Introduction

Cancer treatment decisions are often made based on histological examination. Given that tumor profiles change with time and treatment and that tumor tissue is heterogeneous, other easily accessible and less invasive approaches are needed to monitor responses to treatment and predict relapse.
The term “liquid biopsy” (LB) was introduced to represent multifunctional circulating biomarkers in the peripheral blood of cancer patients. LB is a non-invasive alternative to tissue biopsies and appears to be a promising approach for personalized medicine.
It all starts with a simple blood draw.

Technical features

With the “liquid biopsy” we can be able to know:
1. response to different treatment regimens and provide an estimate of the risk of progression months before imaging manifestations;
2. if a patient has minimal residual disease after completing chemotherapy or surgery. Such information will be useful in deciding whether the patient requires further adjuvant treatment and may provide better stratification against current clinicopathological criteria and better guidance in determining subsequent treatment, as the molecular profile of ctDNA has been found to more closely mirror relapsing/metastatic disease versus primary tumour;
3. acquisition of mutations that confer sensitivity/resistance to therapies. This may help prompt an early change in treatment regimen before disease progression.
4. Finally, liquid biopsy may be an alternative to tissue biopsy in patients in whom tissue biopsy is contraindicated.

Possible Applications

• Advanced diagnosis of residual disease after treatment
• Personalized neoplasm therapy

Advantages

• Have new concepts on neoplastic pathology available such as:minimal residual disease after primary treatment
• Diagnostic anticipation compared to traditional imaging
• Sensitivity/Resistance to drugs