Phantom publications among applicants to a colorectal surgery residency program

Management after local excision of small rectal cancers. Indications for completion total mesorectal excision and possible alternatives

The treatment of superficial rectal cancers (local excision, or proctectomy with total mesorectal excision (TME) remains controversial. Endoscopy and endorectal ultrasonography are essential for the precise initial definition of these small cancers. During endoscopy, the depth of the lesion can be estimated using virtual chromoendoscopy with magnification, thereby aiding the assessment of the possibilities of local excision. Current international recommendations indicate completion proctectomy after wide local excision for cases where the pathologic examination reveals poorly-differentiated lesions, lymphovascular invasion, grade 2 or 3 tumor budding, and incomplete resection. But debate persists regarding whether the depth of submucosal invasion can accurately predict the risk of lymph node spread. Recent data from the literature suggest that the depth of submucosal invasion should no longer, by itself, be an indication for additional oncological surgery. Adjuvant radio-chemotherapy could be an alternative to completion proctectomy in patients with pT1 rectal cancer and unfavorable histopathological criteria. A Dutch randomized controlled trial is underway to validate this strategy.

Are the width, length, depth, and area of submucosal invasion predictive of lymph node metastasis in pT1 colorectal cancer?

PURPOSE

Submucosa-limited (pathological T1, pT1) colorectal cancers (CRCs) pose a continuing challenge in the choice of treatment options, which range from local excision to radical surgery. The aim of this study was to evaluate the morphometric and morphologic risk factors associated with regional lymph node metastasis (LNM) in pT1 CRC.

METHODS

We performed a histological review of patients who underwent oncological resection between 2016 and 2022. Tumor grade, budding, poorly differentiated clusters (PDCs), cancer gland rupture, lymphovascular invasion (LVI), and presence of deep submucosal invasion (DSI), as well as width, length, total area, and area of DSI, were evaluated as potential risk factors for LNM.

RESULTS

A total of 264 cases of colon and rectal carcinomas with invasion into the submucosal layer (pT1) were identified. LNM was found in 46 of the 264 cases (17.4%). All morphometric parameters, as well as DSI (P=0.330), showed no significant association with LNM. High grade adenocarcinoma (P=0.050), budding (P=0.056), and PDCs (P<0.001) were associated with LNM. In the multivariate analysis, LVI presence remained the only significant independent risk factor (odds ratio, 15.7; 95% confidence interval, 8.5-94.9; P<0.001).

CONCLUSION

The DSI of T1 CRC, as well as other morphometric parameters of submucosal tumor spread, held no predictive value in terms of LNM. LVI was the only independent risk factor of LNM.

Fibroblast Activation Protein-α (FAP) Identifies Stromal Invasion in Colorectal Neoplasia

The increasing detection of colorectal adenomas and early adenocarcinomas (ADCs) in the context of nationwide screening programs has led to a significant increase in the incidence of inconclusive diagnoses in which histopathologic analysis of endoscopic biopsies does not allow pathologists to provide a reliable diagnosis of stromal invasion. The objective of this study was to analyze the discriminative capacity of the immunohistochemical expression of fibroblast activation protein-α (FAP) in distinguishing colorectal adenomas with low-grade dysplasia (LGD) and high-grade dysplasia (HGD) from invasive intestinal-type ADCs. The study analyzed the first endoscopic biopsies from a series of patients classified as inconclusive or conclusive for stromal invasion based on the pathologic report. In total, 30 ADCs, 52 HGDs, and 15 LGDs were included in the study. FAP expression was detected in 23/30 ADCs and was negative in all adenomas with either LGD or HGD features (100% specificity and 76.7% sensitivity, area under the curve=0.883, CI=0.79-0.98). Considering these findings, we conclude that FAP is a potentially useful tool for helping pathologists identify invasive lesions in colorectal endoscopic biopsies, avoiding unnecessary biopsy repetitions.

Diagnostic yield and repeat biopsies in rectal and nonrectal colorectal adenocarcinoma: Are we hedging on rectal biopsies?

Patients with rectal cancer undergo more repeat biopsies compared to those with nonrectal colon cancer prior to management. We investigated the factors driving the higher frequency of repeat biopsies in patients with rectal cancer. We compared clinicopathologic features of diagnostic and nondiagnostic (in regard to invasion) rectal (n = 64) and colonic (n = 57) biopsies from colorectal cancer patients and characterized corresponding resections. Despite similar diagnostic yield, repeat biopsy was more common in rectal carcinoma, especially in patients receiving neoadjuvant therapy (p < 0.05). The presence of desmoplasia (odds ratio 12.9, p < 0.05) was a strong predictor of making a diagnosis of invasion in both rectal and nonrectal colon cancer biopsies. Diagnostic biopsies had more desmoplasia, intramucosal carcinoma component and marked inflammation, and less low-grade dysplasia component (p < 0.05). Diagnostic yield of biopsy was higher for tumors with high-grade tumor budding, mucosal involvement by high-grade dysplasia/intramucosal carcinoma without low-grade dysplasia and diffuse surface desmoplasia irrespective of tumor location. Sample size, amount of benign tissue, appearance, and T stage did not affect diagnostic yield. Repeat biopsy of rectal cancer is primarily driven by management implications. Diagnostic yield in colorectal cancer biopsies is multifactorial and is not due to differing pathologists' diagnostic approach per tumor site. For rectal tumors, a multidisciplinary strategic approach is warranted to avoid repeat biopsy when unnecessary.

