Vascular Acrosyndromes Associated With Prolonged Tumor Response in Advanced Lung Cancer Patients During Treatment With Antimetabolites: A Report of Two Cases

BACKGROUND: Pemetrexed and gemcitabine are both antimetabolites drugs approved in advanced non-small cell lung cancer (NSCLC). Their toxicity profile is well known. However, rare vascular side effects can occur such as vascular acrosyndromes and especially digital ischemia. The cause of this disfiguring and painful event is still controversial. Amputation is frequently required and has been described as a predictor of poor survival outcomes. CASE PRESENTATION: This report presents two cases of vascular acrosyndrome in NSCLC patients during treatment with antimetabolites (pemetrexed and gemcitabine). Patients presented severe digital ischemia having required prostacyclin analog and chemotherapy discontinuation. In one case, symptoms improved while in the other case symptoms persisted. Both patients experienced prolonged tumor response. These findings suggest a multifactorial mechanism behind digital necrosis including an autoimmune process, which could lead to prolonged tumor control as described with immune checkpoint inhibitors. CONCLUSION: Severe vascular acrosyndrome such as digital ischemia can occur in lung cancer patients treated with antimetabolites. Awareness needs to be raised when using these drugs in patients with predisposing factors. Whether occurrence of chemotherapy-induced immune vascular side effects might explain prolonged tumor response deserves further investigations.