Colonoscopic Treatment of Colon Cancers

Outcome of follow-up colon examination among a population-based cohort of colorectal cancer patients

BACKGROUND & AIMS

The benefit of colonoscopy in the follow-up of colorectal cancer survivors is uncertain, and findings of surveillance colonoscopy are not well-characterized. We sought to estimate survival among colorectal cancer patients according to receipt of a follow-up colon examination and to describe the findings of such exams.

METHODS

We studied health maintenance organization enrollees with colorectal cancer who underwent surgical resection. Mortality was estimated by using survival analysis, and findings of colon examinations were determined by review of pathology reports.

RESULTS

One thousand two patients were eligible for study; 5-year survival was higher (76.8%) for patients who had at least one follow-up exam than for patients who did not undergo follow-up (52.2%, P < .0001). In multivariate analysis, colon examination remained independently associated with improved survival (hazard ratio, 0.58; 95% confidence interval, 0.44-0.75). Twenty patients (3.1%) were diagnosed with a second colorectal cancer, including 9 cancers detected within 18 months of initial cancer diagnosis. Advanced neoplasia was more common (15.5%) among patients followed up between 36-60 months after diagnosis compared with patients followed up within 18 months (6.9%, P = .02). History of adenomas was associated with advanced neoplasia on follow-up (P = .002). Patients with advanced neoplasia on initial follow-up were at high risk for advanced neoplasia on subsequent examinations (13/16, 81%).

CONCLUSIONS

After colorectal cancer resection, patients have a high risk of interval cancers, some of which represent missed lesions at initial diagnosis. Therefore, surveillance colonoscopy within 1 year of initial diagnosis is warranted. After adjusting for key variables, endoscopic surveillance is associated with improved survival.

Clinical and sociodemographic factors associated with colon surveillance among patients with a history of colorectal cancer

BACKGROUND

Substantial variability in the use of colon surveillance among colorectal cancer survivors has been reported. This study sought to examine trends in the use of colon surveillance among patients who have had colorectal cancer and to investigate factors associated with utilization.

METHODS

Health maintenance organization enrollees with a diagnosis of local or regional colon or rectal cancer between January 1993 and December 1999 were studied. Receipt of a colon examination by colonoscopy or by flexible sigmoidoscopy, together with barium contrast radiography of the colon was determined from automated clinical records, and rates of colon surveillance were estimated by using survival analysis.

RESULTS

A total of 1002 patients with a diagnosis of colorectal cancer met inclusion criteria for the study. Colon examinations were performed in 61% of patients within 18 months of diagnosis and in 80% of patients within 5 years of diagnosis. The median time from diagnosis to first colon surveillance examination (14 months) was unchanged over the study period, but the interval between first and second surveillance examinations increased by 17 months (p<0.001). Patients over 80 years of age (relative risk=0.32; 95% CI[0.22, 0.45]) and those with rectal cancer (relative risk=0.80; 95% CI[0.66, 0.97]) were less likely to undergo surveillance. Higher socioeconomic status (relative risk=1.29; 95% CI[1.03, 1.61]) and being married (relative risk=1.27; 95% CI[1.05, 1.53]) were associated with greater utilization. There was lower utilization among African American patients (relative risk=0.70; p=0.14) and increased utilization among other minorities (relative risk=1.47; p=0.06).

CONCLUSIONS

There is substantial variability in the use of colon examination for surveillance in patients with a history of colorectal cancer, and clinical and sociodemographic factors appear to influence the likelihood of surveillance.

Possible contribution of CD44 variant 6 and nuclear beta-catenin expression to the formation of budding tumor cells in patients with T1 colorectal carcinoma

BACKGROUND

In an earlier study, the authors demonstrated that tumor budding was useful for predicting lymph node metastasis in patients with early invasive (T1) colorectal carcinoma. This study was undertaken to clarify the associations between tumor budding, E-cadherin-catenin complex, and CD44 variant 6 abnormalities.

METHODS

In 51 T1 colorectal carcinomas, tumor budding (the number of dedifferentiation units at the invasive margin) on hematoxylin and eosin-stained slides was counted under light microscopy. Immunostaining for E-cadherin, alpha-catenin, beta-catenin, and CD44 variant 6 was performed on formalin fixed, paraffin embedded sections. The associations between locoregional failure (lymph node metastasis or local recurrence) and tumor budding and clinicopathologic parameters and immunoreactivity were examined statistically.

RESULTS

In univariate analysis, tumor budding and nuclear beta-catenin expression were associated significantly with locoregional failure (P = 0.004, 0.01). Multivariate analysis showed that tumor budding alone was associated significantly with locoregional failure (P = 0.02), and the association between nuclear beta-catenin expression and locoregional failure was marginally significant (P = 0.07). Analysis of variance showed that lymphatic invasion alone was associated significantly with tumor budding (P = 0.02), and there was a significant interaction effect for tumor budding between CD44 variant 6 expression and nuclear beta-catenin expression (P = 0.01). There was a significant correlation between expression patterns of these two molecules and locoregional failure (P = 0.01).

CONCLUSIONS

The current results suggest that the up-regulation of CD44 variant 6 through nuclear beta-catenin activation may contribute to the formation of tumor budding, and immunostaining of these two adhesion molecules may be useful in identifying those at high-risk for locoregional failure among patients with T1 colorectal carcinoma.