Clinicopathologic features of early rectal carcinoma and indications for endoscopic treatment

Qualitative and Quantitative Analysis of Posttreatment Strategy After Endoscopic Resection for Patients with T1 Colorectal Cancer at High Risk of Lymph Node Metastasis

BACKGROUND

Although endoscopic resection is increasingly performed to treat submucosal invasive colorectal cancer (T1CRC), approximately 10% are at risk of lymph node metastasis. The Japanese Society for Cancer of the Colon and Rectum guideline indicates that the following risk factors should be considered when deciding whether to perform additional surgical resection with lymph node dissection: depth of T1 invasion, lymphovascular invasion, poor histological grade, and budding grade 2/3. However, there is little information about the prognosis of T1CRC patients, or factors to consider when deciding subsequent treatment of high-risk T1CRC.

METHODS

This retrospective mixed method study was conducted using electronic medical records at Kyoto University Hospital between February 2005 and February 2015. Participants were T1CRC patients at risk of lymph node metastasis with at least one of the above four risk factors. They were assigned either careful follow-up (FU) or additional surgery (AS) through shared decision-making. To identify factors affecting decision-making in the FU group, we performed qualitative content analysis of electronic medical records. The prognosis of the groups was compared using the Kaplan-Meier method and the log-rank test.

RESULTS

Of 161 T1CRC patients, 18 were included in the FU group and 19 in the AS group. The median follow-up time was 39.5 (range 23-126) months for the FU group and 62 (range 22-141) months for the AS group. Factors considered in selecting FU were advanced age, comorbidities, the sole presence of the "depth" risk factor, and lower rectal cancer. For AS, the risk factors cited in the guideline were considered. There was one recurrent case in each group during the research period. There were no significant differences in overall survival, cause-specific survival, or recurrence-free survival between the groups.

CONCLUSIONS

Age, comorbidities, and lower-rectal cancer location were considered in deciding posttreatment strategy among high-risk T1CRC patients, alongside with positive vertical margin, depth, lymphovascular invasion, poor histologic grade, and budding. During the research period, there was no prognostic difference between the FU and AS groups.

Challenges associated with the pathological diagnosis of colorectal tumors less than 10 mm in size

Various techniques including cold snare polypectomy and endoscopic mucosal resection are used for the removal of small colorectal polyps. Specimens of resected polyps are prepared in pathology laboratories and analyzed to make a pathological diagnosis. However, reports on how different resection methods influence the pathological diagnosis are limited. This article discusses the problems associated with the failure of polyp retrieval and fragmentation of small specimens during collection and the effects of certain parameters on the pathological diagnosis, particularly with regard to surgical margins. In the future, although pathologists are expected to encounter problems as a result of minor findings that are not clinically problematic, relatively rare cases such as submucosal invasion by a small carcinoma should not be overlooked.

Long-term outcomes after treatment for pedunculated-type T1 colorectal carcinoma: a multicenter retrospective cohort study

BACKGROUND

The risk for lymph node metastasis and the prognostic significance of pedunculated-type T1 colorectal carcinomas (CRCs) require further study. We aimed to assess the validity of the 2014 Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines based on long-term outcomes of pedunculated-type T1 CRCs.

METHODS

In this multicenter retrospective cohort study, we examined 176 patients who underwent resection endoscopically or surgically at 14 institutions between January 1990 and December 2010. Patients meeting the JSCCR curative criteria were defined as "endoscopically curable (e-curable)" and those who did not were "non-e-curable". We evaluated the prognosis of 116 patients (58 e-curable, 58 non-e-curable) who were observed for >5 years after treatment.

RESULTS

Overall incidence of lymph node metastasis was 5 % (4/81; 95 % confidence interval 1.4-12 %: three cases of submucosal invasion depth ≥1000 μm [stalk invasion] and lymphatic invasion, one case of head invasion and budding grade 2/3). There was no local or metastatic recurrence in the e-curable patients, but six of them died of another cause (observation period, 80 months). There was no local recurrence in the non-e-curable patients; however, distant metastasis was observed in one patient. Death due to the primary disease was not observed in non-e-curable patients, but six of them died of another cause (observation period, 72 months).

CONCLUSIONS

Our data support the validity of the JSCCR curative criteria for pedunculated-type T1 CRCs. Endoscopic resection cannot be considered curative for pedunculated-type T1 CRC with head invasion alone.

Long-term outcomes after treatment for T1 colorectal carcinoma

PURPOSE

Long-term outcomes of patients with T1 colorectal carcinoma (CRC) treated by endoscopic resection (ER) or surgical resection are unclear in relation to the curative criteria in the Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines. The aim of this study was to retrospectively compare the long-term outcomes among patients with T1 CRC in relation to the treatment methods.

METHODS

We examined 322 T1 CRC cases treated between January 1992 and August 2008 at Hiroshima University Hospital. Patients who did not meet the curative criteria in the JSCCR guidelines were defined as "non-endoscopically curable" and classified into three groups: underwent ER alone (group A: 45 patients), underwent additional surgery after ER (group B: 106 patients), and underwent surgical resection alone (group C: 92 patients).

RESULTS

Of the 322 T1 CRC patients, 79 were categorized as endoscopically curable and 243 as non-endoscopically curable. Among the endoscopically curable T1 CRC patients, recurrence and 5-year OS rates were 0 and 94.2%, respectively. In groups A, B, and C, recurrence rates were 4.4, 6.6, and 4.3%, and OS rates were 85.6, 95.1, and 96.3%, respectively (p < 0.05). Local recurrence or distant/lymph node metastasis was observed in 13 patients (group A: 2; group B: 7; group C: 4). Death due to primary CRC occurred in six patients (group B: 4; group C: 2).

CONCLUSION

Long-term outcomes support the curative criteria according to the JSCCR guidelines. ER for T1 CRC did not worsen clinical outcomes in cases that required additional surgical resection.

Endoscopic submucosal dissection as total excisional biopsy for clinical T1 colorectal carcinoma

BACKGROUND/AIMS

Only the depth of submucosal invasion can be estimated prior to determining the indications for endoscopic submucosal dissection (ESD) as a curative treatment for colorectal carcinoma (CRC). Here we evaluated the outcomes of ESD for clinical T1 CRCs.

