Recurrence Outcomes Less Favorable in T1 Rectal Cancer than in T1 Colon Cancer.

BACKGROUND: With the implementation of screening programs worldwide, diagnosis of early-stage colorectal cancer steadily increased, including T1 cancer. Current T1 cancer treatment does not differ according to anatomic location. We therefore compared the disease-free survival of T1 cancer arising from the rectum versus the colon. METHODS: The hospital-based study included subjects with T1 cancer at National Taiwan University Hospital from 2005 to 2014. Clinical, colonoscopy, and histopathology were reviewed for patients with a mean follow-up time of 7.1 (0.7-12.9) years. We conducted Kaplan-Meier analysis to compare the risk of recurrence by cancer location and Cox regression analysis to identify risk factors for T1 cancer recurrence. RESULTS: The final cohort included a total of 343 subjects with T1 cancer (mean age, 64.9 ± 11.7 years; 56.1% male), of whom 25 underwent endoscopic resection alone. Of the subjects who underwent surgery, 50 had lymph node metastasis and 268 did not. Kaplan-Meier analysis showed that the risk of recurrence was higher in T1 rectal cancer than T1 colon cancer (p = .022). Rectal location and larger neoplasm size were independent risk factors for recurrence, with hazard ratios of 4.84 (95% confidence interval, 1.18-19.92), and 1.32 (95% confidence interval, 1.06-1.65), respectively. The occurrence of advanced histology did not differ between T1 rectal and colon cancers (p = .58). CONCLUSION: T1 cancers arising from the rectum had less favorable recurrence outcomes than those arising from the colon. Further studies are needed to examine whether adjuvant radiotherapy or chemotherapy can reduce the risk of recurrence in T1 rectal cancer. IMPLICATIONS FOR PRACTICE: Current T1 colorectal cancer treatment and surveillance do not differ according to anatomic location. Clinical, colonoscopy, and histopathology were reviewed for 343 patients with T1 cancer with a mean follow-up time of 7.1 years. Kaplan-Meier analysis showed that the risk of recurrence was higher in T1 rectal cancer than T1 colon cancer. Moreover, the rectal location was an independent risk factor for recurrence. T1 cancers from the rectum had less favorable recurrence outcomes than those arising from the colon. It is critical to clarify whether adjuvant therapy or more close surveillance can reduce recurrence risk in T1 rectal cancer.

Mitigating the impact of COVID-19 on colorectal cancer screening: Organized service screening perspectives from the Asia-Pacific region.

Colorectal cancer(CRC) is one of the most prevalent malignancies in the Asia-Pacific region, and many countries in this region have launched population CRC service screening. In this study, CRC screening key indicators, including the FIT(fecal immunochemical test) screening rate (or participation rate) and the rate of undergoing colonoscopy after positive FIT in 2019 and 2020, were surveyed in individual countries in the Asia-Pacific region. The impact of the pandemic on the effectiveness of CRC screening was simulated given different screening rates and colonoscopy rates and assuming the pandemic would persist or remain poorly controlled for a long period of time, using the empirical data from the Taiwanese program and the CRC natural history model. During the COVID-19 pandemic, most of the programs in this region were affected, but to different extents, which was largely influenced by the severity of the local pandemic. Most of the programs continued screening services in 2020, although a temporary pause occurred in some countries. The modeling study revealed that prolonged pauses of screening led to 6% lower effectiveness in reducing CRC mortality. Screening organizers should coordinate with health authorities to elaborate on addressing screening backlogs, setting priorities for screening, and applying modern technologies to overcome potential obstacles. Many novel approaches that were developed and applied during the COVID-19 pandemic, such as the risk-stratified approach that takes into account personal CRC risk and the local epidemic status, as well as new digital technologies, are expected to play important roles in CRC screening in the future.

Adjunctive use of chromoendoscopy may improve the diagnostic performance of narrow-band imaging for small sessile serrated adenoma/polyp.

