Apixaban or Enoxaparin After Head and Neck Cancer Surgery

Inclusion criteria

Participants must:

• Provide signed and dated informed consent.
• Be willing and able to comply with study procedures and follow-up.
• Be 18-89 years old (male or female).
• Have a negative pregnancy test within 24 hours before surgery (if woman of childbearing potential).
• Have biopsy-proven head and neck cancer, or a suspected cancer awaiting tissue diagnosis (can be confirmed by frozen section at surgery).
• Be scheduled for major inpatient or outpatient oncologic head and neck surgery (defined as >45 minutes operative time).
• Be an appropriate surgical candidate (adequate performance status).

Eligible diagnoses include (not limited to):

• Squamous cell carcinoma of oral cavity, hypopharynx, larynx, nasal cavity
• Malignancies from major salivary glands
• Non-melanoma skin cancers (squamous cell, basal cell, Merkel cell carcinoma)
• Unknown primary tumors of head and neck

Exclusion criteria

Participants cannot:

• Lack a tissue diagnosis of head and neck cancer during the study period.
• Have one of these conditions instead of eligible cancer: Benign disease; Primary thyroid cancer (lower VTE risk); Lymphoma (not primarily surgical); or Melanoma
• Fail to undergo definitive head and neck oncologic surgery (e.g., only diagnostic biopsy).
• Have surgery limited to tissue diagnosis only (e.g., direct laryngoscopy, excisional lymph node biopsy).
• Be unable (patient or caregiver) to administer the study drug.
• Have a positive pregnancy test on the day of surgery.
• Have a known history of prior DVT or PE (since extended anticoagulation would be indicated).
• Have hereditary or acquired bleeding/clotting disorders.
• Have severe renal impairment (CrCl <30 mL/min).
• Have conditions that, in the investigator's judgment, make study participation unsafe or confound results.