Risk factors for residual cancer and lymph node metastasis after noncurative endoscopic resection of early colorectal cancer

Long-term outcomes and lymph node metastasis following endoscopic resection with additional surgery or primary surgery for T1 colorectal cancer

Optimal management of T1 colorectal cancer (CRC) remains controversial. This study compared the long-term outcomes of endoscopic resection with additional surgical resection (ER + ASR) versus primary surgical resection (PS) in patients with T1 CRC and identified risk factors for lymph node metastasis (LNM). This retrospective cohort study included 373 patients with T1 CRC who underwent ER + ASR or PS between January 2010 and December 2020 at a tertiary center in Taiwan. Surgical and oncological outcomes, including recurrence rates, LNM, 5-year overall survival (OS), and 5-year recurrence-free survival (RFS) were compared. Univariate and multivariate analyses identified risk factors for LNM. No significant differences were observed between the ER + ASR and PS groups in surgical outcomes, recurrence rates, LNM, 5-year OS (93% vs. 89%, P = 0.18), or 5-year RFS (89% vs. 88%, P = 0.47). Patients with ≥ 2 high-risk factors had significantly lower 5-year OS and RFS compared to those with ≤ 1 risk factor (p < 0.01). Poor histology grade and lymphovascular invasion were independent risk factors for LNM. ER + ASR and PS had comparable long-term outcomes in patients with T1 CRC. A multidisciplinary approach and standardized protocols are required for optimal management of early-stage CRC.

Investigation of vertical margin involvement in endoscopic resection for T1 colorectal cancer

OBJECTIVES

The resection of vertical margin-negative submucosally invasive colorectal cancer (CRC) relies on the pathological risk assessment of lymph node metastasis. However, no large-scale study has clarified the endoscopic resection (ER) outcome for submucosally invasive CRC, focusing on the vertical margin status. This retrospective study aimed to examine vertical margin involvement in ER for submucosally invasive CRC and explore the treatment consequences associated with vertical margin status.

METHODS

We analyzed 395 submucosally invasive CRC cases in 389 patients who underwent ER at our hospital between 2008 and 2020. The presence of residual tumors and simultaneous lymph node metastasis in patients who underwent additional surgery was assessed and compared between the vertical incomplete ER and the vertical margin-negative groups.

RESULTS

Among the patients, 270 were men, with a median age of 69 years. The vertical incomplete ER rate was 21.5%, with positive vertical margins and unclear vertical margins identified in 12.2% and 9.3% of the cases, respectively. Among 154 patients who underwent additional surgery after ER, the vertical incomplete ER group had a significantly higher residual tumor rate than the vertical margin-negative group (P = 0.001). The vertical incomplete ER group had a significantly higher lymph node metastasis rate than the vertical margin-negative group (P = 0.029).

CONCLUSION

This study clarified the substantial risk of vertical incomplete ER in submucosally invasive CRC and revealed the high risk of residual tumor and lymph node metastasis in vertical incomplete ER for submucosal CRC.

Prognostic Factors for Lymph Node Metastases in pT1 Colorectal Cancer Differ According to Tumor Morphology: A Nationwide Cohort Study

OBJECTIVE

To investigate whether there is a differential impact of histopathological risk factors for lymph node metastases (LNM) in pedunculated and nonpedunculated pT1 colorectal cancers (CRC).

BACKGROUND

Tumor budding, lymphovascular invasion (LVI), and venous invasion (VI) are recognized risk factors for LNM in pT1 CRC. Whether the importance of these factors varies according to tumor morphology is unknown.

METHODS

Patients undergoing resection with lymphadenectomy for pT1 CRC in Denmark from January 2016 to January 2019 were identified in the Danish Colorectal Cancer Database and clinicopathological data was reviewed. Prognostic factors for LNM were investigated using multivariable analyses on the cohort as a whole as well as when stratifying according to tumor morphology (pedunculated vs. nonpedunculated).

