Sometimes, lung cancer treatment can cause changes in memory or other types of thinking skills. You may notice that it’s harder to remember things or thoughts feel “foggy” after starting cancer treatment. It may seem harder to complete a task or feel like it takes more mental effort to focus. Some people refer to this as “chemo brain” or “chemo fog.” These changes may occur with chemotherapy, immunotherapy, or targeted therapy, as well as radiation therapy when it’s used to treat the brain.

Sometimes, other factors like emotional stress, depression, lung cancer itself, or underlying medical conditions can cause changes in memory and thinking skills. It’s important to talk to your healthcare team if you notice these changes so they can determine the cause and offer ways to manage your symptoms.

Signs and symptoms of memory loss and changes in thinking skills can vary based on the types of treatments you’ve received, the doses, and other health conditions you may have. Memory and thinking changes can be mild or severe and can start during or after cancer treatment is completed.

Signs and symptoms of memory and thinking changes due to lung cancer treatment can include:

• Trouble focusing or holding attention
• Taking longer to plan or make decisions
• Trouble finding the right words
• Taking longer to learn new things
• Confusion

Chemotherapy, immunotherapy, and targeted therapy can all cause changes in memory and thinking skills because they produce inflammation that can impact the brain. Radiation therapy can cause changes in memory and thinking skills—but only when the brain is being treated. Radiation therapy that is directed to the entire brain (whole-brain therapy or prophylactic cranial irradiation) poses a higher risk for thinking-related side effects than radiation directed to small areas of the brain (stereotactic radiation therapy). The higher the dose and number of treatments you receive, the greater the impact they have on the brain.

If you’re receiving whole-brain radiation or prophylactic brain irradiation, ask your radiation oncologist about radiation therapy techniques and medicines that may reduce the risk of memory loss and changes in thinking skills.

There are many practical ways to manage memory loss and changes in thinking skills.

Practical tips:

• Using a list, reminders, or alarms to keep track of what needs to be done
• Setting up and following regular routines
• Decreasing distractions around you and doing one task at a time
• Exercising to improve focus, mental alertness, and mood
• Using meditation to relax and clear your mind
• Completing the more difficult mental tasks when you have the most energy

Your healthcare team can assess your specific symptoms and can offer more ways to manage or treat underlying conditions that may be causing memory or thinking problems. Examples of these underlying conditions include:

• Poor nutrition
• Dehydration
• Lack of sleep and/or feeling fatigued
• Anxiety and/or depression

It’s always a good idea to tell a member of your healthcare team when you notice a side effect from treatment or a symptom that concerns you. Often, these problems can be managed or eased with help from your healthcare team or through palliative care services. Memory loss is a common side effect of lung cancer treatment, with many options to help manage it.

Contact your healthcare team if you have:

• Any change in your memory or other thinking skills
• Memory issues that interfere with work, social abilities, or completing daily tasks
• Anxiety or depression due to changes in thinking skills or memory