Bone marrow-disseminated tumor cells in patients with carcinoma of the esophagus or cardia

Lymph Node and Bone Marrow Micrometastases Define the Prognosis of Patients with pN0 Esophageal Cancer

BACKGROUND

Pathological routine lymph node staging is postulated to be the main oncological prognosticator in esophageal cancer (EC). However, micrometastases in lymph nodes (LNMM) and bone marrow (BNMM) are discussed as the key events in tumor recurrence. We assessed the prognostic significance of the LNMM/BNMM status in initially pN0 staged patients with curative esophagectomy.

METHODS

From 110 patients bone marrow aspirates and lymph node tissues were analyzed. For LNMM detection immunohistochemistry was performed using the anticytokeratin antibody AE1/AE3. To detect micrometastases in the bone marrow a staining with the pan-keratin antibody A45-B/B3 was done. Results were correlated with clinicopathologic parameters as well as recurrence and death during follow-up time.

RESULTS

Thirty-eight (34.5%) patients showed LNMM, whereas in 54 (49.1%) patients BNMM could be detected. LNMM and BNMM positive patients showed a correlation to an increased pT category (p = 0.017). Univariate and multivariate analyses revealed that the LNMM/BNMM status and especially LNMM skipping the anatomical lymph node chain were significant independent predictors of overall survival and recurrence-free survival.

CONCLUSIONS

This study indicates that routine pathological staging of EC is insufficient. Micrometastases in lymph nodes and the bone marrow seem to be the main reason for tumor recurrence and they are a strong prognosticator following curative treatment of pN0 EC.

Postoperative morbidity and mortality after neoadjuvant chemotherapy versus upfront surgery for locally advanced gastric cancer: a propensity score matching analysis

Background

Cohort studies have shown that neoadjuvant chemotherapy (NAC) is not associated with increased risk of postoperative complications and mortality as compared to upfront surgery (SURG).

Objective

The aim of this study was to compare postoperative morbidity and mortality after NAC with SURG.

Patients and methods

Patients who underwent gastrectomy with D2 lymphadenectomy for advanced gastric cancer (GC) between 2010 and 2017 were selected. The impact of neoadjuvant chemotherapy on surgical safety was investigated by using propensity score matching.

Results

Three hundred and seventy-seven patients were included. After propensity score matching, 86 patients in each group were matched. The percentage of patients with one or more complications was 10.5% in NAC group and 15.1% in SURG group (P=0.361), there was no mortality developed in either group. The total blood loss was significantly more in the NAC group than that in the SURG group (320.79 vs 243.37 ml, P<0.04). In univariate and multivariate of the matched cohort, sex, age (<70), BMI (<24), ASA grade, surgical procedure (open vs laparoscopy), gastrectomy extent, cTNM and Charlson index comorbidity were not associated with postoperative complications (all P>0.05).

Conclusion

This study showed that postoperative morbidity and mortality were similar for NAC group and SURG group.

Lymph node regression and survival following neoadjuvant chemotherapy in oesophageal adenocarcinoma

BACKGROUND

The aim was to define the pathological response in lymph nodes following neoadjuvant chemotherapy for oesophageal adenocarcinoma and to quantify any associated survival benefit.

METHODS

Lymph nodes retrieved at oesophagectomy were examined retrospectively by two pathologists for evidence of a response to chemotherapy. Patients were classified as lymph node-negative (either negative nodes with no evidence of previous tumour involvement or negative with evidence of complete regression) or positive (allocated a lymph node regression score based on the proportion of fibrosis to residual tumour). Lymph node responders (score 1, complete response; 2, less than 10 per cent remaining tumour; 3, 10-50 per cent remaining tumour) and non-responders (score 4, more than 50 per cent viable tumour; 5, no response) were compared in survival analyses using Kaplan-Meier and Cox regression analysis.

RESULTS

Among 377 patients, 256 had neoadjuvant chemotherapy. Overall, 68 of 256 patients (26·6 per cent) had a lymph node response and 115 (44·9 per cent) did not. The remaining 73 patients (28·5 per cent) had negative lymph nodes with no evidence of regression. Some patients had a lymph node response in the absence of a response in the primary tumour (27 of 99, 27 per cent). Lymph node responders had a significant survival benefit (P < 0·001), even when stratified by patients with or without a response in the primary tumour. On multivariable analysis, lymph node responders had decreased overall (hazard ratio 0·53, 95 per cent c.i. 0·36 to 0·78) and disease-specific (HR 0·42, 0·27 to 0·66) mortality, and experienced reduced local and systemic recurrence.

