Incidence trend of malignant polyps through the data of a specialized colorectal cancer registry: clinical features and effect of screening

Long-term oncological outcomes of endoscopic full-thickness resection after previous incomplete resection of low-risk T1 CRC (LOCAL-study): study protocol of a national prospective cohort study

BACKGROUND

T1 colorectal cancer (CRC) without histological high-risk factors for lymph node metastasis (LNM) can potentially be cured by endoscopic resection, which is associated with significantly lower morbidity, mortality and costs compared to radical surgery. An important prerequisite for endoscopic resection as definite treatment is the histological confirmation of tumour-free resection margins. Incomplete resection with involved (R1) or indeterminate (Rx) margins is considered a strong risk factor for residual disease and local recurrence. Therefore, international guidelines recommend additional surgery in case of R1/Rx resection, even in absence of high-risk factors for LNM. Endoscopic full-thickness resection (eFTR) is a relatively new technique that allows transmural resection of colorectal lesions. Local scar excision after prior R1/Rx resection of low-risk T1 CRC could offer an attractive minimal invasive strategy to achieve confirmation about radicality of the previous resection or a second attempt for radical resection of residual luminal cancer. However, oncologic safety has not been established and long-term data are lacking. Besides, surveillance varies widely and requires standardization.

METHODS/DESIGN

In this nationwide, multicenter, prospective cohort study we aim to assess feasibility and oncological safety of completion eFTR following incomplete resection of low-risk T1 CRC. The primary endpoint is to assess the 2 and 5 year luminal local tumor recurrence rate. Secondary study endpoints are to assess feasibility, percentage of curative eFTR-resections, presence of scar tissue and/or complete scar excision at histopathology, safety of eFTR compared to surgery, 2 and 5 year nodal and/or distant tumor recurrence rate and 5-year disease-specific and overall-survival rate.

DISCUSSION

Since the implementation of CRC screening programs, the diagnostic rate of T1 CRC is steadily increasing. A significant proportion is not recognized as cancer before endoscopic resection and is therefore resected through conventional techniques primarily reserved for benign polyps. As such, precise histological assessment is often hampered due to cauterization and fragmentation and frequently leads to treatment dilemmas. This first prospective trial will potentially demonstrate the effectiveness and oncological safety of completion eFTR for patients who have undergone a previous incomplete T1 CRC resection. Hereby, substantial surgical overtreatment may be avoided, leading to treatment optimization and organ preservation. Trial registration Nederlands Trial Register, NL 7879, 16 July 2019 ( https://trialregister.nl/trial/7879 ).

Statistical methods for measuring trends in colorectal cancer incidence in registries: A systematic review

Background

Monitoring cancer trends in a population is essential for tracking the disease’s burden, allocating resources, and informing public health policies. This review describes variations in commonly employed methods to estimate colorectal cancer (CRC) incidence trends.

Methods

We performed a systematic literature search in four databases to identify population-based studies reporting CRC incidence trends, published between January 2010 and May 2020. We extracted and described data on methods to estimate trends and assess model validity, and the software used.

Results

This review included 145 articles based on studies conducted in five continents. The majority (93%) presented visual summaries of trends combined with absolute, relative, or annual change estimates. Fourteen (10%) articles exclusively calculated the relative change in incidence over a given time interval, presented as the percentage of change in rates. Joinpoint regression analysis was the most commonly used method for assessing incidence trends (n= 65, 45%), providing estimates of the annual percentage change (APC) in rates. Nineteen (13%) studies performed Poisson regression and 18 (12%) linear regression analysis. Age-period-cohort modeling- a type of generalized linear models- was conducted in 18 (12%) studies. Thirty-nine (37%) of the studies modeling incidence trends (n=104, 72%) indicated the method used to evaluate model fitness. The joinpoint program (52%) was the statistical software most commonly used.