METHODS

Of 660 patients who underwent ESD for CRC at the Hiroshima University Hospital between June 2003 and December 2013, we examined the outcomes of 37 (6%; 26 men, 11 women; mean age ± SD, 68 ± 12 years) who underwent ESD as total excisional biopsy for various reasons, in spite of an endoscopic diagnosis of T1 CRC.

RESULTS

The mean lesion size was 25 ± 14 mm; 14 lesions were protruding and 23 were superficial. The en bloc resection rate was 100% (37/37). The histological en bloc resection rate was 92% (34/37). ESD resulted in a positive vertical margin in 3 cases. Deep submucosal invasion was seen in 3 cases, 2 of which had severe submucosal fibrosis. Although severe submucosal fibrosis was not found in other cases, pathologic examination of the deepest invasive portion of the tumor revealed poorly differentiated adenocarcinoma. The rates of post-ESD bleeding and perforation were 8% (3/37) and 5% (2/37), respectively. All patients recovered under conservative therapy. No cases of recurrence were noted in patients without additional surgical resection when the lesions satisfied the curative conditions listed in the 2014 Japanese Society for Cancer of the Colon and Rectum guidelines.

CONCLUSION

En bloc resection by ESD as total excisional biopsy for clinical T1 CRC is a highly effective treatment and establishes a precise histological diagnosis.

Evidence-based clinical practice guidelines for management of colorectal polyps

BACKGROUND

Recently in Japan, the morbidity of colorectal polyp has been increasing. As a result, a large number of cases of colorectal polyps that are diagnosed and treated using colonoscopy has now increased, and clinical guidelines are needed for endoscopic management and surveillance after treatment.

METHODS

Three committees [the professional committee for making clinical questions (CQs) and statements by Japanese specialists, the expert panelist committee for rating statements by the modified Delphi method, and the evaluating committee by moderators] were organized. Ten specialists for colorectal polyp management extracted the specific clinical statements from articles published between 1983 and September 2011 obtained from PubMed and a secondary database, and developed the CQs and statements. Basically, statements were made according to the GRADE system. The expert panel individually rated the clinical statements using a modified Delphi approach, in which a clinical statement receiving a median score greater than seven on a nine-point scale from the panel was regarded as valid.

RESULTS

The professional committee created 91CQs and statements for the current concept and diagnosis/treatment of various colorectal polyps including epidemiology, screening, pathophysiology, definition and classification, diagnosis, treatment/management, practical treatment, complications and surveillance after treatment, and other colorectal lesions (submucosal tumors, nonneoplastic polyps, polyposis, hereditary tumors, ulcerative colitis-associated tumor/carcinoma).

CONCLUSIONS

After evaluation by the moderators, evidence-based clinical guidelines for management of colorectal polyps have been proposed for 2014.

Towards safer and appropriate application of endoscopic submucosal dissection for T1 colorectal carcinoma as total excisional biopsy: future perspectives

According to the Japanese Society for Cancer of the Colon and Rectum Guidelines 2014 for the Treatment of Colorectal Cancer, cases with T1 colorectal carcinoma should be considered for additional colectomy with lymph node dissection when histologically complete en bloc resection is endoscopically carried out and when one of the four risk factors listed below is present. These four risk factors are: (i) submucosal (SM) invasion depth ≥1000 μm; (ii) positive vascular invasion; (iii) poorly differentiated adenocarcinoma, signet ring cell carcinoma, or mucinous carcinoma; and (iv) grade 2/3 budding at the deepest part of SM invasion. However, the probability of lymph node metastasis is extremely low if none of these risk factors are present, with the exception of SM invasion depth ≥1000 μm. Consequently, it is assumed that there will be an increasing number of cases where no additional surgery is done, or cases of moderate invasive carcinoma in which endoscopic treatment is carried out to achieve an excisional biopsy, for which complete resection is applicable. In these cases, the preoperative diagnosis, resection techniques such as endoscopic submucosal dissection, features of resected specimens, and the accuracy of pathological diagnosis are all extremely important.

The evolution in the detection of extramural venous invasion in rectal cancer: implications for modern-day practice

SUMMARY 

Venous invasion has been considered a poor prognostic factor in rectal cancer for over half a century. This term has evolved in recent years and now applies specifically to tumor invasion into extramural veins – extramural venous invasion. This distinction from intramural venous invasion is important as it is more clinically relevant. Extramural venous invasion can be identified by histopathology and MRI but until recently there has been a lack of consistency in definitions and detection techniques. This paper reviews the historical evidence for the prognostic importance and detection of venous invasion in rectal cancer.

[Primary squamous cell carcinoma of the ascending colon: report of a case and Korean literature review]

Primary squamous cell carcinoma of the colon is an extremely rare malignancy. A 48-year-old male visited our hospital for screening colonoscopy. Colonoscopic examination showed a 1 cm sized sessile polyp in the ascending colon. The patient underwent endoscopic mucosal resection (EMR) without any complication. The pathologic findings were compatible with squamous differentiation of tumor cells in inflammatory colonic mucosa. The tumor was confined to the mucosa and the margins of the excised tissue were found to be free of the tumor. There were no other primary sites and no distant metastases in the extensive evaluation using a whole body CT scan and PET-CT. Additional surgical resection was not done. Follow-up colonoscopy performed eight month later showed a whitish scar without evidence of local recurrence and follow-up PET-CT demonstrated no evidence of recurrence. Herein, we report a case of primary squamous cell carcinoma of the ascending colon presenting as a sessile polyp which was removed by EMR.

Endoscopic resection as the first-line treatment for early colorectal cancer: comparison with surgery

INTRODUCTION

Endoscopic resection has emerged as an alternative therapeutic option for selected cases of early colorectal cancer. However, even now, few data are available on the comparative effectiveness of endoscopic versus surgical resection of early colorectal cancer. The aim of our study was to compare the clinical outcomes in patients with early colorectal cancer who underwent endoscopic resection and those who underwent surgical resection.