Long-term prognosis of curative endoscopic submucosal dissection for early colorectal cancer according to submucosal invasion: a multicenter cohort study

Background

Endoscopic submucosal dissection (ESD) can provide a high en bloc resection rate and has been widely applied as curative treatment for early colorectal cancer (ECC). However, surgical treatment is occasionally required, and reports on the long-term prognosis of ESD are insufficient. This study aimed to investigate the long-term outcomes of ECC removal by ESD, including local recurrence and metastasis.

Methods

This multicenter study was conducted retrospectively on 450 consecutive patients with ECC who were treated with ESD between November 2003 and December 2013. Clinical, pathological, and endoscopic data were collected to determine tumor depth, resection margin, lymphovascular invasion, and recurrence.

Results

The median follow-up period was 53.8 (12–138 months). The en bloc resection rate was 85.3% (384) and in intramucosal cancer being 84.1% and in superficial submucosal invasion (SM1) cancer being 89.8% (p = 0.158). The curative resection rate was 76.0% (n = 342), and there was no statistical difference between the two groups (77.3% vs. 71.4%, p = 0.231). The overall recurrence free survival rate (RFS) was 98.7% (444/450). In patients with curative resection, there was no statistically significant difference in RFS according to invasion depth (intramucosal: 99.3% vs. SM1: 97.1%, p = 0.248).

Conclusions

Patients with curatively resected ECC treated with ESD showed favorable long-term outcomes. Curatively resected SM1 cancer has a RFS similar to that of intramucosal cancer.

Publication misrepresentation among pediatric anesthesiology fellowship applicants: A retrospective single-center cohort study

BACKGROUND

Many medical specialties have found publication misrepresentation in residency and fellowship applications, but pediatric anesthesia fellowship application data is lacking.

AIMS

We sought to determine the prevalence of publication misrepresentation among pediatric anesthesia fellowship applications.

METHODS

In this retrospective cohort study, fellowship applications to Stanford University's pediatric anesthesiology fellowship program from 2009 to 2019 were reviewed. Only peer-reviewed journal articles listed as accepted or published were included. Nine additional variables were collected: applicant age, gender, citizenship status, American vs. international medical school, public vs. private medical school, allopathic doctor versus osteopathic doctor, number of years between college and medical school, additional degrees, and application year. The primary outcome was the rate of publication misrepresentation, defined as peer-reviewed journal citations listed on the application that could not be verified or on which the applicant was not listed as an author. Secondary outcomes were the associations between publication misrepresentation and the additional collected variables.

RESULTS

1280 peer-reviewed journal publications from 877 applicants were reviewed. 3.4% of all citations listed as peer-reviewed journal articles were misrepresented and 9.0% of all applicants with at least 1 publication had ≥1 misrepresented publications. 30.2% of publications labelled "misrepresented" were located in our search of databases but did not have the applicant as an author, and 69.8% could not be located using the search databases. Only one of the 9 collected variables (public vs private medical school) was significantly associated with publication misrepresentation.

CONCLUSIONS

In this single-center retrospective study, publication misrepresentation was found to occur in one out of 11 pediatric anesthesia fellowship applications with at least one publication. Since residency and fellowship applicant publications may be heavily weighted during the application process, programs may want to include additional inquiries into the accuracy of applicant publications.

The risk of lymph node metastasis in T1 colorectal cancer: new parameters to assess the degree of submucosal invasion

PURPOSE

In T1 colorectal cancer, the depth is the main factor assessing the degree of submucosal invasion (DSI) to predict the risk of lymph node metastasis (LNM). The width (WSI) and the area of submucosal invasion (ASI) have been suggested as additional parameters to assess the risk of LNM. A review of the literature was undertaken on the correlation between WSI and ASI parameters and the incidence of LNM.

METHODS

A Medline, PubMed, and Cochrane Library search was performed to retrieve all studies reporting correlation between WSI/ASI and risk of LNM in T1 colorectal cancer.

