SEER Inquiry System - Report
Produced: 01/17/2025 3:43 PM
Question 20180077
Inquiry Details
References:
#1: Solid Tumor Rules. Head and Neck
#2: 2018 SEER Manual, 144
Question:
Solid Tumor Rules (2018)/Histology--Head & Neck: How is histology coded for a p16-positive squamous cell carcinoma of the base of tongue? Is p16-positive squamous cell carcinoma equivalent to a diagnosis of squamous cell carcinoma human papilloma virus (HPV)-positive (8085)? See Discussion.
Discussion:
Table 6 (Tumors of the Oropharynx, Base of Tongue, Tonsils, Adenoids) in the Head and Neck Equivalent Terms and Definitions lists both squamous cell carcinoma HPV-positive and squamous cell carcinoma HPV-negative as subtypes/variants of squamous cell carcinoma (the NOS histology, 8070). Squamous cell carcinoma HPV-positive and squamous cell carcinoma HPV-negative are also listed in the 2018 ICD-O-3 update table.
Previous clarification from the standard setters regarding the 2018 ICD-O-3 Update table indicated that histology codes 8085 and 8086 (HPV-positive and HPV-negative squamous cell carcinoma, respectively) included p16+ and p16- squamous cell carcinoma, respectively. Presumably, this clarification was made because p16 is a surrogate marker for HPV, and capturing whether a tumor is HPV-related or not has implications for staging for 2018 and later diagnoses. However, this clarification was not added to the 2018 ICD-O-3 Update table via errata, nor do the Head and Neck Equivalent Terms and Definitions or Histology Coding Rules address this.
Is a diagnosis of p16-positive squamous cell carcinoma equivalent to a diagnosis of squamous cell carcinoma HPV-positive (8085)? If so, will this clarification be added to the Head and Neck Solid Tumor Rules?
Answer:
HPV-positive is not equivalent to HPV-mediated (p16+). According to the 2018 SEER Manual, HPV-type 16 refers to virus type and is different from p16 overexpression (p16+). HPV status is determined by tests designed to detect viral DNA or RNA. Tests based on ISH, PCR, RT-PCR technologies detect the viral DNA or RNA; whereas, the test for p16 expression, a surrogate marker for HPV, is IHC. HPV testing must be positive by viral detection tests in order to code histology as 8085.