PELVIC NEUROBLASTOMA-IMPLICATIONS FOR A NEW FAVORABLE SUBGROUP - A CHILDRENS CANCER GROUP EXPERIENCE

Background: The survival in neuroblastoma is influenced by patient age , disease stage, tumor site, and several biologic factors. This study was undertaken to determine if primary pelvic lesions are associated w ith an unusually favorable outcome. Methods: Nine hundred eighty-six p atients registered on Children's Cancer Group studies from 1980 to 199 3 were reviewed, and 41 (4.3%) were found to have pelvic tumors. Survi val was analyzed, and correlations among age, stage of disease, surgic al resectability, histopathology, serum ferritin, and N-myc oncogene a mplification were evaluated. Results: Age at diagnosis was comparable between patients with pelvic and nonpelvic tumors. Disease distributio n was similar, with stages III and IV comprising 78% (32 of 41) of pel vic lesions compared with 73% (692 of 945) for nonpelvic tumors. There was no outcome difference in favorable stages (I, II, and IV-S), with 3-year progression-free survival rates of 88% and 82% for pelvic and nonpelvic sites, respectively. However, in stages III and IV, the 3-ye ar progression-free survival was 70% for pelvic lesions compared with 47% for nonpelvic tumors (p = 0.04). Some favorable biologic factors w ere more common in children with pelvic lesions. Conclusions: The pelv is is an unusual primary site for neuroblastoma but represents a more favorable prognostic subgroup, which is most evident in advanced-stage disease.