Local excision carcinoma in early stage

Construction and analysis of dysregulated lncRNA-associated ceRNA network in colorectal cancer

Colorectal cancer (CRC) is one of the most frequently diagnosed digestive system cancer. The aim of the present study was to investigate the interactions among messenger RNAs (mRNAs), microRNAs (miRNAs), and long noncoding RNAs (lncRNAs) in CRC to reveal the mechanisms of CRC. Differentially expressed genes (DEGs) were identified from public gene expression data sets. One thousand eighty-one common dysregulated mRNAs in two data sets were identified. Gene function analysis and protein-protein interaction network analysis indicated that these DEGs might play important roles in CRC. LINC00365 was selected through coding- noncoding network analysis and its expression was validated upregulated in 22 paired clinical samples and four CRC cell lines. A competing endogenous RNA network composed of 70 miRNAs, nine mRNAs, and LINC00365 was constructed. Eight of nine mRNAs were validated upregulated in The Cancer Genome Atlas data set. Our results suggested that LINC00365 was an oncogene in CRC and it could regulate the expression of several mRNAs through sponging miRNAs.

Comparison of trans-anal endoscopic operation and trans-anal excision of rectal tumors

Background

Trans-anal endoscopic operation (TEO) has developed to facilitate proper tumor location and ensure excision safely.

Methods

We reviewed 92 patients enrolled in our database between 2006 and 2014 who were diagnosed with early rectal tumors and who underwent conventional trans-anal excision (TAE) or TEO. Clinical data were collected prospectively to compare safety and feasibility between two techniques.

Results

Ninety-two patients underwent trans-anal local excision for lower rectal tumors. TEO and TAE were performed in 48 and 44 patients, respectively. Age, sex, and comorbidities were similar. There was no significant difference in tumor diameter (1.6 ± 1.68 cm vs. 1.17 ± 1.17, respectively). Tumor height, however, was higher in the TEO (7.46 ± 3 cm) than the TAE group (3.84 ± 1.88 cm, p < 0.001). Four complications, perianal abscess, and two perforations, occurred in the TEO group, whereas no major complications occurred in the TAE. Seven patients (14.6%) underwent TEO underwent a salvage operation compared to only a single patient in TAE group (2.3%, p = 0.039). Eight patients (17.4%) diagnosed with adenocarcinoma developed recurrence, four in each group. Disease-free survival was similar between groups (TEO – 41.8 months, 95% RI 39.4–44.1; TAE 79.7 months, 95% RI 72.2–87.3). However, more TAE patients (n = 7, 15.9%) than TEO patients (n = 2, 4.2%) underwent chemotherapy.

Conclusions

TEO treatment of local rectal tumors is safe and feasible and can achieve an adequate resection margin. Local recurrence was similar in both groups. However, the numbers of salvage operations and minor complications were higher in the TEO group.

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TEO is treatment modality of choice in addressing lower rectal lesions.

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Evolving of TEO technique facilitate higher standard of academic teaching.

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TEO has few drawbacks; first, long term learning curve; second, technique is demanding (through single port + narrow space).

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TEO has promising results in the field of surgical oncology with equivalent results to conventional surgery.

Analysis of 116 cases of rectal cancer treated by transanal local excision

BACKGROUND

The purpose of this research was to evaluate the therapeutic effects and prognostic factors of transanal local excision (TAE) for rectal cancer.

METHODS

We retrospectively analyzed 116 cases that underwent TAE for rectal cancer from 1995 to 2008. A Cox regression analysis was used to analyze prognostic factors.

RESULTS

The survival times for the patients were from 14 to 160.5 months (median time, 58.5 months). The 5-year and 10-year overall survival rates were 72% and 53%, respectively. In all 16 cases experienced local recurrence (13.8%). Pathological type, recurrence or metastasis, and depth of infiltration (T stage) were the prognostic factors according to the univariate analysis, and the latter two were independent factors affecting patient prognosis. For patients with T1 stage who underwent adjuvant radiotherapy, there was no local recurrence; for those in T2 stage, the local recurrence rate was 14.6%. In addition, there was no difference between the patients who received radiotherapy and those who did not (T1: P = 0.260, T2: P = 0.262 for survival rate and T1: P = 0.480, T2: P = 0.560 for recurrence).

CONCLUSIONS

The result of TAE for rectal cancer is satisfactory for T1 stage tumors, but it is not suitable for T2 stage tumors.

