Rare Pelvic Malignant Tumors in Adults: Treatment Features and Clinical Outcome in Nonmetastatic Disease (Single Institution Experience).

Background: Nearly 200 cancers repertories are rare, and more than 20% are pelvic neoplasia. Diagnosis and treatment are challenging, even in reference centers, and survival is influenced by the aggressiveness of certain histologies and absence of a standard of care.
Patients and Methods: The authors report the results of a retrospective analysis of patients that attended the Institute of Oncology, Bucharest, between 2004 and 2015, for nonmetastatic pelvic malignant tumor treatment and follow-up. The outcomes are compared between the rare and common histology groups.
Results: Of the 60 cases analyzed, 17 patients (28.33%) bore a rare tumor, 33 (55%) were women, and the median age was 59 years. The majority was concerned by bladder (41.66%, 25 patients) and cervix (23.33%, 14 patients) neoplasms. For a median follow-up of 27.5 months, relapse was registered in 27 patients (45%), of whom 9 (33.33%) were from the rare group (53% of this subpopulation). The highest relapse rates were recorded in patients with rare bladder tumors (66.7%, 4 patients) compared with 42.1% (8 patients) in the common group (p = 0.294) and in prostate localization (66.7%, 2 patients) compared with 16.7% (1 patient) (p = 0.134). Estimated median relapse-free survival (RFS) was 60, 12 months in the rare group and 67 months for common tumors.
Conclusions: In nonmetastatic rare pelvic tumor patients, the outcome was found to be poorer than in those concerned by common histologies stratified by organ. A higher rate of relapse and the lowest median RFS were observed in bladder and prostatic cancers.