A direct comparison of the prevalence of advanced adenoma and cancer between surveillance and screening colonoscopies

A case of an enlarged rectal adenoma while achieving a clinical complete response with chemotherapy for advanced rectal cancer

The effect of chemotherapeutic agents on concomitant colorectal adenomas in patients with advanced colorectal cancer is not clear. We report a case of an enlarged rectal adenoma while achieving a clinical complete response with chemotherapy for an advanced rectal adenocarcinoma. A 78-year-old man was referred to our hospital for evaluation of bloody stools. The clinical diagnosis was an advanced lower rectal adenocarcinoma with para-aortic lymph node metastases, and a sessile polyp on the proximal aspect of the rectal tumor. The rectal adenocarcinoma was treated with chemotherapy, including 1 cycle of capecitabin plus oxaliplatin (CapeOX), 22 cycles of tegafur/gimeracil/oteracil (S-1) plus irinotecan (IRIS), and 1 cycle of tegafur (UFT) plus calcium folinate (LV). One year after the last course of chemotherapy, colonoscopy showed a scar without visible rectal tumor; CT imaging confirmed no para-aortic lymphadenopathy. The patient had a clinical complete response to chemotherapy. In contrast, the polyp increased in size. The polyp was removed by endoscopic mucosal resection (EMR). The pathologic evaluation showed a well-differentiated tubular adenocarcinoma with adenoma localized in the mucosa. No recurrence of the advanced adenocarcinoma or intramucosal adenocarcinoma with adenoma occurred for 2 years after EMR. This case indicates the importance of careful surveillance for synchronous adenomas, even in patients with advanced colorectal cancer.

Screening for Colorectal Cancer Is Associated With Lower Disease Stage: A Population-Based Study

BACKGROUND & AIMS

Screening for colorectal cancer (CRC) using fecal occult blood tests (FOBT) is associated with reduced CRC incidence and mortality. Population-based FOBT screening has led to identification of CRCs at earlier stages and longer patient survival times. We investigated the stage distribution of CRCs detected by colonoscopy in a large outpatient cohort.

METHODS

We performed a retrospective analysis of colonoscopies performed on 524,954 outpatients (age, ≥55 y) in Germany from January 2006 through December 2009. Patients with chronic inflammatory bowel diseases, and those with a personal history of adenoma or CRC, were excluded. Colonoscopy findings were categorized on the basis of the most advanced lesion found; histologic samples were obtained from all patients with suspected cancer and analyzed. Cancers were staged based on Union Internationale Contre le Cancer criteria. We analyzed absolute and relative frequencies of CRCs identified and tumor stages for patients who underwent colonoscopy for screening, evaluation of a positive FOBT, and evaluation of symptoms.

RESULTS

Of the 6065 CRCs identified, 1750 were found in the screening group, 1075 in subjects with positive FOBT, and 3240 in patients with symptoms. Stage I CRC was detected more frequently in subjects who received screening colonoscopies (41.15%) or in those with positive FOBT (39.10%), than in individuals with symptoms (24.42%; P < .001). In contrast, the detection rates of stage IV CRC were 10.67%, 10.76%, and 18.64%, respectively (P < .001). We observed a shift toward lower T stages in the screening and FOBT work-up groups compared with the group with symptoms. Compared with subjects with symptoms, the odds of diagnosing CRC at an advanced stage were significantly lower in the screening group (odds ratio, 0.533; 95% confidence interval, 0.451-0.631) and the FOBT work-up group (odds ratio, 0.570; 95% confidence interval, 0.469-0.694).

CONCLUSIONS

In this large population-based study, CRC detected by colonoscopies performed for screening and evaluation of positive FOBTs had a lower stage than those diagnosed by colonoscopies in symptomatic patients. These findings support the value of screening colonoscopy to reduce the burden of CRC.

Screening colonoscopy volume and detection of colorectal neoplasms: a state-wide study from Bavaria, Germany

Screening colonoscopy enables early detection of colorectal cancer and its precancerous lesions. The aim of this study was to assess the association of screening colonoscopy volume with colorectal neoplasm detection rate in routine practice. A registry-based study of individuals aged at least 55 years who underwent screening colonoscopy in Bavaria, Germany, between 2007 and 2009 was performed. Colorectal neoplasm detection rates (95% confidence intervals) were determined per physician. Physicians were grouped according to the number of screening colonoscopies performed per year (<50, 50-99, 100-199, ≥200). A total of 203 363 individuals (median age 64 years, 55.2% women) underwent screening colonoscopy between 2007 and 2009. Colonoscopies were performed by 509 physicians. The detection rate of any neoplasm increased with screening colonoscopy volume from 21.9% among physicians conducting fewer than 50 screening colonoscopies per year to 27.5% among physicians conducting 200 or more screening colonoscopies per year (P-value for trend <0.0001). Increases in detection rates with colonoscopy volume were also observed for advanced neoplasms and for colorectal cancer (P-value for trend 0.16 and <0.0001, respectively). Differences were largest between physicians conducting fewer than 50 screening colonoscopies per year and other physicians. These results support a potential role of a minimum colonoscopy volume for high-quality colonoscopy screening. Differences in neoplasm detection rates were high between physicians conducting fewer than 50 screening colonoscopies per year and physicians with higher screening colonoscopy volume.

