Background: The AJCC recently published the 8th edition of its cancer staging system. Significant changes were made to the staging algorithm for soft tissue sarcoma (STS) of the extremities or trunk, including the addition of 2 additional T (size) classifications in lieu of tumor depth and grouping lymph node metastasis (LNM) with distant metastasis as stage IV disease. Whether these changes improve staging system performance is questionable. Patients and Methods: This retrospective cohort analysis of 21,396 adult patients with STS of the extremity or trunk in the SEER database compares the AJCC 8th edition staging system with the 7th edition and a newly proposed staging algorithm using a variety of statistical techniques. The effect of tumor size on disease-specific survival was assessed by flexible, nonlinear Cox proportional hazard regression using restricted cubic splines and fractional polynomials. Results: The slope of covariate-adjusted log hazards for sarcoma-specific survival decreases for tumors >8 cm in greatest dimension, limiting prognostic information contributed by the new T4 classification in the AJCC 8th edition. Anatomic depth independently provides significant prognostic information. LNM is not equivalent to distant, non-nodal metastasis. Based on these findings, an alternative staging system is proposed and demonstrated to outperform both AJCC staging schemes. The analyses presented also disclose no evidence of improved clinical performance of the 8th edition compared with the previous edition. Conclusions: The AJCC 8th edition staging system for STS is no better than the previous 7th edition. Instead, a proposed staging system based on histologic grade, tumor size, and anatomic depth shows significantly higher predictive accuracy, with higher model concordance than either AJCC staging system. Changes to existing staging systems should improve the performance of prognostic models. Until such improvements are documented, AJCC committees should refrain from modifying established staging schemes.
David S. Ettinger, Mark Agulnik, Justin M. M. Cates, Mihaela Cristea, Crystal S. Denlinger, Keith D. Eaton, Panagiotis M. Fidias, David Gierada, Jon P. Gockerman, Charles R. Handorf, Renuka Iyer, Renato Lenzi, John Phay, Asif Rashid, Leonard Saltz, Lawrence N. Shulman, Jeffrey B. Smerage, Gauri R. Varadhachary, Jonathan S. Zager and Weining (Ken) Zhen
David S. Ettinger, Charles R. Handorf, Mark Agulnik, Daniel W. Bowles, Justin M. Cates, Mihaela Cristea, Efrat Dotan, Keith D. Eaton, Panagiotis M. Fidias, David Gierada, G. Weldon Gilcrease, Kelly Godby, Renuka Iyer, Renato Lenzi, John Phay, Asif Rashid, Leonard Saltz, Richard B. Schwab, Lawrence N. Shulman, Jeffrey B. Smerage, Marvaretta M. Stevenson, Gauri R. Varadhachary, Jonathan S. Zager, Weining (Ken) Zhen, Mary Anne Bergman and Deborah A. Freedman-Cass
The NCCN Guidelines for Occult Primary tumors provide recommendations for the evaluation, workup, management, and follow-up of patients with occult primary tumors (cancers of unknown primary). These NCCN Guidelines Insights summarize major discussion points of the 2014 NCCN Occult Primary panel meeting. The panel discussed gene expression profiling (GEP) for the identification of the tissue of origin and concluded that, although GEP has a diagnostic benefit, a clinical benefit has not been demonstrated. The panel recommends against GEP as standard management, although 20% of the panel believes the diagnostic benefit of GEP warrants its routine use. In addition, the panel discussed testing for actionable mutations (eg, ALK) to help guide choice of therapy, but declined to add this recommendation.