A 71-year-old man with a common type of lung cancer, adenocarcinoma, was treated with the targeted drug sotorasib. His cancer had a specific mutation called KRAS G12C, which sotorasib is designed to block. At first, the drug likely helped, but eventually his cancer stopped responding. When doctors biopsied the tumor again, they found something unexpected: the cancer had transformed into a different, more aggressive type called pulmonary giant cell carcinoma (PGCC).
This is a single case report, meaning it describes just one patient. It does not prove that sotorasib caused the transformation, but it shows that such a change can happen. The finding is important because it suggests that when targeted therapy fails, a new biopsy may reveal a completely different cancer that needs a different treatment.
The report also reviewed similar cases in medical literature, adding context. However, because this is only one case, we cannot know how often this transformation occurs. The main takeaway for doctors and patients is to consider re-biopsy after resistance develops, to guide next steps.
This case does not report any side effects or safety issues beyond the transformation itself. More research is needed to understand the link between sotorasib and this cancer change.
