Radiofrequency ablation of 231 unresectable hepatic tumors: indications, limitations, and complications

BACKGROUND

Radiofrequency ablation (RFA) is increasingly used for the local destruction of unresectable hepatic malignancies. There is little information on its optimal approach or potential complications.

METHODS

Since late 1997, we have undertaken 91 RFA procedures to ablate 231 unresectable primary or metastatic liver tumors in 84 patients. RFA was performed via celiotomy (n = 39), laparoscopy (n = 27), or a percutaneous approach (n = 25). Patients were followed with spiral computed tomographic (CT) scans at 1 to 2 weeks postprocedure and then every 3 months for 2 years.

RESULTS

Intraoperative ultrasound (IOUS) detected intrahepatic disease not evident on the preoperative scans of 25 of 66 patients (38%) undergoing RFA via celiotomy or laparoscopy. In 38 of 84 patients (45%), RFA was combined with resection or cryosurgical ablation (CSA), or both. RFA was used to treat an average of 2.8 lesions per patient, and the median size of treated lesions was 2 cm (range, 0.3-9 cm). The average hospital stay was 3.6 days overall (1.8 days for percutaneous and laparoscopic cases). Ten patients underwent a second RFA procedure (sequential ablations) and, in one case, a third RFA procedure for large (one patient), progressive (seven patients), and/or recurrent (three patients) lesions. Seven (8%) patients had complications: one skin burn; one postoperative hemorrhage; two simple hepatic abscesses; one hepatic abscess associated with diaphragmatic heat necrosis following sequential percutaneous ablations of a large lesion; one postoperative myocardial infarction; and one liver failure. There were three deaths, one (1%) of which was directly related to the RFA procedure. Three of the complications, including one RFA-related death, occurred after percutaneous RFA. At a median follow-up of 9 months (range, 1-27 months), 15 patients (18%) had recurrences at an RFA site, and 36 patients (43%) remained clinically free of disease.

CONCLUSIONS

Celiotomy or laparoscopic approaches are preferred for RFA because they allow IOUS, which may demonstrate occult hepatic disease. Operative RFA also allows concomitant resection, CSA, or placement of a hepatic artery infusion pump, and isolation of the liver from adjacent organs. Percutaneous RFA should be reserved for patients at high risk for anesthesia, those with recurrent or progressive lesions, and those with smaller lesions sufficiently isolated from adjacent organs. Complications may be minimized when these approaches are applied selectively.

Chemokine receptor CXCR4 expression in colorectal cancer patients increases the risk for recurrence and for poor survival

PURPOSE

Liver metastasis is the predominant cause of colorectal cancer (CRC) related mortality. Chemokines, soluble factors that orchestrate hematopoetic cell movement, have been implicated in directing cancer metastasis, although their clinical relevance in CRC has not been defined. Our hypothesis was that the chemokine receptor CXCR4 expressed by CRC is a prognostic factor for poor disease outcome.

METHODS

CRC cell lines (n = 6) and tumor specimens (n = 139) from patients with different American Joint Committee on Cancer (AJCC) stages of CRC were assessed. Microarray screening of select specimens and cell lines identified CXCR4 as a prominent chemokine receptor. CXCR4 expression in tumor and benign specimens was assessed by quantitative real-time reverse transcription polymerase chain reaction and correlated with disease recurrence and overall survival.

RESULTS

High CXCR4 expression in tumor specimens (n = 57) from AJCC stage I/II patients was associated with increased risk for local recurrence and/or distant metastasis (risk ratio, 1.35; 95% CI, 1.09 to 1.68; P = .0065). High CXCR4 expression in primary tumor specimens (n = 35) from AJCC stage IV patients correlated with worse overall median survival (9 months v 23 months; RR, 2.53; 95% CI, 1.19 to 5.40; P = .016). CXCR4 expression was significantly higher in liver metastases (n = 39) compared with primary CRC tumors (n = 100; P < .0001).

CONCLUSION

CXCR4, a well-characterized chemokine receptor for T-cells, is differentially expressed in CRC. CXCR4 gene expression in primary CRC demonstrated significant associations with recurrence, survival, and liver metastasis. The CXCR4-CXCL12 signaling mechanism may be clinically relevant for patients with CRC and represents a potential novel target for disease-directed therapy.

Increased integrity of free circulating DNA in sera of patients with colorectal or periampullary cancer: direct quantitative PCR for ALU repeats

BACKGROUND

Cell-free DNA circulating in blood is a candidate biomarker for malignant tumors. Unlike uniformly truncated DNA released from apoptotic nondiseased cells, DNA released from dead cancer cells varies in size. We developed a novel method to measure the ratio of longer to shorter DNA fragments (DNA integrity) in serum as a potential biomarker for patients with colorectal cancer (CRC) or periampullary cancers (PACs).

