Maintenance Therapy for Lung Cancer

Maintenance therapy refers to ongoing therapy for a disease that is administered after a person has already undergone a successful course of treatment. This approach is commonly used to control chronic illnesses such as Crohn's disease, and it has become increasingly accepted as a way to treat non-small cell lung cancer (NSCLC).

In the case of lung cancer, you would undergo first-line chemotherapy, and if that halts the growth of tumors, you might receive maintenance therapy to keep the cancer in check. The goal is to improve quality of life while offering a chance for longer survival.

How Maintenance Therapy Works

Maintenance therapy is specifically used with advanced lung cancer that has progressed too far to be cured by surgery or radiation. It is used for disease management, not to cure disease, and it does more than palliative treatment (which focuses only on easing symptoms).

Supporting Chemotherapy Treatment

Once NSCLC cancer has reached stage 3B or stage 4, chemotherapy is considered the best course of treatment. Using a combination of drugs that work together to kill malignant cells, oncologists can often stop metastatic lung cancer from spreading. There are many drug combinations used, but most of these include a “platinum” drug such as Platinol (cisplatin).

Standard treatment for NSCLC includes four to six cycles of combination therapy with platinum drugs. Beyond that, most patients would experience unacceptable levels of toxicity and side effects that would severely impact their health.

Once chemotherapy stops, tumors could begin growing again. To keep the cancer managed, your doctor may recommend replacing the combination of drugs with another drug.

Used in this capacity, such drugs are called maintenance therapy because they maintain a state in which cancer is under control. The treatment will continue to be used until there's evidence that the tumors are growing and spreading again.

Goals of Maintenance Therapy

There are several ways that maintenance therapy can help NSCLC patients:

• Identify a more effective treatment: Since everyone's cancer is different, it's impossible to know what you'll respond to best. Introducing a new drug via maintenance therapy allows doctors to expose you to a medication that may work better than something you've tried before.
• Protect against chemotherapy resistance: Too often, chemo drugs that work well at first stop being effective, and cancer starts growing again. This happens when your body builds up a resistance after prolonged exposure. Switching up the medications may help avoid this problem.
• Optimize chemotherapy: When a new drug is incorporated or part of a combination of drugs is stopped, it can actually result in the chemotherapeutic agents being more effective.
• Create antiangiogenic effects: This means that the drugs will stop tumor blood vessels from forming, which prevents the tumors from growing.
• Improve antitumor immunity: Some maintenance therapies help your own immune system destroy cancer cells.

The treatments are not an attempt to cure cancer. Instead, the hope is to offer longer progression-free survival (the amount of time you can live without cancer growing).

Medications Used

Your doctors will consider several factors when choosing which type of medications to prescribe for maintenance therapy. Options include a single, non-platinum-based chemotherapy drug; an immunotherapy drug that boosts your immune system; or a targeted therapy drug.

One chemotherapy drug is currently approved by the U.S. Food and Drug Administration (FDA) for maintenance therapy in treating NSCLC:

• Alimta (pemetrexed): This drug shown to improve one's survival rate when used after chemotherapy.

One immunotherapy drug has also been approved:

• Imfinzi (durvalumab): Like other immunotherapy medications, this helps your own immune system fight cancer. In addition to positive outcomes for progression-free survival, Imfinzi users show a durable response, which means they continue to respond positively to the drugs for extended periods.

Targeted therapy drugs that have been approved for maintenance therapy include:

• Avastin (bevacizumab): A man-made therapy that stops the growth of blood vessels, Avastin is an example of continuation maintenance.
• Tarceva (erlotinib): Another medication that targets EGFR mutations in lung cancer patients, this drug is only approved as a maintenance therapy for patients with the genetic abnormality.

Several other medications (and combinations of medications) are also being studied in clinical trials. For instance:

• Iressa (gefitinib): This targeted therapy drug is approved as a first-line treatment for NSCLC patients who have an EGFR mutation. However, it has shown to be successful as a maintenance therapy even for those who don't have the mutation.

Who Benefits Most From Maintenance Therapy?

As with most treatments for lung cancer, there are certain people who respond much better than others to therapy.

Studies of Alimta have shown that it seems to be more effective for people with lung adenocarcinoma. In fact, it seems to extend the survival rate significantly in patients with that type of NSCLC who use Alimta for maintenance therapy. 

The greatest benefit for maintenance therapy with Tarceva was found for women, never-smokers, and, again, those diagnosed with adenocarcinoma. Among those groups, Traceva resulted in longer overall survival while also relieving symptoms and allowing for a higher quality of life.

Side Effects

One of the advantages of maintenance therapy is the possibility of lower toxicity once you're moved off chemotherapy or at least moved to a lower dosage of the drugs.

However, there are still risks of complications and problems that can range from mild to severe.

Chemotherapy-Related

Those who are highly sensitive may still suffer some of the common side effects of chemotherapy while on Alimta alone. These include:

• Fatigue
• Nausea
• Loss of appetite

Other serious side effects may include male infertility, low blood cell count, kidney problems, skin irritation, and pneumonitis.

Targeted Therapy-Related

Avastin and Tarceva, like other targeted therapy drugs, offer the chance for good outcomes without the more inconvenient or serious side effects associated with chemotherapy. There are still some drawbacks to these drugs, though. The most common is a skin rash.

Approximately 90% of patients on targeted therapy drugs that act on EGFR mutations develop an acne-like skin rash within two weeks of starting treatment. For the most part, though, the skin rash can be managed with over-the-counter creams or prescription treatments.

Immunotherapy-Related

Imfinzi boosts the immune system to help you fight cancer, but once the immune system is revved up, it may also attack healthy tissue. This can affect the pulmonary, intestinal, and renal systems, among others.

That said, the most common side effects of the immunotherapy drug are:

• Cough
• Fatigue
• Lung inflammation
• Upper respiratory infections
• Shortness of breath
• Rash

A Word From Verywell

Maintenance treatments may allow you to manage your illness as you would a chronic disease and offer you a good chance to enjoy a longer, more fulfilling life. But you will need to have frequent check-ins with your doctor, and you should be ready to alter treatments if there are signs that the current maintenance therapy is no longer working.

Before you begin maintenance therapy, be sure you are open to the need for flexibility and be prepared to handle possible setbacks.