Specimen length as a perioperative surrogate marker for adequate lymphadenectomy in colon cancer: the surgeon's role.

The objective of this study was to determine whether there is a correlation between the length of the sigmoid colon removed and the number of harvested lymph nodes (LNs). Pathology charts of 137 sigmoid resections that were done over a 5-year period were reviewed. The length of removed sigmoid specimen reported in the pathology reports was correlated with the number of LNs retrieved from the specimen. The mean and median numbers of retrieved LNs were 9 and 10, respectively. There was an increase in the number of retrieved LNs with increasing length of resected sigmoid colon. For Dukes' B patients, the average length of the resected specimen was 15.1 cm for those with < 12 LNs and 20.3 cm for those with > 12 LNs (P = 0.01). Our data suggest that the surgeon may play an important role in determining the extent of LN harvesting during large bowel resection for cancer.

Angiogenic switch in earliest stages of human colonic tumorigenesis.

BACKGROUND: Angiogenesis is activated in numerous physiological and pathological conditions. We examined whether new vessel formation exists in the earliest stages of colonic tumorigenesis. MATERIALS AND METHODS: Microvascular density (MVD) was examined in 176 formalin-fixed and paraffin-embedded aberrant crypt foci (ACF) dissected from macroscopically-normal mucosa obtained from patients with colorectal cancer. ACF were classified as non-hyperplastic, non-dysplastic (NH-ACF, n = 80), hyperplastic (H-ACF, n = 72) and dysplastic (D-ACF, n = 24). Mucosal strips were stained with methylene blue solution and screened under x 40 magnification for ACF. The identified ACF were microdissected and stained with an anti-CD-34 monoclonal antibody. MVD in ACF were compared to that of normal corresponding mucosa. RESULTS: The mean MVD for normal mucosa and ACF were 13.7 +/- 7.7 and 23 +/- 13, respectively. Microvessel counts increased in NH-ACF versus normal mucosa (18.7 +/- 10 vs. 13.7 +/- 7.7, p = 0.05), in H-ACF versus NH-ACF (24.8 +/- 14 vs. 18.7 +/- 10, p = 0.002) and in D-ACF versus H-ACF (31.7 +/- 10 vs. 24.8 +/- 14, p = 0.014). We further evaluated the effect of low-dose aspirin on MVD in ACF. No effect of aspirin on microvessel counts could be detected. CONCLUSION: Our data suggest that angiogenesis occurs in ACF which are the earliest morphologically identifiable preneoplastic and early neoplastic lesions in colonic mucosa. With progression from NH-ACF to D-ACF there is a progressive, statistically significant increase in MVD, suggesting active angiogenesis during the earliest steps of colorectal tumorigenesis.