METHODS

292 early colorectal cancer lesions in 287 patients who were treated with either endoscopic resection or colorectal surgery (open or laparoscopic colorectal resection) between January 2005 and December 2010 were retrospectively analyzed. After excluding 54 deep submucosal lesions [and/or tumor budding (Grade 2 or 3)], a total of 168 lesions with mucosal/superficial submucosal invasion were treated by endoscopic resection, and 70 lesions with mucosal/superficial submucosal invasion were treated by colorectal surgery.

RESULTS

In the endoscopic resection group, the en bloc resection rate and the complete resection rate were 91.1 and 91.1%, respectively. In the colorectal surgery group, both the en bloc resection rate and the curative resection rate were 100%. However, using Log rank test in Kaplan-Meier curve, no significant difference in recurrence rate (including metachronous cancer) during the median follow-up period of 37 months (range, 6-98 months) was observed between the two groups (p = 0.647). In addition, a similar morbidity rate was observed for endoscopic resection compared with surgery (5.4 vs. 5.7%, p = 0.760). A significantly shorter hospital stay was observed in the endoscopic resection group than colorectal surgery group [median 2 days (range, 2-29) vs. median 10 days (range, 7-37), p < 0.001).

CONCLUSION

We suggest that endoscopic resection, being equally effective but less invasive than surgery, can be the first-line treatment for well selected early colorectal cancer.

Endoscopic features and management of diminutive colorectal submucosal invasive carcinoma

BACKGROUND AND AIM

The vast majority of diminutive (∼5 mm) colorectal tumors consist of a very low prevalence of advanced neoplasia, and a predict-resect-and-discard policy has been proposed recently in Western countries. The histology of some diminutive colorectal tumors reveals carcinoma, not adenoma, although the frequency is relatively low. Clarifying the endoscopic features of diminutive submucosal invasive colorectal carcinoma (CRC) during colonoscopy is important for managing diminutive lesions.

METHODS

A total of 111 cases of submucosal invasive CRC ≤ 10 mm were analyzed. The incidence of submucosal invasion in early CRC per gross type, size, location, pit pattern diagnosis, and rate of lymph node (LN) metastasis was evaluated.

RESULTS

In diminutive tumors, the overall submucosal invasion rate in early CRC was 9.6%; however, depressed tumors had a significantly higher frequency of submucosal invasion than protruded or flat elevated tumors. There were no significant differences in the distribution of submucosal invasive CRC between the diminutive tumors and those that were 6-10 mm. The pit pattern diagnosis of diminutive submucosal invasive CRC was type VI pit pattern in all cases. Each case of submucosal invasive CRC was completely resected by en bloc endoscopic resection, and there were no cases of LN metastasis.

CONCLUSION

Diminutive tumors with depression have a high frequency of submucosal invasive CRC and an initial indication for endoscopic resection.

When is local excision appropriate for "early" rectal cancer?

Local excision is increasingly performed for “early stage” rectal cancer in the US; however, local recurrence after local excision has become a controversial issue in Western countries. Local recurrence is considered to originate based on the type of tumor and procedure performed, and in surgical margin-positive cases. This review focuses on the inclusion criteria of “early” rectal cancers for local excision from the Western and Japanese points of view. “Early” rectal cancer is defined as T1 cancer in the rectum. Only the tumor grade and depth of invasion are the “high risk” factors which can be evaluated before treatment. T1 cancers with sm1 or submucosal invasion <1,000 μm are considered to be “low risk” tumors with less than 3.2 % nodal involvement, and are considered to be candidates for local excision as the sole curative surgery. Tumors with a poor tumor grade should be excluded from local excision. Digital examination, endoscopy or proctoscopy with biopsy, a barium enema study and endorectal ultrasonography are useful for identifying “low risk” or excluding “high risk” factors preoperatively for a comprehensive diagnosis. The selection of an initial local treatment modality is also considered to be important according to the analysis of the nodal involvement rate after initial local treatment and after radical surgery.

Risk factors for vertical incomplete resection in endoscopic submucosal dissection as total excisional biopsy for submucosal invasive colorectal carcinoma

PURPOSE

Endoscopic submucosal dissection (ESD) for colorectal tumor is a minimally invasive treatment. Histologic information obtained from the entire ESD specimen is important for therapy selection in submucosal invasive colorectal carcinoma (SMca). This study aimed to identify risk factors for vertical incomplete resection (vertical margin-positive [VM+]) when ESD was performed as total excisional biopsy for SMca.

METHODS

From June 2003 through December 2011, 78 SMca cases were resected by ESD at Hiroshima University Hospital. Patient and tumor characteristics, intraoperative variables, and histopathology were compared between the VM+ group and the vertical complete resection (vertical margin-negative) group. The ability of magnifying endoscopy (ME) and endoscopic ultrasonography (EUS) to predict VM+ was assessed.

RESULTS

ESD resulted in VM+ in eight cases (10.3 %), with a greater percentage invading to a depth of ≥2,000 vs. <2,000 μm (P = 0.047). Severe submucosal fibrosis was found in five of the eight cases (62.5 %, P = 0.017). Poor differentiation was seen at the deepest invasive portion in six cases (75.0 %), and two of six cases had an invasion depth <2,000 μm. Of 39 EUS cases, 36 not showing deep invasion close to the muscularis propria were completely resected by ESD.

CONCLUSIONS

Submucosal fibrosis and poor differentiation at the deepest invasive portion may be risk factors for VM+ in colorectal ESD for tumors with submucosal deep invasion. ME plus EUS is more likely to help determine whether ESD is indicated as complete total excisional biopsy for SMca.

Risk analysis of submucosal invasive rectal carcinomas for lymph node metastasis to expand indication criteria for endoscopic resection

In the 2010 guidelines for the treatment of colorectal cancer from the Japanese Society for Cancer of the Colon and Rectum (JSCCR), the criteria for identifying curable submucosal invasive colorectal carcinoma after endoscopic resection is as follows: differentiated adenocarcinoma, no vascular invasion, submucosal invasion depth <1000 μm and budding grade 1 (low grade). A total of 118 rectal submucosal carcinomas, treated by primary surgical resection or additional surgical resection with lymph node (LN) dissection, were analyzed. Relationships between clinicopathological findings and LN metastasis were evaluated. LN metastasis was found in 11.0% (13/118). There were no significant differences between clinicopathological findings and LN metastasis except for budding grade. Multivariate logistic regression analysis showed budding grade 2/3 (high grade) to be the independent risk factor for LN metastasis. When cases that met the curative condition of histological grade, tumor budding grade and vessel invasion together according to JSCCR 2010 criteria, the incidence of LN metastasis was only 2.2% (1/46, 95% confidence interval: 0.06-11.5%), regardless of the degree of submucosal invasion depth. In conclusion, even in cases of rectal carcinoma with submucosal deep invasion, the risk of LN metastasis is minimal under certain conditions.