CONCLUSION

Lymph node regression is a strong prognostic factor and may be more important than response in the primary tumour.

Anti-tumoral effects of low molecular weight heparins: A focus on the treatment of esophageal cancer

Esophageal cancer is one of the most prevalent types of cancer globally. With current treatment options, the survival is poor, and there are ongoing efforts to find new and more efficient therapeutic approaches. There are several reports on the anti-tumoral effects of low-molecular-weight heparins (LMWH). We have assessed the possible survival benefits and underlying mechanisms of LMWHs in malignancies with a focus on esophageal cancer. We conclude that the effects of LMWHs on survival of cancer patients is probably due to a combination of direct anti-tumoral, anti-angiogenic, and immunomodulatory effects and indirect effects on the coagulation system.

A comparison of the left thoracoabdominal and Ivor-Lewis esophagectomy

The purpose of this study was to assess the oncological outcomes of a large multicenter series of left thoracoabdominal esophagectomies, and compare these to the more widely utilized Ivor-Lewis esophagectomy. With ethics approval and an established study protocol, anonymized data from five centers were merged into a structured database. The study exposure was operative approach (ILE or LTE). The primary outcome measure was time to death. Secondary outcome measures included time to tumor recurrence, positive surgical resection margins, lymph node yield, postoperative death, and hospital length of stay. Cox proportional hazards models provided hazard ratios (HR) with 95% confidence intervals (CI) adjusting for age, pathological tumor stage, tumor grade, lymphovascular invasion, and neoadjuvant treatment. Among 1228 patients (598 ILE; 630 LTE), most (86%) had adenocarcinoma (AC) and were male (81%). Comparing ILE and LTE for AC patients, no difference was seen in terms of time to death (HR 0.904 95%CI 0.749-1.1090) or time to recurrence (HR 0.973 95%CI 0.768-1.232). The risk of a positive resection margin was also similar (OR 1.022 95%CI 0.731-1.429). Median lymph node yield did not differ between approaches (LTE 21; ILE 21; P = 0.426). In-hospital mortality was 2.4%, significantly lower in the LTE group (LTE 1.3%; ILE 3.6%; P = 0.004). Median hospital stay was 11 days in the LTE group and 14 days in the ILE group (P < 0.0001). In conclusion, this is the largest series of left thoracoabdominal esophagectomies to be submitted for publication and the only one to compare two different transthoracic esophagectomy strategies. It demonstrates oncological equivalence between operative approaches but possible short- term advantages to the left thoracoabdominal esophagectomy.

Disseminated tumour cells with highly aberrant genomes are linked to poor prognosis in operable oesophageal adenocarcinoma

BACKGROUND

Chromosomal instability (CIN) has repeatedly been identified as a prognostic marker. Here we evaluated the percentage of aberrant genome per cell (PAG) as a measure of CIN in single disseminated tumour cells (DTC) isolated from patients with operable oesophageal adenocarcinoma (EAC), to assess the impact of CIN^high DTCs on prognosis.

METHODS

We isolated CK18^positive DTCs from bone marrow (BM) or lymph node (LN) preparations of operable EAC patients. After whole-genome amplification, single DTCs were analysed for chromosomal gains and losses using metaphase-based comparative genomic hybridisation (mCGH). We calculated the PAG for each DTC and determined the critical threshold value that identifies high-risk patients by STEPP (Subpopulation Treatment Effect Pattern Plot) analysis in two independent EAC patient cohorts (cohort #1, n=44; cohort #2; n=29).

RESULTS

The most common chromosomal alterations observed among the DTCs were typical for EAC, but the DTCs showed a varying PAG between individual patients. Generally, LNDTCs displayed a significantly higher PAG than BMDTCs. STEPP analysis revealed an increasing PAG of DTCs to be correlated with an increased risk for short survival in two independent EAC cohorts as well as in the corresponding pooled analysis. In all three data sets (cohort #1, cohort #2 and pooled cohort), PAG^high DTCs conferred an independent risk for a significantly decreased survival.

CONCLUSIONS

The analysis of PAG/CIN in solitary marker-positive DTCs identifies operable EAC patients with poor prognosis, indicating a more aggressive minimal residual disease.

