Prognostic implications of advancing nodal stage in anal cancer: evaluating AJCC 8 staging changes through an NCDB analysis

• Published in: International journal of colorectal disease Vol. 35; no. 11; pp. 2099 - 2104
• Main Authors: Scher, Eli D., Elson, Joshua K., Kharofa, Jordan R.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.11.2020; Springer; Springer Nature B.V
• Subjects: Anal cancer; Anus; Colorectal cancer; Gastroenterology; Hepatology; Internal Medicine; Medicine; Medicine & Public Health; Original Article; Proctology; Squamous cell carcinoma; Surgery; Tumor staging; Staging; Anal cancer; Radiation; AJCC
• ISSN: 0179-1958; 1432-1262
• DOI: 10.1007/s00384-020-03688-7

Purpose In the AJCC8, nodal staging for squamous cell carcinoma of the anus (SCCA) has been changed to a binary format (N0 or N+), and overall stage groups have been redefined. We evaluated the effect of AJCC8 nodal stage by T stage and hypothesized similar survival regardless of the extent of AJCC7-defined nodal involvement. Methods The National Cancer Database (NCDB) was used to identify patients’ SCCA. Overall survival (OS) for each T stage within the AJCC7 was compared with increasing nodal stage, as well as for the new AJCC8 overall stage groups and subsets. Results There were 6738 patients analyzed. The 5-year OS by AJCC8 stage was I = 81%, IIA = 78%, IIB = 64%, IIIA = 69%, IIIB = 59%, IIIC = 57% ( p  < 0.0001). In AJCC8 IIIA (T1–2, N+), there was no difference in 5-year OS between T1N+ or T2N+ patients (70.3% vs 68.6%, p  = 0.09). A significant survival difference was demonstrated between AJCC7 N1, N2, and N3 for patients with either T1 ( p  = 0.0047) or T2 ( p  = 0.0389) disease. In the AJCC 8 IIIC (T3–4, N+) group, there was no difference in 5-year OS between T3N+ and T4N+ (58% vs 55%, p  = 0.81). There was no OS difference between AJCC7 N1–3 for either T3 ( p  = 0.19) or T4 (0.35) disease. Conclusion For earlier T stages, advancing nodal stage per AJCC7 retains prognostic implications for OS. Survival in AJCC8 stage IIIA is heterogeneous and is largely driven by burden of nodal disease in patients with T1–2 disease.