Conclusion

This review identified variation in the calculation of CRC incidence trends and inadequate reporting of model fit statistics. Our findings highlight the need for increasing clarity and transparency in reporting methods to facilitate interpretation, reproduction, and comparison with findings from previous studies.

A systematic review of methods to estimate colorectal cancer incidence using population-based cancer registries

Background

Epidemiological studies of incidence play an essential role in quantifying disease burden, resource planning, and informing public health policies. A variety of measures for estimating cancer incidence have been used. Appropriate reporting of incidence calculations is essential to enable clear interpretation. This review uses colorectal cancer (CRC) as an exemplar to summarize and describe variation in commonly employed incidence measures and evaluate the quality of reporting incidence methods.

Methods

We searched four databases for CRC incidence studies published between January 2010 and May 2020. Two independent reviewers screened all titles and abstracts. Eligible studies were population-based cancer registry studies evaluating CRC incidence. We extracted data on study characteristics and author-defined criteria for assessing the quality of reporting incidence. We used descriptive statistics to summarize the information.

Results

This review retrieved 165 relevant articles. The age-standardized incidence rate (ASR) (80%) was the most commonly reported incidence measure, and the 2000 U.S. standard population the most commonly used reference population (39%). Slightly more than half (54%) of the studies reported CRC incidence stratified by anatomical site. The quality of reporting incidence methods was suboptimal. Of all included studies: 45 (27%) failed to report the classification system used to define CRC; 63 (38%) did not report CRC codes; and only 20 (12%) documented excluding certain CRC cases from the numerator. Concerning the denominator estimation: 61% of studies failed to state the source of population data; 24 (15%) indicated census years; 10 (6%) reported the method used to estimate yearly population counts; and only 5 (3%) explicitly explained the population size estimation procedure to calculate the overall average incidence rate. Thirty-three (20%) studies reported the confidence interval for incidence, and only 7 (4%) documented methods for dealing with missing data.

Conclusion

This review identified variations in incidence calculation and inadequate reporting of methods. We outlined recommendations to optimize incidence estimation and reporting practices. There is a need to establish clear guidelines for incidence reporting to facilitate assessment of the validity and interpretation of reported incidence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-022-01632-7.

Endoscopic full-thickness resection of T1 colorectal cancers: a retrospective analysis from a multicenter Dutch eFTR registry

BACKGROUND

Complete endoscopic resection and accurate histological evaluation for T1 colorectal cancer (CRC) are critical in determining subsequent treatment. Endoscopic full-thickness resection (eFTR) is a new treatment option for T1 CRC < 2 cm. We aimed to report clinical outcomes and short-term results.

METHODS

Consecutive eFTR procedures for T1 CRC, prospectively recorded in our national registry between November 2015 and April 2020, were retrospectively analyzed. Primary outcomes were technical success and R0 resection. Secondary outcomes were histological risk assessment, curative resection, adverse events, and short-term outcomes.

RESULTS

We included 330 procedures: 132 primary resections and 198 secondary scar resections after incomplete T1 CRC resection. Overall technical success, R0 resection, and curative resection rates were 87.0 % (95 % confidence interval [CI] 82.7 %-90.3 %), 85.6 % (95 %CI 81.2 %-89.2 %), and 60.3 % (95 %CI 54.7 %-65.7 %). Curative resection rate was 23.7 % (95 %CI 15.9 %-33.6 %) for primary resection of T1 CRC and 60.8 % (95 %CI 50.4 %-70.4 %) after excluding deep submucosal invasion as a risk factor. Risk stratification was possible in 99.3 %. The severe adverse event rate was 2.2 %. Additional oncological surgery was performed in 49/320 (15.3 %), with residual cancer in 11/49 (22.4 %). Endoscopic follow-up was available in 200/242 (82.6 %), with a median of 4 months and residual cancer in 1 (0.5 %) following an incomplete resection.

CONCLUSIONS

eFTR is relatively safe and effective for resection of small T1 CRC, both as primary and secondary treatment. eFTR can expand endoscopic treatment options for T1 CRC and could help to reduce surgical overtreatment. Future studies should focus on long-term outcomes.

