Anal Cancer Stages. American Cancer Society. Available at http://www.cancer.org/cancer/anal-cancer/detection-diagnosis-staging/staging.html. September 9, 2020; Accessed: October 18,2021.
[Guideline] NCCN Clinical Practice Guidelines in Oncology: Anal Carcinoma. National Comprehensive Cancer Network. Available at https://www.nccn.org/professionals/physician_gls/pdf/anal.pdf. Version 2.2021 — June 30,2021; Accessed: October 18, 2021.
American Joint Committee on Cancer. Anus. AJCC Cancer Staging Manual, Staging Form Supplement. Eighth ed. New York, NY: Springer; 2018. 128-131.

Table 1. TNM Classification for Anal Cancer

Primary tumor (T)
TX	Primary tumor cannot be assessed
T0	No evidence of primary tumor
Tis	High-grade squamous intraepithelial lesion (previously termed carcinoma in situ, Bowen disease, anal intraepithelial neoplasia II–III, high-grade anal intraepithelial neoplasia)
T1	Tumor ≤ 2 cm in greatest dimension
T2	Tumor > 2 cm but ≤ 5 cm in greatest dimension
T3	Tumor > 5 cm in greatest dimension
T4	Tumor of any size invades adjacent organ(s) (eg, vagina, urethra, bladder)
Regional lymph nodes (N)
NX	Regional lymph nodes cannot be assessed
N0	No regional lymph node metastasis
N1	Metastasis in inguinal, mesorectal, internal iliac, or external iliac nodes N1a - Metastasis in inguinal, mesorectal, or internal iliac lymph nodes N1b - Metastasis in external iliac lymph nodes N1c - Metastasis in external iliac with any N1a nodes
Distant metastasis (M)
M0	No distant metastasis
M1	Distant metastasis

Table 2. Anatomic stage/prognostic group

Stage	T	N	M
0	Tis	N0	M0
I	T1	N0	M0
IIA	T2	N0	M0
IIB	T3	N0	M0
IIIA	T1-T2	N1	M0
IIIB	T4	N0	M0
IIIC	T3-T4	N1	M0
IV	Any T	Any N	M1

Table 3. Histologic Grade

Grade	Definition
GX	Grade cannot be determined
G1	Well differentiated (low grade)
G2	Moderately differentiated (low grade)
G3	Poorly differentiated (high grade)
G4	Undifferentiated (high grade)

Back to List

Author

Kirby Rebecca Walker, MD Fellow in Complex General Surgical Oncology, Roger Williams Medical Center

Kirby Rebecca Walker, MD is a member of the following medical societies: American College of Surgeons, Texas Medical Association

Disclosure: Nothing to disclose.

Specialty Editor Board

Mary L Windle, PharmD Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Nothing to disclose.

Christopher D Braden, DO Hematologist/Oncologist, Chancellor Center for Oncology at Deaconess Hospital; Medical Director, Deaconess Hospital Outpatient Infusion Centers; Chairman, Deaconess Hospital Cancer Committee

Christopher D Braden, DO is a member of the following medical societies: American Society of Clinical Oncology, American Society of Hematology

Disclosure: Nothing to disclose.

Chief Editor

N Joseph Espat, MD, MS, FACS Harold J Wanebo Professor of Surgery, Assistant Dean of Clinical Affairs, Boston University School of Medicine; Chairman, Department of Surgery, Director, Adele R Decof Cancer Center, Roger Williams Medical Center

N Joseph Espat, MD, MS, FACS is a member of the following medical societies: Alpha Omega Alpha, American Association for Cancer Research, American College of Surgeons, American Medical Association, American Society for Parenteral and Enteral Nutrition, American Society of Clinical Oncology, Americas Hepato-Pancreato-Biliary Association, Association for Academic Surgery, Central Surgical Association, Chicago Medical Society, International Hepato-Pancreato-Biliary Association, Pancreas Club, Sigma Xi, The Scientific Research Honor Society, Society for Leukocyte Biology, Society for Surgery of the Alimentary Tract, Society of American Gastrointestinal and Endoscopic Surgeons, Society of Surgical Oncology, Society of University Surgeons, Southeastern Surgical Congress, Southern Medical Association, Surgical Infection Society

Disclosure: Nothing to disclose.

Additional Contributors

Jeffrey B VanDeusen, MD, PhD Assistant Clinical Professor of Internal Medicine, Medical Director, James Cancer Network, Division of Medical Oncology, Department of Internal Medicine, The Ohio State University Comprehensive Cancer Center

Disclosure: Nothing to disclose.