Predictors of overall and recurrence-free survival after neoadjuvant chemotherapy for gastroesophageal adenocarcinoma: Pooled analysis of individual patient data (IPD) from randomized controlled trials (RCTs)

BACKGROUND

Neoadjuvant chemotherapy improves prognosis of patients with locally advanced gastroesophageal adenocarcinoma. The aim of this study was to identify predictors for postoperative survival following neoadjuvant therapy. These could be useful in deciding about postoperative continuation of chemotherapy.

METHODS

This meta-analysis used IPD from RCTs comparing neoadjuvant chemotherapy with surgery alone for gastroesophageal adenocarcinoma. Trials providing IPD on age, sex, performance status, pT/N stage, resection status, overall and recurrence-free survival were included. Survival was calculated in the entire study population and subgroups stratified by supposed predictors and compared using the log-rank test. Multivariable Cox models were used to identify independent survival predictors.

RESULTS

Four RCTs providing IPD from 553 patients fulfilled the inclusion criteria. (y)pT and (y)pN stage and resection status strongly predicted postoperative survival both after neoadjuvant therapy and surgery alone. Patients with R1 resection after neoadjuvant therapy survived longer than those with R1 resection after surgery alone. Patients with stage pN0 after surgery alone had better prognosis than those with ypN0 after neoadjuvant therapy. Patients with stage ypT3/4 after neoadjuvant therapy survived longer than those with stage pT3/4 after surgery alone. Multivariable regression identified resection status and (y)pN stage as predictors of survival in both groups. (y)pT stage predicted survival only after surgery alone.

CONCLUSION

After neoadjuvant therapy for gastroesophageal adenocarcinoma, survival is determined by the same factors as after surgery alone. However, ypT stage is not an independent predictor. These results can facilitate the decision about postoperative continuation of chemotherapy in pretreated patients.

Western strategy for EGJ carcinoma

In this paper, the epidemiological and clinicobiological behavior of esophagogastric junction (EGJ) adenocarcinoma in the West is compared and contrasted to that in the East, and an overview is provided of current therapeutic strategies employed for this type of tumor in Western countries. It is well known that multimodal treatment is the therapeutic standard in locally advanced EGJ adenocarcinoma, but whether neoadjuvant/perioperative chemotherapy (CT) or neoadjuvant chemoradiotherapy (CRT) is the optimal approach is still debated. Neoadjuvant CRT improves local control in locally advanced Siewert type I and II tumors, so it should be considered the treatment of choice. In the subset of these patients with microscopic systemic disease at diagnosis, more intensive exclusive chemotherapy protocols could be of benefit. Therefore, there is an urgent need to identify these patients before planning the treatment. For Siewert type III tumors, perioperative chemotherapy is the standard. While there is general agreement on the optimal surgical approach for Siewert types I and III (a two-field Ivor Lewis operation and a total gastrectomy with distal esophagectomy, respectively), no standard surgical treatment has been defined for Siewert type II tumors. When data from Western series on proximal and circumferential resection margins and on nodal spread in Siewert type II tumors are taken into account, the optimal surgical approach appears to be Ivor Lewis esophagectomy. Whether the extent of esophageal invasion can correctly predict nodal involvement in middle-upper mediastinal stations as a means to restrict indications for transthoracic esophagectomy requires further investigation in the West.

Preoperative therapy in locally advanced esophageal cancer

Esophageal cancer is an aggressive malignancy associated with dismal treatment outcomes. Presence of two distinct histopathological types distinguishes it from other gastrointestinal tract malignancies. Surgery is the cornerstone of treatment in locally advanced esophageal cancer (T2 or greater or node positive); however, a high rate of disease recurrence (systemic and loco-regional) and poor survival justifies a continued search for optimal therapy. Various combinations of multimodality treatment (preoperative/perioperative, or postoperative; radiotherapy, chemotherapy, or chemoradiotherapy) are being explored to lower disease recurrence and improve survival. Preoperative therapy followed by surgery is presently considered the standard of care in resectable locally advanced esophageal cancer as postoperative treatment may not be feasible for all the patients due to the morbidity of esophagectomy and prolonged recovery time limiting the tolerance of patient. There are wide variations in the preoperative therapy practiced across the centres depending upon the institutional practices, availability of facilities and personal experiences. There is paucity of literature to standardize the preoperative therapy. Broadly, chemoradiotherapy is the preferred neo-adjuvant modality in western countries whereas chemotherapy alone is considered optimal in the far East. The present review highlights the significant studies to assist in opting for the best evidence based preoperative therapy (radiotherapy, chemotherapy or chemoradiotherapy) for locally advanced esophageal cancer.

