COLOGNE, Dec 31 – Scientists in Germany have identified a biological mechanism that helps explain why small cell lung cancer (SCLC), one of the most aggressive forms of lung cancer, relapses quickly despite initially responding to chemotherapy.

A team led by Professor Silvia von Karstedt at the University of Cologne’s Center for Molecular Medicine said the absence of a protein called caspase-8 triggers inflammatory cell death, creating conditions that allow tumours to spread and evade the immune system.

“Without caspase-8, necroptosis sets in, producing inflammation even before tumours form,” von Karstedt said. “This inflammation suppresses the body’s anti-cancer immune response and can promote metastasis.”

The study, published in Nature Communications, found that the inflammation also reprograms cancer cells to behave like immature neuron-like cells, a state linked to relapse and rapid disease progression.

SCLC accounts for about 15% of lung cancers and has a five-year survival rate of just 5%. While chemotherapy often works at first, patients typically relapse within months.

The Cologne team used a genetically engineered mouse model lacking caspase-8 to mimic human SCLC. Their findings suggest that targeting pre-tumoral inflammation could improve therapies and early diagnostics, though it remains unclear if the same process occurs in human patients.

The research was supported by the German Research Foundation under Collaborative Research Centre 1399, which focuses on drug sensitivity and resistance in SCLC.