RESULTS

A total of 1167 eligible patients were identified, of whom 170 had LNM (14.6%). Independent prognostic factors for LNM included LVI [odds ratio (OR)=4.26, P <0.001], VI (OR=3.42, P <0.001), tumor budding (OR=2.12, P =0.002), high tumor grade (OR=2.76, P =0.020), and age per additional year (OR=0.96, P <0.001). On subgroup analyses, LVI and VI remained independently prognostic for LNM regardless of tumor morphology. However, tumor budding was only prognostic for LNM in pedunculated tumors (OR=4.19, P <0.001), whereas age was only prognostic in nonpedunculated tumors (OR=0.61, P =0.003).

CONCLUSIONS

While LVI and LI were found to be prognostic of LNM in all pT1 CRC, the prognostic value of tumor budding differs between pedunculated and nonpedunculated tumors. Thus, tumor morphology should be taken into account when considering completion surgery in patients undergoing local excision.

Risk factors for vertical incomplete resection in endoscopic submucosal dissection of deep invasive submucosal colorectal cancer

INTRODUCTION

It has been recently reported that deep invasive submucosal (T1b) colorectal cancer (CRC) without other pathological risk factors for lymph node metastasis has a low rate of lymph node metastasis, increasing the possibility of endoscopic submucosal dissection (ESD) in the future. However, ESD for T1b CRC is technically difficult, and some lesions cannot be resected en bloc. This study aimed to identify the risk factors associated with vertical incomplete ESD in T1b CRC.

METHODS

We retrospectively studied 140 pathological T1b CRC lesions that underwent initial ESD at our institution between January 2011 and October 2020, and categorized them into positive vertical margin (PVM) and negative vertical margin (NVM) groups. The risk factors for PVM were examined using univariate and multivariate analyses, and a subgroup analysis for T1b CRC with an obvious depressed surface was performed.

RESULTS

Multivariate analysis revealed obvious depression (hazard ratio [HR]: 7.4; 95% confidence interval [CI]: 2.47-22.5) and severe fibrosis (HR: 11.4; 95% CI: 3.95-33.0) as significant risk factors for PVM. Length of depressed surface ≥12 mm (HR: 6.19; 95% CI: 1.56 -24.6) was identified as an independent predictor of PVM for T1b CRC with an obvious depression.

CONCLUSION

Pathological T1b CRC cases with an obvious depression and severe fibrosis are at a high risk of vertical incomplete ESD.

Patient outcomes after non-curative endoscopic submucosal dissection for early colorectal cancer: a single-center, retrospective cohort study

Background

The treatment patterns and outcomes for patients after non-curative endoscopic submucosal dissection (ESD) remain controversial, particularly among those requiring preservation of the anal sphincter or advanced age. This retrospective study aimed to investigate the treatment patterns and outcomes in patients after non-curative ESD for early colorectal cancer (CRC).

Methods

This was a retrospective review in Chinese patients who received non-curative ESD for early CRC, and who were treated in the Cancer Hospital at the Chinese Academy of Medical Sciences from 2010 to 2019. Demographic parameters, clinicopathologic features, treatment patterns, and clinical outcomes were analyzed.

Results

Of the 180 patients who received non-curative ESD, 85 received additional surgery; the remaining 95 patients were kept under surveillance only. Patients in the surveillance-only group tended to be older than those in the additional surgery group. Furthermore, tumors in the surveillance-only group were located in the rectum significantly more often, were better differentiated with a shallower depth of invasion and less perineuronal invasion than in the additional surgery group; there were fewer high-risk factors for residual cancer or lymph node (LN) metastasis in the surveillance-only group compared with the additional surgery group. There was no significant difference in 5-year overall survival (OS) (92.6% versus 92.7%, P=0.355), 5-year disease-free survival (DFS) (94.7% versus 91.9%, P=0.340), 5-year cancer-specific survival (CSS) (93.8% versus 92.7%, P=0.791), or total recurrence rates (4.7% versus 9.5%, P=0.217) between the additional surgery and surveillance-only groups, respectively.

Conclusions

ESD results in favorable outcomes for patients with early CRC. Surveillance in patients who receive non-curative ESD may be an alternative option for those with advanced age and fewer high-risk factors for residual cancer or LN metastasis.

