Influence of pT3 subgroups on outcome of R0-resected colorectal tumors

Prognostic significance of additional histologic features for subclassification of pathological T3 colon cancer

Background

Additional histologic features of T3 colon cancer, such as tumour depth invasion beyond muscularis propria and elastic lamina invasion (ELI), have taken interest for a more accurate staging.

Methods

Patients with pT3 and pT4a (control group) colon adenocarcinoma were retrospectively collected from our institutional database. The study group was divided according to depth of tumour invasion < 5 mm and ≥ 5 mm, and into ELI − and ELI + . Chi-square test was used to compare the clinicopathological characteristics. OS and DFS were estimated using Kaplan–Meier method and compared with the log-rank test. Univariable and multivariable Cox proportional hazard models were employed to assess the effect on OS and DFS.

Results

Out of 290 pT3 tumours, 168 (58%) had a depth of tumour invasion < 5 mm and 122 (42%) ≥ 5 mm. The 5-year OS and DFS were 85.2, 68.7 and 60.9%, and 81.4, 73.9 and 60.1% in pT3 < 5 mm, pT3 ≥ 5 mm, and pT4a respectively (p = 0.001, p = 0.072). Considering ELI − (n = 157, 54%) and ELI + (n = 133, 46%), the 5-year OS and DFS were 78.9, 76.7, and 60.9%, and 75.5, 81.5, and 60.1% in ELI  − , ELI + and pT4a respectively (p = 0.955, p = 0.462). At multivariable analysis, the depth of invasion was found to be an independent predictive factor for OS (HR 2.04, 95%CI 1.28–3.24, p = 0.003) and DFS (HR 1.98, 95%CI 1.24–3.18, p = 0.004), while ELI did not result a prognostic factor for OS nor DFS.

Conclusion

In pT3 colon cancer, depth of tumour invasion ≥ 5 mm is an independent risk factor for OS and DFS, whereas ELI did not result a prognostic factor affecting OS nor DFS.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10147-022-02192-y.

Histotype influences emergency presentation and prognosis in colon cancer surgery

AIM

To investigate whether differences in histotype in colon cancer correlate with clinical presentation and if they might influence oncological outcomes and survival.

METHODS

Data regarding colon cancer patients operated both electively or in emergency between 2009 and 2014 were retrospectively collected from a prospectively maintained database and analyzed for the purpose of this study. Rectal cancer was excluded from this analysis. Statistical univariate and multivariate analyses were performed to investigate possible significant variables influencing clinical presentation, as well as oncological outcomes and survival.

RESULTS

Data from 219 patients undergoing colorectal resection for cancer of the colon only were retrieved. One hundred seventy-four patients had an elective procedure and forty-five had an emergency colectomy. Emergency presentation was more likely to occur in mucinous (p < 0.05) and signet ring cell (p < 0.01) tumors. No definitive differences in 5-year overall (44.7% vs. 60.6%, p = 0.078) and disease-free (51.2% vs. 64.4%, p = 0.09) survival were found between the two groups as a whole, but the T3 emergency patients showed worse prognosis than the elective (p < 0.03). Lymph node invasion, laparoscopy, histology, and blood transfusions were independent variables found to influence survival. Distribution assessed for pTNM stage showed T3 cancers were more common in emergency (p < 0.01).

CONCLUSIONS AND DISCUSSION

Mucinous and signet ring cell tumors are related to emergency presentation, pT3 stage, poorest outcomes, and survival. Disease-free survival in patients who had emergency surgery for T3 colon cancer seems related to the histotype.

Prognostic subdivision of ypT3 rectal tumours according to extension beyond the muscularis propria

Background

The subdivision of T3 in rectal carcinoma according to the depth of invasion into perirectal fat has been recommended in the TNM Supplement since 1993. This study assessed the prognostic impact of this pathological staging in tumours removed after neoadjuvant chemoradiotherapy (ypT3).

Methods

Data from patients with ypT3 rectal carcinoma (less than 12 cm from the anal verge) treated with neoadjuvant chemoradiation and total mesorectal excision were analysed. Tumour category ypT3 was subdivided into ypT3a (5 mm or less) and ypT3b (more than 5 mm), based on histological measurements of maximal tumour invasion beyond the outer border of the muscularis propria.

Results

Important differences between ypT3a (81 patients) and ypT3b (43) were found in 5-year rates of locoregional recurrence (7 versus 18 per cent; P = 0·049), distant metastasis (20 versus 41 per cent; P = 0·002), disease-free survival (73 versus 47 per cent; P = 0·001), overall survival (79 versus 74 per cent; P = 0·036) and cancer-related survival (81 versus 74 per cent; P = 0·007). In Cox regression analyses, the ypT3 subclassification was identified as an independent prognostic factor for disease-free (ypT3b: hazard ratio (HR) 2·13, 95 per cent confidence interval 1·16 to 3·89; P = 0·014), observed (ypT3b: HR 2·02, 1·05 to 3·87; P = 0·035) and cancer-related (ypT3b: HR 2·46, 1·20 to 5·04; P = 0·014) survival. Extramural venous invasion was found to be an additional prognostic factor, but the pathological node category after chemoradiotherapy (ypN) did not influence survival.

Conclusion

In ypT3 rectal carcinomas, the proposed subclassification is superior to ypN in predicting prognosis.

Transanal inside-out rectal resection for ultra-low rectal cancer

Two major issues encountered in the surgical resection of low rectal cancers (tumor located <6 cm from anal verge) are tumor-free surgical resection margin and adequate fields of colo-anal pull-through anastomosis. The clinical consequences of ensuring gross tumor-free surgical resection margin by transanal inside-out rectal resection technique were assessed for ultra-low rectal cancer patients. From February 2009 to September 2011, ultra-low anterior resection with a new method of eversion of the rectum through the anal canal after resecting the distal rectum and colo-anal anastomosis extracorporally performed in 30 patients (age range, 41-80 years) was reviewed. All patients received preoperative neoadjuvant concurrent chemoradiotherapy (CCRT) before the surgical resection. The median operating time was 265 min (range, 220-400 min), and the median intraoperative blood loss was 325 ml (range, 80-855 ml). No in-hospital mortality was noted among these patients. R0 resection (tumor-free margin range, 0.9-2.5 cm) was confirmed in all patients by pathologic reports, except one patient with 0.5 cm tumor-free margin. The new surgical technique of transanal inside-out rectal resection and colo-anal pull-through anastomosis for selected patients with ultra-low rectal cancers seems to be a safe and alternative procedure.