METHODS

Sera from 32 patients with CRC (3 stage I, 14 stage II, 6 stage III, and 9 stage IV patients), 19 patients with PACs (2 stage I, 9 stage II, 1 stage III, and 7 stage IV patients), and 51 healthy volunteers were assessed by quantitative real-time PCR of ALU repeats (ALU-qPCR) with 2 sets of primers (115 and 247 bp) amplifying different lengths of DNA. We used serum directly as a template for ALU-qPCR without DNA purification. DNA integrity was determined as ratio of qPCR results of 247-bp ALU over 115-bp ALU.

RESULTS

ALU-qPCR had a detection limit of 0.01 pg of DNA. Eliminating DNA purification reduced technical artifacts and reagent/labor costs. Serum DNA integrity was significantly increased for stage I/II and III/IV CRC and stage I/II and III/IV PACs (P = 0.002, P = 0.006, P = 0.022, and P <0.0001, respectively). ROC curves for detecting CRC and PACs had areas under the curves of 0.78 and 0.80, respectively.

CONCLUSIONS

Direct ALU-qPCR is a robust, highly sensitive, and high-throughput method to measure serum DNA integrity. DNA integrity is a potential serum biomarker for detection and evaluation of CRC and PACs.

Radiofrequency ablation in 447 complex unresectable liver tumors: lessons learned

BACKGROUND

Radiofrequency ablation (RFA) is a promising technique for unresectable hepatic malignancies. We reviewed our RFA experience to identify variables affecting local recurrence.

METHODS

Patients undergoing RFA between 1997 and 2001 were reviewed for demographics, tumor size, pathology, diagnosis, recurrence, procedures, survival, and complications.

RESULTS

The 447 unresectable liver tumors were ablated in 198 procedures. The 153 patients averaged 61.9 years of age and 1.25 RFA procedures per patient. Follow-up averaged 11 months. Serial ablations were performed in 28 patients, 8 of whom are without evidence of disease. Tumors were most commonly carcinomas of colorectal, hepatocellular, breast, and melanoma histologies. Colorectal carcinomas and hepatomas individually recurred more frequently than all other tumor types combined in univariate analyses (P =.009 and P =.008, respectively). Patients with multiple tumors ablated recurred significantly more frequently (P =.001). Size was also significant in univariate and multivariate analyses (P =.0032 and <.0001, respectively). Eighteen patients experienced 36 complications.

CONCLUSIONS

Size has the highest correlation with local recurrence, but multiple tumors and pathology may also predict local recurrence risk. Large, complex lesions can be safely serially ablated, but because of morbidity and recurrence, RFA should not replace resection as the primary treatment of resectable liver tumors.

Lymphatic mapping and sentinel lymphadenectomy for early-stage melanoma: therapeutic utility and implications of nodal microanatomy and molecular staging for improving the accuracy of detection of nodal micrometastases

OBJECTIVE

Lymphatic mapping and sentinel lymphadenectomy (LM/SL) have been applied to virtually all solid neoplasms since our original description of LM/SL for melanoma. Our objectives were to determine the diagnostic and therapeutic utility of LM/SL, investigate carbon dye for mapping the microanatomy of lymphatic flow within the sentinel node (SN), and determine the prognostic accuracy of molecular assessment of the SN.

METHODS

Since 1985, 1599 patients with AJCC Stage I/II melanoma have been treated by LM/SL at our institution and 4590 have been treated by wide excision (WE) without nodal staging. We examined the incidence of clinical nodal recurrence after WE alone, the incidence of subclinical nodal metastases found by LM/SL, and the incidence of nodal recurrence in basins with histopathology-negative SNs.

RESULTS

In 1514 LM/SL patients with a primary of known Breslow thickness, the incidence of metastasis in nodes claimed to be sentinel was 7.3%, 19.7%, 33.2%, and 39.7% for primary lesions 4.0 mm, respectively. In 3652 WE-only patients, the corresponding rates of nodal recurrence were 12.0%, 32.0%, 34.4%, and 30.1%. Thus, LM/SL detected only 60% of expected nodal metastases from primary melanomas <2.01 mm. Forty of 1599 (3.1%) patients developed recurrence in basins with immunohistochemistry (IH)-negative SNs. To determine whether nonrandom intranodal distribution of tumor cells could explain missed SN metastases, we coinjected carbon particles and blue dye during LM/SL in 166 patients: 25 (16%) patients had nodal metastases, all of which were found only in nodal subsectors containing carbon particles. When paraffin-embedded SNs from a subset of 162 IH-negative patients were re-examined by quantitative multimarker reverse-transcriptase polymerase chain reaction (qRT) assay, 49 (30%) gave positive signals. These patients had a significantly higher risk of disease recurrence and death than did patients whose IH and qRT results were negative (p < 0.0001). Comparison of 287 prognostically matched pairs of patients who underwent immediate (after LM/SL) versus delayed (after observation) dissection of nodal metastases revealed 5-, 10-, and 15-year survival rates of 73%, 69%, and 69% versus 51%, 37%, and 32%, respectively (P < or = 0.001).

CONCLUSIONS

SN assessment based on intranodal compartmentalization of lymphatic flow (carbon dye mapping) should increase the accuracy of IH and, in combination with multimarker qRT assessment, will allow confident identification of most patients for whom surgery alone is curative. Our data suggest a significant therapeutic benefit for immediate dissection based on identification of a tumor-involved SN.