Histopathological risk factors for lymph node metastases in T1 colorectal cancer: meta-analysis

BACKGROUND

National screening programmes increase the proportion of T1 colorectal cancers. Local excision may be possible, but the risk of lymph node metastases (LNMs) could jeopardize long-term outcomes. The aim of the present study was to review the association between histopathological findings and LNMs in T1 colorectal cancer.

METHODS

A systematic literature search was conducted using PubMed,Embase, and Cochrane online databases. Studies investigating the association between one or more histopathological factors and LNMs in patients who underwent resection for T1 colorectal cancer were included.

RESULTS

Sixteen observational studies were included in the meta-analysis, including a total of 10 181 patients, of whom 1 307 had LNMs. Lymphovascular invasion (odds ratio (OR) 7.42; P < 0.001), tumour budding (OR 4.00; P < 0.001), depth of submucosal invasion, whether measured as at least 1000 µm (OR 3.53; P < 0.001) or Sm2-3 (OR 2.12; P = 0.020), high tumour grade (OR 3.75; P < 0.001), polypoid growth pattern (OR 1.59; P = 0.040), and rectal location of tumour (OR 1.36; P = 0.003) were associated with LNMs.

CONCLUSION

Distinct histopathological factors associated with nodal metastases in T1 colorectal cancer can aid selection of patients for local excision or major excisional surgery.

Does Additional Laparoscopic-Assisted Surgery after Endoscopic Submucosal Dissection Affect Short Outcomes in Patients with Stage T1 Colorectal Cancer? A Propensity Score-Based Analysis

BACKGROUND

Additional surgery is necessary in cases with non-curative endoscopic submucosal dissection. It is still unknown whether preceding endoscopic submucosal dissection (ESD) for T1 colorectal carcinoma affects the short outcomes of patients who underwent additional surgery or not as compared with surgery alone without ESD.

METHODS

Patients (101 pairs) with T1 colorectal cancer who underwent additional laparoscopic-assisted surgery after endoscopic submucosal dissection (additional surgery group, n = 101) or laparoscopic-assisted surgery alone (surgery alone group, n = 101) were matched (1:1). Short-term morbidity, operation outcomes, and lymph node metastasis of the resected specimen were compared.

RESULTS

There were no significant differences between the additional laparoscopic-assisted surgery and laparoscopic-assisted surgery alone groups in lymph node metastasis (9.9 vs. 5.9%, respectively, p = 0.297), operative time (147.76 ± 52.00 min vs. 156.50 ± 54.28 min, p = 0.205), first flatus time (3.56 ± 1.10 days vs. 3.63 ± 1.05 days, p = 0.282), first stool time (4.30 ± 1.04 days vs. 4.39 ± 1.22 days, p = 0.293), time to intake (5.00 ± 1.18 days vs. 5.25 ± 1.39 days, p = 0.079), blood loss (44.75 ± 45.40 mL vs. 60.40 ± 78.98 mL, p = 0.603), harvest lymph nodes (18.74 ± 7.22 vs. 20.32 ± 9.69, p = 0.438), postoperative surgical complications (p = 0.733), and postoperative length of hospital stay (8.68 ± 4.00 days vs. 8.39 ± 1.94 days, p = 0.401).

CONCLUSION

ESD did not increase the difficulty of additional laparoscopic-assisted surgery, hospital stay, or the incidence of postoperative complications. Additional laparoscopic-assisted surgery is safe and recommended for patients with T1 cancer at high risk of lymph node metastasis and residual cancer after non-curative ESD.

Long-term outcomes and surveillance timing of patients with large non-pedunculated colorectal polyps with histologically incomplete resection in endoscopic resection

BACKGROUND

Histologically incomplete resection of large colorectal polyps is frequently encountered; however, the long-term outcomes or surveillance timing is not well known. We evaluated the incidence rate and time of recurrence of these cases during a long-term follow-up.

METHODS

We performed a retrospective analysis of patients who underwent endoscopic resection for large (≥10 mm in size) non-pedunculated colorectal polyps at a tertiary academic hospital. Patients who had positive or indeterminate lateral margin in the histology and underwent completed surveillance colonoscopy first at 3-12 months and finally at ≥2 years after initial resection were included.

