Oral cavity cancer

Oral cavity cancer can arise in the mobile front portion of the tongue, floor of the mouth, gums, cheek lining, hard palate or inner lip. The tonsils and tongue base are in the oropharynx. This distinction changes staging and treatment discussions, even though both may be called ‘mouth’ or ‘throat’ cancer in everyday language.

Most are squamous cell carcinomas, confirmed by biopsy. A non-healing ulcer, persistent red or white patch, thickening, unexplained bleeding, loose teeth or a neck lump warrants assessment. Dysplasia or a precancerous patch is not the same diagnosis as invasive cancer. Routine HPV testing is not recommended for prognostic classification of primary oral cavity squamous cancer; a p16 result should not automatically apply the HPV-related oropharyngeal staging rules.

Examination and CT or MRI assess the primary tumor, jaw involvement and neck nodes. Chest or other staging imaging is selected according to extent and risk. AJCC currently uses its 8th-edition oral cavity system; head-and-neck sites are not all using the same edition.

Depth of invasion measures how far cancer extends beneath the expected surface level and is not simply the thickness of a raised tumor. A small-looking lesion can therefore have important deeper invasion. Clinical stage is estimated before treatment; the surgical pathology can refine the stage and reveal additional risk.

Surgery is central for many resectable oral cavity cancers. The operation aims for clear margins while preserving as much useful function as possible. Its extent depends on the location and involvement of tongue, jaw or neighboring tissues—not simply on the diagnosis ‘oral cancer’. Some early lesions can be removed locally; larger defects may need a tissue flap or bone reconstruction.

Before agreeing to surgery, discuss expected speech, chewing and swallowing, dental rehabilitation, the tissue donor site, and whether temporary airway or feeding support is likely. Reconstruction restores shape and function but does not guarantee a return to the pre-treatment baseline. If surgery cannot safely remove the cancer, a radiation-based or systemic approach may be considered.

Clinically node-negative means examination and imaging have not identified involved nodes; microscopic deposits can still be present. Tumor site, depth, size and other features guide elective neck management. The team may recommend neck dissection even when no lump is felt. Tumors approaching the midline may require assessment of both sides.

For selected early oral cancers with a clinically negative neck, sentinel lymph node biopsy can be an alternative in experienced services. It maps and samples the first draining nodes; a positive result changes subsequent treatment. Its suitability depends on local expertise and whether neck access is already required for reconstruction. It is not the same as simply watching untreated nodes.

Removing all visible cancer does not always complete treatment. The final report may identify microscopic risks that support postoperative radiation or chemoradiation. Ask for the actual margin and node findings rather than a general description such as ‘high risk’. Recovery and referral should be coordinated so avoidable delays do not disrupt the next step.

The current US pembrolizumab indication includes adults with resectable locally advanced head-and-neck squamous cancer and PD-L1 CPS at least 1 on an authorized test. Treatment begins with pembrolizumab alone before surgery, continues with postoperative radiation with or without cisplatin, and then continues as pembrolizumab alone. This is a defined perioperative pathway, not a reason to skip surgery or necessary postoperative radiation.

The choice should be discussed before the operation, because starting only after surgery is not the same studied sequence. Early low-risk disease is not automatically eligible. Immune-related organ inflammation, autoimmune conditions, transplant history and the risk of disrupting the surgical plan all enter the decision; approval and funding differ between countries.

A local recurrence should first be reviewed for salvage surgery or carefully selected reirradiation. If disease cannot be treated with curative local therapy, the plan focuses on systemic control, symptoms and quality of life. Previous platinum and PD-1 treatment, the interval since treatment and the need for a quick response matter.

Under the US label, first-line pembrolizumab alone for metastatic or unresectable recurrent squamous cancer requires PD-L1 CPS at least 1; pembrolizumab with platinum and fluorouracil has no such PD-L1 threshold. Nivolumab is a labeled option after progression on or after platinum-based therapy. These labels do not prove that switching between PD-1 drugs works after PD-1 resistance. Chemotherapy, cetuximab-based approaches and trials may enter later decisions.

Arrange dental, nutrition and speech/swallowing assessment early. Surgery and radiation can change tongue movement, mouth opening, saliva and the ability to chew safely. A feeding tube may support recovery when oral intake is inadequate; its need and removal plan should be reviewed rather than assumed to be permanent.

Mouth sores, infection, dry mouth and dental decay need an agreed care plan. Tell dental professionals about prior jaw or head-and-neck radiation before extractions or implants. Report inability to swallow fluids, significant bleeding or breathing difficulty urgently; these should not wait for the next routine appointment.

Follow-up checks the mouth, neck, function and any reconstruction, with imaging driven by the treatment plan, risk and findings. New persistent pain, an ulcer or a neck lump should be assessed. Stopping tobacco and areca/betel-nut use and addressing alcohol use are useful parts of care, without assuming that any particular exposure caused an individual’s cancer.

• Biopsy and full surgical pathology, including depth, margins, node count and extranodal extension.
• Original imaging, operation and reconstruction records, radiation plan and systemic treatment dates.
• PD-L1 CPS when relevant, dental status, weight change and current speech/swallowing needs.