Management of T1 colorectal carcinoma with special reference to criteria for curative endoscopic resection

BACKGROUND AND AIM

In guidelines 2010 for the treatment of colorectal cancer from the Japanese Society for Cancer of the Colon and Rectum (JSCCR), the criteria for identifying curable T1 colorectal carcinoma after endoscopic resection were well/moderately differentiated or papillary histologic grade, no vascular invasion, submucosal invasion depth less than 1000 µm and budding grade 1 (low grade). We aimed to expand these criteria.

METHODS

A total of 499 T1 colorectal carcinomas, resected endoscopically or surgically, were analyzed. Relationships between clinicopathologic findings and lymph node metastasis were evaluated.

RESULTS

Lymph node metastasis was found in 41 (8.22%) of the 499 cases. The incidence of lymph node metastasis was significantly higher in lesions featuring poorly differentiated/mucinous adenocarcinoma, submucosal invasion ≥ 1800 µm, vascular invasion, and high-grade tumor budding than in other lesions. Multivariate logistic regression analysis showed all of these variables to be independent risk factors for lymph node metastasis. When cases that met three of the JSCCR 2010 criteria (i.e. all but invasion < 1000 µm) were considered together, the incidence of lymph node metastasis was only 1.2% (3/249, 95% confidence interval: 0.25-3.48%), and there were no cases of lymph node metastasis without submucosal invasion to a depth of ≥ 1800 µm.

CONCLUSIONS

Even in cases of colorectal carcinoma with deep submucosal invasion, the risk of lymph node metastasis is minimal under certain conditions. Thus, even for such cases, endoscopic incisional biopsy can be suitable if complete en bloc resection is achieved.

Meta-analysis of histopathological features of primary colorectal cancers that predict lymph node metastases

BACKGROUND

Treatment decisions for colorectal cancer vary based on lymph node status. While some histopathological features of the primary tumor correlate with lymph node spread, the relative influences of these risk factors are not well quantified.

OBJECTIVE

This study aims to systematically review published studies relating histopathological features of primary colorectal cancer to the presence of lymph node metastases and to determine how reliable certain factors might be at predicting nodal metastasis when only the primary lesion is available for study.

DATA SOURCES

Inclusive literature search using EMBASE and Ovid MEDLINE databases plus manual reference checks of all articles correlating lymphatic spread with colorectal cancer (any T stage) from 1984 to mid-2008 was performed.

STUDY SELECTION

This search generated two levels of screening utilized on 602 citations, yielding 123 articles for full review. Data reported from 76 articles were chosen.

MAIN OUTCOME MEASURES

The relative influence of each histopathological feature on the likelihood of lymphatic metastases was determined. Fixed-effects meta-analysis was performed, and results were reported as Mantel-Haenszel odds ratios (OR).

RESULTS

Of 42 histopathological features analyzed, only 40.4% were reported in >2 articles. The positive predictive values for the top quartile of most frequently reported risk factors were 25.5-86.4%. Among the commonly reported histopathological findings, lymphatic invasion (OR, 8.62) significantly outperformed tumor depth (T2 vs. T1; OR, 2.62) and overall differentiation (OR, 2.38) in predicting nodal spread. For the rectal cancer subset, risk factors differed from the overall colorectal group in predictive ability; poor differentiation at the invasive front (OR, 6.08) and tumor budding (OR, 5.82) were the most predictive.

LIMITATIONS

This literature search is limited by the small number of studies examining only rectal cancers and the potential changes in histological and/or surgical techniques over the study period.

CONCLUSIONS

No single histopathological feature of colorectal cancer reliably predicted lymph node metastases. Several risk factors that correlate highly with nodal disease are not routine components of standard pathology reports. Until further research establishes histopathological or molecular patterns for predicting lymph node spread, caution should be exercised when basing treatment decisions solely on these factors.

Assessment of likelihood of submucosal invasion in non-polypoid colorectal neoplasms

Although of lower prevalence compared with polypoid neoplasms, the non-polypoid neoplasms, especially the depressed type, are important to diagnose because they belong to a distinct biologically aggressive subset, given the high rate of intramucosal or submucosal cancers. The detection and diagnosis of the non-polypoid colorectal neoplasm presents a challenge and an opportunity. Above all, characteristic colonoscopic findings obtained by a combination of conventional colonoscopy and magnifying chromoendoscopy are useful for determination of the invasion depth of non-polypoid colorectal cancers, an essential factor in selecting a treatment modality.

Size does not determine the grade of malignancy of early invasive colorectal cancer

AIM: To clarify the clinicopathological characteristics of small and large early invasive colorectal cancers (EI-CRCs), and to determine whether malignancy grade depends on size.

METHODS: A total of 583 consecutive EI-CRCs treated by endoscopic mucosal resection or surgery at the National Cancer Center Hospital between 1980 and 2004 were enrolled in this study. Lesions were classified into two groups based on size: small (≤ 10 mm) and large (> 10 mm). Clinicopathological features, incidence of lymph node metastasis (LNM) and risk factors for LNM, such as depth of invasion, lymphovascular invasion (LVI) and poorly differentiated adenocarcinoma (PDA) were analyzed in all resected specimens.

RESULTS: There were 120 (21%) small and 463 (79%) large lesions. Histopathological analysis of the small lesion group revealed submucosal deep cancer (sm: ≥ 1000 &mgr;m) in 90 (75%) cases, LVI in 26 (22%) cases, and PDA in 12 (10%) cases. Similarly, the large lesion group exhibited submucosal deep cancer in 380 (82%) cases, LVI in 125 (27%) cases, and PDA in 79 (17%) cases. The rate of LNM was 11.2% and 12.1% in the small and large lesion groups, respectively.