RESULTS

Eight studies including 1727 patients were identified. All considered the degree of WSI and its influence on LNM: seven assessed different width cut-off of submucosal invasion, and one study the mean width of submucosal invasion in patients having or not involved lymph nodes. The WSI was significantly a prognostic factor for LNM (p < 0.05) in four studies. Both 2 and 3 mm seem to be the most discriminatory cut-off values of submucosal width invasion in defining the risk difference of LNM above and below the cut-off (2 mm, OR = infinite; 3 mm, OR = 6.9). Patients having a cut-off ≤ 5 mm of WSI showed a low risk (5.6%) of LNM rendering radical surgery unnecessary. Four studies assessed the risk of LNM according to the involved submucosal area (width × depth). In two of these, the ASI was a significant prognostic factor for LNM (p < 0.05).

CONCLUSION

The WSI and ASI seem to be reliable prognostic factors for LNM in T1 colorectal cancer. There is no agreement on ideal cut-off value.

Nonsurgical Management Following Local Resection for Early Rectal Cancer in Patients with High-risk Factors: A Single-institute Experience

Objective

Additional surgery is considered for patients at high risk for lymph node metastasis (LNM) after local resection for early rectal cancer. Several factors are considered as indications for additional surgery, although there are currently no definitive criteria. This study aimed to clarify the need for additional surgery based on the number of risk factors for LNM and to evaluate the significance of submucosal invasion on recurrence.

Methods

Patients with early rectal cancer harboring risk factors for LNM who underwent local resection between March 2005 and December 2016 were retrospectively analyzed. Associations among the number of risk factors, prognosis, and additional treatment after local resection were investigated.

Results

A total of 29 eligible patients were classified into the surgery (n = 10), chemoradiotherapy (n = 7), and no-additional-treatment (NAT, n = 12) groups. Among the 29 patients, 15 patients (52%) with only one risk factor did not relapse. The NAT group harbored fewer risk factors for LNM, and 8 of the 12 patients (67%) had only deep submucosal invasion. Local recurrence occurred in one patient in the chemoradiotherapy group. The estimated 5-year overall survival rates were 88.9%, 75.0%, and 81.5% in the surgery, chemoradiotherapy, and NAT groups, respectively. There were no disease-specific deaths in the overall cohort.

Conclusions

In the present study, no recurrence occurred in patients who did not receive additional surgery with deep submucosal invasion as the only risk factor. A multicenter investigation is necessary to confirm the safety of nonsurgical options.

Relationship Between Scholarly Activity and Postgraduate Career Choice: A Bibliometric Analysis of the 2017 Diplomates of the American Board of Dermatology

BACKGROUND

Scholarly productivity is an assessment metric for dermatology residents and faculty. How the bibliometric h-index, a publicly available metric that incorporates the quantity and quality of publications, relates to early career choices of dermatologists has not been investigated.

OBJECTIVE

We determined the h-indices of the 2017 diplomates of the American Board of Dermatology to ascertain its association with career choice.

METHODS

A cross-sectional analysis was performed using the published list of the 2017 diplomates. Gender and PhD status were compiled. The Scopus database was queried for publications and h-indices. The primary outcome was the pursuit of an academic position, nonacademic position, or fellowship after board certification.

RESULTS

Among 475 (96%) diplomates, the median (range) h-index was 2 (0-14). Those with MD and PhD degrees had greater h-indices (6.4 ± 3.1 vs. 2.3 ± 2.3, P < .05). There was a difference (P < .05) in h-index between diplomates pursuing an academic position (3.6 ± 3.1), non-procedural fellowship (3.3 ± 3.1), procedural fellowship (2.5 ± 2.0), and non-academic position (2.1 ± 2.1).

CONCLUSIONS

The h-index quantifies academic productivity and may predict early career choices in dermatology.

Synchronous nodal metastatic risk in screening detected and endoscopically removed pT1 colorectal cancers

BACKGROUND

The population screening campaigns have resulted in increasing the prevalence of endoscopically resected colorectal cancers (CRCs) invading the submucosa (pT1). Synchronous nodal involvement occurs in less than 15 % of these tumors. Histologic criteria currently used for selecting patients needing resection are imprecise and most patients could have been simply followed-up. Tumor infiltrating lymphocytes (TILs) and mismatch repair (MMR) status impact on CRC prognosis. To identify patients requiring completion surgery, the value of histologic variables, TILs and MMR status as risk factors of nodal metastasis was investigated in screening detected and endoscopically removed pT1 CRCs.

METHODS

In 102 endoscopically resected pT1 CRCs, the cancer phenotype, CD3+ and CD8+ TILs, and MMR status were assessed. Univariate and multivariate analyses were used to evaluate the correlation with nodal metastasis.

RESULTS

Positive resection margin, evidence of vascular invasion and tumor budding, wide area of submucosal invasion, and high number of CD3+ TILs were associated with nodal metastasis in univariate analyses. Vascular invasion was statistically independent in multivariate analysis. Evidence of neoplastic cells in the vessels and/or at the excision border featured 5 out of 5 metastatic tumors and 13 out of 97 non-metastatic ones.

