Prognostic factors and prognosis

Factors associated with a favorable prognosis include the following:[1,8-10]

Factors associated with an unfavorable prognosis include the following:[12]

Presence of NF1 appears to be associated with an unfavorable prognosis, but the data are mixed.[4,15]

For patients with localized disease in the MD Anderson Cancer Center study, there was no significant difference in outcome between patients with and without NF1.[9] In other studies, it was not clear whether the absence of NF1 was a favorable prognostic factor as it has been associated with both favorable [8] and unfavorable outcomes.[1,8,10]

In the French Sarcoma Group study, NF1 was associated with other adverse prognostic features, but was not an independent predictor of poor outcome.[12] A retrospective analysis of cancer registry data from the Netherlands identified 784 patients with MPNST; 70 of the patients were aged 18 years or younger.[16][Level of evidence C1] In children with NF1, large tumor size was more common (>5 cm, 92.3% vs. 59.1%). Overall, the estimated 5-year survival rate was 52.4% (standard error [SE], 10.1%) for patients with localized MPNST and NF1, compared with 75.8% (SE, 7.1%) for patients without NF1.

The Cooperative Weichteilsarkom Studiengruppe (CWS) reported a retrospective review of patients with MPNST who were treated on five consecutive CWS trials.[17] A total of 159 patients were analyzed. NF1 was reported in 38 patients (24%). Nodal involvement was documented in 15 patients (9%) at diagnosis, and distant metastases was noted in 15 patients (9%) at diagnosis. Overall, the event-free survival (EFS) rate was 40.5% at 5 years and 36.3% at 10 years. The overall survival (OS) rate was 54.6% at 5 years and 47.1% at 10 years. Older age, positive NF1 status, primary tumor site other than extremity, larger tumor size, higher Intergroup Rhabdomyosarcoma Study (IRS) group, presence of metastatic disease, and failure to achieve first complete remission were identified as adverse prognostic factors for EFS and/or OS in the univariate analysis.