Clinical Presentation
A 58-year-old male was diagnosed 6 years ago with stage IV clear cell renal carcinoma (multiple lung nodules and mediastinal adenopathy). He was offered sunitinib, a tyrosine kinase inhibitor, and achieved a partial response with stable disease. Five years later his scans showed worsening disease. Cabozantinib was offered but was poorly tolerated. He tried ipilimumab plus nivolumab but ipilimumab was dropped after 4 cycles due to diarrhea. His scans improved with 4 more cycles of nivolumab but he had to stop immunotherapy due to hypophysitis, diarrhea, and severe jaw pain. He received a COVID-19 booster vaccine and noticed profound fatigue and anorexia soon after. Over 8 weeks he lost 56 lbs (267 to 211 lb). Relapse was suspected but PET CT showed complete resolution of his lung nodules and multiple areas of adenopathy. Asymptomatic and in remission 6 months after vaccination.
Relevant Literature
Clear cell renal carcinoma is resistant to standard chemotherapy/radiation, which usually offers partial responses. Complete remissions are few. Low glycemic diets in animal models have anticancer activity. HIV causes B cell apoptosis. Coxsackievirus A21 oncolytic properties lyse myeloma and CD138+ plasma cells via intercellular adhesion molecule interaction. SARS-CoV-2 (COVID 19) proteins have oncolytic properties.
Intervention
The patient eliminated sugary food from his diet 6 years ago. Stopped bread 2 years ago. Sunitinib 37.5 mg daily × 5 years. Cabozantinib—poorly tolerated. Ipilimumab + nivolumab × 4 cycles followed by nivolumab × 4 cycles. Stopped treatment; immune side effects. COVID-19 booster.
Outcome
15 lb weight loss due to a low glycemic diet, which began since diagnosis. After 4 years he stopped eating bread. After COVID-19 vaccine had a rapid 56 lb. weight loss, fatigue, and nausea over 8 weeks. No evidence of disease. Asymptomatic, off therapy, weight is ideal (219 lb) 6 months after the vaccine.
Implications for Practice
Effects of SARS-CoV-2 (COVID-19) on cancers remain unknown. A few case reports of cancer remissions after infections are emerging. This is the first case of complete remission after COVID-19 vaccination in a patient on immunotherapy/low glycemic diet. Research is needed to study the contribution of a COVID-19 inflammatory response.
