Iris metastasis as resistance mechanism to atezolizumab, carboplatin, and etoposide but responds to additional irinotecan and anlotinib in a small cell lung cancer patient.

Small cell lung cancer (SCLC) is an aggressive malignancy associated with poor prognosis. Metastasis to sites outside the chest at the time of initial diagnosis, such as bone, brain, and liver metastasis have been found in most SCLC patients. Iris metastases from SCLC have rarely been previously reported, and often cause eye pain and blindness in patients. Here, we report a patient with SCLC who presented with iris metastasis in the right eye and metastasis in the left adrenal gland due to disease progression on first-line therapy, which subsequently caused pain and blindness in the right eye. The patient was treated with second-line irinotecan combined with anlotinib and atezolizumab and did not receive any local treatment in the right eye. After only one cycle of treatment, the iris metastases in the right eye were smaller than before, and the visual acuity in the right eye recovered. At the same time, her left adrenal metastases were also significantly smaller than before. Our case suggests that systemic therapy with effective treatment options can similarly improve iris metastases in patients.