Review question

Do treatments that help the body’s immune system fight cancer cells (immunotherapy) make patients with non-small cell lung cancer (NSCLC) who have had surgery or radiotherapy aimed at a cure, live longer?

Background

Many people with NSCLC, who have had surgery or radiotherapy to cure their cancer, eventually die because the cancer comes back, either in the chest, or somewhere else in the body. There have been a number of clinical trials over the years that have looked at whether immunotherapy helps patients live longer. Some seemed to show a benefit, others did not.

Study characteristics

We searched four computerised databases and five trial registers to 20 January 2017. We looked for all trials that randomly allocated participants to one treatment or another (randomised controlled trials (RCTs)), and included adults (aged 18 years or older) with early non-small cell lung cancer (stages I to III), confirmed by laboratory testing of a sample of the tumour. We found nine RCTs, which included nearly 5000 participants who had received surgery or curative radiotherapy, and were randomly allocated to receive either immunotherapy or no further treatment.

Key results

We found that giving immunotherapy, mainly vaccine-based (aiming to activate the host immune system to induce human immune response to tumour-specific antigens), after surgery or radiotherapy did not, on average, make people live longer. We did not find any results that could tell us whether the addition of immunotherapy improved the quality of life, but it seemed that those who were given vaccine-based immunotherapy may have experienced, on average, more side effects. At the moment, there is no evidence to support or refute giving immunotherapy (mainly vaccine-based) to people with localized NSCLC (stages I to III). RCTs are in progress that are testing new, more promising immunotherapy drugs (e.g. checkpoint inhibitors).

Quality of the evidence

The evidence we found about overall survival and progression-free survival was high quality. When we looked for evidence about how many patients lived to one, two, three, or five years, it was only moderate or low quality, because the RCTs were not very well done, and their results did not agree with each other.