Colonoscopic surveillance after colorectal cancer resection: who needs more intensive follow-up?

Early follow-up colonoscopy after colorectal cancer resection detects significant pathology

BACKGROUND

Colonoscopy is a key component of surveillance after colorectal cancer (CRC) resection. Surveillance intervals for colonoscopy vary across the world, with a limited evidence-base to support guidelines.

OBJECTIVE

To evaluate the timing and outcome of colonoscopies after CRC resection.

METHODS

Retrospective cohort study on prospectively collected data. Included adult patients under surveillance following CRC resection. Patients with organ transplant, inflammatory bowel disease or colon cancer syndromes were excluded. The outcomes of the first (up to) three follow-up colonoscopies were audited and classified for presence of advanced neoplasia (advanced adenoma or adenocarcinoma).

RESULTS

980 patients underwent at least one follow-up colonoscopy with a median time to first colonoscopy of 12.4 months. The findings included 2.7% CRC and 13.2% advanced adenoma. Older age, stage IV disease, and synchronous cancers at surgery were significantly associated with a finding of advanced neoplasia at first colonoscopy. 562 patients underwent a second colonoscopy (median of 35 months after the first surveillance colonoscopy) with findings of 1.8% CRC and 11.4% advanced adenoma. Advanced adenoma on prior colonoscopy was associated with finding advanced neoplasia at the second colonoscopy. 288 patients underwent a third colonoscopy (median of 37 months from the preceding colonoscopy), with similar outcomes of advanced neoplasia being associated with advanced adenoma at the previous colonoscopy. 43 (4.4%) patients developed CRC whilst on surveillance.

CONCLUSIONS

Timely surveillance after CRC resection is important for detecting advanced neoplasia, and prolonged intervals between colonoscopies in the early years after surgery should be avoided.

Deep learning imaging phenotype can classify metabolic syndrome and is predictive of cardiometabolic disorders

BACKGROUND

Cardiometabolic disorders pose significant health risks globally. Metabolic syndrome, characterized by a cluster of potentially reversible metabolic abnormalities, is a known risk factor for these disorders. Early detection and intervention for individuals with metabolic abnormalities can help mitigate the risk of developing more serious cardiometabolic conditions. This study aimed to develop an image-derived phenotype (IDP) for metabolic abnormality from unenhanced abdominal computed tomography (CT) scans using deep learning. We used this IDP to classify individuals with metabolic syndrome and predict future occurrence of cardiometabolic disorders.

METHODS

A multi-stage deep learning approach was used to extract the IDP from the liver region of unenhanced abdominal CT scans. In a cohort of over 2,000 individuals the IDP was used to classify individuals with metabolic syndrome. In a subset of over 1,300 individuals, the IDP was used to predict future occurrence of hypertension, type II diabetes, and fatty liver disease.

RESULTS

For metabolic syndrome (MetS) classification, we compared the performance of the proposed IDP to liver attenuation and visceral adipose tissue area (VAT). The proposed IDP showed the strongest performance (AUC 0.82) compared to attenuation (AUC 0.70) and VAT (AUC 0.80). For disease prediction, we compared the performance of the IDP to baseline MetS diagnosis. The models including the IDP outperformed MetS for type II diabetes (AUCs 0.91 and 0.90) and fatty liver disease (AUCs 0.67 and 0.62) prediction and performed comparably for hypertension prediction (AUCs of 0.77).

CONCLUSIONS

This study demonstrated the superior performance of a deep learning IDP compared to traditional radiomic features to classify individuals with metabolic syndrome. Additionally, the IDP outperformed the clinical definition of metabolic syndrome in predicting future morbidities. Our findings underscore the utility of data-driven imaging phenotypes as valuable tools in the assessment and management of metabolic syndrome and cardiometabolic disorders.

Risk factors for metachronous colorectal cancer and advanced neoplasia following primary colorectal cancer: a systematic review and meta-analysis

BACKGROUND

Identifying risk factors for metachronous colorectal cancer (CRC) and metachronous advanced neoplasia could be useful for guiding surveillance. We conducted a systematic review and meta-analysis to investigate risk factors for metachronous CRC and advanced neoplasia.