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.

Current status of rectal cancer treatment in China

AIM

Colorectal cancer (CRC) is the fourth most common carcinoma in China. For economic reasons, a national CRC registry has not been established and a large-scale screening programme has not been implemented.

METHOD

Clinical studies (since 2000) of CRC epidemiology which originated from China were summarized, and data was analyzed.

RESULTS

In China, the majority of hospitals in central cities and even in county hospitals are able to provide medical care for CRC patients. Due to socio-economic disparities, medical conditions and skill level, there is a wide variation in the treatment. Most oncologists make their clinical decisions based on the National Comprehensive Cancer Network (NCCN) guidelines, although some domestic guidelines are now available. On 11 October 2011, the China Ministry of Health released national guidelines for CRC treatment. Owing to language difficulties, research on CRC in China has only had a limited exposure in the international literature, due in some part to lack of understanding of the current position in the country.

CONCLUSION

The national guidelines for CRC treatment will give a degree of standardization of the treatment of CRC nationwide and will ensure that higher quality care will be available, especially in rural areas. Chinese colorectal surgeons urgently need to exchange their knowledge and experience with international colleagues.

Update and debate issues in surgical treatment of middle and low rectal cancer

Based on a review of the literature, this paper provides an update on surgical treatment of middle and low rectal cancer and discusses issues of debate surrounding that treatment. The main goal of the surgical treatment of rectal cancer is radical resection of the tumor and surrounding lymphatic tissue. Local excision of early rectal cancer can be another treatment option, in which the patient can avoid possible complications related to radical surgery. Neoadjuvant chemoradiation therapy (CRT) has been recommended for patients with cT3-4N0 or any T N+ rectal cancer because CRT shows better local control and less toxicity than adjuvant CRT. However, recent clinical trials showed promising results for local excision after neoadjuvant CRT in selected patients with low rectal cancer. In addition, the "wait and see" concept is another modality that has been reported for the management of tumors that show complete clinical remission after neoadjuvant CRT. Although radical surgery for middle and low rectal cancer is the cornerstone therapy, an ultralow anterior resection with or without intersphincteric resection (ISR) has become an alternative standard surgical method for selected patients. Many studies have reported on the oncological safety of the ISR, but few of them have addressed the issue the functional outcome. Furthermore, an abdominoperineal resection (APR) has problems with high rates of tumor perforations and positive circumferential resection margins, and those factors have contributed to its having a high rate of local recurrence and a poor survival rate for rectal cancer compared with sphincter-saving procedures. Recently, great efforts have been made to reduce these problems, and the total levator excision or the extended APR concept has emerged. Surgical management for low rectal cancer should aim to radically excise the tumor and to preserve as much of the sphincter function as possible by using multidisciplinary approaches. However, further prospective clinical trials are needed for tailored treatment of rectal cancer patients.

Local excision for rectal carcinoma

Local excision is an alternative approach to radical proctectomy for rectal cancer, but from an oncologic standpoint, it is a compromise, and its role remains controversial. Careful patient selection is essential because local excision is generally considered only for early rectal cancer with no evidence of nodal metastasis, parameters that can be predicted by clinical examination, and various radiologic modalities with variable accuracy. In this review, we present the literature evaluating the oncologic adequacy of local excision, including transanal endoscopic microsurgery and the results of salvage surgery after local excision. An overview of local excision in the context of perioperative adjuvant therapies is included. Finally, we suggest a treatment algorithm for local excision in rectal cancer.

Complications after transanal endoscopic microsurgical resection correlate with location of rectal neoplasms

PURPOSE

Transanal endoscopic microsurgery (TEM) is a technique that has found its place in routine practice due to its minimal invasive character and associated low morbidity. The purpose of this study was to assess the influence of anatomical variables of rectal neoplasms as well as surgeon experience on postoperative complications in patients undergoing TEM at a tertiary care center.

METHODS

Data from 288 patients undergoing TEM over a 16 year period were entered in a prospective data base. Anatomical data of rectal neoplasms, operative data, and early postoperative outcome were analyzed retrospectively.

RESULTS

Overall surgical complications [OR 7.0 (1.5-45,5); p < 0.01] and bleeding [OR 222 (82 - 14316); p < 0.01] correlated with the localization of the neoplasm on the lateral wall of the rectum. Furthermore there was a trend for more surgical overall complications as well as bleeding in neoplasms with a diameter of >2 cm and neoplasms located >8 cm from the anal verge. Complications did not correlate with the number of TEM procedures performed.

