CHONC cheat sheet

Squamous cell carcinoma of the head and neck typically arises from accumulated genetic alterations (TP53 mutation, CDKN2A loss, EGFR amplification) in fields of mucosal change driven by tobacco and alcohol.

HPV-positive oropharyngeal SCC is driven by E6/E7 inactivating p53 and Rb; it carries a markedly better prognosis and distinct staging from HPV-negative disease.

Levels of the neck are defined by the spinal accessory nerve (level II/III boundary) and the omohyoid muscle (level III/IV boundary); level I is bounded by the digastric and hyoid.

The facial nerve exits the stylomastor foramen and divides within the parotid into temporal, zygomatic, buccal, marginal mandibular, and cervical branches.

Lymph node levels I-V are separated by the hyoid, cricoid cartilage, and spinal accessory nerve; level VI is the anterior (central) compartment.

Tumor hypoxia reduces radiosensitivity (oxygen enhancement ratio ~3); a high Ki-67 or hypoxic gene signature predicts poorer local control.

Perineural spread along cranial nerves V and VII is a hallmark of salivary and cutaneous malignancies and requires imaging of the skull base.

The recurrent laryngeal nerve runs in the tracheoesophageal groove and is at risk during thyroidectomy and central compartment dissection.

T staging of oral cavity cancer is driven by depth of invasion (DOI) and size: DOI >5 mm upstages T1 to T2; DOI >10 mm upstages to T3.

In the AJCC 8th edition, HPV-positive oropharyngeal cancer uses a separate staging system (pT0-T3, N0-N2, M0) with lower stage for the same anatomic burden.

Extranodal extension (ENE) is a major adverse pathologic feature; in HPV-negative disease it upstages to N3b and portends worse survival.

Clinical nodal staging requires assessment of size, number, laterality, and fixation; radiologic ENE on CT/MRI should be documented as cN.

PET-CT is the preferred modality for detecting occult distant metastasis and second primaries in locally advanced disease; it also aids radiotherapy planning.

Nasopharyngeal carcinoma staging distinguishes T4 by intracranial extension or cranial nerve involvement; N3 is defined by nodes >6 cm or supraclavicular involvement.

Sentinel lymph node biopsy is an option for early oral cavity cancer (cT1-2N0) to avoid elective neck dissection in selected patients.

Recurrence or second primary should be suspected when new symptoms or imaging changes occur; restaging with PET-CT guides salvage decisions.

A multidisciplinary tumor board (surgeon, radiation oncologist, medical oncologist, pathologist, radiologist, speech pathology) should review all newly diagnosed head and neck cancers before treatment.

Early-stage oral cavity and larynx cancers are primarily treated with single-modality surgery or radiotherapy; concurrent chemoradiation is reserved for locally advanced disease.

For locally advanced larynx cancer, organ preservation with concurrent chemoradiation is an alternative to total laryngectomy in selected patients, with equivalent survival in trials.

Postoperative radiotherapy is indicated for adverse features: positive margins, ENE, pT3-4, perineural invasion, lymphovascular invasion, or multiple positive nodes.

Concurrent cisplatin (100 mg/m2 every 3 weeks) with radiotherapy is the standard radiosensitizer for locally advanced disease; cetuximab is an alternative when cisplatin is contraindicated.

Induction chemotherapy may be considered for borderline resectable disease or to select patients for organ preservation, but does not improve overall survival over concurrent chemoradiation.

Treatment planning should incorporate dental evaluation before radiotherapy to reduce osteoradionecrosis risk.

Shared decision-making must document patient goals, performance status, and preferences, especially when choosing between surgery and organ preservation.

Neck dissection levels: radical (I-V), modified radical (spares one or more non-lymphatic structures), selective (preserves levels based on primary site), and extended (adds non-lymphatic structures).

Elective neck dissection is indicated for cN0 oral cavity cancer with DOI >3-4 mm; sentinel node biopsy is an alternative in early lesions.

Margins: a clear margin is generally >5 mm; close margins (1-5 mm) and positive margins increase local recurrence and often prompt postoperative radiotherapy.

Free flap reconstruction (radial forearm, fibula, anterolateral thigh) is preferred for large defects; pedicled flaps (pectoralis major) are options when free tissue is not feasible.

Total laryngectomy requires tracheostoma creation and lifelong airway management; salvage laryngectomy after failed chemoradiation carries higher complication rates.