CONCLUSIONS

Completion surgery should be recommended only in pT1 CRC with vascular invasion or with tumor cells reaching the margin. In all other cases, the treatment choice should result from a multidisciplinary discussion on the patient-centered evaluation of the risk-benefit ratio.

Lymphovascular Infiltration, Not Depth of Invasion, is the Critical Risk Factor of Metastases in Early Colorectal Cancer: Retrospective Population-based Cohort Study on Prospectively Collected Data, Including Validation

OBJECTIVE

To identify clinical and histopathological risk factors of LNM in T1 CRC.

SUMMARY OF BACKGROUND DATA

The requisite of additional surgery after locally resected T1 CRC is dependent on the risk of LNM. Depth of submucosal invasion is used as a key predictor of lymphatic metastases although data are conflicting on its actual impact.

METHODS

Retrospective population-based cohort study on prospectively collected data on all patients with T1 CRC undergoing surgical resection in Sweden, 2009-2017 and Denmark 2016-2018. The Danish cohort was used for validation. Potential risk factors of LNM investigated were; age, sex, tumor location, submucosal invasion, grade of differentiation, mucinous subtype, lymphovascular, and perineural invasion.

RESULTS

One hundred fifty out of the 1439 included patients (10%) had LNM. LVI (P < 0.001), perineural invasion (P < 0.001), mucinous subtype (P = 0.006), and age <60 years (P < 0.001) were identified as independent risk factors whereas deep submucosal invasion was only a dependent (P = 0.025) risk factor and not significant in multivariate analysis (P = 0.075). The incidence of LNM was 51/882 (6%) in absence of the independent risk factors. The Danish validation cohort, confirmed our findings regarding the role of submucosal invasion, LVI, and age.

CONCLUSIONS

This is a large study on LNM in T1 CRC, including validation, showing that LVI and perineural invasion, mucinous subtype, and low age constitute independent risk factors, whereas depth of submucosal invasion is not an independent risk factor of LNM. Thus, our findings provide a useful basis for management of patients after local excision of early CRC.

Lymphatic network remodeling after small bowel resection

BACKGROUND

Short gut syndrome (SGS) following massive small bowel resection (SBR) is a major cause of pediatric mortality and morbidity secondary to nutritional deficiencies and the sequelae of chronic total parenteral nutrition use, including liver steatosis. Despite the importance of lymphatic vasculature in fat absorption, lymphatic response after SBR has not been studied. We hypothesize that lymphatic vessel integrity is compromised in SGS, potentially contributing to the development of impaired lipid transport leading to liver steatosis and metabolic disease.

METHODS

Mice underwent 50% proximal SBR or sham operations. Imaging of lymphatic vasculature in the lamina propria and mesentery was compared between sham and SBR Prox1 ERCre-Rosa26^LSLTdTomato mice. mRNA expression levels of lymphangiogenic markers were performed in C57BL/6J mice.

RESULTS

Lymphatic vasculature was significantly altered after SBR. Mesenteric lymphatic collecting vessels developed new branching structures and lacked normal valves at branch points, while total mucosal lymphatic capillary area in the distal ileum decreased compared to both sham and intraoperative controls. Intestinal Vegfr3 expression also increased significantly in resected mice.

CONCLUSIONS

Intestinal lymphatics, in both the lamina propria and mesentery, dramatically remodel following SBR. This remodeling may affect lymphatic flow and function, potentially contributing to morbidities and nutritional deficiencies associated with SGS.

Long-term prognosis after treatment for T1 carcinoma of laterally spreading tumors: a multicenter retrospective study

PURPOSE

Long-term prognosis of T1 laterally spreading tumors (LSTs) after treatment have not been clarified. This study compared clinicopathological characteristics and long-term prognosis of T1 LSTs.

METHODS

We retrospectively assessed 169 patients with 169 T1 LSTs between January 1992 and December 2008 by ten hospitals. Patients who did not meet the Japanese Society for Cancer of the Colon and Rectum (JSCCR) 2016 guidelines for the treatment of colorectal carcinoma (CRC) criteria were defined as non-endoscopically curable. The number of non-endoscopically curable patients with LST-granular/ nodular mixed (LST-G-M) was 61, that with LST-non-granular/ flat elevated (LST-NG-FE) was 23, and that with LST-non-granular/ pseudo depressed (LST-NG-PD) was 23. Clinicopathological variables and long-term prognosis were analyzed.

RESULTS

For overall patients, tumor size, number of non-endoscopically curable cases, and rate of submucosal invasion depth ≥ 1000 μm for the LST-G-M group were significantly higher than those in the other groups. For non-endoscopically curable patients, the tumor size for those with LST-G-M was significantly larger than those in the other groups. The rate of submucosal invasion width ≥ 4000 μm and type B/C muscularis mucosae with LST-G-M was higher than that with LST-NG-FE. All recurrences occurred in non-endoscopically curable patients with LST-G-M. Five-year overall and disease-free survivals for non-endoscopically curable patients with LST-G-M were significantly shorter than those for patients with non-endoscopically curable LST-NG-FE and PD.