BACKGROUND AND AIM: Endoscopic diagnosis of sessile serrated adenoma/polyp (SSA/P) is challenging because of their subtle appearance. Narrow-band imaging (NBI) is useful for diagnosis, but its utility with concurrent chromoendoscopy (CE), especially to detect small SSA/P, is unproven. METHODS: This prospective study enrolled 367 consecutive patients who underwent screening colonoscopy with the finding of serrated polyps. Patients were divided into derivation and validation cohorts: Diagnostic criteria using different endoscopic modalities were generated by regression analysis in the derivation cohort and were validated in the validation cohort for sensitivity, specificity, and accuracy. RESULTS: There were 180 patients with 119 SSA/P and 147 hyperplastic polyps (HP) in the derivation cohort and 187 patients with 177 SSA/P and 125 HP in the validation cohort. With white-light endoscopy plus NBI, mucus cap, surface grooves, and expanded crypt were most associated with SSA/P. With white-light endoscopy plus CE, II-O pit pattern, mucus cap, and superficial telangiectasia were most associated with SSA/P. With the combined use of these three modalities, II-O pit pattern, mucus cap, and surface grooves were most associated with SSA/P. For large serrated polyp, NBI in combination with CE had a better accuracy than NBI alone (91% vs 86%, P = 0.025) to distinguish SSA/P from HP. CE alone had a better accuracy than NBI alone for distinguishing small SSA/P from small HP (85% vs 72%, P < 0.0001). CONCLUSION: Compared with NBI alone, adjunctive use of CE can improve the diagnostic accuracy for distinguishing SSA/P from HP, especially for small SSA/P.

Fecal Immunochemical Test Detects Sessile Serrated Adenomas and Polyps With a Low Level of Sensitivity.

BACKGROUND & AIMS: The serrated pathway is a distinct pathway of colorectal carcinogenesis that has been implicated in development of a substantial proportion of interval colorectal cancers. The fecal immunochemical test (FIT) detects early neoplasms with a higher level of sensitivity than the guaiac test. We investigated the sensitivity of the FIT in detection of sessile serrated adenomas/polyps (SSA/Ps). METHODS: We performed a prospective study of 6198 asymptomatic subjects (mean age, 59.0 ± 7.0 years) who received concurrent screening colonoscopies and FITs at the Health Management Center of National Taiwan University Hospital from August 2010 through November 2014. The sensitivity of FIT for conventional adenoma, advanced adenoma, and SSA/P at different cutoffs was calculated, and results were compared by using multivariate analysis adjusted for potential confounders. RESULTS: Prevalence values of SSA/P, adenoma, and advanced adenoma were 1.4%, 20.2%, and 5.5%, respectively. At cutoffs of 10, 15, and 20 µg hemoglobin/g feces, the FIT detected all SSA/Ps with 12.3%, 6.2%, and 6.2% sensitivity, large SSA/Ps with 18.4%, 10.5%, and 10.5% sensitivity, and advanced adenomas with 32.4%, 24.5%, and 20.9% sensitivity, respectively. Multivariate analysis revealed that positive results from the FIT did not differ significantly between individuals with SSA/P and those with non-advanced adenoma or those with negative findings from colonoscopy. Patients with large SSA/Ps were less likely to have positive results from the FIT than patients with advanced adenoma, with odds ratios of 0.44 (95% confidence interval [CI], 0.18-1.05), 0.30 (95% CI, 0.10-0.90), and 0.37 (95% CI, 0.12-1.12) at cutoffs of 10, 15, and 20 µg hemoglobin/g feces, respectively, after adjusting for lesion size, even with synchronous conventional adenoma. CONCLUSIONS: In a prospective study of 6198 subjects receiving the FIT and colonoscopy, we found that the FIT detected SSA/Ps with significantly lower levels of sensitivity than conventional adenoma. Further studies are needed to determine the effects of these findings on the effectiveness of FIT-based colorectal cancer screening program.