RESULTS

Of 169 polyps (148 patients), 37 (21.9%) and 132 (78.1%) polyps had positive and indeterminate lateral margins, respectively. The median time intervals of the first and last surveillance from the initial resection were 6 (3-12) and 48 (24-114) months, respectively. The recurrence rate was 9.5% (16/169) during follow-up, and the mean time to recurrence was 31.9 months. Thirteen (81.3%) polyps recurred after ≥12 months. Most (14/16, 87.5%) recurrent polyps were benign, and 2 cases had advanced cancer. The only factor that was significantly associated with recurrence in the univariate and multivariate analyses was ≥3 piecemeal resections (odds ratio in the multivariate analysis, 16.92; 95% CI, 1.19-241.81; p = 0.037).

CONCLUSION

During the long-term follow-up, the only factor that was significantly associated with recurrence was ≥3 piecemeal resections, and most recurrences occurred after ≥12 months. Thus, a histologically incomplete resection with ≤2 piecemeal resections and no findings of suspected submucosal cancer may be considered as complete resection, and these patients may undergo first surveillance colonoscopy after 1-2 years.

Is Additional Surgery Necessary After Non-Curative Endoscopic Submucosal Dissection for Early Colorectal Cancer?

BACKGROUND

Although endoscopic submucosal dissection (ESD) is considered to be a curative treatment for early colorectal cancer, additional surgery with lymph node dissection is routinely recommended for patients treated in non-curative ESD, owing to the risk of residual cancer and lymph node metastasis (LNM). However, in clinical practice, few patients are found to have either residual cancer or LNM after additional surgery. Therefore, we conducted this study to determine the risk factors associated with residual cancer and LNM.

METHODS

Patients with early colorectal cancer after non-curative ESD and additional surgery from January 2015 to May 2019 were retrospectively identified. Clinicopathological characteristics were collected to determine the predictors of residual cancer and LNM.

RESULTS

A total of 62 patients were enrolled for analysis in this study. After additional surgery, residual cancer and LNM was detected in 12 patients (19.35%). Clinicopathological comparison of patients with the presence or absence of residual cancer and LNM demonstrated that piecemeal resection (80% vs. 14.04%, P < 0.001), submucosal invasion greater than 2000 μm (26.09% vs. 0%, P = 0.026), lymphovascular infiltration (37.5% vs. 13.04%, P = 0.033), and perineuronal invasion (75% vs. 15.52%, P = 0.004) were more frequent in residual cancer and LNM cases. Multivariate analysis identified lymphovascular infiltration (P = 0.031) as the only significantly independent risk factor associated with residual cancer and LNM.

CONCLUSIONS

Additional surgery with lymphadenectomy should be performed after non-curative ESD owing to the high risk of residual cancer and LNM, especially in cases with lymphovascular infiltration.

Clinical outcomes of positive resection margin after endoscopic mucosal resection of early colon cancers

BACKGROUND/AIMS

When determining the subsequent management after endoscopic resection of the early colon cancer (ECC), various factors including the margin status should be considered. This study assessed the subsequent management and outcomes of ECCs according to margin status.

METHODS

We examined the data of 223 ECCs treated by endoscopic mucosal resection (EMR) from 215 patients during 2004 to 2014, and all patients were followed-up at least for 2 years.

RESULTS

According to histological analyses, the margin statuses of all lesions after EMR were as follows: 138 cases (61.9%) were negative, 65 cases (29.1%) were positive for dysplastic cells on the resection margins, and 20 cases (8.9%) were uncertain. The decision regarding subsequent management was affected not only by pathologic outcomes but also by the endoscopist's opinion on whether complete resection was obtained. Surgery was preferred if the lesion extended to the submucosa (odds ratio [OR], 25.46; 95% confidence interval [CI], 7.09-91.42), the endoscopic resection was presumed incomplete (OR, 15.55; 95% CI, 4.28-56.56), or the lymph system was invaded (OR, 13.69; 95% CI, 1.76-106.57). Fourteen patients (6.2%) had residual or recurrent malignancies at the site of the previous ECC resection and were significantly associated with presumed incomplete endoscopic resection (OR, 4.59; 95% CI, 1.21-17.39) and submucosal invasion (OR, 5.14; 95% CI, 1.18-22.34).

