ABSTRACT
Thymic carcinoma (TC) is a rare and aggressive malignancy of the thymus associated with less than 25% 5 years survivability. Our case report showcases the successful treatment of advanced metastatic TC using a multidisciplinary approach and the utility of checkpoint inhibitors in treatment of recurrent TC. A 50-year-old man presented with Raynaud's phenomenon and was found to have a stage IVb TC (T3N2M0). Eight months after management with neoadjuvant chemotherapy, surgical resection and adjuvant chemoradiotherapy, patient was diagnosed with metastasis of TC to the liver and a concurrent stage III (T2N1M0) primary sigmoid colon adenocarcinoma. Following complete resection of the colon adenocarcinoma, the patient started palliative-intent treatment for TC with pembrolizumab given PD-L1 tumor proportionate score of 100%. This resulted in a sustained complete response for 38 months. Our patient did have immune-related adverse events involving multiple organs but was able to continue pembrolizumab for a standard treatment duration of 2 years with multidisciplinary care. When recurrent disease was noted in a portocaval lymph node, pembrolizumab was reinitiated and a second complete response was achieved. The patient has maintained that complete response while maintaining an acceptable quality of life, showing that treatment with pembrolizumab is effective in patients after discontinuation with prior immunotherapy.
Fighting Thymic Carcinoma: A Story of Immunotherapy and Multidisciplinary Care Triumph The thymus is a gland located in the chest that plays a major role in the immune system, particularly before adulthood. Thymic carcinoma (TC) is a type of cancer affecting the thymus that is often challenging to treat given its inadequate response to chemotherapy and tendency to spread to other organs. A 50-year-old man was found to have advanced stage thymic carcinoma, which is associated with a less than 25% 5-year survival rate. Eight months after completing a rigorous treatment protocol of chemotherapy, surgery and radiation therapy, his original thymic cancer was found to have metastasized to the liver. Simultaneously, he was diagnosed with stage III sigmoid colon cancer. He underwent curative surgery for colon cancer and was started on pembrolizumab for thymic cancer. Pembrolizumab is an immunotherapy drug that boosts the body's own immune system to fight against the cancer. Inadvertently, it can turn immune cells against healthy tissues, which results in symptoms called immune-related adverse events (irAEs). Indeed, he experienced various irAEs involving multiple organs. These events were effectively managed by involving multiple specialists and initiating medications to calm the immune system and allow him to continue immunotherapy. He had a complete response to treatment and was able to complete the standard treatment course of two years. He retained a complete response for over three years before his tumor recurred. He was restarted on pembrolizumab and achieved a complete response again. This case highlights a unique presentation of metastatic TC and the utility of a multidisciplinary approach for treatment to maintain a high quality of life five years after diagnosis.