CONCLUSIONS

Our data supported adequacy of the JSCCR guidelines for the treatment of CRC criteria for endoscopically curable patients after T1 LSTs treatment. Patients with T1 LST-G-M should be followed up more carefully.

Endoscopic full-thickness resection for T1 early rectal cancer: a case series and video report

BACKGROUND AND STUDY AIMS

 Endoscopic treatment of malignant colorectal polyps is often challenging, especially for early rectal cancer (ERC) localized close to the dentate line. Conversely, the surgical approach may result in temporary or definitive stoma and in frequent post-surgical complications. The Full-Thickness Resection Device (FTRD ^® ) System (Ovesco Endoscopy, Tübingen, Germany) is a novel system that, besides having other indications, appears to be promising for wall-thickness excision of intestinal T1 carcinoma following incomplete endoscopic resection. However, follow-up data on patients treated with this device are scarce, particularly for ERC.

PATIENTS AND METHODS

 Six consecutive patients with incomplete endoscopic resection of T1-ERC were treated with the FTRD and their long-term outcomes were evaluated based on a detailed clinical and instrumental assessment.

RESULTS

 The endoscopic en bloc full-thickness resection was technically feasible in all patients. The histopathologic analysis showed a complete endoscopic resection in all cases, and a full-thickness excision in four. Neither complications, nor disease recurrence were observed during the 1-year follow-up period.

CONCLUSIONS

 The FTRD System is a promising tool for treating ERC featuring a residual risk of disease recurrence after incomplete endoscopic mucosal resection in patients unfit for surgery or refusing a surgical approach.

Histopathologic risk factors for lymph node metastasis in patients with T1 colorectal cancer

PURPOSE

Evaluating the risk of lymph node metastasis (LNM) is critical for determining subsequent treatments following endoscopic resection of T1 colorectal cancer (CRC). This study analyzed histopathologic risk factors for LNM in patients with T1 CRC.

METHODS

This study involved 745 patients with T1 CRC who underwent endoscopic (n = 97) or surgical (n = 648) resection between January 2001 and December 2015 at the National Cancer Center, Korea. LNM in endoscopically resected patients, which could not be evaluated directly, was estimated indirectly based on follow-up results and histopathologic reports of salvage surgery. The relationships of depth of submucosal invasion, histologic grade, budding, vascular invasion, and background adenoma with LNM were evaluated statistically.

RESULTS

Of the 745 patients, 91 (12.2%) were found to be positive for LNM. Univariate and multivariate analyses identified deep submucosal invasion (P = 0.010), histologic high grade (P < 0.001), budding (P = 0.034), and vascular invasion (P < 0.001) as risk factors for LNM. Among the patients with one, two, three, and four risk factors, 6.0%, 18.7%, 36.4%, and 100%, respectively, were positive for LNM.

CONCLUSION

Deep submucosal invasion, histologic high grade, budding, and vascular invasion are risk factors for LNM in patients with T1 colorectal cancer. If any of these risk factors are present, additional surgery following endoscopic resection should be determined after considering the potential risk of LNM and each patient's situation.

Utility of the sentinel node concept for detection of lateral pelvic lymph node metastasis in lower rectal cancer

Background

There are two lymphatic flows in lower rectal cancer; one along the inferior mesenteric artery and another towards the internal iliac artery. The benefit of dissection of lateral pelvic (LP) lymph nodes (LPLN) remains controversial. This study aimed to clarify the possibility of detecting the sentinel node (SN) of the LP region (LPSN) and examine metastasis, including micrometastasis, using a radio isotope (RI) method.

Methods

In total, 62 patients with clinical (c)T1-T4 rectal cancer were enrolled in this study (11, 16 and 35 patients had tumor located in the upper, middle and lower rectal third, respectively). LPSNs were detected using a radio-isotope method in which 99 m technetium-tin colloid was endoscopically injected into the submucosa in patients with cT1, and into the muscularis propria in patients with cT2, cT3 and cT4. All patients underwent curative resection with lymphadenectomy. LPSN metastases were diagnosed by HE staining, immunohistochemical staining using AE1/AE3 as a primary antibody and by RT-PCR using CEA as a marker.

Results

Of the lower rectal (c)T2–4 tumors, 38.4% had lateral pelvic lymphatic flow that was significantly greater than that of cT1 tumors in the upper and middle thirds of the rectum (p = 0.0074). HE and immunohistochemical staining did not detect LPSN metastases but RT-PCR detected micrometastasis of three SNs. The remaining half of LPSNs were immunohistochemically re-examined; in all three cases, isolated tumor cells were detected.

Conclusion

The SN concept may be useful for detecting lateral pelvic lymphatic flow and LPSN metastases, including micrometastasis in lower rectal cancer.