METHODS

Searches were conducted in MEDLINE, Embase, Web of Science and Cochrane Central Registry of Controlled Trials for articles (searching period: 1945 to Feburary, 2021) that reported the results of an association between any factor and metachronous advanced neoplasia or metachronous CRC. There were no restrictions on the publication date or language. Random effects models were fitted to estimate the combined association between the risk factors and metachronous CRC or advanced neoplasia. The Risk of Bias In Non-Randomised Studies of Interventions tool (ROBINS-I) was used to assess the risk of bias of included studies.

RESULTS

In total, 22 observational studies with 625,208 participants were included in the systematic review and meta-analysis. Of these, 13 studies investigated risk factors for metachronous CRC and 9 for advanced neoplasia. The risks of metachronous CRC or advanced neoplasia were higher if the first CRC was diagnosed in the presence of a synchronous advanced lesion (pooled risk ratio (RR) from 3 studies: 3.61, 95% confidence interval (CI): 1.44-9.05; and pooled RR from 8 studies: 2.77, 95% CI: 2.23-3.43, respectively). The risk of metachronous CRC was lower, but the risk of metachronous advanced neoplasia was higher if the first CRC was distal (compared with proximal) (pooled RR from 3 studies: 0.48, 95% CI: 0.23-0.98; and pooled RR from 2 studies: 2.99, 95% CI: 1.60-5.58 respectively). The risk of metachronous advanced neoplasia increased with age (pooled RR from 3 studies: 1.07 per year of age, 95% CI: 1.03-1.11). There was no evidence that any lifestyle risk factors studied were associated with the risk of metachronous CRC or advanced neoplasia.

CONCLUSIONS

The identified risk factors for metachronous CRC and advanced neoplasia might be useful to tailor the existing surveillance guidelines after the first CRC. There were potential limitations due to possible misclassification of the outcome, confounding and risk of bias, and the findings cannot be generalised to high-risk genetic syndrome cases.

Early-Onset Colorectal Cancer Is Associated with a Lower Risk of Metachronous Advanced Neoplasia than Traditional-Onset Colorectal Cancer

BACKGROUND

Colorectal cancer (CRC) incidence in the USA has increased in adults under age 50. Current CRC surveillance guidelines do not consider age at diagnosis, and there are limited data available on outcomes from surveillance colonoscopies in early-onset CRC (EO-CRC) to guide recommendations on surveillance intervals.

AIMS

To compare surveillance outcomes between EO-CRC and traditional-onset colorectal cancer (TO-CRC).

METHODS

In a retrospective cohort study in a large tertiary care academic medical center, we collected data on patients with a diagnosis of CRC between 2000 and 2014 who received surgery with curative intent. We used log-rank test and inverse probability of treatment weighted Cox regression analysis to compare the development of metachronous advanced neoplasia (MAN) in patients with EO-CRC (diagnosed ages 18-49) and TO-CRC (diagnosed ages 50-75).

RESULTS

Patients with EO-CRC (n = 107) were more likely to present with advanced-stage disease (62% versus 35%, p < 0.0001), rectal tumors (45% versus 27%, p < 0.01), and a family history of CRC (30% versus 16%, p = 0.02) compared to those with TO-CRC (n = 139). Patients with EO-CRC had lower risk of MAN (adjusted HR 0.44, 95% CI 0.22-0.88) than TO-CRC patients. The 5-year event rate for MAN was lower for patients with EO-CRC compared to patients with TO-CRC (5.8% vs. 16.1%, p = 0.07). The presence of synchronous neoplasia or history of diabetes was also predictive of MAN.

CONCLUSIONS

EO-CRC was independently associated with a lower risk of developing MAN compared to TO-CRC. Shorter surveillance intervals may not be warranted in EO-CRC; however, large prospective studies are needed.

Risk factors of advanced metachronous neoplasms in surveillance after colon cancer resection

BACKGROUND/AIMS

Regular surveillance colonoscopy after colon cancer resection is recommended for detecting metachronous adenoma and cancer. However, risk factors for metachronous neoplasms have not been fully evaluated. We aimed to assess risk factors for advanced metachronous neoplasms during surveillance colonoscopy after colon cancer resection.

METHODS

Patients who underwent curative colectomy for nonmetastatic colon cancer between January 2002 and December 2012 were evaluated and followed up to December 2017.