CONCLUSION

TEM resection of neoplasms located on the lateral rectal wall have a higher risk of bleeding. The learning curve for transanal endoscopic microsurgery appears to be negligible in surgeons with experience in minimal invasive surgery.

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.

Preoperative Staging of Rectal Cancer: Comparison of 3-T High-Field MRI and Endorectal Sonography

OBJECTIVE

The aim of this study was to compare phased-array 3-T MRI and endorectal sonography in the preoperative staging of rectal cancer.

MATERIALS AND METHODS

During an 8-month period, 24 patients with rectal cancer underwent both 3-T MRI performed with phased-array coils and 7.5- to 10-MHz endorectal sonography in the 3 weeks before surgical resection. Three radiologists independently reviewed the MR and endorectal sonographic images. The histopathologic findings in resected specimens were used to evaluate the sensitivities and specificities of these techniques for invasion of the muscularis propria and perirectal tissue and for lymph node involvement. Receiver operating characteristic (ROC) analysis was used to compare the diagnostic accuracies of the techniques.

RESULTS

For muscularis propria invasion, the mean sensitivities of both MRI and endorectal sonography were 100%, and the mean specificities were 66.7% and 61.1%, respectively. The differences in the mean sensitivities and specificities were not statistically significant (p > 0.05 in each case). For perirectal tissue invasion, MRI and endorectal sonography had comparable sensitivities and specificities (91.1% vs 100%, 92.6% vs 81.5%; p > 0.05 in each case). They also had similar sensitivities and specificities for lymph node involvement (63.6% vs 57.6%, 92.3% vs 82.1%; p > 0.05 in each case). ROC curves for muscularis propria invasion and lymph node involvement showed no differences in diagnostic accuracy. The mean area under the ROC curve for endorectal sonography (A(Z) = 0.996) for perirectal tissue invasion, however, showed higher accuracy than that of MRI (A(Z) = 0.938, p = 0.028).

CONCLUSION

The sensitivity, specificity, and accuracy of 3-T MRI were similar to those of endorectal sonography for muscularis propria invasion and lymph node involvement, but for perirectal tissue invasion, 3-T MRI was less accurate than endorectal sonography.

Chirurgie du cancer du rectum

Surgical resection is the only curative procedure for carcinoma of the rectum. Heald's development of total mesorectal excision has made it the standard approach for mobile, non-fixed tumors; it permits optimal local control with less than 10% local recurrence at five years and minimizes nerve damage and genito-urinary complications. Although initial short-term results of laparoscopic approaches are very promising, the final role of laparoscopy has not yet been established. Neo-adjuvant radiotherapy should be proposed for locally advanced (T3, T4, and/or N+) tumors of the low and mid-rectum. Radiochemotherapy coupled with intersphincteric dissection offers hope for sphicter-sparing extirpation of even the lowest of rectal cancers. Local resection through a trans-anal approach may be considered for small (<3 cm.), mobile, well-differentiated tumors lying within 8 cm. of the anal verge if rectal echo-endoscopy shows an in-situ tumor or a T1 lesion with no evidence of lymphadenopathy. Future strategies may enlarge the indications for local resection if and when radiochemotherapy can achieve a complete local response (tumor sterilization).

Preoperative staging of rectal cancer with MR Imaging: correlation with surgical and histopathologic findings

Rectal cancer is a common malignancy that continues to have a highly variable outcome, with local pelvic recurrence after surgical resection usually leading to incurable disease. The success of tumor excision depends largely upon accurate tumor staging and appropriate surgical technique, although the results of recent surgical trials indicate that evaluation of the involvement of the mesorectal fat and mesorectal fascia is even more important than T staging for treatment planning. Magnetic resonance (MR) imaging is increasingly being used to evaluate tumor resectability in patients with rectal cancer and to determine which patients can be treated with surgery alone and which will require radiation therapy to promote tumor regression. High-spatial-resolution MR imaging has proved useful in clarifying the relationship between a tumor and the mesorectal fascia, which represents the circumferential resection margin at total mesorectal excision. Phased-array surface coil MR imaging in particular plays a vital role in the therapeutic management of rectal cancer. At present, phased-array MR imaging best fulfills the clinical requirements for preoperative staging of rectal cancer. However, preoperative evaluation of the other prognostic factor, nodal status, is still problematic, and further studies will be needed to better define the role of MR imaging in this context.

