title: Evaluation of AJCC tumor staging for cutaneous squamous cell carcinoma and a proposed alternative tumor staging system.
abstract: OBJECTIVE
  This study proposes an alternative tumor staging system for cutaneous squamous cell carcinoma (CSCC) that more precisely defines the small subset of tumors with a high risk of metastasis and death.
  
  
  OBJECTIVE
  To identify risk factors for poor outcomes in CSCC and evaluate the 2010 American Joint Committee on Cancer (AJCC) tumor (T) staging system's ability to stratify occurrence of these outcomes.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  A single academic hospital.
  
  
  METHODS
  Study participants were identified via a pathology and dermatopathology database search for patients diagnosed as having high-risk CSCC.
  
  
  RESULTS
  Two hundred fifty-six primary high-risk CSCCs were included. Outcomes for AJCC tumor stages T2 to T4 were statistically indistinguishable because only 4 cases (<2% of the cohort) were AJCC stages T3 or T4, which require bone invasion. Subsequently, the bulk of poor outcomes (83% of nodal metastases, 92% of deaths from CSCC) occurred in AJCC stage T2 cases. An alternative tumor staging system was developed with the aim of better stratifying this stage T2 group. Four risk factors were found to be statistically independent prognostic factors for at least 2 outcomes of interest in multivariate modeling. These factors (poor differentiation, perineural invasion, tumor diameter ≥2 cm, invasion beyond subcutaneous fat) were incorporated in the alternative staging with 0 factors indicating T1, 1 factor indicating T2a; 2 to 3 factors, T2b; and 4 factors or bone invasion, T3. Stages T2a and T2b significantly differed in incidences of all 4 end points. Stage T2b tumors comprised only 19% of the cohort but accounted for 72% of nodal metastases and 83% of deaths from CSCC.
  
  
  CONCLUSIONS
  The proposed alternative tumor staging system offers improved prognostic discrimination via stratification of stage T2 tumors. Validation in other cohorts is needed. Meanwhile, stage T2b tumors are responsible for most poor outcomes and may be a focus of high-risk CSCC study.
authors: Department of Dermatology, Mayo Clinic Florida, Jacksonville, USA.
authors: Anokhi
authors: A
authors: Jambusaria-Pahlajani
authors: Peter A
authors: PA
authors: Kanetsky
authors: Pritesh S
authors: PS
authors: Karia
authors: Wei-Ting
authors: WT
authors: Hwang
authors: Joel M
authors: JM
authors: Gelfand
authors: Faith M
authors: FM
authors: Whalen
authors: Rosalie
authors: R
authors: Elenitsas
authors: Xiaowei
authors: X
authors: Xu
authors: Chrysalyne D
authors: CD
authors: Schmults
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008495:Medical Oncology / Q000379:methods*; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D009367:Neoplasm Staging / Q000379:methods*; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000473:pathology*; D012955:Societies, Medical; D014481:United States