CONCLUSIONS

Subsequent surgery was associated with submucosa invasion, lymphatic invasion, and cancer-positive margins. Presumed completeness of the resection may be helpful for guiding the subsequent management of patients who undergo endoscopic resection of ECC.

Association of Poor Differentiation or Positive Vertical Margin with Residual Disease in Patients with Subsequent Colectomy after Complete Macroscopic Endoscopic Resection of Early Colorectal Cancer

In the presence of unfavorable pathologic results after endoscopic resection of colorectal cancer, colectomy is routinely performed. We determined the risk factors for residual diseases in patients with colectomy after complete macroscopic endoscopic resection of early colorectal cancer. We identified consecutive patients who underwent endoscopic resection of early colorectal cancer and subsequently underwent colectomy, from January 2011 to December 2014. Clinicopathologic risk factors related to the residual disease were analyzed. In total, 148 patients underwent endoscopic resection and subsequent colectomy. Residual disease on colectomy was noted in 16 (10.9%) patients. The rates of poorly differentiated/mucinous histology (p = 0.028) and of positive or unknown vertical resection margin (p = 0.047) were higher in patients with residual disease than in those without. In multivariate analysis, a poorly differentiated/mucinous histology and positive or unknown vertical resection margin were significantly associated with residual disease (odds ratio = 7.508 and 2.048, p = 0.015 and 0.049, resp.). After complete macroscopic endoscopic resection of early colorectal cancer, there is a greater need for additional colectomy in cases with a positive or unknown vertical resection margin or a poorly differentiated/mucinous histology, because of their higher risk of residual cancer and lymph node metastasis.

Tumor Budding Detection by Immunohistochemical Staining is Not Superior to Hematoxylin and Eosin Staining for Predicting Lymph Node Metastasis in pT1 Colorectal Cancer

BACKGROUND

Tumor budding is recognized as an important risk factor for lymph node metastasis in pT1 colorectal cancer. Immunohistochemical staining for cytokeratin has the potential to improve the objective diagnosis of tumor budding over detection based on hematoxylin and eosin staining. However, it remains unclear whether tumor budding detected by immunohistochemical staining is a significant predictor of lymph node metastasis in pT1 colorectal cancer.

OBJECTIVE

The purpose of this study was to clarify the clinical significance of tumor budding detected by immunohistochemical staining in comparison with that detected by hematoxylin and eosin staining.

DESIGN

This was a retrospective study.

SETTINGS

The study was conducted at Niigata University Medical & Dental Hospital.

PATIENTS

We enrolled 265 patients with pT1 colorectal cancer who underwent surgery with lymph node dissection.

MAIN OUTCOME MEASURES

Tumor budding was evaluated by both hematoxylin and eosin and immunohistochemical staining with the use of CAM5.2 antibody. Receiver operating characteristic curve analyses were conducted to determine the optimal cutoff values for tumor budding detected by hematoxylin and eosin and CAM5.2 staining. Univariate and multivariate analyses were performed to identify the significant factors for predicting lymph node metastasis.

RESULTS

Receiver operating characteristic curve analyses revealed that the cutoff values for tumor budding detected by hematoxylin and eosin and CAM5.2 staining for predicting lymph node metastases were 5 and 8. On multivariate analysis, histopathological differentiation (OR, 6.21; 95% CI, 1.16-33.33; p = 0.03) and tumor budding detected by hematoxylin and eosin staining (OR, 4.91; 95% CI, 1.64-14.66; p = 0.004) were significant predictors for lymph node metastasis; however, tumor budding detected by CAM5.2 staining was not a significant predictor.

LIMITATIONS

This study was limited by potential selection bias because surgically resected specimens were collected instead of endoscopically resected specimens.