AJCC Cancer Staging Manual 7th edition criteria for colon cancer: do the complex modifications improve prognostic assessment?

BACKGROUND

The 7th edition of the AJCC Cancer Staging Manual (AJCC-7) includes substantial changes for colon cancer (CC), which are particularly complex in patients with stage II and III disease. We used a national cancer database to determine if these changes improved prediction of survival.

STUDY DESIGN

The database of the Surveillance, Epidemiology and End Results Program was queried to identify patients with pathologically confirmed stage I to III CC diagnosed between 1988 and 2008. Colon cancer was staged by the 6(th) edition of the AJCC Cancer Staging Manual (AJCC-6) and then restaged by AJCC-7. Five-year disease-specific survival and overall survival were compared.

RESULTS

After all exclusion criteria were applied, AJCC-6 and AJCC-7 staging was possible in 157,588 patients (68.9%). Bowker's test of symmetry showed that the number of patients per substage was different for AJCC-6 and AJCC-7 (p < 0.001). The Akaike information criteria comparison showed superior fit with the AJCC-7 model (p < 0.001). However, although AJCC-7 staging yielded a progressive decrease in disease-specific survival and overall survival of patients with stage IIA (86.3% and 72.4%, respectively), IIB (79.4% and 63.2%, respectively), and IIC (64.9% and 54.6%, respectively) CC, disease-specific survival and overall survival of patients with stage IIIA disease increased (89% and 79%, respectively). Subset analysis of patients with >12 lymph nodes examined did not affect this observation.

CONCLUSIONS

The AJCC-7 staging of CC does not address all survival discrepancies, regardless of the number of lymph nodes examined. Consideration of other prognostic factors is critical for decisions about therapy, particularly for patients with stage II CC.

Cryosurgical ablation and radiofrequency ablation for unresectable hepatic malignant neoplasms: a proposed algorithm

BACKGROUND

Thermal ablation of unresectable hepatic tumors can be achieved by cryosurgical ablation (CSA) or radiofrequency ablation (RFA). The relative advantages and disadvantages of each technique have not yet been determined.

HYPOTHESIS

Radiofrequency ablation of malignant hepatic neoplasms can be performed safely, but is currently limited by size. Cryosurgical ablation, while associated with higher morbidity, is more effective for larger unresectable hepatic malignant neoplasms.

DESIGN

Retrospective analysis of prospective patient database.

PATIENTS AND METHODS

Between July 1992 and September 1999, 308 patients with liver tumors not amenable to curative surgical resection were treated with CSA and/or RFA (percutaneous, laparoscopic, celiotomy). No patient had preoperative evidence of extrahepatic disease. All patients underwent laparoscopy with intraoperative ultrasound if technically possible. Both RFA and CSA were performed under ultrasound guidance. Resection, as an adjunctive procedure, was combined with ablation in certain patients.

RESULTS

Laparoscopy identified extrahepatic disease in 12% of patients, and intraoperative hepatic ultrasound identified additional lesions in 33% of patients, despite extensive preoperative imaging. Radiofrequency ablation alone or combined with resection or CSA resulted in reduced blood loss (P<.05), thrombocytopenia (P<.05), and shorter hospital stay compared with CSA alone (P<.05). Median ablation times for lesions greater than 3 cm were 60 minutes with RFA and 15 minutes with CSA (P<.001). Local recurrence rates for lesions greater than 3 cm were also greater with RFA (38% vs 17%).

CONCLUSIONS

Laparoscopy and intraoperative ultrasound are essential in staging patients with hepatic malignant neoplasms. Radiofrequency ablation when combined with CSA reduces the morbidity of multiple freezes. Although RFA is safer than CSA and can be performed via different approaches (percutaneously, laparoscopically, or at celiotomy), it is limited by tumor size (<3 cm). Percutaneous RFA should be considered in high-risk patients or those with small local recurrences.

Molecular staging of early colon cancer on the basis of sentinel node analysis: a multicenter phase II trial

PURPOSE

Approximately 30% of patients with American Joint Committee on Cancer stage I or II colorectal cancer (CRC) develop systemic disease. We hypothesized that multimarker reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of sentinel lymph nodes (SNs) draining a primary CRC could detect micrometastases not detected by conventional histopathologic analysis.

PATIENTS AND METHODS

In a multi-institutional study, 40 patients with primary CRC underwent dye-directed lymphatic mapping at the time of colon resection. Each dye-stained SN was tagged, and the tumor and regional nodes were resected en bloc. All lymph nodes were examined by conventional hematoxylin and eosin (HE) staining. In addition, each SN was cut into multiple sections for cytokeratin immunohistochemical (CK-IHC) staining and for RT-PCR and electrochemiluminescent detection of three markers: beta-chain human chorionic gonadotropin, hepatocyte growth factor receptor, and universal melanoma-associated antigen. Whenever possible, RT-PCR assay was also performed on primary tumor tissue. The detection sensitivity of individual markers was 10(-3) to 10(-4) microg of RNA and one to five tumor cells in 10(7) lymphocytes of healthy donors.

