Comprehensive management of HPV‐related squamous cell carcinoma of the head and neck of unknown primary

Answer questions and earn CME/CNE The recently released eighth edition of the American Joint Committee on Cancer (AJCC) Staging Manual, Head and Neck Section, introduces significant modifications from the prior seventh edition. This article details several of the most significant modifications, and the rationale for the revisions, to alert the reader to evolution of the field. The most significant update creates a separate staging algorithm for high-risk human papillomavirus-associated cancer of the oropharynx, distinguishing it from oropharyngeal cancer with other causes. Other modifications include: the reorganizing of skin cancer (other than melanoma and Merkel cell carcinoma) from a general chapter for the entire body to a head and neck-specific cutaneous malignancies chapter; division of cancer of the pharynx into 3 separate chapters; changes to the tumor (T) categories for oral cavity, skin, and nasopharynx; and the addition of extranodal cancer extension to lymph node category (N) in all but the viral-related cancers and mucosal melanoma. The Head and Neck Task Force worked with colleagues around the world to derive a staging system that reflects ongoing changes in head and neck oncology; it remains user friendly and consistent with the traditional tumor, lymph node, metastasis (TNM) staging paradigm. CA Cancer J Clin 2017;67:122-137. © 2017 American Cancer Society.

Evidence for transcriptional activation of the viral oncoproteins E6 and E7 is regarded as the gold standard for the presence of clinically relevant human papillomavirus (HPV), but detection of E6/E7 mRNA requires RNA extraction and polymerase chain reaction amplification-a challenging technique that is restricted to the research laboratory. The development of RNA in situ hybridization (ISH) probes complementary to E6/E7 mRNA permits direct visualization of viral transcripts in routinely processed tissues and has opened the door for accurate HPV detection in the clinical care setting. Tissue microarrays containing 282 head and neck squamous cell carcinomas from various anatomic subsites were tested for the presence of HPV using p16 immunohistochemistry, HPV DNA ISH, and an RNA ISH assay (RNAscope) targeting high-risk HPV E6/E7 mRNA transcripts. The E6/E7 mRNA assay was also used to test an additional 25 oropharyngeal carcinomas in which the HPV status as recorded in the surgical pathology reports was equivocal due to conflicting detection results (ie, p16 positive, DNA ISH negative). By the E6/E7 mRNA method, HPV was detected in 49 of 282 (17%) HNSCCs including 43 of 77 (56%) carcinomas from the oropharynx, 2 of 3 (67%) metastatic HNSCCs of an unknown primary site, 2 of 7 (29%) carcinomas from the sinonasal tract, and 2 of 195 (1%) carcinomas from other head and neck sites. p16 expression was strongly associated with the presence of HPV E6/E7 mRNA: 46 of 49 HPV-positive tumors exhibited p16 expression, whereas only 22 of 233 HPV-negative tumors were p16 positive (94% vs. 9%, P<0.0001). There was also a high rate of concordance (99%) between the E6/E7 mRNA method and HPV DNA ISH. For the selected group of discordant HNSCCs (p16/HPV DNA), the presence of E6/E7 transcripts was detected in 21 of 25 (84%) cases. The E6/E7 mRNA method confirmed the presence of transcriptionally active HPV-related HNSCC that has a strong predilection for the oropharynx and is strongly associated with high levels of p16 expression. Testing for HPV E6/E7 transcripts by RNA ISH is ideal because it confirms the presence of integrated and transcriptionally active virus, permits visualization of viral transcripts in tissues, and is technically feasible for routine testing in the clinical laboratory.

The literature on the spontaneous regression of cancer is reviewed from 1966 to 1987 to update reviews by Everson & Cole and by Boyd. These authors reviewed all cases of spontaneous regression from 1900 to 1965. We then report the entire series from 1900 to 1987. We also attempted to determine what attributions for spontaneous regressions have been reported. Although almost half of the authors failed to speculate or specify a possible cause for the spontaneous regression, the remainder postulated responsible factors such as immunological or endocrine, surgical, necrosis, infection, or operative trauma. The only unorthodox treatment to appear in the literature was the psychological. We conclude that the literature on the spontaneous regression of cancer is still unable to provide unambiguous accounts of the mechanisms operating to affect these regressions.