RESULTS

A total of 293 patients were enrolled in this study. Among these, 179 (61.1%) were male, and the mean age was 63.2 ± 10.4 years. On perioperative clearing colonoscopy, synchronous high-risk adenomas (number ≥ 3, size ≥ 10 mm, high-grade dysplasia, villous histology, and serrated adenoma ≥ 10 mm) were detected in 95 patients (32.4%), and they were significantly associated with male sex, old age (≥ 65 years), current alcohol consumption, and current smoking (p < 0.05). During the follow-up period (mean 74.4 ± 36.4 months), advanced metachronous neoplasms were found in 45 patients (15.4%), including metachronous cancer in four (1.4%). In multivariate analysis, distal colon cancer (distal-to-splenic flexure; odds ratio [OR], 4.402; 95% confidence interval [CI], 1.658 to 11.689; p = 0.003), synchronous highrisk adenomas (OR, 3.225; 95% CI, 1.503 to 6.918; p = 0.003), and hypertension (OR, 2.270; 95% CI, 1.058 to 4.874; p = 0.035) were significant risk factors for advanced metachronous neoplasms.

CONCLUSION

During surveillance after curative colon cancer resection, patients with distal colon cancer, synchronous high-risk adenomas, and hypertension may need meticulous follow-up to improve overall outcomes.

Higher incidence of metachronous advanced neoplasia in patients with synchronous advanced neoplasia and left-sided colorectal resection for colorectal cancer

BACKGROUND AND AIMS

There is an increased risk of developing metachronous colorectal cancer (CRC) in the remnant colorectum after surgical resection of CRC. We evaluated the incidence of metachronous advanced neoplasia (AN) after surgery for CRC according to resection type and synchronous AN.

METHODS

This cohort study included patients who underwent surgical resection for initial CRC at a tertiary cancer center in Japan between September 2002 and December 2012. The cumulative probability of metachronous AN was calculated using the Kaplan-Meier method and was evaluated by the log-rank test.

RESULTS

Metachronous AN was detected in 145 of 1731 included patients, and the 5-year cumulative probability of metachronous AN was 13.1%. There was no significant difference in the incidence of metachronous AN in the right-sided colorectal resection versus left-sided colorectal resection (LCR) groups (log-rank test P = .151), whereas the incidence of metachronous AN was significantly higher in patients with synchronous AN (log-rank test P < .001). In subgroup analysis of patients according to resection type and synchronous AN, the LCR group with synchronous AN showed a significantly higher incidence of metachronous AN than the other groups (log-rank test P < .001).

CONCLUSIONS

We found that synchronous AN, but not resection type, was independently associated with the incidence of metachronous AN in patients who underwent surgical resection of CRC. In addition, subjects with synchronous AN after LCR had a potentially increased risk for metachronous AN. Thus, it may be useful to perform risk stratification according to synchronous AN and resection type.

Left-Sided Colectomy: One of the Important Risk Factors of Metachronous Colorectal Adenoma After Colectomy for Colon Cancer

BACKGROUND

Patients with a history of colonic resection for cancer have an increased risk for the development of metachronous malignant lesions. However, there is a lack of data on the detection rates of premalignant lesions during colonoscopy surveillance in these patients, and the few existing studies have shown conflicting results.

AIMS

To identify the risk factor of metachronous premalignant lesions after colon cancer surgery.

METHODS

We retrospectively screened consecutive patients who had undergone colonic surgery to treat colon cancer at the Chungnam National University Hospital between September 2009 and April 2014. We measured polyp, adenoma, and advanced adenoma detection rates (PDR, ADR, AADR) from the second surveillance colonoscopy in patients with left-sided colectomy (LCR) or right-sided colectomy (RCR). Multivariate analysis was performed to adjust for other confounding factors.

RESULTS

A total of 348 patients were enrolled (220 LCR patients and 128 RCR patients). The PDR, ADR, and AADR in patients in the LCR and RCR groups were 56.4, 43.6, and 11.8% and 35.9, 26.6, and 9.4%, respectively. PDR and ADR in the LCR group were significantly higher than those in the RCR group. A multivariate analysis showed that male sex, hypertension, body mass index higher than 25, and LCR (odds ratio 2.090; 95% confidence interval 1.011-4.317) were associated with adenoma recurrence.

CONCLUSIONS

The LCR group had a higher adenoma recurrence rate than the RCR group. Further studies are required to determine the optimal surveillance intervals according to the type of colonic resection.