Small colorectal cancers resembling submucosal tumor with massive submucosal invasion and lymph node metastasis: A report of two cases and review of the literature

Colorectal cancer resembling submucosal tumor (SMT) is very rare. We herein report two cases of small colon carcinoma resembling SMT (80-year-old female and 67-year-old male), which massively invaded into the submucosal layer and accompanied marked lymphatic invasion and lymph node metastasis. We also reviewed the reported cases of colorectal carcinoma resembling SMT (SMT-like group, n=70) and analyzed the clinicopathological characteristics of this group compared with typical colorectal carcinoma cases operated at our institution (control group, n=1723). Tumors in the SMT-like group were significantly smaller in size compared with the control group; the median diameter measured 22mm vs. 37mm (P<0.01), respectively. Histologically, although the tumors in the SMT-like group were small in diameter, they almost all invaded into the submucosal (T1) or deeper layer (T2-4), and the rate of poorly differentiated adenocarcinoma or mucinous adenocarcinoma was significantly higher than that in the control group (48.6% vs. 7.7%; P<0.01). In the subgroup analysis of T1 tumors, the rate of lymphatic invasion in the SMT-like group was also significantly higher than that in the control group (43.8% vs. 15.4%; P<0.01). Carcinoma resembling SMT appears to be invasive and has a high risk of lymphatic invasion even if small in size. Therefore, surgical treatment with dissection of the regional lymph nodes might be necessary in cases with any signs of massive submucosal invasion.

Lymph node metastasis risk according to the depth of invasion in early gastric cancers confined to the mucosal layer

BACKGROUND

Early gastric cancers (EGCs) within the mucosal layer of the gastric wall have a small risk of lymph node (LN) metastasis.

METHODS

We reviewed clinicopathology data for patients who underwent surgery for EGC between 2001 and 2013 at the National Cancer Center, Korea. Poisson regression analyses were performed to compare the risk of LN metastasis according to the depth of tumor invasion in patients with mucosal EGCs.

RESULTS

Among the 1776 EGC patients included, 580 (32.7 %) had tumors confined to the lamina propria (LP; LP group) and 1196 (67.3 %) had tumors invading the muscularis mucosae (MM; MM group). Seventy-one patients (4.0 %) had LN metastasis, and the MM group had a significantly higher rate of LN metastasis (59 patients, 4.9 %) than the LP group (12 patients, 2.1 %; P = 0.004). A multivariate analysis showed that tumors invading the MM (adjusted risk ratio 1.95; P = 0.045) were significantly associated with LN metastasis in addition to well-known risk factors, including tumor size greater than 3 cm, presence of ulceration, undifferentiated histologic type, and lymphovascular invasion. The incidence of LN metastasis was 1.87 % (95 % confidence interval 0.23-6.59 %) within tumors invading the MM that met the expanded criterion for endoscopic resection of differentiated histologic type of size 3 cm or smaller with ulceration. LN metastasis was not found in tumors meeting the absolute criteria for endoscopic resection.

CONCLUSIONS

EGCs invading the MM had a higher rate of lymph node metastasis than those confined to the LP. Further study is needed to evaluate whether different curative treatment criteria are needed for LP-confined and MM-invading EGCs.

Differences in the pathological diagnosis of colorectal neoplasia between the East and the West: Present status and future perspectives from Japan

It is well known that there are discrepancies in the diagnosis of gastrointestinal neoplasia between Western and Japanese pathologists. In the West, colorectal cancer (CRC) is defined by invasion through the muscularis mucosa into the submucosa, especially depending on the presence of desmoplasia. In Japan, however, CRC is defined based on a combination of nuclear and architectural abnormalities, regardless of invasion status. As a result, intramucosal carcinoma is diagnosed as high-grade dysplasia and even intramucosal carcinoma with poorly differentiated component is classified as 'Tis' in the West. It is logical and reasonable that the term 'T1' is used to currently describe intramucosal carcinoma. Use of the term 'high-grade dysplasia' for intramucosal CRC is outdated. In order to determine appropriate clinical treatment of CRC, the various risk factors of metastasis should be fully evaluated. With improved contributions and communication between pathologists and clinicians, overtreatment and inadequate follow up can be avoided. The discrepancies in the diagnosis of CRC between Western and Japanese pathologists may be addressed by an increase in East-West exchange. In addition, in the future, molecular analysis may also be useful for establishment of standardized diagnostic criteria of CRC.

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.