CONCLUSION: Small EI-CRC demonstrated the same aggressiveness and malignant potential as large cancer.

The lymphatic infiltration identified by D2-40 monoclonal antibody predicts lymph node metastasis in submucosal invasive colorectal cancer

BACKGROUND AND STUDY AIMS

Lymphatic infiltration has been recognized as a significant risk factor for lymph node metastasis of submucosal invasive colorectal cancer (SICC), but it is difficult to detect microscopically on hematoxylin and eosin (H&E)-stained slides. We therefore identified lymphatic infiltration of tumor cells with D2-40 monoclonal antibody, which reacts specifically against the endothelium of lymphatic vessels, to make an objective and precise diagnosis.

PATIENTS AND METHODS

The surgical specimens of 122 consecutive patients with nonpedunculated SICC were examined for lymphatic infiltration by immunohistochemical staining with D2-40 monoclonal antibody (LI-D) and for venous infiltration by Elastica van Gieson staining (VI-E).

RESULTS

Lymph node metastasis was found in 20 patients. Multivariate analysis showed that LI-D (p = 0.0415) and VI-E (p = 0.0119) were significant risk factors for lymph node metastasis. Regardless of the presence of risk factors including at least either lymphatic infiltration or venous infiltration, no lymph node metastasis-positive patients were found (0%) among the 25 patients whose colorectal cancer had a submucosal invasive depth of less than 1,500 microm. No lymph node metastasis was found in any of the patients with a depth of submucosal invasion of less than 3,000 microm, who had no risk factors, including LI-D or VI-E.

CONCLUSIONS

Correct evaluation of lymphatic infiltration by immunohistochemical staining with D2-40 monoclonal antibody may play a crucial role in determining whether there are indications for additional treatment in the management of endoscopically resected SICC.

Risk factors for occult lymph node metastasis of colorectal cancer invading the submucosa and indications for endoscopic mucosal resection

PURPOSE

Although risk factors for histologically overt lymph node metastasis in patients with early-stage colorectal cancer have been clarified, the risk factors for occult lymph node metastasis are not clear. This study was designed to clarify risk factors for lymph node metastasis, including occult metastasis, in patients with colorectal cancer invading the submucosa and to determine the criteria for endoscopic resection of early colorectal cancer.

METHODS

The risk factors for lymph node metastasis, including occult metastasis, were analyzed in 86 cases of surgically resected colorectal cancer invading the submucosa. The lymph nodes were assessed by immunohistochemistry with cytokeratin antibody CAM5.2.

RESULTS

The frequencies of overt and occult metastasis to the lymph nodes were 13 percent (11/86) and 13 percent (10/75), respectively. Multivariate analysis showed vascular invasion (P = 0.001) and tumor budding (P = 0.003) to be independent risk factors for lymph node metastasis, including occult metastasis. For tumors with submucosal invasion < or =1,000 microm, no lymph node metastasis was found. The frequencies of lymph node metastasis for tumors with submucosal invasion of 1,000 to 2,000 microm and >2,000 microm were 21 and 37 percent, respectively. In considering combinations of risk factors, there was no lymph node metastasis in tumors having neither vascular invasion nor tumor budding and submucosal invasion of < or =3,000 microm.

CONCLUSIONS

Vascular invasion, tumor budding, and the degree of submucosal invasion were significant risk factors for lymph node metastasis, including occult metastasis. These three factors can be used in combination to identify patients requiring additional surgery after endoscopic resection.

Immunohistochemical molecular markers as predictors of curability of endoscopically resected submucosal colorectal cancer

AIM: To clarify the usefulness of immunohistochemical molecular markers in predicting lymph node metastasis of submucosal colorectal cancer.

METHODS: We examined microvessel density, lymphatic vessel density, the Ki-67 labeling index, expression of MUC1 and Matrix metalloproteinase-7 (MMP-7) in tumor cells, and expression of cathepsin D in stromal cells at the invasive front by immunostaining of samples resected from 214 patients with submucosal colorectal cancer. Pathologic features were assessed on hematoxylin-eosin-stained samples. We evaluated the relations between clinicopathologic/immunohistochemical features and lymph node metastasis.

RESULTS: Lesions of the superficial type, with an unfavorable histologic grade, budding, lymphatic involvement, high microvessel density (≥ 40), high lymphatic vessel density (≥ 9), high Ki-67 labeling index (≥ 42), and positivity of MUC1, cathepsin D, and MMP-7 showed a significantly high incidence of lymph node metastasis. Multivariate analysis revealed that high microvessel density, unfavorable histologic grade, cathepsin D positivity, high lymphatic vessel density, superficial type, budding, and MUC1 positivity were independent risk factors for lymph node metastasis. A combined examination with four independent immunohistochemical markers (microvessel density, cathepsin D, lymphatic vessel density, and MUC1) revealed that all lesions that were negative for all markers or positive for only one marker were negative for lymph node metastasis.

CONCLUSION: Analysis of a combination of immuno-histochemical molecular markers in endoscopically resected specimens of submucosal colorectal cancer allows prediction of curability regardless of the pathologic features visible of hematoxylin-eosin-stained sections.

Local therapy for rectal cancer: still controversial?

PURPOSE

Many considerations, such as morbidity, sexual and urinary dysfunction, or risk of definitive stoma have led to the increased popularity of local therapy in the therapeutic strategy for rectal cancer. However, its role in curative intent is still controversial with oncologic long-term results lower than those obtained by radical surgery.

METHODS

MEDLINE, EMBASE, LILACS, Abstract books, and reference lists from reviews were searched with English language publications to review the current status of evidence for local therapy in rectal cancer, looking especially at the oncologic results and patient selection. We have focused on the new strategies combining neoadjuvant and adjuvant treatment to explain their place in the management of rectal cancer.

RESULTS AND CONCLUSIONS

The key to potentially curative local treatment for rectal cancer is patient selection by identifying the best candidates with preoperative tumor staging and clinical and pathologic assessment of favorable features. Low-risk T1 is suitable for local excision alone. Limited data suggest that adjuvant chemoradiotherapy may be helpful in patients with unfavorable T1 and T2 lesions, achieving a local recurrence rate<20 percent. However, the efficacy of salvage surgery after local excision is uncertain.

