[Analysis of factors influencing the success rate of organoid culture in 1231 cases of colorectal cancer].

To investigate the risk factors for organoid culture failure in colorectal cancer. This was a retrospective observational study. Tumor specimens were obtained from 1130 patients with colorectal cancer who had undergone surgery or biopsy and had no other concurrent malignancies at Nanfang Hospital of Southern Medical University from December 2021 to November 2022. Organoid culture was performed on 1231 tumor tissue samples. Univariate analysis and multivariate logistic regression were used to analyze the factors that might have influenced the rate of successful organoid culture of colorectal cancer tissue samples. The median (range) duration of organoid culture was 7 (3-12) days. The overall rate of successful culture was 76.3% (939/1231). The rate of successful organoid cultures varied according to the sampling site, malignant ascites having the highest success rate (96.4%, 27/28), followed by liver metastases (83.1%, 54/65), lung metastases (8/10), primary tumors (76.0%, 816/1074), omental metastases (10/14), peritoneal metastases (61.5%, 16/26), ovarian metastases (3/5), and lymph node metastases (5/9). The difference in rates of successful organoid culture between primary tumors and malignant ascites was statistically significant (=0.012), whereas none of the other rates of successful organoid culture success differed significantly (all >0.05). The rate of successful organoid culture was 96.4% (27/28) for malignant ascites obtained by abdominal puncture, 76.5% (864/1130) for surgical specimens, and 65.8% (48/73) for endoscopic biopsies; these differences are statistically significant (χ=10.773, =0.005). The rate of successful organoid culture was 62.5% (40/64) in the neoadjuvant chemoradiotherapy group, which is significantly lower than in the non-adjuvant (76.9%, 787/1023) and chemotherapy groups (77.8%, 112/144) (χ=7.134, =0.028). Multivariate logistic regression analysis revealed that endoscopic biopsy (OR=0.557, 95%CI: 0.335-0.924, =0.024) and neoadjuvant chemoradiotherapy (OR=0.483, 95%CI: 0.285-0.820, =0.007) were independent risk factors for failure of organoid culture of colorectal cancer samples. Malignant ascites (OR=8.537, 95%CI:1.154-63.131,=0.036) and abdominal puncture (OR=8.294, 95% CI: 1.112-61.882, =0.039) were identified as independent protective factors. The rate of successful organoid culture was influenced by the sampling site, sampling method, and chemoradiotherapy. The rate of successful organoid culture was lower for endoscopic biopsies and in patients receiving preoperative neoadjuvant chemoradiotherapy, and higher for malignant ascites. We consider that culture of malignant ascites is preferable when peritoneal metastases are suspected.