Oral Cavity Cancer Timeline: Immunotherapy, Surgery and Radiation

For some advanced oral cavity cancers that can be removed and test positive for the PD-L1 marker, the immunotherapy drug pembrolizumab is given before surgery and continued during and after radiation, for about a year in all.

This page is one of the treatment-track timelines for advanced oral cavity cancer. The steps before treatment, how a track is chosen and the long-term follow-up schedule are covered on the oral cavity cancer treatment timelines page.

Who follows this track

This is a newer approach. It applies to some people with advanced cancer that can be removed and whose biopsy tests positive for PD-L1, a protein that helps predict response to immunotherapy. In a large study published in 2025, adding pembrolizumab this way lengthened the time people lived without the cancer returning. Because the first doses come before surgery, this track is discussed early, at the tumor board.

Before treatment (weeks 0 to 3)

The biopsy, scans and appointments are the same as on every track (see the overview page), with the PD-L1 test added to the biopsy.

Pembrolizumab before surgery (about weeks 3 to 9)

• Pembrolizumab is given through an IV every 3 weeks, 2 doses before surgery.

• Most people feel little change during these weeks. Immunotherapy can occasionally cause inflammation of the thyroid, skin, bowel, lungs or other organs, which the care team watches for with blood tests and symptom checks.

Surgery (about week 10)

The operation, including the neck dissection, reconstruction, tracheostomy and hospital stay of about 6 to 10 days, is the same as on the surgery alone timeline.

Radiation with pembrolizumab (about weeks 16 to 22)

• Radiation starts about 6 weeks after surgery, 5 days a week for about 6 to 6.5 weeks.

• Cisplatin chemotherapy is added when the pathology report shows high-risk features (cancer at the margin or outside a lymph node).

• Pembrolizumab continues every 3 weeks, 3 doses during radiation.

• Radiation side effects are the same as on the other radiation tracks: sore mouth and throat, dry mouth, swallowing trouble, tiredness and weight loss. A feeding tube is sometimes needed for a while.

Pembrolizumab after radiation (about weeks 22 to 61)

Pembrolizumab continues every 3 weeks for 12 more doses, which brings the full course to about a year. A PET-CT scan about 12 weeks after radiation sets a new baseline. On this timeline, the follow-up clock is drawn starting when pembrolizumab ends.

Quality of life on this track

In the large study of this approach, in which mouth cancer was the most common cancer site, quality-of-life scores changed by 3 points or less during the 2 doses before surgery, which is not a noticeable change. About 6 months and 1 year after radiation began, overall, swallowing and speech scores were within about 3 points of those of people treated without pembrolizumab. Average scores at each time point have not been published, so the timeline describes the results in words. The questionnaires are described on the quality-of-life questionnaires page.

Check-ups and long-term care

• Check-ups follow the usual schedule: every 1 to 3 months in the first year, every 2 to 6 months in the second, every 4 to 8 months in years 3 to 5, then yearly.

• Dental visits and possible fluoride treatments continue for life.

• A thyroid blood test (TSH) every 6 to 12 months for the first 3 years checks for an underactive thyroid, which both radiation and immunotherapy can cause.

• Swallowing exercises, jaw stretching and lymphedema care continue as needed.