Comparison of Colonoscopy Surveillance Outcomes Between Young and Older Colorectal Cancer Patients

BACKGROUND

Young-onset colorectal cancer is uncommon, but the incidence is increasing. Despite several guidelines for colonoscopic surveillance following colorectal cancer resection, there is little consistency regarding the timing and age-adjusted strategies of surveillance colonoscopy after surgery of young-onset colorectal cancer. The aim of this study was to compare the outcomes of surveillance colonoscopy between sporadic colorectal cancer patients with young and older age after curative resection.

METHODS

We retrospectively reviewed 569 colorectal cancer patients who underwent curative resection between January 2006 and December 2010. The primary outcome was comparison of the development of metachronous advanced neoplasia during surveillance colonoscopy between young and older colorectal cancer patients.

RESULTS

There were 95 patients in the young age group and 474 patients in the older age group. The mean time interval from surgery to the development of metachronous advanced neoplasia was 99.2 ± 3.7 months in the young age group and 84.4 ± 2.5 months in the old age group (P = 0.03). In the multivariate analysis, age (OR, 3.56; P = 0.04) and family history of colorectal cancer (OR, 2.66; P = 0.008) were associated with the development of metachronous advanced neoplasia. None of the young patients without both family history of colorectal cancer and high-risk findings at index colonoscopy showed advanced neoplasia during the follow-up period.

CONCLUSIONS

Age and family history of colorectal cancer are independent risk factors for the occurrence of advanced neoplasia after curative colorectal cancer resection, suggesting age-adjusted strategies of surveillance colonoscopy.

Clinical Significance of Preoperative Virtual Colonoscopy for Evaluation of the Proximal Colon in Patient With Obstructive Colorectal Cancer

Purpose

Virtual colonoscopy is the most recently developed tool for detecting colorectal cancers and polyps, but its effectiveness is limited. In our study, we compared the result of preoperative virtual colonoscopy to result of preoperative and postoperative colonoscopy. We evaluated also the accuracy of preoperative virtual colonoscopy in patients who had obstructive colorectal cancer that did not allow passage of a colonoscope.

Methods

A total of 164 patients who had undergone preoperative virtual colonoscopy and curative surgery after the diagnosis of a colorectal adenocarcinoma between November 2008 and August 2013 were pooled. We compared the result of conventional colonoscopy with that of virtual colonoscopy in the nonobstructive group and the results of preoperative virtual colonoscopy with that of postoperative colonoscopy performed at 6 months after surgery in the obstructive group.

Results

Of the 164 patients, 108 were male and 56 were female patients. The mean age was 62.7 years. The average sensitivity, specificity, and accuracy of virtual colonoscopy for all patients were 31.0%, 67.2%, and 43.8%, respectively. In the nonobstructive group, the average sensitivity, specificity, and accuracy were 36.6%, 66.2%, and 48.0%, respectively, whereas in the obstructive group, they were 2%, 72.4%, and 25.4%. Synchronous cancer was detected via virtual colonoscopy in 4 of the 164 patients.

Conclusion

Virtual colonoscopy may not be an effective method for the detection of proximal colon polyps, but it can be helpful in determining the therapeutic plan when its results are correlated with the results of other studies.

Incidence and predictors of adenoma after surgery for colorectal cancer

OBJECTIVE

Patients with colorectal cancer (CRC) are at increased risk for developing metachronous premalignant and malignant lesions. However, its real incidence and underlying risk factors are still unclear, and therefore quality measures for colonoscopy under this indication have not been completely established. The aim of this study was to assess the incidence of and risk factors for the development of adenomas after surgery for CRC.

PATIENTS AND METHODS

A total of 535 patients submitted to curative surgery for CRC between January 2008 and December 2011 were selected and their clinical records and surveillance colonoscopies were reviewed.

RESULTS

During a median follow-up of 62 months, 39.4% of the patients developed adenomas, 17.6% advanced adenomas and 3.4% developed metachronous cancers. Male sex [adjusted odds ratio (AOR)=1.99; 95% confidence interval (CI): 1.29-3.07] was an independent risk factor for adenomas during follow-up and absence of a high-quality baseline colonoscopy was the only independent risk factor for advanced adenomas (AOR=1.78; 95% CI: 1.03-3.07) and metachronous cancer (AOR=7.05; 95% CI: 1.52-32.66). In patients who had undergone a high-quality colonoscopy at baseline and at the first follow-up, the presence of adenomas (odds ratio=12.30; 95% CI: 2.30-66.25) and advanced adenomas (odds ratio=10.50; 95% CI: 2.20-50.18) in the first follow-up colonoscopy was a risk factor for the development of metachronous advanced adenomas during the subsequent surveillance.

