MelPRO-0322 (CRISTINA Trial) [miCrobiome pRedIctS aPD1 effecTivnes In melaNoma pAtietns]

Patients with resectable stage IIIB-D melanoma will have a lymph node core biopsy to confirm metastatic lesions, following standard procedures. Additionally, a portion of the tumor tissue will be preserved for biomarker analysis. Participants will then be instructed to submit fecal samples and complete a dietary questionnaire before receiving three doses of PD1 monotherapy, in accordance with the center\'s routine practice, typically spanning 6-10 weeks. Between weeks 10 and 12, a radiological assessment of the response will be conducted. Following this, participants will undergo regional lymphadenectomy, and the pathological response will be evaluated. After surgery, patients will be placed on adjuvant therapy for 12 months as per routine practice of the center . Subsequently, they will be monitored for five years, adhering to the institution\'s standard follow-up protocol.