Endoscopic follow-up after surgery for colorectal cancer

OBJECTIVE

Follow-up surgery for colorectal cancer is recommended. The yield of endoscopy is unknown and was therefore studied.

METHODS

Patients with colorectal cancer in the years 2003, 2004 and 2005 were included. Evaluation was done in July 2014.

RESULTS

Cancer was diagnosed in 267 patients. These were divided into three groups: group 1-still alive (n = 88), group 2-died within 1 year after diagnosis (n = 67), and group 3-died more than 1 year after diagnosis (n = 112). Patients in group 3 showed a trend towards non-cancer-related death (p = 0.06). Endoscopic follow-up was done in 101 patients (37.6 %). Patients still alive underwent more often follow-up colonoscopy (p < 0.001). Patients still alive had more often synchronous polyps detected during index endoscopy compared with patients of groups 2 and 3 (p = 0.03). Follow-up revealed more often new polyp(s) (p = 0.006). If no polyps were seen during the time of diagnosing cancer, follow-up endoscopy detected polyp(s) in 26 % of cases. Two newly developed cancers in group 1 and three in group 3 were diagnosed.

CONCLUSION

Endoscopic follow-up after curative surgery for colorectal cancer has a high diagnostic yield. Whether detection and removal of polyps increases survival is not yet clear.

Identification of physicians with unusual performance in screening colonoscopy databases: a Bayesian approach

BACKGROUND

The adenoma detection rate (ADR) is an important surrogate measure of performance quality for screening colonoscopies.

OBJECTIVE

To demonstrate how physicians with unusual performance concerning the adenoma detection rate may be identified in screening colonoscopy databases.

DESIGN

Bayesian random-effects modeling and Winsorization of potential outliers were applied to develop a robust model for the majority of providers. Divergence was assessed with adjustment for multiple testing. The steps in the analysis were visualized by using funnel plots. Additionally, minimum requirements for the number of colonoscopies with 1 or more detected adenomas were derived.

SETTING

Data from 422 physicians offering screening colonoscopy and participating in a quality assurance program in Bavaria, Germany, were used.

PATIENTS

A total of 69,738 asymptomatic individuals 55 to 79 years of age.

INTERVENTION

Screening colonoscopy.

MAIN OUTCOME MEASUREMENTS

Physician-specific ADRs.

RESULTS

The overall ADR in the sample was 26%. From an initial model, 62 physicians (15%) were identified as potential outliers. A model with normally distributed random effects was then chosen as the robust null model. Of the potential outliers, 10 (16%) were confirmed as physicians with unusual performance at a false discovery rate of 5%. For all of them, the observed ADR was lower than expected, and together they accounted for 1.4% of all included colonoscopies.

LIMITATIONS

Analysis of routine data.

CONCLUSION

The applied statistical approach appears suitable to identify unusual performance in screening colonoscopy databases. Its application may help to evaluate and improve the quality of colonoscopy in population-based colorectal cancer screening programs.

Which adenomas are detected by fecal occult blood testing? A state-wide analysis from Bavaria, Germany

Guaiac-based fecal occult blood tests (gFOBTs) are the most widely used noninvasive tests for colorectal cancer screening. While it is well known that they detect only a minority of colorectal adenomas, evidence for the characteristics of adenomas associated with detection is sparse. We derived estimates of the positive likelihood ratio (LR+), a summary measure of diagnostic performance, according to adenoma characteristics by comparing findings at colonoscopy among 19,208 and 181,128 participants who underwent colonoscopy to follow-up a positive gFOBT and as a primary screening examination, respectively, in Bavaria, Germany, in 2007-2009. Age and sex-adjusted estimates of LR+ (95% confidence intervals, 95% CI) ranged from 1.09 (1.05-1.13) for adenomas <1 cm to 2.52 (2.30-2.75) for adenomas >2 cm, and were much higher for pedunculated adenomas (1.96, 95% CI 1.85-2.08) than for flat or sessile adenomas (1.11, 95% CI 1.02-1.21 and 1.12, 95% CI 1.08-1.16, respectively). Villous or tubulovillous structure and dysplasia were likewise associated with a higher chance to be detected by gFOBT. Diagnostic performance was worse for proximal than for distal adenomas (age and sex adjusted LR+:1.16, 95% CI 1.09-1.23 and 1.35, 95% CI 1.29-1.41, respectively) which was explained by the lower proportions of large, pedunculated and nontubular adenomas in the proximal colon. Size, pedunculated shape, and nontubular histology are the key determinants of detection which also explain lower detection rates of adenomas located in the proximal colon.