CONCLUSION

Undergoing a high-quality baseline colonoscopy is the most important factor for reducing the incidence of advanced lesions after CRC surgery. All patients remain at high-risk for adenomas and advanced adenomas, but standardized follow-up should be adjusted after the first year of follow-up.

Colorectal Cancer: Postoperative Follow-up and Surveillance

Follow-up and surveillance form an important aspect of care in patients with colorectal cancers (CRC). Most recurrences will occur within 2 years of surgery and 90% by 5 years. Follow up protocols have not been well defined in stage I disease and the approach should be individualized. As 40% of patients with stages II and III will develop recurrences, intensive postoperative follow-up strategy is recommended for them. It includes visit to the clinician for clinical examination, serum carcinoembryonic antigen (CEA), computed tomography (CT) of the chest and abdomen, colonoscopy, and flexible proctosigmoidoscopy in rectal cancers. Surveillance should be undertaken in those who are medically fit for repeat surgical procedures or for chemoradiotherapy. The concept of intensive post operative surveillance is based on the fact that some of these patients can have resectable/curable recurrence.

The care of the colorectal cancer survivor

PURPOSE OF REVIEW

The gastroenterology literature emphasizes factors that increase colorectal cancer (CRC) incidence but presents little about management after initial CRC treatments. The purpose of this review is to describe the remarkably increasing numbers of CRC survivors in whom surveillance guidelines are often not followed and patient care is fragmented. The gastroenterologist can play an important role in this care to improve prognosis and overall health.

RECENT FINDINGS

Existing surveillance recommendations by specialty societies for CRC survivors are fairly consistent but implementation occurs in less than half. The gastroenterologist can help to coordinate care to ensure appropriate surveillance and also can help to diagnose and treat chemotherapy and radiotherapy complications in survivors which can affect the quality of life long after the initial treatment. The gastroenterologist also can focus on host factors, including management of obesity, exercise programs, and the diet and can introduce potential chemopreventive agents such as nonsteroidal anti-inflammatory drugs when positive prospective studies are forthcoming. Interested gastroenterologists also have a role in participating in such prospective studies.

SUMMARY

The gastroenterologist should enhance her/his role for coordinated management of CRC survivors to improve patient surveillance care, to treat posttherapy complications and encourage preventive measures to improve prognosis and quality of life.

Detection of Polyps After Resection of Colorectal Cancer

Purpose

Because colonoscopy after colorectal cancer surgery is important for detecting synchronous or metachronous colorectal neoplasms, we designed this study to investigate, by using postoperative colonoscopy, the miss rate for and the location of polyps remaining after colorectal cancer surgery.

Methods

In a prospectively-collected patient database, 264 patients were shown to have undergone a colorectal cancer resection between May 2012 and June 2013. Of these, 116 who had received a complete colonoscopy preoperatively and postoperatively were included in this study.

Results

Of these 116 patients, 68 were males and 48 were females; their mean age was 63 years. The mean time after surgery at which postoperative colonoscopy was performed was 7.1 months (range, 3-15 months). On postoperative colonoscopy, a total of 125 polyps were detected. Of these, there were no cancerous lesions; 46 (36.8%) were neoplastic polyps, and 79 (63.2%) were nonneoplastic polyps. Fifty-nine polyps (47.2%) and 15 polyps (12%) were located in the proximal and the distal parts of the anastomosis, respectively. The miss rates for the total numbers of polyps and of neoplastic polyps remaining after surgery were 37.4% and 24.2%, respectively. The incidence of neoplastic polyps increased during postoperative colonoscopy as it had during preoperative colonoscopy (r = 0.164, P = 0.048).

Conclusion

Colonoscopic surveillance after colorectal cancer resection results in the detection of pathologic polyps in one-fourth of the cases. During postoperative colonoscopy, careful examination of the proximal colon is necessary. Patients in whom multiple neoplastic polyps had been detected during preoperative colonoscopy require careful and thorough follow-up.