In March 2022, a 59-year-old man was admitted to the clinic with a persistent cough producing blood-streaked sputum for 6 months, which worsened over the last 2 months. He arrived with stable vital signs, without chest heartburn or pain, and without dizziness or palpitations (ECOG score: 1). The patient had a history of coronary heart disease for 10 years with one stent implanted in the circumflex, and cardiac ultrasound indicated that cardiac function was lower than normal. There was no previous history of hypertension or diabetes mellitus. CT scan with chest contrast revealed a right hilar mass enveloping the right pulmonary artery, and the right hilar lymph node was about 2.3 cm. A pathological tissue biopsy was performed by tracheoscopy to consider squamous carcinoma, which was finally diagnosed as stage IIIB squamous carcinoma of the right lung (pT4N2M0), and no surgical indication was available at this stage. A craniocerebral MRI enhancement scan and abdominal CT non-contrast scan did not reveal metastases. Cardiac ultrasound showed that the left ventricular ejection fraction (LVEF) was reduced with 50%. In addition, the electrocardiogram (ECG), cardiac enzymes, and liver and kidney functions were normal.
Subsequently, the patient was treated with nab-paclitaxel 300 mg + carboplatin 400 mg + tislelizumab (PD-1 inhibitor) 200 mg for one cycle. The treatment went well, and the patient had no discomfort. Two weeks later, the patient's cardiac enzymes were significantly elevated on clinic recheck: creatine kinase (CK) 195 U/L (reference: 0-173), CK isoenzyme 165 U/L (reference: 0-24), lactic dehydrogenase (LDH) 238 U/L (reference: 15-220). We considered the development of immunotherapy-related cardiotoxicity (G2); thus, the patient was administered trimetazidine to support myocardial nutrition. On the next day, the cardiac enzymes showed that CK isoenzyme decreased to 100 U/L, CK 212 U/L, and LDH 245 U/L. Cardiac ultrasound showed LVEF 43%, 7% lower than the baseline, so myocardial nutrition therapy was continued. Before the second cycle of treatment, all the cardiac enzymes returned to normal on recheck ( Figure 1 ).
After extensive consideration of the necessity of treatment and the differences in the incidence of cardiotoxicity among different types of ICIs, we decided to initiate one cycle of chemotherapy combined with PD-L1 inhibitor treatment after the cardiac enzymes had returned to normal. Specific dosage included nab-paclitaxel 300 mg + carboplatin 400 mg + sugemalimab (PD-L1 inhibitor) 1,200 mg. The patient was rechecked after a month; the results of troponin, CK, and LDH were normal, while that of CK isoenzyme was mildly increased (72 U/L). Four cycles of sugemalimab combined with chemotherapy later, cardiac enzymes and ECG remained normal, and LVEF increased from 43% to 55%. Treatment is currently ongoing. Tumor markers including carcinoembryonic antigen (CEA, from 5.45 ng/mL to 3.78 ng/mL), cytokeratin 19 fragment (CYFRA21-1, from 7.3 ng/mL to 2.21 ng/mL), and squamous cell carcinoma-associated antigen (SCC, from 1.05 ng/mL to 0.65 ng/mL) gradually decreased during the treatment. Review of CT scan with contrast for evaluation of the target lesion prompted the efficacy of the final treatment as PR ( Figure 2 ). Subsequently, the patient continued to be followed up and the lesion remained stable without recurrence of cardiotoxicity.
Changes in target lesion size during treatment. (B) CT scan with chest contrast (after 4 months of sugemalimab treatment). The red arrows in the figure mark the target lesions of enlarged lymph nodes. Chest imaging showed a reduction in the size of the hilar lymph nodes from 2.3 cm to 1.4 cm after four cycles of treatment, with an assessment of PR at the end of treatment.