Factors predicting occurrence and therapeutic choice in malignant colorectal polyps: a study of 13 years of colonoscopic polypectomy

Colorectal carcinoma represents a major cause of mortality and 0.2–12% of resected colonic polyps have malignant cells inside. We performed a retrospective study of patients with resected polyps during a period of 13 years. A total of 905 patients had 2033 polyps removed; 122 polyps (109 patients) had malignant cells. Prevalence of malignant polyps with submucosal invasion was 1.23% and for all polyps with malignant cells was 6%; malignant polyps had a larger size (23.44 mm mean diameter) vs benign polyps (9.63 mm); the risk of malignancy was increased in polyps larger than 10 mm, in lateral spreading lesions and in Paris types 0-Ip, 0-Isp, in sigmoid, descending colon and rectum, in sessile serrated adenoma and traditional serrate adenoma subtypes of serrated lesions and in tubulovillous and villous adenoma. In 18 cases surgery was performed, in 62 patients only colonoscopic follow-up was made and in 35 patients no colonoscopic follow-up was recorded. From initially endoscopic resected polyps, recurrence was noted in seven (11.3%) cases; there was a trend toward association with depth of invasion, piecemeal resection, right and rectum location, sessile and lateral spreading type and pathological subtype. In surgical group, post-therapeutic staging was available in 11 cases; nodal involvement was noted in three (27.27%) cases; none had lymphatic or vascular invasion in endoscopically resected polyps. Four patients with no macroscopic local recurrence underwent surgery with no residual tumor. The rate of metastasis was 16.67% in surgical group and 1.61% in endoscopic group. Evaluation of lymph node (LN) invasion was available for 11 operated patients, with LN invasion (N1) in three patients, local residual tumoral tissue in one patient with incomplete resection and no residual tumor (R0 resection) in four patients with endoscopic resection before surgery.

Completion total mesorectal excision following transanal endoscopic microsurgery does not compromise outcomes in patients with rectal cancer

BACKGROUND

Transanal endoscopic microsurgery (TEM) represents a choice of treatment in patients with neoplastic lesions in the rectum. When TEM fails, completion total mesorectal excision (cTME) is often required. However, a concern is whether cTME increases the rate of abdominoperineal resections (APR) and is associated with higher risk of incomplete mesorectal fascia (MRF) resection. The aim of this study was to compare outcomes of cTME with primary TME (pTME) in patients with rectal cancer.

METHODS

This was a nationwide study on all patients with cTME from the Danish Colorectal Cancer Group database between 2005 and 2015. Patients with cTME were compared to patients with pTME after propensity score matching (matching ratio 1:2). Matching variables were age, gender, tumor distance from anal verge, American Society of Anesthesiologists (ASA) score and American Joint Committee on Cancer (AJCC) stage.

RESULTS

A total of 60 patients with cTME were compared with 120 patients with pTME. Patients with cTME experienced more intraoperative complications as compared to pTME patients (18.3% vs. 6.7%, p = 0.021). However, there was no difference in the rate of perforations at or near the tumor/previous TEM site (6.7% vs. 2.5%, p = 0.224), conversion to open surgery (p = 0.733) or 30-day morbidity (p = 0.86). On multivariate analysis, cTME was not a risk factor for APR (OR 2.49; 95% CI 0.95-6.56; p = 0.064) or incomplete MRF (OR 1.32; 95% CI 0.48-3.63; p = 0.596). There was no difference in the rate of local recurrence between cTME and pTME (5.2% vs. 4.3%, p = 0.1), distant metastases (6.8% vs. 6.8%, p = 1), or survival (p = 0.081). The mean follow-up time was 6 years.

CONCLUSION

In our study, the largest so far on the subject, we find no difference in postoperative short- or long-term outcomes between cTME and pTME.