Is surgery-only the adequate treatment approach for T2N0 rectal cancer?

BACKGROUND AND OBJECTIVES

Resection combined with standard lymphadenectomy is generally recommended for T2N0 rectal cancer. In order to evaluate the outcome of this specific tumor category, our own data were reviewed.

METHODS

To evaluate the results of patients with curative resected T2N0 rectal carcinoma, we reviewed data of 164 consecutive patients with adenocarcinoma of the rectum between 1981 and 2003 in our department. In addition, patient characteristics were stratified according to the position of the rectal tumor with respect to the anal verge.

RESULTS

One hundred ten patients (67.1%) underwent anterior resection and 54 patients (32.9%) received abdominoperineal amputation. The follow-up revealed 6 local recurrences (3.7%); in 10 patients (10.0%), metastases were discovered. Regarding the tumor localization nearly no local recurrence or distant metastases were observed in the middle or the upper rectum. However, in the lower rectum the actuarial 5-year recurrence rate was 16.2%.

CONCLUSIONS

Although T2N0 rectal carcinomas are considered as low risk tumors, we found a considerable local recurrence rate of 3.7%. The question arises whether this result can be improved by adjuvant treatment modalities without being compromised by the toxicity of an adjuvant treatment.

Preoperative staging of rectal cancer: accuracy of 3-Tesla magnetic resonance imaging

The purpose of this study was to evaluate the accuracy of 3-Tesla magnetic resonance imaging (MRI) for the preoperative staging of rectal cancer. Thirty-five patients with a primary rectal cancer who underwent preoperative 3-T MRI using a phased-array coil and had a surgical resection were enrolled in the study group. Preoperatively, three experienced radiologists independently assessed the T and N staging. A confidence level scoring system was used to determine if there was any perirectal invasion, and receiver operating characteristic (ROC) curves were generated. The interobserver agreement was estimated using kappa statistics. The overall accuracy rate of T staging for rectal cancer was 92%. The diagnostic accuracy was 97% for T1, 89% for T2 and 91% for T3, respectively. The predictive accuracy for perirectal invasion by the three observers was high (Az>0.92). The interobserver agreement for T staging was moderate to substantial. The overall sensitivity, specificity, and accuracy for the detection of mesorectal nodal metastases were 80%, 98%, and 95%, respectively. In conclusion, preoperative 3-T MRI using a phase-array coil accurately indicates the depth of tumor invasion for rectal cancer with a low variability.

Rectal cancer: local staging and assessment of lymph node involvement with endoluminal US, CT, and MR imaging--a meta-analysis

PURPOSE

To perform a meta-analysis to compare endoluminal ultrasonography (US), computed tomography (CT), and magnetic resonance (MR) imaging in rectal cancer staging.

MATERIALS AND METHODS

Relevant articles published between 1985 and 2002 were included if more than 20 patients were studied, histopathologic findings were the reference standard, and data were presented for 2 x 2 tables; articles were excluded if data were reported elsewhere in more detail. Two reviewers independently extracted data on study characteristics and results. Bivariate random-effects approach was used to obtain summary estimates of sensitivity and specificity for invasion of muscularis propria, perirectal tissue, and adjacent organs and for lymph node involvement. Summary receiver operating characteristic (ROC) curves were fitted for perirectal tissue invasion and lymph node involvement.

RESULTS

Ninety articles fulfilled all inclusion criteria. For muscularis propria invasion, US and MR imaging had similar sensitivities; specificity of US (86% [95% confidence interval [CI]: 80, 90]) was significantly higher than that of MR imaging (69% [95% CI: 52, 82]) (P =.02). For perirectal tissue invasion, sensitivity of US (90% [95% CI: 88, 92]) was significantly higher than that of CT (79% [95% CI: 74, 84]) (P <.001) and MR imaging (82% [95% CI: 74, 87]) (P =.003); specificities were comparable. For adjacent organ invasion and lymph node involvement, estimates for US, CT, and MR imaging were comparable. Summary ROC curve for US of perirectal tissue invasion showed better diagnostic accuracy than that of CT and MR imaging. Summary ROC curves for lymph node involvement showed no differences in accuracy.

CONCLUSION

For local invasion, endoluminal US was most accurate and can be helpful in screening patients for available therapeutic strategies.