RESULTS

One to three SNs were identified in each patient. An average of 15 nodes were removed from each CRC specimen. No nonsentinel (untagged) node contained evidence of tumor if all tagged (sentinel) nodes in the same specimen were histopathology tumor-negative. HE staining of SNs identified tumor in 10 patients (25%), and CK-IHC of SNs identified occult micrometastases in four patients (10%) whose SNs were negative by HE. Of the remaining 26 patients with no evidence of SN involvement by HE or CK-IHC, 12 (46%) had positive RT-PCR results. The number of markers expressed in each SN correlated (P <.04) with the T stage of the primary tumor. There was 79% concordance in marker expression for the respective pairs (n = 38) of primary tumor and histopathologically positive SNs, and 86% (12 of 14) concordance between RT-PCR positive and histopathologically positive SNs.

CONCLUSION

Identification and focused examination of the SN is a novel method of staging CRC. CK-IHC and RT-PCR identified occult micrometastases in 53% of patients whose SNs were negative by conventional staging techniques. These ultrasensitive assays of the SN can identify patients who may be at high risk for recurrence of CRC and therefore are more likely to benefit from systemic adjuvant therapy.

More extensive nodal dissection improves survival for stages I to III of colon cancer: a population-based study

OBJECTIVE

To determine whether analyzing more lymph nodes in colon cancer specimens improves survival.

SUMMARY BACKGROUND DATA

Increasing the number of lymph nodes analyzed has been reported to correlate with improved survival in patients with node-negative colon cancer.

METHODS

The Surveillance, Epidemiology, and End Results database was queried for all patients undergoing resection for histologically confirmed colon cancer between the years 1988 and 2000. Patients were excluded for distant metastases or if an unknown number of nodes was sampled. The number of nodes sampled was categorized into 0, 1 to 7, 8 to 14, and > or =15 nodes. Survival curves constructed using the Kaplan-Meier method were compared using log rank testing. A Cox proportional hazard model was created to adjust for year of diagnosis, age, race, gender, tumor grade, tumor size, TNM stage, and percent of nodes positive for tumor.

RESULTS

The median number of lymph nodes sampled for all 82,896 patients was 9. For all stages examined, increasing nodal sampling was associated with improved survival. Multivariate regression demonstrated that patients who had at least 15 nodes sampled as compared with 1 to 7 nodes experienced a 20.6% reduction in mortality independent of other patient and tumor characteristics.

CONCLUSIONS

Adequate lymphadenectomy, as measured by analysis of at least 15 lymph nodes, correlates with improved survival, independent of stage, patient demographics, and tumor characteristics. Currently, most procedures do not meet this guideline. Future trials of adjuvant therapy should include extent of lymphadenectomy as a stratification factor.

Chemokine receptor CXCR4 expression in patients with melanoma and colorectal cancer liver metastases and the association with disease outcome

OBJECTIVE

To determine the role of chemokine receptor (CR) expression in patients with melanoma and colorectal cancer (CRC) liver metastases.

SUMMARY BACKGROUND DATA

Murine and in vitro models have identified CR as potential factors in organ-specific metastasis of multiple cancers. Chemokines via their respective receptors have been shown to promote cell migration to distant organs.

METHODS

Patients who underwent hepatic surgery for melanoma or CRC liver metastases were assessed. Screening cDNA microarrays of melanoma/CRC cell lines and tumor specimens were analyzed to identify CR. Microarray data were validated by quantitative real-time RT-PCR (qRT) in paraffin-embedded liver metastases. Migration assays and immunohistochemistry were performed to verify CR function and confirm CR expression, respectively.

RESULTS

Microarray analysis identified CXCR4 as the most common CR expressed by both cancers. qRT demonstrated CXCR4 expression in 24 of 27 (89%) melanoma and 28 of 29 (97%) CRC liver metastases. In vitro treatment of melanoma or CRC cells with CXCL12, the ligand for CXCR4, significantly increased cell migration (P < 0.001). Low versus high CXCR4 expression in CRC liver metastases correlated with a significant difference in overall survival (median 27 months vs. 10 months, respectively; P = 0.036). In melanoma, low versus high CXCR4 expression in liver metastases demonstrated no difference in overall survival (median 11 months vs. 8 months, respectively; P = not significant).

CONCLUSIONS

CXCR4 is expressed and functional on melanoma and CRC cells. The ligand for CXCR4 is highly expressed in liver and may specifically attract melanoma and CRC CXCR4 (+) cells. Quantitative analysis of CXCR4 gene expression in patients with liver metastases has prognostic significance for disease outcome.

