Researchers from the Breast Cancer Center at Vall d’Hebron University Hospital (HUVH) have developed a software which calculates the probability of finding tumor sentinel lymph nodes in the armpit of breast cancer patients in the early stages with positive sentinel lymph nodes detected. The new tool determines the value of the tumor burden of these nodes by using a molecular technique (OSNA-one-step nucleic acid simplification) which is already used in several hospitals. For the first time with this tool, specialists have another mechanism to assess if the removal of all sentinel lymph nodes, when a positive one is detected, is the best option. Dr. Isabel Rubio, head of the Mammary Pathology Unit at HUVH, assures that “this calculator is very useful because it provides more information about the patient and benefits her treatment, as we always try to use the treatment and surgery with the less aggressiveness but the highest effectiveness. To develop this tool, thanks to the collaboration in knowledge transfer of Vall d’Hebron Research Institute (VHIR), researchers have focused in the results of a multicenter study done with 600 patients from 8 Spanish research centers.It is estimated that the 10-20 per cent of the patients, with this characteristics, could benefit from this new tool. Nonetheless, it is important to remark that it is an informative tool that doesn’t replace the final criteria of the doctor, who is the last responsible for taking the decision.