IMMUNOREACT 9 metachronous rectal cancers have high HLA-ABC expression on healthy epithelium but a lower infiltration of CD3+ T cells than primary lesions.

Lynch syndrome is rarely associated with rectal cancer (RC) and thus, metachronous RC has been scarcely investigated. This study aimed to analyze the mucosal immune microenvironment in sporadic and metachronous RC. We analyzed the mucosal immune microenvironment in the 25 metachronous RCs present in the IMMUNOREACT 1 and 2 multicentre observational studies (624 patients).

IMMUNOREACT 8: Immune markers of local tumor spread in patients undergoing transanal excision for clinically N0 rectal cancer.

Background: Transanal excision of rectal cancer can be considered the definitive surgical treatment if the depth spread is T1 or lower, and the lesion is completely included within the resection margin. This study aims to analyze the immune microenvironment in healthy rectal mucosa as a possible predictor of tumor infiltration depth, lateral tumor spread, and recurrence of rectal cancer after transanal local excision.

Methods: This study is a subanalysis of data from the IMMUNOREACT 1 and 2 trials (NCT04915326 and NCT04917263, respectively) including all the patients who underwent transanal excision of rectal cancer.

IMMUNOREACT 7: Regular aspirin use is associated with immune surveillance activation in colorectal cancer.

Background: Long-term daily use of aspirin reduces incidence and mortality due to colorectal cancer (CRC). This study aimed to analyze the effect of aspirin on the tumor microenvironment, systemic immunity, and on the healthy mucosa surrounding cancer.

Methods: Patients with a diagnosis of CRC operated on from 2015 to 2019 were retrospectively analyzed (METACCRE cohort).

Robotic Resection of Giant Duodenal Hamartoma After Fluorodeoxyglucose Positron Emission Tomography Magnetic Resonance Imaging (FDG PET-MRI).

Brunner's gland hamartoma is a rare duodenal lesion. Resection for benign neoplasms of the duodenum should be considered in case of malignant potential or in case of symptomatic lesions. An accurate preoperative staging is mandatory in order to allow minimally invasive surgical approach, and to avoid under- or overtreatment.