Head and Neck Malignancies



Head and Neck Malignancies





HEAD & NECK SQUAMOUS CELL CANCER

Alexander N. Shoushtari

Shrujal S. Baxi

David G. Pfister


Epidemiology



  • H&N CA: US ˜50K cases/y, 11K D/y. >90% = H&N squamous cell ca (SCCHN). M:F 3:1


  • RF: Tobacco, EtOH, HPV, EBV betel quid


  • Genetic syndromes: Overall, rare; Fanconi most common. Others: Lynch-2, Bloom, Li-Fraumeni, Xeroderma Pigmentosa


  • Special populations: Nasopharyngeal endemic in southern China and Hong Kong


  • Risk of 2nd CA: ˜3%/y for aerodigestive tracts due to “field cancerization” by tobacco/EtOH (not HPV); → consider selective use of “triple endoscopy” = EGD, bronchoscopy, laryngoscopy


Anatomic Divisions of H&N Cancer



  • Oral cavity: Buccal mucosa, alveolar ridges, floor of mouth, hard palate, tongue (ant 2/3)


  • Oropharynx: Tongue (base), tonsils, soft palate, post pharyngeal wall to level of hyoid


  • Nasopharynx: Superior to soft palate


  • Hypopharynx: Hyoid bone to cricoid cartilage


  • Larynx: Divided into supraglottic, glottic; subglottic (rare)


Molecular Pathogenesis



  • p16 inactivation: Frequent alteration in SCCHN


  • EGFR: Alterations in >90% of all SCCHN; overexpression correlates w/poorer prognosis (JNCI 1998;90:824)


  • CCND1 overexpression affects: ↑ cell cycle progression


  • HPV: E6, E7 viral protein → inhibit p53, Rb, other tumor suppressors


  • EBV: → LMP1, other viral proteins → ↑ cell replication; a/w nasopharyngeal carcinoma (esp. endemic subtype)


  • Others: p53 Mt, PI3K/AKT/mTOR & PTEN inactivation


Pathology



  • Precursor lesions: Hyperplasia → Dysplasia → Carcinoma in situ → Invasive CA Leukoplakia – fixed white plaques; hyperparakeratosis w/hyperplasia Erythroplakia – red patches; often a/w epithelial dysplasia


  • Key pathologic findings



    • tumor – size, differentiation, depth of invasion, LVI or PNI, precursor lesions, surgical margins


    • Nodes – laterality, size, extracapsular extension


  • Molecular studies



    • p16 (+) by IHC in HPV-associated tumors due to inactivated Rb


    • p53 Mt more common in tobacco/EtOH-associated tumors


HPV-Associated SCCHN



  • Serotypes: -16 (>90%), -18 (NEJM 2001;344:1125)


  • Dx: p16 IHC (more sensitive), HPV in-situ hybridization (more specific), HPV DNA PCR


  • Location: Most commonly oropharyngeal


  • Demographics: Younger pt w/min. smoking/EtOH hx, p/w extensive nodal disease → w/u locates small oropharyngeal tumor


  • Prognosis: Better than stage-matched HPV-negative tumors (NEJM 2010;363:24)


Initial Workup of SCCHN



  • Hx – dysphagia, nutrition/wt loss, trismus/pain; EtOH, tobacco, sexual hx


  • Physical – Detailed H&N exam w/mirror exam or direct visualization. Consider triple endoscopy if unknown or diffuse mucosal abnormalities


  • ImagingCT/MRI of neck, chest imaging = CXR at minimum. Consider CT chest or PET/CT if N2 or N3 disease


  • Bx – after imaging if possible to avoid false (+), esp PET/CT; FNA of involved neck node well-tolerated, convenient; tissue HPV testing if oropharynx


  • Multidisciplinary care – rad onc, surgery, med onc; nutrition (PEG if malnutrition at baseline), dental, speech path, smoking/EtOH cessation



Staging (TNM)



  • T stage is variable by site; N & M stages are more uniform


  • Stage I = T1; Stage II = T2; Stage III = T3 or N1 (single ipsilateral LN ≤ 3 cm)


  • Stage IV = still potentially curable



    • IVA = “moderately advanced local disease,” T4 or N2 (single LN 3-6 cm; or 2+ LNs)


    • IVB = “very advanced local disease,” T4b or N3 (any LN > 6 cm)


    • IVC = distant mets = likely incurable


  • Nasopharyngeal staging system differs from other upper aerodigestive ca


Prognosis



  • HPV-associated more favorable than nonHPV; EGFR overexpression → worse













































Prognosis: Approximate OS at 5 y (%)



Historical Staging


Site


Localized


Regional


Distant


Oral cavity


70


44


23


Oropharynx


60


50


30


Hypopharynx


56


35


13


Larynx


75


55


38


Nasopharynx


70


60


45


Int J Can 2005;114:806



Treatment – Curative Intent



  • Surgery & RT alone (early stage) or together (more advanced stage) are mainstays; chemotherapy has ↑ role in latter


  • Surgical margins – clear = 5 mm or more; close margins <5 mm; (+) = CIS or invasive at margin; close/(+) may dictate changes to RT or chemo plan. No OS benefit to adjuvant chemo alone (MACH-NC, Radiother Oncol 2009;92:4)


  • RT – when surgery is not technically feasible or undesirable (eg, larynx preservation). SEs of RT – both short and long term- fatigue, xerostomia, malignancies (sarcomas). EBRT standard 66-70 Gy, 2 Gy fractions to tumor and/or high-risk LNs. “Hyperfractionation” = potential higher cumulative doses in smaller fractions. Increasingly, IMRT used to minimize xerostomia (Lancet Oncol 2011;12:127) and optimize targeting but longer planning, more expertise required.


Role of Chemoradiation (CRT)

Aug 17, 2016 | Posted by in ONCOLOGY | Comments Off on Head and Neck Malignancies

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