial survival was 73±12%. At ten years it was 32±14%. Local recurrence-free survival was 55±11% at five years and zero at 10 years.

Discussion and conclusion: In light of these results, factors of poor prognosis were: late diagnosis, soft tissue invasion, proximal extension, marginal or insufficient resection.