CONCLUSIONS

Tumor budding detected by CAM5.2 staining was not superior to hematoxylin and eosin staining for predicting lymph node metastasis in pT1 colorectal cancer.

Management of colorectal T1 carcinoma treated by endoscopic resection from the Western perspective

Detection of early colorectal cancer is expected to rise in light of national colorectal cancer screening programs. This The present review article delineates current endoscopic risk assessments, differentiating invasive from non-invasive neoplasia, for high likelihood of lymph node metastasis in early colorectal cancer, also termed high-risk early colorectal cancer, and endoscopic and surgical resection methods from a Western hemisphere perspective.

High nuclear expression of protein arginine methyltransferase-5 is a potentially useful marker to estimate submucosal invasion in endoscopically resected early colorectal carcinoma

Protein arginine methyltransferase-5 (PRMT5), a major type II arginine methyltransferase, is an important epigenetic modifier with oncogene-like properties because of its ability to repress the expression of tumor suppressor genes. We determined the correlations between PRMT5 expression or its cellular localization and malignant progression, with special reference to invasiveness, in colorectal adenomas and early colorectal carcinomas (CRCs). We performed immunohistochemical detection of PRMT5 in 108 endoscopically resected tissue samples (6 adenomas with low-grade dysplasia, 34 adenomas with high-grade dysplasia, 30 intramucosal carcinomas, and 38 submucosal invasive carcinomas). Early CRC (55 of 68, 80.9%) showed more frequent nuclear expression of PRMT5 than adenoma (15 of 40, 37.5%) (P < 0.001). Furthermore, high (strong staining in ≥ 50% of nuclei) nuclear expression of PRMT5 was more common in submucosal invasive carcinoma (21 of 38, 55.3%) than in intramucosal carcinoma (9 of 30, 30.0%) (P = 0.037). In conclusion, our data suggests that high nuclear expression of PRMT5 is a potentially useful marker for estimating submucosal invasion of early CRC in endoscopically resected specimens.

The management of malignant polyps in colorectal cancer screening programmes: A retrospective Italian multi-centre study

BACKGROUND

Although recognition of colorectal malignant polyps is increasing, treatment plans lack the evidence of randomised trials.

AIM

To retrospectively evaluate presentation, management and outcomes of screen-detected colorectal malignant polyps, with special focus on the role of histological factors in therapeutic decision-making.

METHODS

We retrospectively analysed data regarding malignant polyps detected during faecal immuno-chemical test-based screening programmes in five centres in North-Eastern Italy between April 2008 and April 2013.

RESULTS

306 malignant polyps in 306 patients were included; 72 patients underwent surgery directly (23.6%). Of 234 patients treated endoscopically, 133 subsequently underwent radicalisation surgery (56.8%) and in 17 there was evidence of residual disease (12.8%). Involved, unsafe (<1mm) or invaluable resection margins and sessile morphology represented the most frequent determinants of subsequent surgery. The mean number of nodes harvested during radicalisation surgery was 7.1±6.4 (range 0-29). Histological diagnosis was re-evaluated according to new guidelines in 125 cases (41%); in 18 this led to modification of the risk class (14.4%).

CONCLUSIONS

Although the rate of surgical treatment following endoscopic resection is similar to other studies, residual disease at surgery was lower than most international series. Adhering to the new histological reporting system and respecting guidelines on node harvesting may favourably influence prognosis.

Relationship between indeterminate or positive lateral margin and local recurrence after endoscopic resection of colorectal polyps

BACKGROUND AND STUDY AIMS

Although endoscopic resection is widely used for the treatment of superficial colorectal neoplasms, the rate of local recurrence of lesions with a positive or indeterminate lateral margin on histologic evaluation is unclear. We aimed to demonstrate the relationship between lateral margin status and local recurrence after the endoscopic resection of intramucosal colorectal neoplasms.

PATIENTS AND METHODS

We retrospectively collected the clinical and pathologic data for 844 endoscopically resected colorectal intramucosal neoplasms with a size of 10 mm or larger. We investigated the relationship between the local recurrence rate and the lateral margin status (categorized as LM0 [negative], LM1 [positive], or LMX [indeterminate]).