Prognostic significance of prospectively detected bone marrow micrometastases in esophagogastric cancer: 10-year follow-up confirms prognostic significance

We have previously reported that most patients with esophagogastric cancer (EGC) undergoing potentially curative resections have bone marrow micrometastases (BMM). We present 10-year outcome data of patients with EGC whose rib marrow was examined for micrometastases and correlate the findings with treatment and conventional pathologic tumor staging. A total of 88 patients with localized esophagogastric tumors had radical en-bloc esophagectomy, with 47 patients receiving neoadjuvant (5-fluorouracil/cisplatin based) chemoradiotherapy (CRT) and the remainder being treated with surgery alone. Rib marrow was examined for cytokeratin-18-positive cells. Standard demographic and pathologic features were recorded and patients were followed for a mean 10.04 years. Disease recurrences and all deaths in the follow-up period were recorded. No patients were lost to follow-up. 46 EGC-related and 10 non-EGC-related deaths occurred. Multivariate Cox analysis of interaction of neoadjuvant chemotherapy, nodal status, and BMM positivity showed that the contribution of BMM to disease-specific and overall survival is significant (P = 0.014). There is significant interaction with neoadjvant CRT (P < 0.005), and lymph node positivity (P < 0.001) but BMM positivity contributes to increase in risk of cancer-related death in patients treated with either CRT or surgery alone. Bone marrow micrometastases detected at the time of surgery for EGC is a long-term prognostic marker. Detection is a readily available, technically noncomplex test which offers a window on the metastatic process and a refinement of pathologic staging and is worthy of routine consideration.

Tumor stage after neoadjuvant chemotherapy determines survival after surgery for adenocarcinoma of the esophagus and esophagogastric junction

PURPOSE

Neoadjuvant chemotherapy is established in the management of most resectable esophageal and esophagogastric junction adenocarcinomas. However, assessing the downstaging effects of chemotherapy and predicting response to treatment remain challenging, and the relative importance of tumor stage before and after chemotherapy is debatable.

METHODS

We analyzed consecutive resections for esophageal or esophagogastric junction adenocarcinomas performed at two high-volume cancer centers in London between 2000 and 2010. After standard investigations and multidisciplinary team consensus, all patients were allocated a clinical tumor stage before treatment, which was compared with pathologic stage after surgical resection. Survival analysis was conducted using Kaplan-Meier analysis and Cox regression analysis.

RESULTS

Among 584 included patients, 400 patients (68%) received neoadjuvant chemotherapy. Patients with downstaged tumors after neoadjuvant chemotherapy experienced improved survival compared with patients without response (P < .001), and such downstaging (hazard ratio, 0.43; 95% CI, 0.31 to 0.59) was the strongest independent predictor of survival after adjusting for patient age, tumor grade, clinical tumor stage, lymphovascular invasion, resection margin status, and surgical resection type. Patients downstaged by chemotherapy, compared with patients with no response, experienced lower rates of local recurrence (6% v. 13%, respectively; P = .030) and systemic recurrence (19% v. 29%, respectively; P = .027) and improved Mandard tumor regression scores (P = .001). Survival was strongly dictated by stage after neoadjuvant chemotherapy, rather than clinical stage at presentation.

CONCLUSION

The stage of esophageal or esophagogastric junction adenocarcinoma after neoadjuvant chemotherapy determines prognosis rather than the clinical stage before neoadjuvant chemotherapy, indicating the importance of focusing on postchemotherapy staging to more accurately predict outcome and eligibility for surgery. Patients who are downstaged by neoadjuvant chemotherapy benefit from reduced rates of local and systemic recurrence.

Targeting therapy for esophageal cancer in patients aged 70 and over

BACKGROUND

While cancer is a disease of the elderly, these patients are under-represented in randomized trials. Esophageal cancer-management in the elderly is challenging because of the morbidity and mortality associated with surgery.

OBJECTIVES

We examined a strategy of neo-adjuvant chemo-radiotherapy (naCRT), followed by surgery or surveillance, in selected patients with cancer aged 70 and older.