Urgent need for a new staging system in advanced colorectal cancer

Despite recent advances in the medical treatment of metastatic colorectal cancer (mCRC), which include irinotecan- and oxaliplatin-based first-line regimens, the concept of planned sequential therapy involving three active agents during the course of a patient's treatment and the increasing use of targeted monoclonal antibodies, 5-year survival rates for patients with advanced CRC remain unacceptably low. For patients with CRC liver metastases, liver resection remains the only chance of cure, with 5-year survival rates ranging from 25% to 40%. However, 80% to 85% of patients with stage IV CRC have liver disease which is considered unresectable at presentation. The rapid expansion in the use of improved combination chemotherapy regimens plus or minus biologics, to render initially unresectable metastases resectable has increased the percentage of patients eligible for potentially curative surgery. However, the current staging criteria for CRC patients with metastatic disease do not reflect these recent changes or the fact that there is also a large variation in the survival of patients with stage IV CRC. For example the survival for a patient with a solitary, resectable liver metastasis is better than that for a patient with stage III disease. A new staging system is therefore needed that acknowledges both the improvements that have been made in surgical techniques for resectable metastases and the impact of modern chemotherapy on rendering initially unresectable CRC liver metastases resectable, while at the same time distinguishing between patients with a chance of cure at presentation and those for whom only palliative treatment is possible.

Prognostic impact of micrometastases in colon cancer: interim results of a prospective multicenter trial

OBJECTIVE

The 25% rate of recurrence after complete resection of stage II colon cancer (CC) suggests the presence of occult nodal metastases not identified by hematoxylin and eosin staining (H&E). Interim data from our ongoing prospective multicenter trial of sentinel node (SN) biopsy indicate a 29.6% rate of micrometastases (MM) identified by immunohistochemical staining (IHC) of H&E-negative SNs in CC. We hypothesized that these MM have prognostic importance.

METHODS

Between March 2001 and August 2006, 152 patients with resectable colorectal cancer were enrolled in the trial. IHC and quantitative RT-PCR (qRT) assay were performed on H&E-negative SNs. Results were correlated with disease-free survival.

RESULTS

The sensitivity of lymphatic mapping was significantly better in CC (75%) than rectal cancer (36%), P<0.05. Of 92 node-negative CC patients 7 (8%) were upstaged to N1 and 18 (22%) had IHC MM. Four patients negative by H&E and IHC were positive by qRT. At a mean follow-up of 25 months, 15 patients had died from noncancer-related causes, 12 had developed recurrence, 5 had died of CC (2 with macrometastases, 3 with MM), and 7 were alive with disease. The 12 recurrences included 4 patients with SN macrometastases and 6 with SN MM (2 by IHC, 4 by qRT). One of the 2 SN-negative recurrences had other positive lymph nodes by H&E. All patients with CC recurrences had a positive SN by either H&E/IHC or qRT. No CC patient with a negative SN by H&E and qRT has recurred (P=0.002).

CONCLUSION

This is the first prospective evaluation of the prognostic impact of MM in colorectal cancer. These results indicate that the detection of MM may be clinically relevant in CC and may improve the selection of patients for adjuvant systemic chemotherapy. Patients with CC who are node negative by cumulative detection methods (H&E/IHC and qRT) are likely to be cured by surgery alone.

Lymphatic mapping and sentinel node analysis: current concepts and applications

Since the introduction of sentinel node biopsy in 1990 as a minimally invasive surgical technique for the diagnosis of melanoma lymphatic metastases, the number of applications has expanded. We review applications and the current status of sentinel node biopsy in melanoma, breast, colon, gastric, esophageal, head and neck, thyroid, and lung cancer. Variations on techniques specific to each organ are explained, and the current role of sentinel node biopsy in diagnosis and treatment is discussed.

Long-term survival after radiofrequency ablation of complex unresectable liver tumors

HYPOTHESIS

Radiofrequency ablation (RFA) may improve survival of high-risk patients with unresectable and refractory tumors.

DESIGN

Retrospective analysis of a prospective database.

SETTING

A tertiary referral cancer center.

PATIENTS AND METHODS

Between November 1, 1997, and January 31, 2005, we performed 219 RFA procedures to ablate 521 hepatic tumors in 181 patients.

RESULTS

Of the 181 patients, 52% were male and 48% were female, and the mean age was 61.3 years (age range, 27-91 years). Radiofrequency ablation was performed via celiotomy (n = 135), via laparoscopy (n = 48), or percutaneously (n = 36). In 106 patients (79%), RFA was used in combination with surgical resection. The most common tumors included colorectal cancer (40.9%), hepatocellular carcinoma (14.9%), carcinoid tumor (13.8%), melanoma (9.4%), and breast cancer (5.0%). The average number of tumors per patient was 3.3 tumors. The average number of RFA-treated lesions per procedure was 2.38 lesions; the mean lesion size was 3.56 cm (lesion size range, 0.8-9.0 cm). At a mean follow-up of 33.2 months (follow-up range, 12-91 months), overall survival was 48.3 months for carcinoid tumors, 25.2 months for hepatocellular carcinoma, 18.5 months for melanoma, 29.7 months for colorectal cancer, and 30.1 months for breast cancer. Seventy-eight patients (43%) developed recurrences. Of 521 tumors that were treated, 125 (24%) recurred; the incidence of local recurrence was 28% for tumors larger than 3 cm vs 18% for tumors 3 cm or smaller (P = .04). Twenty-nine patients underwent serial ablations. Seventy-one patients (39%) were disease free at last follow-up.

