Imaging findings can't mean everything in the era of immunotherapy: a case report and literature review

Immune-checkpoint inhibitors (ICIs) play an important role in the treatment of cancers. However, immunotherapy can also induce atypical response patterns, including pseudoprogression, which is challenging to clinicians. We reported a case of non-small-cell lung cancer showing so-called pseudoprogression during the treatment of pembrolizumab and the patient benefited clinically from continued treatment with ICIs. Therefore, beside imaging evaluation, the assessment of Eastern Cooperative Oncology Group performance status score, numerical rating scale score of cancer pain, tumor markers levels, and neutrophil-to-lymphocyte ratio should be used for response evaluation of tumors in the era of immunotherapy. And more accurate evaluation methods and reliable information are urgently needed to better understand the pseudoprogression. Sometimes drugs can kill cancer cells but rather than getting smaller, as expected, the tumor size increases. This is called 'pseuoprogression', meaning false progression. Here, we report pseudoprogression in a lung cancer patient receiving immunotherapy. The tumor initially got larger, but with continued treatment, it decreased in size. This article reports a case of non-small-cell lung cancer that showed so-called pseudoprogression during immunotherapy combined with chemotherapy. The article also reviewed the mechanisms, clinical manifestations and prognostic indicators of pseudoprogression.