L.V. Phillips

Diagnostic use of the sentinel node in colon cancer

PURPOSE: The aim of this study was to compare the lymphatic drainage of colon cancer with the anatomic distribution of histologic and submicroscopic lymph node metastases. METHODS: Patients attending for colectomy were eligible to enter the study. At the commencement of surgery, 40 MBq of 99mTc colloidal antimony sulfide in 2 ml of Patent Blue dye was injected subserosally around the tumor. Resection was completed in a standard fashion. After resection, specimens were imaged with a gamma camera to determine the site of sentinel lymph nodes, and then dissected, recording the position of the lymph nodes on an anatomic diagram. Recovered lymph nodes were bisected, one-half for routine histology and one-half for assessment by keratin 20 (K20) reverse transcription polymerase chain reaction. The kappa measure of agreement was used to assess concordance between sentinel nodes and histologic and submicroscopic metastases. RESULTS: Four hundred fifty-six lymph nodes were dissected from 26 tumors and evaluated using lymphoscintigraphy and lymph node mapping. Sentinel nodes were evident in 23 tumors (88 percent). The sensitivity of sentinel nodes involvement as a predictor of metastatic disease was 55 percent (95 percent confidence interval, 23–83), with a false negative (nondiagnostic) rate of 45 percent. Sentinel nodes involved the apical group in four tumors, and represented anatomic “skip” lesions in four tumors. CONCLUSIONS: Direct lymphatic drainage to the apical group does occur in colon cancer; however, sentinel node mapping of colon cancer by this technique is of little clinical value because of the poor concordance between lymph node metastases and sentinel nodes.

Prognostic significance of occult metastases in colon cancer.

AbstractPURPOSE: The purpose of this study was to determine the prognostic significance of occult lymph node metastases in colon cancer detected by cytokeratin 20 reverse transcription polymerase chain reaction. METHODS: Two hundred patients undergoing elective colonic resections were enrolled in the study. Lymph nodes from resected specimens were dissected fresh and assessed by both reverse transcription polymerase chain reaction and histopathology. Follow-up was undertaken for up to five years, and the major end point of death was recorded. Univariate survival analysis was performed by the log-rank method and the change-in-estimate method was used to construct multivariate analysis models for the effect of cytokeratin 20 reverse transcription polymerase chain reaction lymph node status on overall survival. RESULTS: A total of 2,317 lymph nodes from 200 patients were assessed by both histopathology and cytokeratin 20 reverse transcription polymerase chain reaction. Forty-eight of 141 (34 percent) histologically lymph node–negative patients had evidence of occult metastases by cytokeratin 20 reverse transcription polymerase chain reaction. An interim analysis was performed at a median of 42 (range, 23–75) months. Cytokeratin 20 reverse transcription polymerase chain reaction lymph node status was a highly significant predictor of overall survival (P < 0.0001) on univariate analysis. In addition, the number of reverse transcription polymerase chain reaction–positive lymph nodes was a significant predictor of survival in the histologically lymph node–negative group (P < 0.0001) on univariate analysis. On multivariate analysis cytokeratin 20 reverse transcription polymerase chain reaction lymph node status had independent prognostic significance for overall survival (P = 0.021; hazard ratio = 2.7) and the number of cytokeratin 20 reverse transcription polymerase chain reaction–positive lymph nodes was a significant predictor of overall survival in the histologically lymph node–negative group (P = 0.005; hazard ratio = 1.1–11.1). CONCLUSION: Cytokeratin 20 reverse transcription polymerase chain reaction has potential as a clinically useful marker for staging colorectal cancer. Further follow-up is required, but if the current trends continue, a study of the effect of adjuvant therapy in patients with occult metastases detected by cytokeratin 20 reverse transcription polymerase chain reaction is indicated.

Analysis of potential markers for detection of submicroscopic lymph node metastases in breast cancer.

SummaryWe have developed sensitive assays for cytokeratin (K) 8, 16, 19, stromelysin 3 (ST3), MUC1 and maspin mRNAs using reverse transcription polymerase chain reaction (RT-PCR) and used these to assess lymph node status in patients undergoing surgery for breast cancer. In addition the RT-PCR assays were tested against lymph nodes from non-cancer patients to determine their specificity. Despite high sensitivity RT-PCR assays for K8, K16, K19, ST3 and maspin were not found to be useful as markers of submicroscopic disease as transcripts of these genes were detected in the great majority of control lymph nodes tested. Expression of MUC1 was also not found to be useful as it was both insensitive and non-specific. The importance of assessing potential markers against an adequately sized control population is demonstrated, as failure to do so can lead to erroneous conclusions.

Elevated Plasma Active Matrix Metalloproteinase-9 Level Is Associated With Coronary Artery In-Stent Restenosis

Objective—This study aimed to determine whether the plasma levels of matrix metalloproteinase-9 (MMP-9) or tissue inhibitor of metalloproteinases-1 (TIMP-1) were altered in patients with a history of symptomatic in-stent restenosis (ISR). Methods and Results—A group of 158 patients with a history of ISR were compared with 128 symptom-free patients. Plasma samples and a detailed risk factor history were collected. Plasma samples were analyzed for pro–MMP-9 and latent MMP-9 and active MMP-9, latent MMP-3, and TIMP-1. Several variables were associated with ISR, including index coronary disease extent and severity (number of diseased vessels and American College of Cardiology/American Heart Association lesion classification), number, diameter, and total length of stent(s) inserted, and plasma high-density lipoprotein cholesterol. Plasma active MMP-9 (odds ratio, 1.96; 95% CI, 1.43 to 2.69) showed independent risk association with ISR. Patients with multiple sites of ISR had significantly higher levels of active MMP-9 compared with patients with only a single ISR lesion or no ISR. Conclusion—Plasma active MMP-9 levels may be a useful independent predictor of bare metal stent ISR.