En-bloc resection of bladder tumors for pathological staging: the value of lateral margins analysis

BACKGROUND

In endoscopic resection of colorectal tumors, the pathological assessment of the lateral margins is a strong predictor of tumor recurrence after resection. The aim of the current study is to evaluate the value of the peritumoral margins assessment in ERBT on tumor recurrence.

METHODS

We retrospectively analyzed the data of 50 consecutive patients with NMIBC and treated by ERBT between January and December 2017.

RESULTS

The lateral margins showed dysplasia in 16 patients and malignancy in three patients. Local recurrence occurred in 14 (28%) patients. It was noted that 57% of patients with recurrence showed some degree of dysplasia or malignancy in the lateral margin; however, on multivariate logistic regression lateral margins lesions were not significantly associated with recurrence (OR 2.175, 95% CI: 0.430-10.996, P=0.35).

CONCLUSIONS

ERBT may improve the pathological report of bladder tumor. There was a trend toward increased rate of recurrence in patients with dysplasia or malignancy in their lateral margins; however, this was not statistically significant on multivariate analysis. Further studies with larger sample sizes are required to assess the value of lateral margin analysis.

Outcomes following polypectomy for malignant colorectal polyps are similar to those following surgery in the general population

OBJECTIVE

Population-based studies on colorectal malignant polyps (MPs) are scarce. The aim of this study was to describe time trends in the incidence of colorectal MPs before and after the introduction of a colorectal mass-screening programmein 2003 and to assess outcomes (survival and recurrence) after endoscopic or surgical resection in patients with MPs.

DESIGN

We included 411 patients with MPs diagnosed between 1982 and 2011 in a well-defined population. Age-standardised incidence rates were calculated. Univariate and multivariate 5-year recurrence and net survival analyses were performed according to gross morphology.

RESULTS

Age-standardised incidence of MPs in patients aged 50-74 years doubled from 5.4 in 1982-2002 to 10.9 per 100 000 in 2003-2011. Pedunculated MPs were more frequently resected endoscopically (38.2%) than were sessile MPs (19.1%; p<0.001). For patients with pedunculated MPs and a pathological margin ≥1 mm, the 5 -year cumulative recurrence rate did not differ significantly between surgical and endoscopic resection (8.2% and 2.4%, respectively). For patients with sessile MPs, it was 3.0% after first-line or second-line surgical resection, 8.6% after endoscopic resection and 17.9% after transanal resection (p=0.016). The recurrence rate decreased dramatically for patients with sessile MPs from 11.3% (1982-2002) to 1.2% (2003-2009) (p=0.010) and remained stable for pedunculated MPs at 4.6% and 6.7%, respectively. Five-year net survival was 81.0% when pathological margins were <1 mm and 95.6% when ≥1 mm (p=0.024).

CONCLUSION

Outcomes following polypectomy in patients with a pathological margin ≥1 mm are similar to those following surgery in the general population. Endoscopic resection needs to be completed by surgery if pathological margins are less than 1 mm.

Malignant colorectal polyps: endoscopic polypectomy and watchful waiting is not inferior to subsequent bowel resection. A nationwide propensity score-based analysis

BACKGROUND AND AIMS

The optimal treatment of patients with malignant colorectal polyps is unsettled. The surgical dilemma following polypectomy is selecting between watchful waiting (WW) and subsequent bowel resection (SBR), but the long-term survival outcomes have not been established yet. This nationwide study compared survival of patients after WW or SBR.

METHODS

Danish nationwide study with 100% follow-up of all patients with malignant colorectal polyps (the Danish Colorectal Cancer Group database) in a 10-year period from 2001 to 2011. All patients' charts and histological reports were individually reviewed. Survival rates were calculated with Cox proportional hazard model after propensity score matching.

