CT is unreliable in locoregional staging of early colon cancer: A nationwide registry-based study.

BACKGROUND AND OBJECTIVE: The option to treat early colon cancer (CC) with local resection, as well as trials investigating neoadjuvant treatment, has increased the importance of identifying early-stage disease in the workup. Most CC patients are T- and N-staged preoperatively with CT, although its reliability in staging early CC remains elusive. The aim of this study was to investigate CT-staging accuracy in early CC by evaluating pT and pN stages in patients staged as cT1-2, and cT and cN stages in patients with pT1 tumors. METHODS: Retrospective population-based cohort study on data from the nationwide Swedish colorectal cancer registry on all CC patients staged as cT1-2 and all patients with pT1 undergoing surgical resection 2009-2018. CT-acquired T- and N-stages were compared with final histopathology. Factors potentially influencing accuracy were analyzed with uni- and multivariate logistic regression. RESULTS: Computed tomography (CT) staged 4849 patients as cT1-2, whereas 2445 (50%) were pT3 and 453 (9%) pT4. Positive predictive value of the cT1-2 stage was 40%. Of 1401 pT1 patients, 624 (45%) were staged as cT1-2, 139 (10%) as cT3, 15 (1%) as cT4 and 623 (44%) as cTx. In all, 1474 (30%) of the cT1-2 patients were pN+, whereas CT staged 1062 (72%) as cN0. A total of 771 patients were staged as cN+, whereas 403 (52%) were pN0. Overall accuracy in determining N+ was 67%, with 26% sensitivity and 88% specificity. Positive and negative predictive values in determining N+ were 48% and 73%, respectively. CONCLUSIONS: This nationwide population-based study shows that CT-staging carries a substantial risk of understaging locally advanced tumors as cT1-2 and pT1 tumors as cTx, in addition to poor N-staging. Thus, CT obtained T- and N-staging should not be used for deciding treatment strategies in early CC.

Cost comparisons of endoscopic and surgical resection of stage T1 rectal cancer.

Background and study aims Management of T1 rectal cancer is complex and includes several resection methods, making cost comparisons challenging. The aim of this study was to compare costs of endoscopic and surgical resection and to investigate hypothetical cost scenarios for the treatment of T1 rectal cancer. Patients and methods Retrospective population-based cost minimization study on prospectively collected data on T1 rectal cancer patients treated using endoscopic submucosal dissection (ESD), transanal endoscopic microsurgery (TEM), open, laparoscopic, or robotic resection, in Skåne County, Sweden (2011-2017). The hypothetical cost scenarios were based on the distribution of high-risk features of lymph node metastases in a national cohort (2009-2017). Results Eighty-five patients with T1 RC undergoing ESD (n = 16), TEM (n = 17), open (n = 35), laparoscopic (n = 9), and robotic (n = 8) resection were included. ESD had a total 1-year cost of 5165 €â€Šand was significantly ( P  < 0.05) less expensive compared to TEM (14871€), open (21 453 €), laparoscopic (22 488 €) and robotic resection (26 562 €). Risk factors for lymph node metastases were seen in 68 % of 779 cases of T1 rectal cancers included in the national cohort. The hypothetical scenario of performing ESD on all T1 RC had the lowest total 1-year per patient cost compared to all other alternatives. Conclusions This is the first study analyzing total 1-year costs of endoscopic and surgical methods to resect T1 rectal cancer, which showed that the cost of ESD was significantly lower compared to TEM and surgical resection. In fact, based on hypothetical cost scenarios, ESD is still justifiable from a cost perspective even when all high-risk cases are followed by surgery in accordance to guidelines.