Prediction of 30-day, 90-day, and 1-year mortality after colorectal cancer surgery using a data-driven approach.

PURPOSE: To develop prediction models for short-term mortality risk assessment following colorectal cancer surgery. METHODS: Data was harmonized from four Danish observational health databases into the Observational Medical Outcomes Partnership Common Data Model. With a data-driven approach using the Least Absolute Shrinkage and Selection Operator logistic regression on preoperative data, we developed 30-day, 90-day, and 1-year mortality prediction models. We assessed discriminative performance using the area under the receiver operating characteristic and precision-recall curve and calibration using calibration slope, intercept, and calibration-in-the-large. We additionally assessed model performance in subgroups of curative, palliative, elective, and emergency surgery. RESULTS: A total of 57,521 patients were included in the study population, 51.1% male and with a median age of 72 years. The model showed good discrimination with an area under the receiver operating characteristic curve of 0.88, 0.878, and 0.861 for 30-day, 90-day, and 1-year mortality, respectively, and a calibration-in-the-large of 1.01, 0.99, and 0.99. The overall incidence of mortality were 4.48% for 30-day mortality, 6.64% for 90-day mortality, and 12.8% for 1-year mortality, respectively. Subgroup analysis showed no improvement of discrimination or calibration when separating the cohort into cohorts of elective surgery, emergency surgery, curative surgery, and palliative surgery. CONCLUSION: We were able to train prediction models for the risk of short-term mortality on a data set of four combined national health databases with good discrimination and calibration. We found that one cohort including all operated patients resulted in better performing models than cohorts based on several subgroups.

Risk factors for lymph node metastasis in patients with pT2 colon cancer in Denmark from 2016 to 2019-A nationwide cohort study.

AIM: The majority of patients with pT2 colon cancer have no lymph node metastasis (LNM). Knowledge of risk factors for LNM in pT2 colon cancer could identify patients at low risk and thereby potential candidates for local tumour excision. The aim of this work was to identify risk factors for LNM in pT2 colon cancer and describe a subgroup of low-risk patients. METHOD: This is a retrospective cohort study of patients with pT2 colon cancer from a nationwide Danish colorectal cancer database. Age, tumour size, location, histological type, mismatch repair protein status and venous, lymphatic and perineural invasion were included as potential risk factors in multivariate analysis. The primary outcome was LNM. RESULTS: We identified 1306 patients with pT2 colon cancer. LNM was present in 244 (19%). Demographic data were comparable in patients with and without LNM, and 864 patients who had complete histological data were included for multivariate analysis. Lymphatic (OR = 3.60, 95% CI 2.14-5.9), venous (OR = 1.70, 95% CI 1.03-2.74) and perineural (OR = 4.61, 95% CI 1.60-13.5) invasion were independent risk factors for LNM. Patients with deficient mismatch repair protein tumours had a decreased risk of LNM (OR = 0.55, 95% CI 0.31-0.95). Patients with clinical Stage I colon cancer and without risk factors had a 10.5% (47/443) risk of LNM. For patients with tumours with deficient mismatch repair protein status and no risk factors, the risk was 7.9%. CONCLUSION: Lymphatic, venous and perineural invasion are significant risk factors for LNM, and we identified a subgroup of patients with a low risk of LNM.

The risk of lymph node metastasis in patients with T2 colon cancer.

AIM: It is often safe to treat pT1 tumours with local resection due to the low risk of lymph node metastasis. The risk of lymph node metastasis in pT2 colon cancer is less well investigated. The recommendation for patients diagnosed with T2 colon cancer is a segmental resection including regional lymph nodes. The aim of this work was to determine the risk of lymph node metastasis in pT2 colon cancer and identify the possible associated clinical and pathological risk factors for lymph node metastasis. METHOD: PubMed and Embase were systematically searched for studies describing patients with T2 colon cancer and lymph node status after histopathological assessment. Lymph node metastasis and the effect of histological and clinical factors were included. RESULTS: Overall, 5489 studies were screened, and 10 studies consisting of a total of 91 460 patients were included in the review. The overall risk of lymph node metastasis was 19.3% (95% confidence interval 19.0%-19.5%). A meta-analysis was not possible as very few studies described the clinical and pathological risk factors for lymph node metastasis. CONCLUSION: The risk of lymph node metastasis in patients with pT2 colon cancers is higher than for pT1. The studies included patients operated on from 1985 to 2015 with variations in surgical procedure, pathological handling, and definition of lymph node metastasis. Further studies reporting risk factors for lymph node metastasis in pT2 colon cancer are warranted as more data are needed to determine if local resection for a subgroup of patients could be an alternative treatment modality.

Combined endoscopic and laparoscopic surgery (CELS) for early colon cancer in high-risk patients.

BACKGROUND: Local excision of early colon cancers could be an option in selected patients with high risk of complications and no sign of lymph node metastasis (LNM). The primary aim was to assess feasibility in high-risk patients with early colon cancer treated with Combined Endoscopic and Laparoscopic Surgery (CELS). METHODS: A non-randomized prospective feasibility study including 25 patients with Performance Status score ≥ 1 and/or American Society of Anesthesiologists score ≥ 3, and clinical Union of International Cancer Control stage-1 colon cancer suitable for CELS resection. The primary outcome was failure of CELS resection, defined as either: Incomplete resection (R1/R2), local recurrence within 3 months, complication related to CELS within 30 days (Clavien-Dindo grade ≥ 3), death within 30 days or death within 90 days due to complications to surgery. RESULTS: Fifteen patients with clinical T1 (cT1) and ten with clinical T2 (cT2) colon cancer and without suspicion of metastases were included. Failure occurred in two patients due to incomplete resections. Histopathological examination classified seven patients as having pT1, nine as pT2, six as pT3 adenocarcinomas, and three as non-invasive tumors. In three patients, the surgical strategy was changed intraoperatively to conventional colectomy due to tumor location or size. Median length of stay was 1 day. Seven patients had completion colectomy performed due to histological high-risk factors. None had LNM. CONCLUSIONS: In selected patients, CELS resection was feasible, and could spare some patients large bowel resection.

