Survival analysis of early-onset locally advanced rectal cancer: a retrospective study based on the Surveillance, Epidemiology, and End Results (SEER) database / 中华胃肠外科杂志

Objective: To investigate the factors influencing tumor-specific survival of early-onset locally advanced rectal cancer. Methods: All-age patients with primary locally advanced rectal cancer from the Surveillance, Epidemiology, and End Results (SEER) database (2010 to 2019) were included in this study. Early- and late-onset locally advanced rectal cancer was defined according to age of 50 years at diagnosis. Early-onset locally advanced rectal cancer was divided into five age groups for subgroup analyses. Age, sex, tumor-specific survival time and survival status of patients at diagnosis, pathological grade, TNM stage, perineural invasion, tumor deposits, tumor size, pretreatment CEA , radiotherapy, chemotherapy, and number of lymph node dissections were included. Progression-free survival (PFS) was analyzed and compared between patients with early- and late-onset rectal cancer. Results: A total of 5,048 patients with locally advanced rectal cancer were included in the study (aged 27-70 years): 1,290 (25.55%) patients with early-onset rectal cancer and 3,758 (74.45%) patients with late-onset rectal cancer. Patients with early-onset rectal cancer had a higher rate of perineural invasion (P<0.001), more positive lymph nodes dissected (P<0.001), higher positive lymph node ratios (P<0.001), and a higher proportion receiving preoperative radiotherapy (P=0.002). Patients with early-onset rectal cancer had slightly better short-term survival than those with late-onset rectal cancer (median (IQR ): 54 (33-83) vs 50 (31-79) months, χ2=5.192, P=0.023). Multivariate Cox regression for all patients with locally advanced rectal cancer showed that age (P=0.008), grade of tumor differentiation (P=0.002), pretreatment CEA (P=0.008), perineural invasion (P=0.021), positive number (P=0.004) and positive ratio (P=0.001) of dissected lymph nodes, and sequence of surgery and radiotherapy (P=0.005) influenced PFS. This suggests that the Cox regression results for all patients may not be applicable to patients with early-onset cancer. Cox analysis showed tumor differentiation grade (patients with low differentiation had a higher risk of death, P=0.027), TNM stage (stage III patients had a higher risk of death, P=0.025), T stage (higher risk of death in stage T4, P<0.001), pretreatment CEA (P=0.002), perineural invasion (P<0.001), tumor deposits (P=0.005), number of dissected lymph nodes (patients with removal of 12-20 lymph nodes had a lower risk of death, P<0.001), and positive number of dissected lymph nodes (P<0.001) were independent factors influencing PFS of patients with early-onset locally advanced rectal cancer. Conclusion: Patients with early-onset locally advanced rectal cancer were more likely to have adverse prognostic factors, but an adequate number of lymph node dissections (12-20) resulted in better survival outcomes.

Predictive value of MRI pelvic measurements for "difficult pelvis" during total mesorectal excision / 中华胃肠外科杂志

Objective: Total mesorectal resection (TME) is difficult to perform for rectal cancer patients with anatomical confines of the pelvis or thick mesorectal fat. This study aimed to evaluate the ability of pelvic dimensions to predict the difficulty of TME, and establish a nomogram for predicting its difficulty. Methods: The inclusion criteria for this retrospective study were as follows: (1) tumor within 15 cm of the anal verge; (2) rectal cancer confirmed by preoperative pathological examination; (3) adequate preoperative MRI data; (4) depth of tumor invasion T1-4a; and (5) grade of surgical difficulty available. Patients who had undergone non-TME surgery were excluded. A total of 88 patients with rectal cancer who underwent TME between March 2019 and November 2021 were eligible for this study. The system for scaling difficulty was as follows: Grade I, easy procedure, no difficulties; Grade II, difficult procedure, but no impact on specimen quality (complete TME); Grade III, difficult procedure, with a slight impact on specimen quality (near-complete TME); Grade IV: very difficult procedure, with remarkable impact on specimen quality (incomplete TME). We classified Grades I-II as no surgical difficulty and grades III-IV as surgical difficulty. Pelvic parameters included pelvic inlet length, anteroposterior length of the mid-pelvis, pelvic outlet length, pubic tubercle height, sacral length, sacral depth, distance from the pubis to the pelvic floor, anterior pelvic depth, interspinous distance, and inter-tuberosity distance. Univariate and multivariate logistic regression analyses were performed to identify the factors associated with the difficulty of TME, and a nomogram predicting the difficulty of the procedure was established. Results: The study cohort comprised 88 patients, 30 (34.1%) of whom were classified as having undergone difficult procedures and 58 (65.9%) non-difficult procedures. The median age was 64 years (56-70), 51 patients were male and 64 received neoadjuvant therapy. The median pelvic inlet length, anteroposterior length of the mid-pelvis, pelvic outlet length, pubic tubercle height, sacral length, sacral depth, distance from the pubis to the pelvic floor, anterior pelvic depth, interspinous distance, and inter-tuberosity distance were 12.0 cm, 11.0 cm, 8.6 cm, 4.9 cm, 12.6 cm, 3.7 cm, 3.0 cm, 13.3 cm, 10.2 cm, and 12.2 cm, respectively. Multivariable analyses showed that preoperative chemoradiotherapy (OR=4.97,95% CI: 1.25-19.71, P=0.023), distance between the tumor and the anal verge (OR=1.31, 95% CI: 1.02-1.67, P=0.035) and pubic tubercle height (OR=3.36, 95% CI: 1.56-7.25, P=0.002) were associated with surgical difficulty. We then built and validated a predictive nomogram based on the above three variables (AUC = 0.795, 95%CI: 0.696-0.895). Conclusion: Our research demonstrated that our system for scaling surgical difficulty of TME is useful and practical. Preoperative chemoradiotherapy, distance between tumor and anal verge, and pubic tubercle height are risk factors for surgical difficulty. These data may aid surgeons in planning appropriate surgical procedures.