Parotidectomy with facial nerve preservation is standard for benign and low-grade malignant tumors; nerve sacrifice is reserved for direct invasion.

Thyroidectomy for differentiated cancer ranges from lobectomy to total thyroidectomy with central neck dissection based on tumor size, nodal status, and risk.

Postoperative complications include pharyngocutaneous fistula, flap failure, chyle leak (thoracic duct injury in left neck), and shoulder dysfunction from spinal accessory nerve injury.

Definitive radiotherapy for head and neck cancer typically delivers 66-70 Gy in 2 Gy fractions; altered fractionation (hyperfractionation or accelerated) improves local control in some settings.

Concurrent cisplatin is the standard radiosensitizer; nephrotoxicity, ototoxicity, and mucositis are key toxicities requiring monitoring.

Cetuximab plus radiotherapy is an alternative for cisplatin-ineligible patients; it carries a risk of acneiform rash and infusion reactions.

Intensity-modulated radiotherapy (IMRT) reduces xerostomia and other late toxicities by conforming dose to target volumes while sparing parotid glands and spinal cord.

Immunotherapy (pembrolizumab, nivolumab) is used for recurrent/metastatic disease and, in selected cases, as first-line therapy with chemotherapy.

Radiation-induced xerostomia is reduced when at least one parotid gland receives a mean dose <26 Gy; submandibular sparing further helps.

Osteoradionecrosis risk rises with dose >60 Gy, pre-existing dental disease, and trauma; pre-radiotherapy dental extraction and fluoride prophylaxis are preventive.

Systemic therapy for recurrent/metastatic disease includes platinum-based chemotherapy, cetuximab, and checkpoint inhibitors; HPV-positive tumors have higher response rates.

Speech and swallowing therapy should begin before treatment (prehabilitation) and continue during and after radiotherapy to reduce dysphagia and aspiration risk.

Prophylactic swallowing exercises during chemoradiation reduce long-term dysphagia and stricture formation.

Trismus prevention includes jaw stretching exercises, especially after radiation to the masticator space; measuring interincisal opening guides therapy.

Nutritional support with a feeding tube (PEG or NG) may be needed during chemoradiation; early dietitian involvement improves outcomes.

Lymphedema of the neck and face after surgery/radiation is managed with manual lymphatic drainage and compression.

Survivorship care includes surveillance for recurrence, second primaries, hypothyroidism after neck radiation, and dental/oral health maintenance.

Smoking cessation and alcohol reduction after treatment lower the risk of second primary cancers and improve overall survival.

Psychosocial support and screening for depression and anxiety are important components of survivorship care for head and neck cancer patients.

Surgical safety checklists and time-outs reduce wrong-site surgery and retained foreign bodies; they are standard in head and neck procedures.

Quality metrics for head and neck cancer include margin status, nodal yield, time to treatment initiation, and adherence to adjuvant radiotherapy.

Radiation oncology quality assurance includes chart rounds, plan review, and dose-volume constraint verification before treatment delivery.

Multidisciplinary tumor board documentation and adherence to evidence-based guidelines (NCCN) are quality indicators.

Infection control and antibiotic stewardship are critical in head and neck surgery given the clean-contaminated nature of the aerodigestive tract.

Informed consent must document discussion of alternatives, risks, and expected outcomes, especially for laryngectomy and major reconstruction.

Peer review and morbidity and mortality conferences are used to identify system errors and improve patient safety.

Practice management includes coding and documentation accuracy (e.g., CPT for neck dissection, free flap) to ensure appropriate reimbursement and compliance.

Informed consent for research requires voluntariness, disclosure of risks and benefits, and capacity; vulnerable populations need additional protections.

Institutional review board (IRB) approval is required before initiating human subjects research; exempt and expedited categories exist.

Conflict of interest disclosure is required for authors, reviewers, and clinicians; undisclosed industry relationships undermine trust.

Research ethics principles: respect for persons, beneficence, and justice (Belmont Report); clinical equipoise justifies randomized trials.

Professionalism includes honesty in documentation, appropriate boundaries with patients, and reporting impaired colleagues.

Publication ethics: authorship requires substantial contribution; ghostwriting and duplicate publication are misconduct.

Clinical trials in head and neck cancer must address generalizability across HPV status, age, and comorbidity burden.

End-of-life discussions and advance care planning are ethical obligations, particularly for patients with advanced or recurrent disease.