Immunotherapy treatment seems able to slow the progression and reduce the risk of recurrence of the most common form of lung cancer, gives hope to a study in which researchers from three major Montreal hospitals contributed.
Used in conjunction with chemotherapy given before surgery and then again after surgery, pembrolizumab also reduced the presence of residual tumors in patients with operable non-small cell lung cancer (NSCLC) and early stage.
Some 800 adults with stage II or III NSCLC that could be surgically removed participated in this study, which was conducted at 227 sites around the world, including the McGill University Health Centre, the Center hospitalier de l’Université de Montréal and the St. Mary’s Hospital Center. Forty-six of these patients had been recruited in the Montreal area.
Half of the subjects were treated with pembrolizumab before and after surgery to remove the cancer, in addition to chemotherapy. The other half was treated in the same way, but with a placebo.
Event-free survival at 24 months was 62.4% in the pembrolizumab group and 40.6% in the placebo group.
Less than or equal to 10% viable residual tumor was observed in 30.2% of pembrolizumab group members and 11% of placebo group members. No viable residual tumor was seen in 18.1% of members of the first group and in 4% of members of the second.
The study’s lead author and surgeon-in-chief, Dr. Jonathan Spicer of the MUHC, said in a statement that “this new treatment is another important step in improving outcomes for patients with this common type. of lung cancer”.
The treatment, he added, “is suitable for all patients with stage II or III non-small cell lung cancer whose tumor is operable. On an annual basis, this represents a large number of patients for whom survival will be significantly improved.”
Pembrolizumab blocks a protein called PD-1 on the surface of the immune system’s “killer” cells, T cells. This protein prevents T cells from attacking normal cells in the body, which is desirable, but also protects certain cancer cells, which is less so.
Blocking PD-1 therefore allows T cells to seek out, attack and destroy cancer cells. It also opens the door to autoimmune side effects, but the study authors assure that the “adverse effects resulting from the addition of pembrolizumab were consistent with what has been previously reported in other similar trials combining immunotherapy and surgery”.
The conclusions of this study are published by the prestigious New England Journal of Medicine.