# From Genomics to AI: Revolutionizing Precision Medicine in Oncology
## 5 Genomics in Prognosis and Early Detection  
Genomics is revolutionizing the prognosis and early detection of cancer, offering more precise methods for assessing disease outcomes and detecting tumors in their early stages. Among the most important tools in cancer prognosis are genomic biomarkers, which help in characterizing the biological behavior of tumors and provide critical insights into the probability of recurrence or progression. Genomic biomarkers are able to predict how aggressive a cancer is and help guide decisions about the most appropriate treatment options. For example, Oncotype DX (Exact Sciences, Madison, WI, USA) and PAM50/Prosigna (NanoString Technologies, Seattle, WA, USA) are widely recognized tests that analyze the gene expression profiles of tumor samples to evaluate the risk of recurrence and the potential benefit of adjuvant therapies, particularly in breast cancer. Oncotype DX examines the activity of 21 genes involved in cancer progression, allowing clinicians to assign a recurrence score that guides treatment decisions, such as chemotherapy [58]. PAM50, which is based on a 50-gene signature, classifies tumors into intrinsic subtypes and provides insight into the likely prognosis, helping clinicians tailor treatments to the individual's tumor profile [59]. These genomic tools enable a more personalized approach to cancer care by identifying patients who may benefit from aggressive treatment and sparing those who are less likely to benefit from unnecessary therapies. Another significant development in cancer monitoring and early detection is the use of ctDNA and cfDNA [60]. Liquid biopsy refers to the analysis of genetic material, such as DNA fragments, circulating freely in body fluids like blood, as opposed to traditional biopsies, which require the extraction of solid tissue samples. cfDNA consists of small fragments of DNA released into the bloodstream from both normal and cancerous cells, whereas ctDNA is a subset of cfDNA that specifically originates from tumor cells and therefore reflects the tumor's unique genetic alterations. This distinction is important because ctDNA provides a more precise snapshot of the tumor's genomic profile [61]. Liquid biopsy, by analyzing ctDNA, allows clinicians to detect pathogenic variants and copy number variations in the tumor genome without the need for invasive tissue biopsies. ctDNA analysis is increasingly used for early cancer detection, especially in cancers where traditional screening methods are limited, such as pancreatic, lung, and colorectal cancers [61]. It is also valuable for monitoring disease progression and detecting minimal residual disease (MRD) after treatment, offering insights into the likelihood of relapse [62]. While liquid biopsy provides a less invasive and more dynamic means to monitor cancer, its sensitivity and specificity can vary depending on tumor type, stage, and the amount of ctDNA shed into the bloodstream, and it may not yet fully replace traditional tissue biopsy, which remains the gold standard for initial diagnosis and detailed histopathological analysis. A comparative summary of the key features distinguishing liquid biopsy from conventional tissue biopsy is presented in Table 4, highlighting the advantages of liquid biopsy in terms of minimal invasiveness, longitudinal monitoring, and the detection of MRD. By combining genetic information with clinical factors, healthcare providers can categorize patients into different risk groups, allowing for more tailored monitoring strategies. Continuous advancements in genomic technologies, including NGS and liquid biopsy platforms, are driving the integration of genomics into routine clinical practice. As the cost of genomic testing decreases and accuracy improves, genomics will become an even