Lung cancer has been one of the leading causes of death worldwide, with an estimated 2.1 million new cases in 2018. Furthermore, lung cancer accounts for almost 25% of all cancer deaths.

Resectable lung cancer, wherein the disease is confined to the lung and can be surgically removed, has a chance for cure. However, even with surgery followed by adjuvant chemotherapy, there is still a high risk of recurrence. Therefore, adjuvant immunotherapy has become a growing field of interest in the management of lung cancer.

The Role of Adjuvant Immunotherapy

Adjuvant immunotherapy aims to stimulate one’s immune system to recognize cancer cells as foreign and destroy them. This is achieved by administering drugs that can enhance the immune system’s response to cancer cells.

There are different types of drugs used for immunotherapy, such as immune checkpoint inhibitors, cancer vaccines, and cytokines.

The use of adjuvant immunotherapy in conjunction with chemotherapy aims to provide a combination of therapy that will optimize the patient’s chance of cure.

Chemotherapy combined with adjuvant immunotherapy has been found to be more effective in prolonging disease-free survival compared to chemotherapy alone in patients with non-small cell lung cancer (NSCLC).

Immune Checkpoint Inhibitors (ICI)

Immune checkpoint inhibitors (ICI) work by blocking specific molecules that inhibit the immune system from attacking cancer cells.

These molecules are called checkpoint proteins, and they help regulate the immune system’s response to foreign substances such as cancer. When they are blocked, the immune system is able to target and attack cancer cells more effectively.

ICI’s have been approved as adjuvant therapy for resectable NSCLC.

In the study IMpower010, the use of atezolizumab (an ICI) in combination with chemotherapy has been shown to significantly improve disease-free survival in patients with resected Stage II to IIIA NSCLC compared to chemotherapy alone. This highlights the importance of adjuvant immunotherapy in the management of NSCLC to improve the outcomes of patients with resectable lung cancer.

Cancer Vaccines

A cancer vaccine aims to elicit an immune response against antigens expressed by cancer cells. Vaccines can be given to prevent or treat cancer.

In the case of adjuvant therapy, cancer vaccines can be given after primary cancer treatment to prevent recurrence. Several cancer vaccines are currently under investigation, including dendritic cell-based vaccines, tumor lysate vaccines, and peptide-based vaccines.

Pancreatic Cancer Vaccination Study-04 (PCV-04), a phase 2 clinical trial, investigated the use of an allogeneic whole cell vaccine as adjuvant therapy for NSCLC.

The trial showed promising results with the vaccine group having a better disease-free survival compared to the control group. However, more studies are needed to confirm the efficacy of cancer vaccines in adjuvant therapy for NSCLC.

Cytokines

Cytokines are signaling molecules that play a crucial role in the immune system’s response to cancer. They can stimulate the immune system to recognize and attack cancer cells by enhancing the production and activity of immune cells.

Interferon alfa-2b is a type of cytokine that has shown some efficacy in adjuvant therapy for NSCLC.

A meta-analysis of 16 randomized trials showed that adjuvant interferon alfa-2b in combination with chemotherapy improved overall survival in patients with resected NSCLC compared to chemotherapy alone. However, the use of interferon alfa-2b in adjuvant therapy is associated with significant toxicity, limiting its use in clinical practice.

Conclusion

Adjuvant immunotherapy in conjunction with chemotherapy has shown promising results in improving the outcomes of patients with resectable NSCLC.

Immune checkpoint inhibitors have been approved for adjuvant therapy, offering a new treatment option for patients. Cancer vaccines and cytokines are still under investigation, and further studies are needed to confirm their efficacy in adjuvant therapy for NSCLC.

The development of adjuvant immunotherapy has opened a new avenue for improving the outcomes of patients with resectable NSCLC via optimization of personalized treatment strategies.