CONCLUSION

A significant number of patients whose hepatic malignancies are unresectable or refractory to chemotherapy may be considered for RFA as part of a multimodality therapeutic regimen. In these patients, RFA is safe and may prolong survival.

Validation of lymphatic mapping in colorectal cancer: in vivo, ex vivo, and laparoscopic techniques

BACKGROUND

The use of lymphatic mapping (LM) is being investigated to improve the staging of colorectal cancer (CRC) and thereby identify patients who might benefit from adjuvant chemotherapy. This study evaluated in vivo, laparoscopic, and ex vivo approaches for the ultrastaging of CRC.

METHODS

Seventy-five CRC patients were enrolled in a study of LM with peritumoral injection of isosulfan blue dye. LM was undertaken during open colon resection (OCR) in 64 patients, during laparoscopic colon resection (LCR) in 9 patients, and after specimen removal (ex vivo) in 2 patients. Ex vivo LM was also undertaken in 6 patients after unsuccessful in vivo LM. All nodes were examined by hematoxylin and eosin (H&E) staining; in addition, sentinel lymph nodes (SNs) were multisectioned and examined by immunohistochemical staining with cytokeratin (CK-IHC).

RESULTS

At least one SN was identified in 72 patients (96%). In vivo LM identified SNs in 56 of 64 (88%) patients undergoing OCR and in 9 of 9 (100%) patients undergoing LCR. Ex vivo LM was undertaken as the initial mapping procedure in 2 cases of intraperitoneal colon cancer and after in vivo LM had failed in 6 cases of extraperitoneal rectal carcinoma; an SN was identified in 7 of the 8 cases. Focused examination of the SN correctly predicted nodal status in 53 of 56 OCR cases, 9 of 9 LCR cases, and 6 of 7 ex vivo cases. Multiple sections and CK-IHC identified occult micrometastases in 13 patients (17%), representing 10 OCR, 1 LCR, and 2 ex vivo cases.

CONCLUSIONS

LM of drainage from a primary CRC can be accurately performed in vivo during OCR or LCR. Ex vivo LM can be applied when in vivo techniques are unsuccessful and may be useful for rectal tumors. During LCR, colonoscopic injection can be used to mark the primary tumor and define the lymphatic drainage so that adequate resection margins are obtained. These LM techniques improve staging accuracy in CRC.

Lymphatic mapping and focused analysis of sentinel lymph nodes upstage gastrointestinal neoplasms

BACKGROUND

Lymph node analysis is essential for staging gastrointestinal (GI) neoplasms. Intraoperative lymphatic mapping and sentinel lymphadenectomy were originally described for melanoma but have not yet been investigated for most GI neoplasms.

HYPOTHESES

(1) Lymphatic mapping and sentinel lymphadenectomy is feasible in GI neoplasms, (2) the sentinel node (SN) status reflects the regional node status, and (3) focused analysis of the SN improves staging accuracy.

DESIGN

Prospective patient series.

PATIENTS AND METHODS

Lymphatic mapping was performed in 65 patients with GI neoplasms by injecting 0.5 to 1 mL of isosulfan blue dye around the periphery of the neoplasm. Blue-stained SNs were analyzed by hematoxylin-eosin staining, multiple sectioning, and cytokeratin immunohistochemistry.

RESULTS

Lymphatic mapping identified at least 1 SN in 62 patients (95%). Of the 36 cases with nodal metastasis, 32 (89%) had at least 1 positive SN and 15 (42%) had nodal metastasis only in the SN. In 11 cases, tumor deposits were identified by multiple sectioning (n = 2) or immunohistochemistry (n = 9) only. In 5 cases (8%), lymphatic mapping identified aberrant lymphatic drainage that altered the extent of the lymphadenectomy.

CONCLUSIONS

Lymphatic mapping and sentinel lymphadenectomy are feasible in GI neoplasms and identify aberrant lymphatic drainage. The SN status accurately reflects the regional node status. Focused analysis of the SN increases the detection of micrometastases and may improve selection of patients for adjuvant treatment.

Epigenetic inactivation of ID4 in colorectal carcinomas correlates with poor differentiation and unfavorable prognosis

PURPOSE

ID4 gene is a member of the inhibitor of DNA binding (ID) family proteins that inhibit DNA binding of basic helix-loop-helix transcription factors. The epigenetic inactivation of ID4 gene on colorectal cancer (CRC) development and its clinical significance was assessed.

EXPERIMENTAL DESIGN

In CRC cell lines, ID4 methylation status of the promoter region was assessed by methylation-specific PCR and bisulfite sequencing. The mRNA expression level was assessed by quantitative real-time reverse transcription-PCR. The methylation status of 9 normal epithelia, 13 adenomas, 92 primary CRCs, and 26 liver metastases was assessed by methylation-specific PCR. ID4 protein expression was assessed by immunohistochemistry analysis of tissue specimen.