Preoperative prediction of lymph node status in patients with colorectal cancer. Developing a predictive model using machine learning.

PURPOSE: Develop a prediction model to determine the probability of no lymph node metastasis (pN0) in patients with colorectal cancer. METHODS: We used data from four Danish health databases on patients with colorectal cancer diagnosed between 2001 and 2019. The registries were harmonized into one common data model (CDM). Patients with clinical T4 tumors, undergoing palliative or acute surgery, and patients undergoing neoadjuvant therapy were excluded. Preoperative data was used to train the model. A postoperative model including tumor-specific variables potentially available after local tumor resection was also developed. Additionally, both models were compared with a model based on age, sex, and clinical N stage to resemble current standards. A Least Absolute Shrinkage and Selection Operator (LASSO) logistic regression analysis for prediction was used. RESULTS: In total, 35,812 patients with 16,802 variables were identified in the CDM, and 194 variables affected the probability of pN0 preoperative. The area under the receiver operating characteristic curve (AUROC) was 0.64 (95% CI 0.63-0.66), and the area under the precision-recall curve (AUPRC) was 0.75 (95% CI 0.74-0.76). The mean predicted risk was 0.649, observed risk was 0.650, and calibration-in-large was 0.998. Adding histopathological data from the tumor improved the model slightly by increasing AUROC to 0.69. In comparison, the AUROC of the current standard clinical staging model was 0.57. CONCLUSION: Using Danish National Patient Registry data in a machine learning-based predictive model showed acceptable results and outperforms current tools for clinical staging in predicting pN0 status in patients scheduled for CRC surgery.

Anastomotic Leakage After Stoma Reversal Combined with Incisional Hernia Repair.

BACKGROUND: Stoma reversal in patients with an incisional hernia represents a clinical dilemma, as it remains unknown whether hernia repair should be concomitantly employed. We aimed at examining postoperative complications and mortality in patients undergoing stoma reversal with or without concomitant hernia repair. METHODS: This study included all patients subjected to stoma reversal between 2010 and 2016 at our institution. Patients were grouped according to conductance of concomitant incisional hernia repair or not. The primary outcome was anastomotic leak (AL). Secondary outcomes were surgical site occurrences (SSO), overall surgical complications, 90-day mortality and overall survival. RESULTS: In total, 142 patients were included of whom 18 (13%) underwent concomitant hernia repair. The incidence of AL was significantly higher in patients subjected to concomitant hernia repair (four out of 18 [22.2%]) compared with patients undergoing stoma reversal alone (three out of 124 [2.4%], P = 0.002). Additional variables associated with AL were duration of surgery (P < 0.001) and ischemic heart disease (P = 0.039). Twenty-two patients (15.5%) developed a SSO: eight (44.4%) in the hernia repair group and 14 (11.3%) in the non-hernia repair group (P < 0.001). In the multivariable analysis, concomitant hernia repair remained significantly associated with development of postoperative complications (OR = 5.92, 95% CI = 1.54-25.96, P = 0.012). CONCLUSIONS: Compared with stoma reversal alone, incisional hernia repair concomitant with stoma reversal was associated with a higher incidence of AL and other complications.

[Colon cancer surgery in the high-risk patient].

The incidence of colon cancer increases with age. With national screening in Denmark, the incidence of early stage cancer is high. With the increasing possibilities of personalised treatment for colon cancer, it is important to choose the right treatment for the right patient. Patient characteristics such as age, co-morbidity, low functioning level and frailty increases the risk of post-operative adverse outcomes. The pathologic assessment and assessment of the patient's immune system offers many tools for assessing the patient's long-term outcomes such as relapse and mortality, and this is discussed in this review.

Local involvement of the lower urinary tract in primary colorectal cancer - outcome after en-bloc resection.

UNLABELLED: Invasion of urinary organs due to advanced colorectal cancer can comprise a surgical challenge in achieving negative resection margins. The aim of the study was to asses the outcome of patients with colorectal cancer invading the lower urinary organs. MATERIAL AND METHODS: This is a cohort study that retrospectively evaluated the surgical and pathological findings after the resection of colorectal cancer with adjacent urological organs due to advanced colorectal cancer. Patients with primary colorectal cancer invading urological organs where primary resection was attempted were included. RESULTS: The study included 31 patients who underwent surgery in our department between 1997 and 2012. Median age was 65 years (range 44-77 years). Seventeen patients underwent partial cystectomy, one had partial prostatectomy performed, eight patients underwent cystoprostatectomy, two had cystectomy performed and three had prostatectomy performed. Overall morbidity rate was 71% (95% Confidence Interval (CI): 55-84%, n=22). The 30-day mortality rate was 10% (95% CI: 0-23%, n=3). Twentyseven of 31 patients had free resection margins. Four of 28 patients developed distant metastasis (14%, 95% CI: 4-29%), 11% developed local recurrence (95% CI: 0-25%, n=3). Median follow-up was 41 months (range 0-150 months). Histopathological examination revealed tumour invasion in 52% (95% CI: 35-69%, n=15) of the resected urological organs. The overall five-year survival rate was 70%. The five-year survival rate in the radical resection group was 74%. CONCLUSIONS: En-bloc resection of colorectal cancer with adjacent urological organs has a high morbidity rate. However it is still possible to achieve negative resection margins in most cases.