Lymphatic vessel density at the site of deepest penetration as a predictor of lymph node metastasis in submucosal colorectal cancer

PURPOSE

Lymph node metastasis is an important factor that influences curability after endoscopic treatment of submucosal colorectal cancer. This study was designed to determine the usefulness of identification of lymphatic vessels by immunohistochemistry in predicting lymph node metastasis of submucosal colorectal cancer.

METHODS

Lymphatic involvement was assessed by hematoxylin and eosin staining and podoplanin immunostaining on samples resected from 268 patients with submucosal colorectal cancer. Lymphatic vessel density was estimated by two investigators by average count of three fields (x200) in the area of greatest number of podoplanin-positive capillaries at the site of deepest submucosal penetration. Relations with other clinicopathologic parameters also were investigated.

RESULTS

Lesions with high lymphatic vessel density (> or =9 vessels per field) showed a significantly greater incidence of lymph node metastasis than did those with low lymphatic vessel density (<9 vessels per field; 23.3 vs. 8.4 percent). By multivariate analysis, lymphatic vessel density was determined to be an independent risk factor for lymph node metastasis of submucosal colorectal cancer (P = 0.0044). Lymphatic vessel density also correlated with tumor budding and the degree of inflammation at the invasive front.

CONCLUSIONS

Identification of lymphatic vessels by podoplanin immunostaining provides objective and accurate evaluation of lymphatic involvement. Lymphatic vessel density at the site of deepest penetration is a useful predictor of lymph node metastasis of submucosal colorectal cancer.

Mucinous carcinoma identified as lung metastasis from an early rectal cancer with submucosal invasion by immunohistochemical detection of villin

We encountered a male patient aged 64 with pulmonary mucinous carcinoma in whom a diagnosis of pulmonary metastasis from early rectal cancer with submucosal invasion was made based on an immunohistochemical examination. A rectal cancer was detected together with a mass in the lung. The mass in the lung was consistent with mucinous adenocarcinoma, whereas the invasion of rectal cancer was confined to the submucosa; thus, distant metastases appeared unlikely. These lesions were assessed using immunohistochemical staining for cytokeratin and thyroid transcription factor-1, which failed to make a definite diagnosis. A further assessment was made by staining for villin. Both neoplasms were positive for this protein, demonstrating a common brush-border pattern. A lung metastasis from rectal cancer with submucosal invasion was diagnosed. Villin is considered useful for detecting primary neoplastic lesions based not only on its specificity but also on its staining pattern, which is different from that of other proteins.

Incidence and localization of lymphoid follicles in early colorectal neoplasms

AIM

To investigate the incidence and localizations of lymphoid follicles (LFs) in early colorectal neoplasms in human beings.

METHODS

From July 1992 to September 1999, a total of 1,324 early colorectal neoplasms were removed endoscopically or surgically at our hospital; 1,031 (77.9%) were available for analysis in this study. Localization of LFs was defined histologically: as submucosal LFs, if located under the muscularis mucosa; and as intramucosal LFs, if located across or over the muscularis mucosa.

RESULTS

Histologically, the materials included 903 intramucosal neoplasms and 128 submucosal cancers. Overall incidence of LFs was 27.2% (280/1 031). The incidence of LFs was significantly higher in females (33.6% vs 24.9%, P=0.0064), the right-sided colon (32.2% vs 25.6%, P=0.0403) and in flat or depressed type lesions (34.6% vs 25.2%, P<0.0001) as compared to males, left-sided colon and protruding type lesions, respectively. The incidences of intramucosal neoplasms and submucosal cancers were 24.3% and 43.8%, respectively (P<0.0001). Localizations of LFs (intramucosal LF/submucosal LF) in depressed, flat, and protruding types were 1/24, 14/36, and 131/74, respectively.

CONCLUSION

The incidence of LFs in early human colorectal neoplasms significantly differs by gender, location, macroscopic type, and histology. Moreover, localization significantly differs by macroscopic type.

Predictive histopathologic factors for lymph node metastasis in patients with nonpedunculated submucosal invasive colorectal carcinoma

PURPOSE

Risk factors for lymph node metastasis in patients with nonpedunculated submucosal invasive colorectal carcinoma remain to be characterized. This study examines the relationship between lymph node metastasis and clinicopathologic factors in nonpedunculated submucosal invasive colorectal carcinoma.

METHODS

The study cohort comprised 155 patients who had undergone surgical treatment for nonpedunculated submucosal invasive colorectal carcinoma. The clinicopathologic factors investigated included gender, age, tumor location, macroscopic type, tumor size, histologic type and grade, intramucosal growth pattern, lymphatic invasion, venous invasion, degree of focal dedifferentiation at the submucosal invasive front, status of the remaining muscularis mucosa, and the depth and width of submucosal invasion.

RESULTS

Lymph node metastases were found in 19 patients (12.3 percent). Univariate analysis showed that lymphatic invasion, focal dedifferentiation at the submucosal invasive front, status of the remaining muscularis mucosa, and depth of submucosal invasion all had a significant influence on lymph node metastasis. Multivariate analysis showed lymphatic invasion (P = 0.014) and high-grade focal dedifferentiation at the submucosal invasive front (P = 0.049) to be independent factors predicting lymph node metastasis. No lymph node metastasis was found in tumors with a depth of submucosal invasion of <1.3 mm.

CONCLUSIONS

Lymphatic invasion and high-grade focal dedifferentiation at the submucosal invasive front are important predictors of lymph node metastasis in patients with nonpedunculated submucosal invasive colorectal carcinoma. Depth of submucosal invasion can be used as an identifying marker for patients who do not require subsequent surgery after endoscopic resection.

Venous invasion may predict lymph node metastasis in early rectal cancer

AIM

The aim of this study was to evaluate the role of histopathological and demographic characteristics in predicting lymph node metastasis in patients with adenocarcinoma of the rectum confined to the mucosal and submucosal layers.