RESULTS

CRC cell lines were shown to be hypermethylated, and mRNA expression was suppressed and could be restored by 5-aza-cytidine treatment. In clinical specimens from normal epithelia, adenomas, primary CRCs, and liver metastases, the frequency of ID4 hypermethylation was 0 of 9 (0%), 0 of 13 (0%), 49 of 92 (53%), and 19 of 26 (73%), respectively, with a significant elevation according to CRC pathological progression. Methylation status of primary CRCs significantly correlated with histopathological tumor grade (P = 0.028). Immunohistochemistry analysis showed ID4 expression of normal colon epithelia, adenomas, and unmethylated primary CRCs but not hypermethylated CRC specimens. Among 76 American Joint Committee on Cancer stage I to IV patients who had undergone curative surgical resection, overall survival was significantly poorer in patients with hypermethylated ID4 bearing tumors (P = 0.0066).

CONCLUSIONS

ID4 gene is a potential tumor suppressor gene for which methylation status may play an important role in the CRC progression.

Radiofrequency ablation of unresectable hepatic malignancies: lessons learned

Radiofrequency ablation (RFA) is increasingly used for the local destruction of unresectable hepatic malignancies. Relative contraindications include tumors in proximity to vital structures that may be injured by RFA and lesions whose size exceeds the ablation capabilities of the probe system employed. Given current technology, we believe that RFA should be cautiously utilized for lesions greater than 5 cm in diameter. Open (celiotomy) and laparoscopic approaches to RFA allow intraoperative ultrasonography, which may demonstrate occult hepatic disease. In addition, RFA performed via celiotomy can be accompanied by resection or cryosurgical ablation, and isolation of the liver from adjacent organs. Percutaneous RFA should be reserved for patients who cannot undergo general anesthesia, those with recurrent or progressive lesions, and those with smaller lesions sufficiently isolated from adjacent organs. Complications may be minimized when these approaches are selectively applied.

Deoxycholate is an important releaser of peptide YY and enteroglucagon from the human colon

Peptide YY (PYY) and enteroglucagon are hormonal peptides found in endocrine cells of the distal intestinal mucosa. Although it is known that plasma concentrations of both peptides increase in response to feeding, the mechanism by which ingested food causes release of colonic hormones is not understood. The release of PYY and enteroglucagon was measured in response to intraluminal stimuli in 176 patients having investigative colonoscopy. Introduction of air, saline (isotonic and hypertonic), glucose (isotonic and hypertonic), oleic acid (without bile salts), and casein hydrolysate all failed to release PYY but glucose caused a small but significant increase in enteroglucagon concentrations. In contrast with the lack of effect of nutrients, infusion of deoxycholic acid produced a rapid and marked dose responsive increase in plasma PYY concentrations when introduced into the sigmoid colon. PYY release was statistically significant at doses between 3.3 mM to 30 mM; for example 10 mM deoxycholate caused a sixfold increase in plasma PYY concentrations. Infusion of 10 mM deoxycholate into the transverse colon or caecum produced an increase of PYY that was similar to the responses in the sigmoid colon. There was also a significant release of enteroglucagon in response to infusion of this bile salt into the sigmoid colon at doses between 3.3 mM and 30 mM. The enteroglucagon response to 10 mM deoxycholate was similar in all three colonic regions. When oleic acid was added to deoxycholate as an emulsion, the release of PYY and enteroglucagon was similar to that seen with the bile salt alone. These findings suggest that bile salts may play an important part in the control of colonic endocrine function and may explain the increased circulating concentrations of colonic regulatory peptides that are seen in malabsorption states and after small bowel resection in humans.

Gastrointestinal carcinoid tumors and second primary malignancies

The development of second primary malignancies (SPM) in patients with gastrointestinal carcinoid tumors is a well-described phenomenon, with reported rates as high as 55%. There is a predilection for gastrointestinal and genitourinary adenocarcinomas, but a variety of other malignancies have been reported as well. The etiology of this malignant predisposition may be rooted in the tumorigenic properties of the various neuroendocrine peptides elaborated and secreted by neuroendocrine cells. Peptides such as secretin, gastrin, bombesin, cholecystokinin (CCK), and vasoactive intestinal peptide (VIP) are believed to promote the growth of tumor cells. As many as 30 peptides and amines identified in neuroendocrine cells may have similar properties. This review of the literature on carcinoid-associated second primary malignancies is accompanied by a case report of metastatic carcinoid identified during surgical exploration for a perforating colon adenocarcinoma.

Prognostic relevance of occult nodal micrometastases and circulating tumor cells in colorectal cancer in a prospective multicenter trial

PURPOSE

Nodal micrometastasis and circulating tumor cells detected by multimarker quantitative real-time reverse transcription-PCR (qRT-PCR) may have prognostic importance in patients with colorectal cancer.

EXPERIMENTAL DESIGN

Paraffin-embedded sentinel lymph nodes from 67 patients and blood from 34 of these patients were evaluated in a prospective multicenter trial of sentinel lymph node mapping in colorectal cancer. Sentinel lymph nodes were examined by H&E staining and cytokeratin immunohistochemistry. Sentinel lymph nodes and blood were examined by a four-marker qRT-PCR assay (c-MET, melanoma antigen gene-A3 family, beta1-->4-N-acetylgalactosaminyltransferase, and cytokeratin-20); qRT-PCR results were correlated with disease stage and outcome.