RESULTS

In total, 389 lesions were evaluated as LM0 and showed no local recurrence. Of the 455 lesions evaluated as LMX or LM1, 30 showed local recurrence within a median period of 6.3 months (range, 1.7 - 48.1) from the initial endoscopic resection. The local recurrence rate of the en bloc-LMX group (2.2 %) was significantly lower than that of the piecemeal-LMX group (15.2 %). Of the 30 cases of recurrence, 28 were successfully treated with a second endoscopic resection. Of the two lesions that showed further recurrence, one was treated with a third endoscopic resection, whereas the other - which was a piecemeal-LMX lesion - was eventually diagnosed as invasive cancer and treated with surgery.

CONCLUSIONS

The local recurrence rate was lower in the en bloc-LMX group than in the piecemeal-LMX group. Thus, we believe that en bloc-LMX lesions that are completely and confidently resected endoscopically can be treated as en bloc-LM0 lesions.

Early stage colon cancer

Evidence has now accumulated that colonoscopy and removal of polyps, especially during screening and surveillance programs, is effective in overall risk reduction for colon cancer. After resection of malignant pedunculated colon polyps or early stage colon cancers, long-term repeated surveillance programs can also lead to detection and removal of asymptomatic high risk advanced adenomas and new early stage metachronous cancers. Early stage colon cancer can be defined as disease that appears to have been completely resected with no subsequent evidence of involvement of adjacent organs, lymph nodes or distant sites. This differs from the clinical setting of an apparent “curative” resection later pathologically upstaged following detection of malignant cells extending into adjacent organs, peritoneum, lymph nodes or other distant sites, including liver. This highly selected early stage colon cancer group remains at high risk for subsequent colon polyps and metachronous colon cancer. Precise staging is important, not only for assessing the need for adjuvant chemotherapy, but also for patient selection for continued surveillance. With advanced stages of colon cancer and a more guarded outlook, repeated surveillance should be limited. In future, novel imaging technologies (e.g., confocal endomicroscopy), coupled with increased pathological recognition of high risk markers for lymph node involvement (e.g., “tumor budding”) should lead to improved staging and clinical care.

Transanal endoscopic microsurgery after endoscopic resection of malignant rectal polyps: a useful technique for indication to radical treatment

BACKGROUND

Management of malignant rectal polyps (MRPs) after endoscopic polypectomy (EP) is still debated. It is sometimes difficult to decide whether to simply follow-up (FU) or to treat such a removed lesion. Transanal endoscopic microsurgery (TEM) could have a role both in T staging and in treating MRPs after EP.

METHODS

Patients who underwent a full-thickness TEM within 3 months after an EP between January 2008 and October 2012 were retrospectively analyzed. If post-TEM histology showed locally advanced rectal cancer, patients underwent a total mesorectal excision (TME) within 4-6 weeks. Patients without malignant disease or pT1sm1 cancers at post-TEM histology were followed up every 3 months for 2 years with clinical examination, flexible rectal endoscopy, and neoplastic markers monitoring.

RESULTS

A total of 39 patients were included. Post-EP histology was adenocarcinoma in 27/39 cases (69.2 %) and adenoma in 12/39. Mean operative time was 64.2 min; no 30-day mortality occurred; 30-day morbidity was 2.7 % (rectal bleeding in 1/39 cases). Post-TEM histology showed a T2 cancer in 5/39 patients, four with and one without a previous cancer diagnosis, who were further treated by TME (four RARs and one APR) and are disease free with a mean FU of 24.2 months. Post-TEM histology showed adenoma in 10/39 cases and fibrosis in 24/39. These patients are disease free with a mean FU of 13 months.

CONCLUSIONS

A full-thickness TEM after EP of MRPs can establish the presence of residual malignant disease and its depth of invasion, precisely defining the indication to TME. In event of benign post-EP histology, TEM must be performed in presence of macroscopic residual disease, in order to obtain an RO resection and finally exclude cancer, while, in absence of macroscopic residual disease, only close FU is required.