METHODS

A prospectively-accrued database identified 56 consecutive patients over a 90-month period, who were aged 70years and over, presented with esophageal carcinoma and were treated with neo-adjuvant CRT (naCRT)±surgery.

RESULTS

Of 129 eligible patients, 66 (51%) received palliative measures, while 63 (49%) had curative intervention, namely 7 had surgery and 56 had naCRT±surgery. Of these 56 patients, 33 (59%) had adenocarcinoma (AC) and 23 (41%) had squamous cell carcinoma (SCC). Twenty-five (45%) had a complete clinical response (cCR), of which 6 had immediate resection; 4 (67%) had a complete pathological response (pCR); 19 patients with a cCR declined or were unfit for surgery and underwent surveillance; of these, 3 had interval esophagectomy; 16 were not offered or declined resection. Eight (50%) have survived ≥3years. Mean overall survival was 28months for the entire cohort; 47months for cCRs; 61months for patients undergoing primary resection, 46months for cCRs who did not undergo resection and 29months for those undergoing interval resection for recurrent disease. In cCRs, surgery did not provide a survival advantage (p=0.861).

CONCLUSION

cCR yields an overall 3-year survival of 50% without operation. As 45% of patients have a cCR to naCRT, obligatory resection in high-risk cCR patients makes little sense. With the option for salvage esophagectomy in re-emergent disease, this selective strategy is an attractive alternative for elderly patients with cancer.

Lymph node micrometastases detected by carcinoembryonic antigen mRNA affect long-term survival and disease-free interval in early-stage lung cancer patients

The majority of stage I lung cancer patients undergo a complete resection of their tumor; however, they still harbor a considerable risk of mortality due to recurrences. A correlation between the presence of lymph node micrometastases and poor prognosis has been observed. The aim of this study was to correlate the lymph node molecular staging with the 5-year survival and disease-free interval following pulmonary lobectomy for non-small cell lung cancer (NSCLC). A quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) for carcinoembryonic antigen (CEA) mRNA was performed on primary lung tumors and regional lymph nodes from 55 surgically resected NSCLC patients classified as clinical stage I. CEA mRNA was found to be present in all the primary tumors. RT-PCR revealed the presence of cancer cells in the lymph nodes of 20 patients (36.3%) and routine staining detected lymph node metastases in 11 patients. Significant differences in survival and disease-free intervals were observed in patients with lymph node micrometastases versus patients with negative lymph nodes (P=0.0026 and P=0.0044, respectively). Multivariate analyses confirmed that micrometastases were an independent predictor for worse prognosis (P=0.0098) and a short disease-free interval (P=0.0137). This study demonstrated strong correlations between the molecular detection of lymph node micrometastases and 5-year survival rates and disease-free interval in patients who underwent pulmonary lobectomy for early-stage lung cancer.

Lymph node, peritoneal and bone marrow micrometastases in gastric cancer: Their clinical significance

The 7th TNM classification clearly states that micrometastases detected by morphological techniques (HE stain and immunohistochemistry) should always be reported and calculated in the staging of the disease (pN1mi or M1), while patients in whom micrometastases are detected by non-morphological techniques (e.g., flow cytometry, reverse-transcriptase polymerase chain reaction) should still be classified as N0 or M0. In gastric cancer patients, micrometastases have been detected in lymph nodes, the peritoneal cavity and bone marrow. However, the clinical implications and/or their prognostic significance are still a matter of debate. Current literature suggests that lymph node micrometastases should be encountered for the loco-regional staging of the disease, while skip lymph node micrometastases should also be encountered in the total number of infiltrated lymph nodes. Peritoneal fluid cytology examination should be obligatorily performed in pT3 or pT4 tumors. A positive cytology classifies gastric cancer patients as stage IV. Although a curative resection is not precluded, these patients face an overall dismal prognosis. Whether patients with a positive cytology should be treated similarly to patients with macroscopic peritoneal recurrence should be evaluated further. Gastric cancer cells are detected with high incidence in the bone marrow. However, the published results make comparison of data between groups almost impossible due to severe methodological problems. If these methodological problems are overcome in the future, specific target therapies may be designed for specific groups of patients.

