Cancer is one of the most lethal diseases and has distinct variants that affect over 60 organs in the human body. The necessity of advanced methodologies for the early diagnosis of cancer has grown over the past decades. Among various biomarkers, microRNAs (miRNAs) have emerged as highly specific and minimally invasive indicators for cancer detection, prognosis, and treatment monitoring. Their stability in biological fluids and their critical role in gene regulation make them valuable targets for diagnostic applications. Plasmonic biosensors have gained massive attention owing to their unique optical properties, such as surface plasmon resonance, making them promising tools for the sensitive and selective analysis of cancer-associated biomarkers. In contrast to previous reviews, this work offers a comprehensive overview of advancements from approximately the past five years, particularly in the detection of cancer-associated miRNAs. It emphasizes emerging plasmonic sensing strategies, integration with novel nanomaterials, and enhanced signal amplification techniques. By focusing on these recent innovations, this review provides new insights into the potential of plasmonic biosensors to improve cancer diagnosis and treatment.