Familial abdominal aortic aneurysms in the Otago region of New Zealand

PURPOSE To investigate the familial incidence and phenotypic characteristics of patients with abdominal aortic aneurysms (AAA) in the Otago region of New Zealand. METHODOLOGY A retrospective audit based pilot study and a prospective study of patients having abdominal aortic aneurysm repair from September 1988 to September 1999 was performed. RESULTS 248 probands were enrolled, of which 19.4% had one or more first degree relative affected. The age at diagnosis of the familial (70.2) and non-familial (70.5) patients was similar. The proportion of females was increased in the familial subgroup. Hypercholesterolaemia was the only phenotypic feature to differentiate familial from non-familial patients and was associated with an earlier age of presentation. In the familial families, brothers were the most common relative affected and 77% of the families had two patients with AAA. CONCLUSION 19.4% of patients operated on in the Otago area for AAA had a familial component to their aneurysm.

Active matrix metalloproteinases 3 and 9 are independently associated with coronary artery in-stent restenosis

OBJECTIVE This study aimed to determine whether plasma levels of active matrix metalloproteinases (MMP) are predictors of in-stent restenosis (ISR) in New Zealand patients treated with bare-metal coronary stents. METHODS A group of 152 patients with a history of ISR were compared with 151 symptom free 1-year post-stenting patients (non-ISR). Demographic and angiographic characteristics were collected. Plasma samples were analyzed for the active forms of MMP-1, -2, -3 and -9 as well as tissue inhibitor of metalloproteinases (TIMP-1) using ELISA-based isoform sensitive assays. RESULTS Both active MMP-9 and active MMP-3 were independently associated with history of ISR. Elevated levels of both active MMP-3 and -9 had an adjusted odds ratio of 11.8 (95% CI: 4-35, p<0.0001) for association with ISR, with 37% of ISR patients having such levels versus 11% on non-ISR. The addition of both of the MMP biomarkers significantly increased the area under the curve (AUC) of a receiver operator characteristic (ROC) analysis incorporating the significant demographic and angiographic variables (AUC 0.85 versus 0.78, p<0.005). CONCLUSION Measures of plasma active MMP isoforms appear to be independently associated with ISR, and assessment of multiple MMP markers yields cumulative utility.

Intra-individual changes of active matrix metalloproteinase-9 are associated with clinical in-stent restenosis of bare metal stents.

Objectives: Increased chronic postprocedural levels of active matrix metalloproteinase-9 (MMP-9) have been associated retrospectively with a history of in-stent restenosis (ISR). This study aimed to determine whether index or post-percutaneous coronary intervention (PCI) plasma levels of active MMP-9 are a predictor of subsequent clinical ISR, in a standard population of patients treated with bare metal coronary stents. Methods: Four hundred thirty-two patients were prospectively recruited and sampled at index and 3 and 6 months after PCI. Those who developed symptomatic angiographically confirmed ISR were compared to randomly selected, asymptomatic controls, stratified by index presentation in a nested case-control design. Plasma samples were analyzed for the active form of MMP-9. Results: In all, 35 patients (8.1%) developed ISR, and these were compared to 98 controls. The increase in active MMP-9 over 3 months was significantly greater in the ISR group (p = 0.030) and independent of the established risk factors. Index clinical presentation was not associated with acute changes in active MMP-9; however, patients with ST-elevation myocardial infarction had greater increases in active MMP-9 at 3 months. Conclusions: The change in active MMP-9 over 3 months after bare metal coronary stent placement appears to be independently associated with the development of ISR in a standard PCI population.

Seasonal variation and stability of matrix metalloproteinase-9 activity and tissue inhibitor of matrix metalloproteinase-1 with storage at -80°C.

OBJECTIVE To determine whether active matrix metalloproteinase (MMP)-9 and tissue inhibitor of matrix metalloproteinase (TIMP)-1 displayed seasonal variation and were stable in storage. METHODS Plasma active MMP-9 and TIMP-1 were measured at three time-points in 163 individuals. RESULT There was no evidence for seasonal variation or declining levels for up to three years of storage at -80°C. CONCLUSION Active MMP-9 and TIMP-1 appear to be stable seasonally, and in storage for at least three years.

Pro-MMP-9/TIMP-1 ratio correlates poorly with a direct assessment of MMP-9 activity.

OBJECTIVE To determine if the pro-MMP-9/TIMP-1 ratio is an accurate surrogate for endogenously active MMP-9 levels. METHODS Plasma active MMP-9, pro-MMP-9 and TIMP-1 were measured in 295 patients. RESULTS There was a weak negative correlation between the pro-MMP-9/TIMP-1 ratio and active MMP-9. TIMP-1 was more closely correlated with active MMP-9 than pro-MMP-9. CONCLUSION Pro-MMP-9/TIMP-1 ratio measured with ELISA is not a good surrogate measure for active MMP-9, and direct measurements of active MMP-9 are therefore recommended.