Local Excision for Organ Preservation in Early REctal Cancer With No Adjuvant Treatment (LORENA Trial).
Rectal cancer is one of the most frequent malignant tumors nowadays. There are several possible treatment options including chemotherapy, radiotherapy and surgery. Surgery for early stage rectal cancer can be either a radical surgery (RS) or a local excision (LE). A radical surgery removes the rectum including the tumor and the lymph nodes through which it spreads, improving survival but with a possible impact in the patients quality of life (QoL). A local excision only removes the tumor and a safety margin of healthy rectum. This has the potential to avoid the possible complications and QoL decrease. However there are some complications after a LE and also poor prognostic factors inherent to the tumor biology that can lead the surgical team to perform a RS after LE with worse outcomes. These are impossible to know before the procedure. The goal of this registry is to determine the frequency of these poor prognostic biological factors and complications in patients undergoing LE for early rectal cancer. The main question it aims to answer are: • How frequently does LE allow for rectum preservation? Participants will undergo LE for early rectal cancer when it is considered the best treatment by their surgeons according to their expertise and protocols. Patients will follow the standard treatment that would be given to them, and the biological prognostic factors and the appearance of complications will be recorded.
• Patients age 18 years or older.
• Histologic proof of infiltrating rectal adenocarcinoma. or
• Preoperative biopsy compatible with rectal adenoma or intramucous adenocarcinoma with endoscopic or radiological suspicion of infiltrating adenocarcinoma.
‣ Endoscopic criteria: Kudo´s crypt pattern of V or higher, despite non confirmatory preoperative histology. endoscópicos: patrón de criptas V o superior según la clasificación de Kudo, que define lesiones infiltrantes, a pesar de que la histología preoperatoria no sea confirmatoria .
⁃ Ultrasonographic criteria: hipoecogenic rectal tumor invading the intermediate hyperecogenic layer (submucosal), but does not infiltrate the hypoecogenic outer layer (muscularis propia).
⁃ Radiological criterio in MR: tumor invades the submucosal layer without infiltration of the rectal muscularis propia. The usual low signal submucosal image is substituted with an aberrant signal, meaning the loss of the zebra pattern in a normal rectal wall.
• Rectal neoplasm with an inferior limit no further than 2cm proximal to the anorectal verge, both in digital rectal examination and in radiology examinations, ideally magnetic resonance (MR).
• Rectal neoplasms up to 3 cm of major diameter.
• Clinical preoperative staging of cT1N0M0, based on endoscopy, MR, +/- endorectal ultrasound.
• Cases in which LE as exclusive treatment with curative intent is prescribed after MDT discusión, regardless of the approach both via flexible endoscopy and transanal endoscopic microsurgery and its variations.
• Neoplasms with low risk histologic criteria known preoperatively or lack of information regarding this aspect:
‣ Submucosal infiltration of less than 1000µm (sm1 in the Kikuchi classification) .
⁃ Tumor budding absent.
⁃ En bloc resection in patients with a previous endoscopic resection.
⁃ Vascular, lymphatic and perineural invasión absent.
⁃ Low histologic grade.