Laparoscopic Low Anterior Resection and Eversion Technique Combined With a Nondog Ear Anastomosis for Mid- and Distal Rectal Neoplasms: A Preliminary and Feasibility Study

The transanal eversion and prolapsing technique is a well-established procedure, and can ensure an adequate distal margin for patients with low rectal neoplasms. Potential leakage risks, however, are associated with bilateral dog ear formation, which results from traditional double-stapling anastomosis. The authors determined the feasibility of combining these techniques with a commercial stapling set to achieve a nondog ear (end-to-end) anastomosis for patients with mid- and distal rectal neoplasms. Patients with early-stage (c/ycT1-2N0), mid- to distal rectal neoplasms and good anal sphincter function were included in this study. Laparoscopic low anterior resection was performed with a standard total mesorectal excision technique downward to the pelvic floor as low as possible. The bowel was resected proximal to the lesion with an endoscopic linear stapler. An anvil was inserted extracorporeally into the proximal colon via an extended working pore. The distal rectum coupled with the lesion was prolapsed and everted out of the anus. The neoplasm was resected with a sufficient margin above the dentate line under direct sight. A transrectal anastomosis without dog ears was performed intracorporeally to reconstitute the continuity of the bowel. Eleven cases, 6 male and 5 female patients, were included in this study. The mean operative time was 191 (129-292) minutes. The mean blood loss was 110 (30-300) mL. The median distal margin distance from the lower edge of the lesion to the dentate line was 1.5 (0.5-2.5) cm. All the resection margins were negative. Most patients experienced uneventful postoperative recoveries. No patient had anastomotic leak. Most patients had an acceptable stool frequency after loop ileostomy closure. Our preliminary data demonstrated the safety and feasibility of achieving a sound anastomosis without risking potential anastomotic leakage because of dog ear formation.

Practice parameters for early rectal cancer management: Italian Society of Colorectal Surgery (Società Italiana di Chirurgia Colo-Rettale; SICCR) guidelines

The introduction of new technologies for diagnosis and screening programs led to an increasing rate of early detection of colorectal cancer. This, associated with the evolution of endoscopic techniques of local excision, led to the assessment of new strategies to reduce morbidity related to treatment, especially for early rectal cancer (ERC). Nevertheless, the definition of ERC and its staging and treatment algorithm are still under debate. The Italian Society of Colorectal Surgery developed practice guidelines to provide recommendations on the diagnosis, staging and treatment of ERC. A systematic review on the topic was performed by a multidisciplinary group of experts selected based on their clinical and scientific expertise in endoscopy, endoscopic ultrasound, magnetic resonance and surgery, with the aid of an external international audit.

Practice parameters for early colon cancer management: Italian Society of Colorectal Surgery (Società Italiana di Chirurgia Colo-Rettale; SICCR) guidelines

Early colon cancer (ECC) has been defined as a carcinoma with invasion limited to the submucosa regardless of lymph node status and according to the Royal College of Pathologists as TNM stage T1 NX M0. As the potential risk of lymph node metastasis ranges from 6 to 17% and the preoperative assessment of lymph node metastasis is not reliable, the management of ECC is still controversial, varying from endoscopic to radical resection. A meeting on recent advances on the management of colorectal polyps endorsed by the Italian Society of Colorectal Surgery (SICCR) took place in April 2014, in Genoa (Italy). Based on this material the SICCR decided to issue guidelines updating the evidence and to write a position statement paper in order to define the diagnostic and therapeutic strategy for ECC treatment in context of the Italian healthcare system.

Long-Term Outcomes of Endoscopic Versus Surgical Resection of Superficial Submucosal Colorectal Cancer

BACKGROUND

The long-term outcomes of endoscopic resection of superficial submucosal colorectal cancer (CRC) had not been adequately compared with those of surgical resection.

AIMS

We aimed to compare the long-term clinical outcomes of endoscopic resection of superficial submucosal CRC to those of surgical resection.

METHODS

Submucosal CRC patients with a tumor depth of sm1 or less than 1 mm from the muscularis mucosa were enrolled. Patients with unfavorable histology, such as poorly differentiated cancer or lymphovascular invasion, were excluded. Recurrence-free survival and overall survival were investigated in 87 patients who underwent endoscopic resection and in 171 patients who underwent surgical resection.

RESULTS

The mean ages of the endoscopic and surgical resection groups were 59.7 and 59.8 years, respectively. Hospital stay was shorter in the endoscopic resection group (1.7 ± 1.6 vs. 8.6 ± 3.8 days; p < 0.001). The 3- and 5-year recurrence-free survival rates were 98.7 and 96.7 % in the endoscopic resection group and 98.7 and 97.5 % in the surgical resection group, respectively (p = 0.837). The 3- and 5-year overall survival rates were 100.0 and 95.2 % in the endoscopic resection group and 98.7 and 92.8 % in the surgical resection group, respectively (p = 0.928). Recurred cases showed an unfavorable histology that was overlooked at the time of initial resection.

CONCLUSIONS

Long-term outcomes after endoscopic resection of superficial submucosal CRC are comparable to those after surgical resection. Thorough initial histopathological evaluations are needed to guarantee the correct indication for endoscopic resection of submucosal CRC.