RESULTS

A total of 692 patients were included (WW, 424 (61.3%), SBR, 268 (38.7%)) with a mean follow-up of 7.5 years (3-188 months). Following propensity score matching, there was no significant difference in overall or disease-free survival (p = 0.344 and p = 0.184) or rate of local recurrence (WW, 7.2%, SBR, 2%, p = 0.052) or distant metastases (WW, 3.3%, SBR, 4.6%, p = 0.77). In the SBR group, there was no residual tumor or lymph node metastases in the resected specimen in 82.5% of the patients.

CONCLUSION

Subsequent bowel resection may not be superior to endoscopic polypectomy and watchful waiting with regard to overall and disease-free survival in patients with malignant colorectal polyps.

Optical diagnosis of malignant colorectal polyps: is it feasible?

BACKGROUND AND STUDY AIMS

As colorectal cancer screening programs are being implemented worldwide, an increasing number of early (T1) cancers are being diagnosed. These cancers should be recognized during colonoscopy because they require a specific therapeutic approach. Several studies have shown that Asian experts can reliably recognize T1 cancers during colonoscopy. In daily practice, however, accurate endoscopic diagnosis of T1 cancers still seems challenging. We evaluated the performance of optical diagnosis of T1 cancers by European colonoscopy experts, general gastroenterologists and gastrointestinal fellows.

PATIENTS AND METHODS

We collected endoscopic images of 43 colonic lesions: 19 T1 cancers (excluding intramucosal carcinoma) and 24 benign polyps ranging from 7 mm to 30 mm in size. Seven colonoscopy experts, 7 general gastroenterologists, and 14 gastrointestinal fellows assessed these images. We calculated sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) and their 95 % confidence intervals for optical diagnosis of T1 cancers.

RESULTS

Overall sensitivity for correct diagnosis of T1 cancers was 60 % (95 % CI;45 - 72). Sensitivity was highest for experts (67 %: 95 %CI; 48 - 81), when compared to general gastroenterologists (53 %: 95 %CI; 37 - 69) and gastrointestinal fellows (59 %: 95 %CI;45 - 72). The overall NPV was 75 % (95 %CI;60 - 86); NPV was lowest for general gastroenterologists 72 % (95 %CI;57 - 83) vs 78 % (95 %CI;63 - 89) for experts and 75 % (95 %CI;60 - 85) for gastrointestinal fellows.

CONCLUSIONS

In this image-based study, both sensitivity for the optical diagnosis of a T1 cancer and NPV for excluding a T1 cancer were insufficient. Experts performed best with a sensitivity of 67 % and a NPV of 78 %, while the performance of fellows in the last year of training was comparable to that of experts. Our study indicates that training for endoscopic diagnosis for T1 cancers is urgently needed to ensure optimal clinical practice for treatment of these lesions.

Interference of mucin 1 inhibits progression of colon carcinoma by repression of Wnt/β-catenin signaling

Mucin 1 (Muc1) is a tumor-associated glycoprotein and has an important role in cancer progression and metastasis. The aim of the study was to explore the effects and mechanism of Muc1 silencing on proliferation and tumor-forming capacity of colon cancer cell lines. In the present study, we first screened the colon cancer cell lines with high expression of Muc1 by western blot analysis. Then, the effective siRNA was selected and used for silencing endogenous Muc1. The results by MTT and vitro scratch assay showed that interference of Muc1 could effectively inhibit HCC2998 proliferation and migration (p<0.01). Also, colony-forming ability in Muc1-siRNA groups was significantly decreased compared with the control group (p<0.01). Cell cycle is detected by flow cytometry that suggested that Muc1-siRNA1 induced cell cycle arrest at S phase in HCC2998. Next, the expression and distribution of β-catenin in cytoplasm and the nucleus was detected by western blot and the results revealed that the expression of β-catenin was redistributed in Muc1-siRNA group. A higher β-catenin level was detected in cytoplasm, while a lower β-catenin level was located in nucleus, compared with controls (p<0.05). The tumorigenicity experiments showed that inhibition of Muc1 could significantly suppress the growth of HCC2998 in nude mice models (p<0.01). This study would effectively provide new clues for colon cancer therapy.