Ask an expert: How are different types of lung cancer treated?

Many patients may be keen to know their exact prognosis when they are diagnosed with lung cancer. However, as revered consultant medical oncologist Dr Jay Naik explains, the treatment journey of one patient with lung cancer can vary greatly from the next and the best steps to take may not always be clear straight away. In this informative article, the esteemed specialist sheds light on the different types of lung cancer and how they are treated, along with the complexities involved in the different variations of the disease.

Are there different types of lung cancer?

The main subdivisions of lung cancer are small cell lung cancer, non-small cell lung cancer, and that's further divided in terms of thoracic cancers to include mesothelioma, which is a cancer of the lining of the lung. Unfortunately, most lung cancers in the UK tend to be diagnosed at quite a late stage, after they've spread beyond the lungs themselves. Therefore, for most patients, treatment is designed to try and keep control of the cancer. This usually contains some traditional chemotherapies, but increasingly involves other types of treatment as well.

How are different types of lung cancer treated?

For small cell lung cancer, the backbone of treatment continues to be a combination of chemotherapy, with two different chemotherapy drugs given every three weeks. For a proportion of patients, we've also started to use immunotherapy, a type of treatment that stimulates the body's immune system to fight the cancer. Cancers are pretty good at hiding from the immune system, but the latest treatments we have at our disposal help to “take the brakes off” our body’s natural protective response. This wakens up our immune system, so it can spot the cancer and start to deal with it.

One of the biggest changes and a really exciting development in lung cancer treatment has been in non-small cell lung cancer, where immunotherapy has made a significant difference in terms of helping to control cancer. This has allowed a much larger proportion of patients to live for a number of years now with treatment, with some even gaining long term control of their disease.

We know that in a proportion of lung cancers, there are very particular changes in the cancer, which we call mutations. These mutations lead to a change in a particular protein which drives the action of the cancer. This is very promising, as if there is a very specific change that's causing the cancer to behave in a particular way, we can target that in treatment. In fact, tablet medications are now generally available which can target those changes, helping to improve the patient’s prognosis.

There are at least half a dozen different changes, with the archetype being a change in the protein called EGFR. This change occurs at present in somewhere between seven and ten people in every hundred. Although it’s not common, for these patients there are treatments available which have a high chance of working. In every one hundred patients who have this change, seventy to eighty will get a shrinkage of the tumour and control of their disease for a reasonably good period of time. There are increasing numbers of examples of these types of targeted treatments, which can be administered in tablet medications. This also applies in cases of mesothelioma, which traditionally was treated with chemotherapy. These days, however, immunotherapy is increasingly being used to improve outcomes for these patients too.

As an oncologist, lung cancer is an exciting field to work in because of the innovation in treatment options. For a long time, apart from a couple types of chemotherapy, including a drug called Platinum which was the backbone of treatment, we had very little else to offer. Through this new explosion of understanding about cancers, a number of more refined options are available for people based upon their individual type of tumour.

For lung cancer patients, a conversation between with your oncologist about your situation, what the options are and which is best for you is so important. Sometimes, it can take a bit of time to get all the information you need and that can be quite difficult as people with a diagnosis of cancer are often keen to have treatment straight away. However, it’s important to understand that waiting a little while (hopefully only 2 or 3 weeks) to get extra information can make the difference between an average choice and a really good individualised option for that patient and hopefully, a better outcome.

Does lung cancer spread quickly?

Much like other cancers, the rate at which lung cancer spreads really depends upon its type. Small cell lung cancer, which accounts for around fifteen per cent of lung cancers, spreads fast. Often, large glands form in the chest which can spread quite quickly to other organs and parts of the body, such as the liver, the bones and the brain. Other types of lung cancer can spread, but generally tend to do so more slowly. Equally, there are more unusual types of lung cancer which don't spread very quickly at all.

Compared to other types of cancer, it's generally perceived that lung cancers tend to spread more quickly. However, this really depends upon the individual case. The most important thing is to consider your particular type of cancer and what is driving it in order to understand how it might behave.

What is the most difficult type of lung cancer to treat?

This is a tricky question to answer as it depends on what exactly is meant by difficult to treat. This could relate to the likelihood of response or cure, for instance, and these factors is largely dependent on the type of lung cancer in question.

Small cell lung cancer historically grows quickly, but also shrinks quickly and tends to respond very well to treatment. However, when cancer of this type relapses, it becomes harder to treat each time. Therefore, patients with small cell lung cancer may get a very good response initially but may not be well enough to have further treatment should it recur. It’s important to note that treatment for small cell lung cancer is less likely to work each time you use it and there are a limited number of treatments available.

Targeted treatments tend to provoke an excellent response, but the challenges lie beyond that initial stage. In cases of patients who are relatively young (in their forties or younger, for instance) you may well achieve two years of good control but following this, you will need to find another option moving forward and finding another effective solution can be difficult.

In terms of cancers which have a very particular change, such as EGFR, the role of immunotherapy is much more complex and therefore finding subsequent effective treatments can be very difficult. This is also an issue for patients with mesothelioma for similar reasons as historically, there have not been great numbers of treatments for this type of cancer.

In some cases of mesothelioma, however, the cancer doesn’t grow very quickly and therefore with some subtypes of the disease, we hold off on treatment and adopt a ‘wait and see’ approach over a period of time. In fact, I have previously looked after patients who have managed to do this for two years before having to think about starting treatment.

The complexities of lung cancer treatment are highly individual and depend on a number of factors, including what is most important to you as a patient, what aims you have and what we know about the tumour itself. Combining all of this information in a discussion gives us the best basis to decide what to do next.

You can read more about life expectancy and expected outcomes for patients with lung cancer in Dr Naik’s other detailed article on the topic.

If you wish to schedule a consultation with Dr Naik, you can do so by visiting his Top Doctors profile.