Detection and prognostic impact of micrometastasis in colorectal cancer.

Review of literature was performed on studies with prognostic impact of micrometastasis in colorectal cancer. Among 16 studies included, micrometastasis was detected in 26.5% of patients. Most analysis revealed that micrometastasis carries a poorer prognosis compared to node negative disease (NND). The results of those studies were compared with our pilot study of 109 patients with colon cancer, showing improved prognosis of micrometastasis after being upstaged and treated with chemotherapy when compared with NND.

A prospective trial comparing 1% lymphazurin vs 1% methylene blue in sentinel lymph node mapping of gastrointestinal tumors.

BACKGROUND: Methylene blue (M), as a dye in sentinel lymph node mapping (SLNM), has been introduced as an alternative to lymphazurin (L) after the recent shortage of L. M has been evaluated in breast cancer in multiple studies with favorable results. Our study compares L with M in the SLNM of gastrointestinal (GI) tumors. METHODS: Between Jan 2005 and Aug 2008, 122 consecutive patients with GI tumors were enrolled. All patients (pts) underwent SLNM with either L or M by subserosal injection of 2-5 mL of dye. Efficacy and rates of adverse reactions were compared between the two dyes. Patients were prospectively monitored for adverse reactions including anaphylaxis, development of blue hives, and tissue necrosis. RESULTS: Of 122 pts, 60 (49.2%) underwent SLNM using L and 62 (50.8%) underwent SLNM using M. Colon cancer (CrCa) was the most common site in both groups. The success rate of L and M in SLNM was 96.6% and 96.7%, respectively, with similar numbers of total number of lymph nodes per pt, SLNs per pt (<3), nodal positivity, skip metastasis, and accuracy. The only adverse reaction in the L group was oxygen desaturation >5% in 5% (3/60) of pts, compared with none in the M group. Cost per vial of L was $210 vs $7 for M. CONCLUSION: The success rate, nodal positivity, average SLNs per patient, and overall accuracy were similar between L and M. Absence of anaphylaxis and lower cost make M more desirable than L in SLNM of GI tumors.

The prognostic value of additional malignant lesions detected by magnetic resonance imaging versus mammography.

BACKGROUND: Nodal positivity is correlated with a poorer prognosis in breast cancer. A study was composed to compare nodal positivity in patients with single versus multiple lesions found on magnetic resonance imaging (MRI) and mammogram (MMG). METHODS: A retrospective study of breast cancer patients undergoing MRI and MMG was performed. Nodal positivity was compared in patients with additional invasive lesions found on MRI versus single invasive lesions found on MRI and MMG. RESULTS: A total of 425 patients were included. The overall nodal positivity was 23.8%. Patients with single versus multiple malignant lesions had nodal positivity of 20.9% vs 31.1% (P = .04). MRI detected multiple lesions in 120 patients, 80 of which were not detected by MMG (18.8%). Comparing single lesions with additional malignant lesions detected by MRI only, nodal positivity increased from 20.9% to 51.6% (P = .0002). CONCLUSIONS: Patients with additional invasive lesions on MRI had significantly higher nodal positivity than single invasive lesions. Hence, addition of MRI in early-stage breast cancer may have prognostic value because of detection of potential node-positive patients.

Aberrant drainage of sentinel lymph nodes in colon cancer and its impact on staging and extent of operation.

BACKGROUND: The role of aberrant lymphatic drainage in changing operations for patients undergoing sentinel lymph node mapping in colon cancer has not been described on a large scale. METHODS: Patients with colon cancer underwent sentinel lymph node mapping and standard oncologic resection. Aberrant lymphatic drainage was identified outside the standard resection margin, requiring change of the extent of operation. Objectives were to identify the frequency of aberrant lymphatic drainage leading to changes of operation and staging. RESULTS: Among 192 patients undergoing standard oncologic resection, 42 (22%) had extended surgery because of aberrant lymphatic drainage. Nodal positivity was higher in patients undergoing change of operation, at 62% compared with 43% of those undergoing only standard oncologic resection. In 19 of 192 patients (10%), positive sentinel nodes were found in aberrant locations. CONCLUSIONS: Sentinel node mapping in patients with colon cancer detects aberrant drainage in 22% of patients, changing the extent of operation.

Nodal positivity in breast cancer correlated with the number of lesions detected by magnetic resonance imaging versus mammogram.

BACKGROUND: Magnetic resonance imaging (MRI) in breast cancer can detect more than 15% additional lesions than mammography. We investigated lymph node metastases rates in patients with multifocal or multicentric disease detected by MRI compared with patients with a single lesion detected by mammography and magnetic resonance imaging. METHODS: A retrospective analysis of breast cancer patients undergoing MRI and mammography was performed. The objective was to compare lymph node metastases rates in patients with additional lesions detected by MRI versus a single lesion detected by mammography or MRI. RESULTS: Of 413 patients, 318 were included for the study. The overall nodal metastases rate was 24.8%. MRI detected multiple lesions in 83 (26.1%) patients; 67 (21.1%) patient MRI findings were not detected by mammography. The lymph node metastases rate was 37.3% when ≥ 2 lesions were detected compared with 20.2% when a single malignant lesion was detected (P = .01). The evaluation of the 67 patients with additional lesions detected by MRI revealed 32 patients with invasive lesions, 29 with benign lesions, and 6 with in situ disease. Comparing patients with single malignant lesions with patients with additional malignant lesions detected by MRI, the lymph node metastases rate increased from 20.2% to 50% (P = .002). CONCLUSIONS: Our study shows a significant increase in the lymph node metastases rate in patients with additional malignant lesions detected by MRI. This finding suggests that MRI-detected malignant lesions are biologically significant and may predict more aggressive disease.

Comparison of nodal positivity between SLNM vs conventional surgery in colon cancer patients with <12 and ≥12 lymph nodes harvested.

BACKGROUND: Examination of ≥12 lymph nodes (LNs) ensures accurate staging in colon cancer. The aim of this study was to compare nodal positivity between sentinel LN mapping (SLNM) and conventional surgery in patients with <12 and ≥12 LNs harvested. METHODS: From 1993 to 2008, 407 and 380 patients with colon cancer underwent SLNM and conventional surgery, respectively. Total LNs harvested and nodal positivity were analyzed. Patients were grouped according to number of LNs harvested: 2 to 11, 12 to 25, or >25. RESULTS: The average numbers of LNs harvested in the groups with 2 to 11, 12 to 25, and >25 LNs harvested for SLNM and conventional surgery, respectively, were 8.3 and 7.1 (P < .0001), 17.2 and 16.5 (P = .09), and 34.2 and 32.1 (P = .40). Nodal positivity for SLNM and conventional surgery in the groups with <12 and ≥12 LNs harvested was 42% and 29% (P = .01) and 50% and 36% (P = .003), respectively. Overall nodal positivity was 47% for SLNM and 32% for conventional surgery (P < .0001). When SLNM with 2 to 11 LNs was compared with conventional surgery with 12 to 25 LNs, nodal positivity was 42% versus 36% (P = .35). CONCLUSIONS: SLNM possessed higher nodal positivity compared with conventional surgery. SLNM is a valuable adjunct to accurate nodal staging in colon cancer.