RESULTS

In H&E-negative sentinel lymph node patients that recurred, cytokeratin immunohistochemistry and qRT-PCR detected metastasis in 30% and 60% of patients, respectively. Disease-free survival differed significantly by multimarker qRT-PCR upstaged sentinel lymph node (P = 0.014). qRT-PCR analysis of blood for circulating tumor cells correlated with overall survival (P = 0.040).

CONCLUSION

Molecular assessment for micrometastasis in sentinel lymph node and blood specimens may help identify patients at high risk for recurrent colorectal cancer, who could benefit from adjuvant therapy.

Prospective multicenter trial of staging adequacy in colon cancer: preliminary results

HYPOTHESIS

Lymph node evaluation is an important prognostic factor in colorectal cancer (CRC). A 25% recurrence rate in patients with node-negative CRC suggests that current staging practices are inadequate. Focused analysis of the sentinel node (SN) by multiple sectioning and immunohistochemistry improves staging accuracy.

DESIGN

Prospective phase 2 multicenter trial.

SETTING

Tertiary referral cancer centers.

PATIENTS

Between March 2001 and June 2005, 132 patients were enrolled with clinical stage I and II CRC in a prospective multicenter trial (R01-CA90484).

INTERVENTION

During a standard oncologic resection, lymphatic mapping was performed and the SN identified either by the surgeon or the pathologist. Hematoxylin-eosin staining was performed on all lymph nodes and immunohistochemistry, on lymph nodes negative by hematoxylin-eosin staining.

MAIN OUTCOME MEASURES

Micrometastases greater than 0.2 mm but less than 2 mm and isolated tumor cells less than 0.2 mm were defined according to the sixth edition of the American Joint Committee on Cancer Cancer Staging Manual.

RESULTS

The 63 men and 69 women had a median age of 74 years. Sixty-eight patients (52%) underwent a right hemicolectomy; 3 (2.3%), a transverse colectomy; 9 (7%), a left colectomy; 15 (11%), a sigmoid colectomy; 34 (26%), a low anterior resection; 1 (1%), an abdominal perineal resection; and 2 (2%), a total colectomy. Of the 111 evaluable primary tumors, 19 (17%) were T1 lesions; 17 (15%), T2; 72 (65%), T3; and 3 (2.7%), T4 tumors. Thirty-three patients (30%) were classified as stage I; 46 (41%), stage II, and 32 (29%), stage III. The SN was identified by the surgeon in 127 patients (96%) and by the pathologist in 5 patients (4%). The median number of SNs and total lymph nodes examined were 3 and 14.5, respectively. The sensitivity of lymphatic mapping and SN analysis was 88.2% and the false-negative rate, 7.4% (6/81). Of the 6 false-negative results, 4 were attributed to lymphatic channels obliterated by tumor. Upstaging occurred in 28 patients (23.6%).

CONCLUSIONS

In a multicenter trial, ultrastaging of colon cancer is feasible and accurate. In stage II CRC, 24% of patients had nodal carcinoma cells not detected by conventional staging methods. Surgical technique (adequate lymph node retrieval) and focused pathological analysis may improve staging accuracy and the selection of patients for chemotherapy. The unnecessary toxicity and expense of chemotherapy may be avoided in those patients who are truly node negative.

Ultrastaging of early colon cancer using lymphatic mapping and molecular analysis

Approximately one-third of node-negative colon cancers will recur, possibly due to understaging and inadequate pathological examination of lymph nodes (LNs). We evaluated the sensitivity, accuracy and feasibility of staging based on lymphatic mapping, focused examination, and molecular analysis of the sentinel node (SN) in patients with primary colorectal carcinoma. Between 1996 and 2000, 100 patients with colon carcinoma (CRC) underwent lymphatic mapping immediately after peritumoral injection of 1.0 cc of isosulphan blue dye. All LNs in the CRC specimen were examined by routine haematoxylin and eosin (H&E) staining. Sentinel nodes were examined by step serial sectioning, cytokeratin immunohistochemistry (CK-IHC) and/or reverse transcriptase-polymerase chain reaction (RT-PCR) analysis in an attempt to identify occult micrometastatic disease. Lymphatic mapping was successful in 97% of the cases. There were 5 false-negative cases, predominately associated with T3/T4 tumours. Aberrant lymphatic drainage was identified in 8 patients (8%) altering the operative approach. 26 patients had H&E-positive LNs. In 74 patients who were node-negative by routine H&E, 18 (24%) had occult nodal micrometastases missed on routine H&E examination, but detected by focused analysis of the SN. RT-PCR analysis of the SN was performed in 40 patients, 26 of which were negative by H&E and CK-IHC. In 12/26 (46%) of these patients, there was additional evidence of micrometastatic disease. In this study, focused examination of the SN in conjunction with RT-PCR analysis identified micrometastatic disease in a significant number of node-negative patients. This may have important implications when selecting patients for adjuvant treatment protocols.