As you go through treatment after a diagnosis of head and neck cancer, at some point you come across the word "immunotherapy." On first hearing, it feels vague. It is called an anticancer drug, but what makes it different from the chemotherapy infusions you knew before, and does it even apply to you? It is hard to get a sense of it. In fact, immunotherapy is not a drug that strikes the cancer cells directly. It is closer to releasing the "brake" that has been stopping your own immune cells from recognizing the cancer. Cancer cells wrap themselves in a kind of disguise to evade attack by immune cells, and immunotherapy strips away that disguise so the immune cells once again recognize the cancer as the enemy.
So can any patient with head and neck cancer use it? Not quite. It is usually considered first when, despite surgery, radiation or prior chemotherapy, the cancer grows back or spreads elsewhere - in other words, in a recurrent or metastatic situation. It is uncommon to start straight away with immunotherapy at the initial diagnosis stage. And before using the drug, a tissue biopsy is often done to check how much of a marker called PD-L1 is expressed on the cancer. The higher this level, the better the chances of a good response to immunotherapy are thought to be; but a low level does not automatically rule it out, and the care team decides by looking at the overall picture.
Once treatment actually begins, what people come to hope for is more than simply "the cancer shrinking." A feature of immunotherapy is that, in patients who respond, the effect tends to last relatively long. Not everyone benefits, but once the body begins to recognize the cancer properly, there are cases where it stays stably controlled for a good while. That said, it can take time for the effect to appear, so some people grow impatient after expecting a dramatic change within a few weeks. Knowing in advance that this drug tends to work slowly makes the wait much easier on the mind.
The matter of side effects cannot be left out either. They look somewhat different from the hair loss or severe nausea that come to mind with conventional chemotherapy. Because immunotherapy activates the immune system, that immunity can sometimes turn on normal organs as well. Skin rashes, hormonal problems such as in the thyroid, and rarely inflammation of the lungs, intestines or liver can occur. Most are manageable, but if you have unusual fatigue, shortness of breath, or persistent diarrhea, do not brush it off; it is important to tell your care team right away, because catching it early makes it far easier to handle.
In short, immunotherapy for head and neck cancer is not a cure-all, but it is a treatment that has opened a new option for patients whose existing treatment has hit a wall. Whether it suits your situation, and what benefits and risks you take on together, ultimately has to be weighed by combining your test results with your overall health. This article is a general explanation to aid understanding, so please be sure to decide on actual treatment in full consultation with your care team.