A recent study suggests that immunotherapy can continue to fight lung cancer long after treatment ends due to side effects. This groundbreaking discovery offers hope to patients who are forced to stop therapy prematurely.
How Immune Checkpoint Inhibitors Work
Immune checkpoint inhibitors work by removing the brakes from the immune system, allowing it to aggressively target and destroy cancer cells. However, this powerful response can backfire. The same immune activation that fights tumors can also trigger serious side effects like pneumonia, liver inflammation, or colitis. When this happens, doctors often stop the treatment to protect the patient’s overall health.
Long-Term Control Without Continued Treatment
Despite the early discontinuation of therapy, researchers found that patients’ immune systems often continued to suppress the cancer. According to findings published April 18 in Clinical Cancer Research, it took nearly 13 months on average for lung cancer to begin spreading again after patients stopped immunotherapy.
As reported by MedicineNet, these patients also lived an average of 3.5 years after discontinuing treatment. Notably, those who remained on the drugs longer before stopping experienced better long-term outcomes.
Time on Treatment Matters
The study revealed a clear connection between duration of treatment and outcomes after discontinuation:
- Less than 3 months of treatment: Cancer progression paused for 6 months; survival averaged 22 months.
- 3 to 6 months of treatment: Cancer stalled for 14 months; survival averaged 43 months (about 3.5 years).
- More than 6 months of treatment: Cancer control lasted 26 months; survival reached 87 months (over 7 years).
“These outcomes suggest that patients can experience prolonged disease control and survival after stopping treatment due to toxicity or if side effects are impacting their quality of life,” said lead investigator Dr. Frederica Pecci, a research fellow at Dana-Farber Cancer Institute in Boston.
Weighing Risks and Benefits
Discontinuing treatment is a tough decision. Between 3% and 12% of patients on a single immune checkpoint inhibitor stop due to serious side effects. That number climbs to 25% when patients receive a combination of these drugs.
“When immunotherapy activates the immune system, the goal is to selectively target cancer cells,” explained Dr. Mark Awad, chief of thoracic oncology at Memorial Sloan Kettering Cancer Center. “But this activation can also cause inflammation in other organs. Whenever we see these side effects, we question whether we should keep giving immunotherapy or stop it temporarily or permanently.”
Analyzing Nearly 2,800 Patient Cases
To better understand the long-term effects of discontinuation, researchers reviewed data from about 2,800 patients with advanced non-small cell lung cancer who were treated with immune checkpoint inhibitors. Roughly 10% of these patients had to stop treatment due to adverse reactions.
The research team also identified clinical and pathological markers that may help doctors predict which patients could continue benefiting from immunotherapy even after it ends.
Role of Steroids and Immune-Suppressing Drugs
Interestingly, using steroids or other immune-suppressing medications during treatment did not negatively impact patients’ survival after stopping immunotherapy. This finding suggests that doctors might safely manage side effects without compromising long-term outcomes.