METHODS

Fifty-nine patients with early rectal cancer underwent resection of the rectum including lymph nodes and five showed lymph node metastasis (8.6%). Pathology slides of these patients were reviewed by a single pathologist. Demographic and clinical characteristics of these 59 patients were correlated with the existence of nodal metastasis. Formal tests of comparability were carried out by using Fisher's exact test. Logistic regression models were fitted to data to examine possible relationships with 12 covariates measured from each patient and to obtain corresponding odds ratios (as well as a 95% confidence interval for the odds ratios). These covariates included age at surgery, gender, morphology, histology, degree of differentiation, Haggitt's classification for polyps according to the level of invasion, lymphatic and venous invasion, desmoplastic reaction, degree of lymphocytic invasion, presence of lymphoid follicles and presence of infiltrating or pushing margins.

RESULTS

A significantly higher rate of lymph node metastasis occurs in the presence of venous invasion (P < 0.01). Venous invasion was present in three of five (60%) patients with lymph node metastasis and only four of 54 (7%) patients without lymph node metastasis. Other variables did not achieve statistical significance.

CONCLUSIONS

Only the presence of venous invasion was found to be highly significant. The odds ratio of lymph node metastasis increased 18-fold for a patient who had venous invasion compared with a patient who did not. This suggests that the presence of venous invasion in early rectal cancer may provide valuable information to determine which patients would benefit from radical surgery, or adjuvant radiation therapy after sphincter-sparing surgery owing to an increased risk of lymph node metastasis.

Angiogenesis at the site of deepest penetration predicts lymph node metastasis of submucosal colorectal cancer

PURPOSE

Intratumor microvessel count has been reported as a useful prognostic factor in patients with cancer of various organs. This study was undertaken to clarify the relation between microvessel count and lymph node metastasis in submucosal colorectal cancer.

METHODS

Microvessel count was estimated in 254 invasive tumors that had been resected from patients with submucosal colorectal cancer. Immunohistochemistry with antibodies against CD34 was performed on archival specimens, and microvessel counts were estimated based on the average count of three fields (original magnification, x400) in the most vascular area at the site of deepest submucosal penetration.

RESULTS

Microvessel count ranged from 10 to 98, with a median of 40. Lesions with high microvessel counts (> or =40) had a significantly higher incidence of lymph node metastasis than those with low microvessel counts (<40; 21.8 percent vs. 6.2 percent). None of the 79 lesions with low microvessel counts and submucosal invasion up to a depth of 1,500 microm had metastasized to the lymph nodes. In multivariate analysis, microvessel count was an independent risk factor for lymph node metastasis in submucosal colorectal cancer (P = 0.0026).

CONCLUSION

Microvessel count at the site of deepest submucosal penetration can be one of the most useful predictors for lymph node metastasis. Analysis that combines microvessel count and depth of submucosal invasion may predict the occurrence of lesions without lymph node metastasis.

Cathepsin D expression as a possible predictor of lymph node metastasis in submucosal colorectal cancer

The aim of this study was to clarify the usefulness of cathepsin D expression as a predictor of lymph node metastasis in submucosal colorectal cancer (CRC). Cathepsin D expression was examined immunohistochemically in cancer and stromal cells located at the deepest portion of 254 invasive tumours that had been resected from patients with submucosal CRC. In cancer cells, the expression was classified according to differences in intracellular localisation: polarity positive, apical type (PA); polarity positive, basal type (PB); polarity negative (PN); or no expression (NE). Lesions with PN or NE expression showed a significantly higher incidence of lymph node metastasis than those with PA or PB expression. Alternatively, lesions with positive expression in stromal cells showed a significantly higher incidence of lymph node metastasis than that of those with negative expression. None of the lesions with PA or PB expression and negative expression in stromal cells had metastasised to the lymph node. In conclusion, analysis combining cathepsin D expression in cancer and stromal cells may be a quite useful predictor for lymph node metastasis and may broaden the indications for curative endoscopic treatment of submucosal CRC.

Role of local excision in the treatment of rectal cancer

Local excision (LE) of properly selected rectal cancers can provide long-term survival, with minimal morbidity, negligible mortality, and excellent functional results. The role of LE has evolved over the past century. Initially, to avoid the excessive mortality of abdominal surgery, aggressive LE was performed to control the symptoms of rectal cancer. As abdominal surgery became safer, LE was restricted for use in palliation or high-risk patients. Better preoperative tumor staging resulted in an expanded role for LE, including curative-intent treatment of selected T(1-2) rectal cancers. Techniques for LE include snare polypectomy, transanal excision, transanal endoscopic microsurgery, and posterior approaches. The high local recurrence rate and compromised survival reported in modern series, despite efforts to properly select patients with cancers suitable for LE, have convinced the authors to restrict the use of curative-intent LE in good-risk patients only to the most favorable rectal cancers. Close follow-up after LE is critical, because radical surgical salvage is usually possible if recurrence is identified promptly. Whether adjuvant chemoradiation can expand the role of curative intent LE remains controversial.

[Local treatment of rectal cancer]

Transanal local excision is only indicated in small rectal carcinomas with limited infiltration and high differentiation, and is followed by a 5-year survival rate around 90%. Endo-cavity irradiation has similar indications and results, but can only be performed by trained teams. The main risk of these local treatments is tumoral recurrence. A rigorous selection of patients is necessary and a rigorous postoperative survey.

Rectal carcinoma: double-contrast MR imaging for preoperative staging

PURPOSE

To evaluate and compare the imaging findings and staging of rectal carcinoma by using conventional magnetic resonance (MR) imaging, MR imaging with an enema of superparamagnetic ferristene-based contrast material, and MR imaging with an enema of ferristene solution plus intravenous injection of gadodiamide.

MATERIALS AND METHODS

Twenty-nine patients (17 women, 12 men; age range, 39-91 years) referred with a diagnosis of rectal carcinoma were examined. Analysis of the rectal wall and staging of the tumor were performed. In all patients, the MR imaging findings were correlated with the histopathologic findings.

