Pembrolizumab-Induced Cold Agglutinin Disease.

BACKGROUND The introduction of immunotherapy in the management of metastatic lung cancer appears to be changing their natural history. Most patients tolerate immunotherapy without any significant adverse events. Nevertheless, a significant number of patients still experience adverse effects. Autoimmune hemolytic anemia has been described as mostly related to warm autoantibodies. The following case report describes cold agglutinin disease with hemolysis secondary to Pembrolizumab therapy for the treatment of metastatic lung cancer. CASE REPORT A 58-year-old woman noted a left neck mass 4 months prior to her presentation. A biopsy confirmed the presence of metastatic adenocarcinoma, consistent with primary lung cancer. Further evaluation revealed the tumor to be PDL-1-positive. She was started on Pembrolizumab, Pemetrexed, and carboplatin chemotherapy regimen. Her CBC was within normal limits when she started therapy, but within 4 weeks hemoglobin dropped to 4.3 g/dL. Further evaluation showed high cryoglobulin levels and a high cold agglutinin titer. Complement C3 DAT was positive. A peripheral smear showed clumps of red cells and the serum IgM was elevated. The diagnosis of CAD was made. She was then started on Rituximab. Imaging showed a significant response, with decreased disease burden. CONCLUSIONS Our case shows a unique presentation of CAD, initially presumed to be myelosuppression secondary to chemotherapy. Instead, a peripheral smear revealed Pembrolizumab to be the cause of cold agglutinin disease. Due to the relatively unknown association between these 2 entities, patient care was delayed. Finally, after initiation of Rituximab therapy, the patient's CBC began to recover.

The Role of Immunotherapy and Radiation Therapy in Tumor Chemosensitivity in Advanced Head and Neck Cancer.

BACKGROUND Cancer is the second leading cause of death internationally, resulting in millions of deaths each year. While treatment in the past has heavily relied on surgery and radiotherapy, chemotherapy and immunotherapy are being increasingly utilized depending on disease presentation. CASE REPORT A 56-year-old male presented to the Emergency Department with a 3-week history of a rapidly enlarging left supraclavicular neck mass. Computed tomography scan revealed a 12×13 cm mass extending from the angle of the mandible to the supraclavicular area. A biopsy confirmed advanced stage squamous cell carcinoma of the head and neck. The patient was started on a chemotherapy regimen of docetaxel, cisplatin, and 5-fluorouracil (TCF). The tumor progressed through chemotherapy, which was switched to cetuximab; however, this therapy was discontinued after an anaphylactic reaction. Palliative radiation treatment was begun along with pembrolizumab. Pembrolizumab was continued, and after 9 cycles, the patient's cancer was almost in complete remission. Three months later, disease progression was once again noted with pembrolizumab treatment, which was subsequently discontinued. The patient was started on paclitaxel and carboplatin chemotherapy regimen as a last resort, despite failure of prior TCF treatment, and the patient responded, this time with complete remission in 4 months. CONCLUSIONS This case demonstrates a unique outcome in which a patient who previously was resistant to chemotherapy, later responded to chemotherapy after a trial of radiation therapy and immunotherapy. Immunotherapy may have a synergistic effect with radiation therapy and play a role in tumor sensitivity to chemotherapy in head and neck cancer treatment.