Area of submucosal invasion and width of invasion predicts lymph node metastasis in pT1 colorectal cancers

BACKGROUND

The prediction of lymph node metastasis by current histopathological methods is imprecise.

OBJECTIVE

The aim of this study was to evaluate currently used and possible new high-risk features associated with lymph node metastasis to identify the markers of lymph node metastasis.

DESIGN/PATIENT/SETTING

Two hundred seven pT1 cancers were identified through the Northern and Yorkshire Cancer Registry and Information Services database and digitally scanned. Phenotypic and quantitative features of the pT1 cancers were evaluated. Lymph node metastasis and high-risk feature status were obtained through pathology reports of resections, and high-risk phenotypic features were identified.

RESULTS

Lymph node metastasis was noted in 19 patients (9.2%). pT1 cancers with lymph node metastasis had a significantly wider area of invasion (p = 0.001) and greater area of submucosal invasion (p < 0.001) compared with pT1 cancers without lymph node metastasis. Qualitative features such as grade of differentiation and vascular and lymphatic invasion were significant predictors of lymph node metastasis (p < 0.0001, p = 0.039, and p = 0.018). Modified receiver-operating characteristics curves generated cutoff values of 11.5 mm for the width of invasion and 35 mm(2) for the area of submucosal invasion. When tested separately with other qualitative factors on multivariate analysis, both width greater than 11.5 mm (OR, 12.12; 95% CI, 2.19-67.23; p = 0.004) and area of submucosal invasion greater than 35 mm(2) (OR, 22.44; 95% CI, 2.7-186.63; p = 0.004) was predictive of lymph node metastasis.

LIMITATIONS

This is a retrospective study and is limited by its small sample size.

CONCLUSION

This study has shown that the width and area of submucosal invasion are potential predictors of lymph node metastasis and superior to the depth of invasion. Together with the other qualitative phenotypic features, these quantitative factors could be used to decide the most appropriate treatment for pT1 cancers.

New insights into the lymphovascular microanatomy of the colon and the risk of metastases in pT1 colorectal cancer obtained with quantitative methods and three-dimensional digital reconstruction

AIMS

UK faecal occult blood test screening has tripled the proportion of pT1 colorectal cancers. The risk of metastasis is predicted by depth of invasion, suggesting that access to deep lymphovascular vessels is important. The aim of this study was to quantify the distribution and size of the submucosal vasculature, and generate a novel three-dimensional (3D) model to validate the findings.

METHODS AND RESULTS

Thirty samples of normal large bowel wall were immunostained with CD31, a vascular endothelium marker, to identify blood vessels, which were quantified and digitally analysed for their number, circumference, area and diameter in the deep mucosa and submucosa (Sm1, Sm2, and Sm3). The model required serial sections, a double immunostain (using CD31 and D2-40), and 3D reconstruction. Significant differences were shown between submucosal layers in the number, circumference and area of vessels (P < 0.001). Blood vessels were most numerous in the mucosa (11.79 vessels/0.2 mm(2)) but smaller [median area of 247 μm(2) , interquartile range (IQR) 162-373 μm(2)] than in Sm2, where they were fewer in number (6.92 vessels/0.2 mm(2)) but considerably larger (2086 μm(2), IQR 1007-4784 μm(2)). The 3D model generated novel observations on lymphovascular structures.

CONCLUSIONS

The number and size of blood vessels do not increase with depth of submucosa, as hypothesized. The distribution of vessels suggests that we should investigate the area or volume of submucosal invasion rather than the depth.

Tumor location and nature of lymphatic vessels are key determinants of cancer metastasis

Tumor metastasis to lymph nodes is a key indicator of patient survival, and is enhanced by the neo-lymphatics induced by tumor-secreted VEGF-C or VEGF-D, acting via VEGFR-3 signalling. These targets constitute important avenues for anti-metastatic treatment. Despite this new understanding, clinical observations linking metastasis with tumor depth or location suggest that lymphangiogenic growth factors are not the sole determinants of metastasis. Here we explored the influence of tumor proximity to lymphatics capable of responding to growth factors on nodal metastasis in a murine VEGF-D over-expression tumor model. We found that primary tumor location profoundly influenced VEGF-D-mediated lymph node metastasis: 89 % of tumors associated with the flank skin metastasised, in contrast with only 19 % of tumors located more deeply on the body wall (p < 0.01). Lymphatics in metastatic tumors arose from small lymphatics, and displayed distinct molecular and morphological profiles compared with those found in normal lymphatics. Smaller lymphatic subtypes were more abundant in skin (2.5-fold, p < 0.01) than in body wall, providing a richer source of lymphatics for VEGF-D(+) skin tumors, a phenomenon also confirmed in human samples. This study shows that the proximity of a VEGF-D(+) primary tumor to small lymphatics is an important determinant of metastasis. These observations may explain why tumor location relative to the lymphatic network is prognostically important for some human cancers.