Unfortunately lung cancers often spread to the brain in late stages. Sometimes the brain involvement is detected before the patient has any signs or symptoms, while in other cases,  patients may be very unwell and experiencing limb weakness or drowsiness.

Untreated brain tumours are life-threatening. The first consideration when treating patients with lung cancers which have spread to the brain is to understand whether they will urgently need some form of local procedure such as surgery or radiation therapy in order to stabilise their condition. Fortunately, we now have effective anti-cancer drugs that can penetrate the brain, which provide effective control of the brain tumours without the need for surgery or radiation therapy.

Some, although not all, lung cancers may have gene alterations or mutations. The presence of such gene alterations allow doctors to use specialised oral pills that specifically target these mutations. These targeted drugs are often effective to control the lung cancers outside the brain and also within the brain. For example, lung cancers that harbour EGFR mutations can be effectively treated by an oral pill called Osimertinib, while lung cancers that have ALK gene rearrangements can be effectively managed using oral pills such as Alectinib, Brigatinib or Lorlatinib. Lung cancer patients treated with these oral pills often benefit from a reduction in the size of lung and the brain tumours, significantly extending survival rates.

Previously when these drugs were not available, lung cancers could only be treated using conventional chemotherapy and patients with advanced lung cancer would only live for a year or so. With the availability of these newer oral targeted pills, patients with stage IV lung cancers often now live for three years or more. Importantly, this prolonged survival is associated with a relatively good quality of life – patients can often return to their usual work or social activities.

Other than these oral targeted pills, another very exciting and important advance in lung cancer treatment over the past five years is the use of immunotherapy to enhance the immune system of cancer patients, so that the body’s own immune cells can destroy and control the lung cancer for months or years. However, immunotherapy can cause unique immune injuries within the body and lung cancer patients must be carefully monitored for these side effects during treatment.

While these newer exciting drugs can effectively control lung cancer growth, improve symptoms and prolong survival, this treatment does not usually cure patients with stage IV lung cancer. Cancers often mutate with time, which can render the ongoing treatment ineffective. This is why it is vital that scientists and doctors continue to work hard to come up with newer drugs to overcome this drug resistance. It is heartening to know that the overall survivals of stage IV lung cancer patients have markedly improved over the past 10-15 years, and that the future continues to look bright.