RESULTS

The contrast material enema caused distention of the rectum and an intraluminal signal void, whereas the gadodiamide injection caused enhancement of the mucosa on T1-weighted images. This enhancement enabled evaluation of the normal rectal wall and differentiation of the mucosa, tunica muscularis, and perirectal space, which was not possible on the nonenhanced images. Double-contrast (ferristene solution plus gadodiamide) MR imaging was superior to imaging with only ferristene-based contrast material and had a sensitivity of 100%, specificity of 70%, and accuracy of 90% in distinguishing tumor stages worse than Dukes A.

CONCLUSION

Double contrast material-enhanced MR imaging enables accurate rectal carcinoma staging, which is not possible at nonenhanced imaging.

MUC-1 expression as a predictor of the curative endoscopic treatment of submucosally invasive colorectal carcinoma

PURPOSE

This study was undertaken to clarify the clinical significance of MUC-1 expression in the endoscopic treatment of colorectal carcinoma with submucosal invasion.

METHODS

One hundred eighty-four colorectal carcinomas with submucosal invasion were examined. The depth of submucosal invasion was classified as scanty or massive. The histologic subclassification at the deepest invasive portion was defined as well-differentiated, moderately well-differentiated, moderately to poorly differentiated, poorly differentiated, or mucinous adenocarcinoma. MUC-1 expression was examined immunohistochemically at the deepest invasive portion. In addition, the Ki67 labeling index was also examined immunohistochemically.

RESULTS

Lymph node metastases were detected in 28 (15.2 percent) of 184 lesions. Lesions with both scanty submucosal invasion and well-differentiated or moderately well-differentiated adenocarcinomas had no lymph node metastases. MUC-1 expression was detected in 88 (47.8 percent) of 184 lesions and correlated significantly with the presence of lymph node metastases. The Ki67 labeling index also correlated significantly with lymph node metastases. Furthermore, lesions with both MUC-1-negative and low Ki67 labeling index showed no lymph node metastases, even in lesions with massive submucosal invasion. Multivariate analysis indicated that MUC-1 expression was one of the most important risk factors for lymph node metastases and histologic grade among the clinicopathologic factors usually examined.

CONCLUSION

MUC-1 expression is one of the accurate predictors of the presence of lymph node metastases among the clinicopathologic factors commonly used. Combined analysis of MUC-1 expression and Ki67 labeling index may be a useful indicator of lymph node metastases and may broaden the indications for the curative endoscopic treatment of carcinoma with massive submucosal invasion.

Desmoplastic response in biopsy specimens of early colorectal carcinoma is predictive of deep submucosal invasion

PURPOSE

The aim of this study was to evaluate the role of histopathology of biopsy specimens in predicting depth of infiltration in early colorectal carcinomas before treatment.

METHODS

Early colorectal carcinomas that had been resected surgically or endoscopically between 1984 and 1995 were analyzed. Histopathologic findings, including differentiation of adenocarcinoma and a desmoplastic response were investigated.

RESULTS

One hundred nine early colorectal carcinomas consisted of 73 lesions of carcinoma in situ, 13 submucosal carcinomas with minimum invasion, 8 lesions with moderate invasion, and 15 lesions with deep invasion. Of 73 carcinoma in situ lesions, 72 (approximately 99 percent) showed well-differentiated adenocarcinomas and no desmoplastic response. Twelve (92 percent) of 13 submucosal carcinomas with minimum invasion also revealed well-differentiated adenocarcinoma without a desmoplastic response. Sixty-three percent (5/8) of lesions with moderate invasion revealed well-differentiated adenocarcinoma. None of the lesions had a desmoplastic response. Among lesions with deep invasion, 73 percent (11/15) demonstrated moderately differentiated adenocarcinoma, and 11 lesions had a prominent desmoplastic response (73 percent; P < 0.01).

CONCLUSIONS

These results suggest that if histopathologic findings of biopsy specimens taken from them before treatment demonstrated adenocarcinoma associated with a desmoplastic response, the lesions had at least deep invasion carcinomas. These lesions should be resected surgically. Submucosal carcinomas with minimum invasion, which have no desmoplastic response, could be treated endoscopically.

Sphincter preservation in rectal cancer. Preoperative radiation therapy followed by local excision

Radiation therapy followed by local excision results in local control rates that appear comparable to those of local excision alone (in highly selected patients) or local excision followed by adjuvant radiation therapy. A significant drawback of this approach, however, is the potential loss of important histological information, such as risk of lymph node metastasis, depth of tumor penetration, and presence of lymphatic or vascular invasion. Radiation therapy followed by local excision may be an option for treatment of more advanced T3 rectal cancers in patients who either refuse radical surgery or are medically unfit. The available data in the literature do not support the routine use of local excision after radiation therapy in otherwise healthy patients with locally advanced rectal cancer.

Sphincter preservation therapy for distal rectal carcinoma: a review

BACKGROUND

There has been increasing interest in the use of sphincter-preserving therapy for patients with distal rectal carcinomas. The outcomes of conservative treatments for early stage rectal carcinoma appear to be comparable to that achieved with abdominoperineal resection.

METHODS

Retrospective and prospective clinical series of patients with distal rectal carcinoma treated by local excision alone, local excision with postoperative adjuvant therapy, preoperative radiation followed by local excision, or radical circumferential sphincter-sparing surgeries were reviewed. The local control rates, salvage rates, and treatment complications in patients treated by these various methods were examined.

RESULTS

Patients with T1 distal rectal carcinoma with favorable clinical and histopathologic characteristics treated with local excision alone had a local control rate of greater than 90% in most series. Postoperative chemoradiation improved local control for those with T1 disease with unfavorable characteristics, or those with T2 disease. Most T3 patients had failure rates of greater than 30% despite adjuvant local and systemic therapy. With high dose preoperative radiation, approximately 80% of patients with locally advanced or unresectable tumors were able to undergo sphincter-preservation treatment.

CONCLUSIONS

Patients with favorable T1 rectal carcinoma are likely to be adequately treated with local excision alone. Patients with T1 disease with unfavorable characteristics as well as T2 patients will benefit from postoperative chemoradiation. The use of local therapy in T3 patients needs to be carefully considered because these patients are at relatively high risk for local recurrence despite adjuvant therapy. Preoperative radiation followed by either local excision or radical circumferential sphincter-sparing resections appears promising in allowing sphincter preservation in patients with locally advanced tumors.