Disseminated and circulating tumor cells in gastrointestinal oncology

Circulating (CTCs) and disseminated tumor cells (DTCs) are two different steps in the metastatic process. Several recent techniques have allowed detection of these cells in patients, and have generated many results using different isolation techniques in small cohorts. Herein, we review the detection results and their clinical consequence in esophageal, gastric, pancreatic, colorectal, and liver carcinomas, and discuss their possible applications as new biomarkers.

CK19 mRNA expression in the bone marrow of patients with esophageal squamous cell carcinoma and its clinical significance

The 5-year survival rate in resectable patients with esophageal cancer is only 20% to 36%. Regional relapse and distant metastasis are responsible for the failure of treatment and the majority of cancer-related deaths. Earlier detection of metastases, especially micrometastases, has the potential for more accurate risk stratification in subsequent therapy decisions. No effective techniques have yet been found to detect metastases in erroneously thought to have early stage disease. This study was designed to investigate the clinical significance of bone marrow micrometastases detected by reverse transcriptase-polymerase chain reaction (RT-PCR) in patients with esophageal cancer. Expression of CK19 mRNA in the bone marrow of 61 patients with esophageal squamous cell carcinoma (ESCC) and 15 benign pulmonary and esophageal disease patients was assessed via RT-PCR. Correlation of CK19 mRNA expression to the clinicopathologic features and prognosis of the 61 patients was analyzed: 21.3% (13/61) were positive for expression of CK19 mRNA in patients with ESCC. No CK19 mRNA was detected of the 15 benign pulmonary and esophageal disease patients. CK19 mRNA expression did not correlate with the clinicopathologic features of the patients with ESCC, but patients with CK19 mRNA-positive bone marrow had earlier recurrence and shorter survival after surgery. In multivariate analysis, CK19 mRNA was found to be an independent predictor of a poor outcome. CK19 mRNA may be used as a molecular maker to detect bone marrow micrometastases in patients with ESCC and may help to select the proper therapy and predict the prognosis.

The role of lymphadenectomy in esophageal cancer

OBJECTIVE

To address the role of lymphadenectomy in the treatment of esophageal cancer.

BACKGROUND

The role of lymphadenectomy in esophageal cancer surgery is controversial, and there is a lack of uniformity as to what the term means.

METHODS

The published data was reviewed to evaluate the evidence base for, and the terminology associated with, lymphadenectomy for esophageal cancer.

RESULTS

Recommendations are given for a standardization of terminology for radical and nonradical lymphadenectomy procedures. Although there is no doubt that the presence of lymph node metastases worsens prognosis for a patient, there is a lack of high-level evidence to support lymphadenectomy. Logically, the best procedure, from a staging and perhaps theoretical oncologic point of view, is a 3-field lymphadenectomy but it is not clear which patients, if any, are most likely to benefit.

CONCLUSIONS

Well-designed randomized controlled trials are required to test, in a scientific manner, which of these procedures we should be offering our patients.

Lessons from an aggressive cancer: evolutionary dynamics in esophageal carcinoma

Rapid progression to metastatic disease and an intrinsic resistance to any type of systemic therapy are hallmarks of aggressive solid cancers. The molecular basis for this phenotype is not clear. A detailed study of the somatic progression from local to early systemic esophageal cancer revealed rapid diversification of cancer cells isolated from various sites, but also evidence for early clonal expansion. These findings have implications for diagnostic pathology and therapeutic decision making.

Detection of lymph node metastases in oesophageal cancer

Background

The importance of lymph node status in oesophageal cancer cannot be disputed. It is therefore surprising that no standardization exists in either terminology or methodology in lymph node analysis.

Methods

All online databases were searched to identify articles published from 1970 onwards. This was supplemented by hand searching references of retrieved articles.

Results and conclusion

Without accurate identification of lymph node metastases, patients cannot be staged properly, nor can best practice for the treatment of oesophageal cancer be determined. This review outlines the problem and proposes recommendations for standardization in terminology and methodology for the detection of lymph node metastases in oesophageal cancer.

Histological type of esophageal cancer might affect response to neo-adjuvant radiochemotherapy and subsequent prognosis

BACKGROUND

This study investigates response and prognosis after neo-adjuvant chemoradiation (CTx/RTx) in patients with advanced esophageal carcinoma, according to histological type.

PATIENTS AND METHODS

Patients with uT3 carcinoma of the esophagus treated with curative-intention esophagectomy from 1997 until 2006 were included in this retrospective analysis. Patients receiving preoperative CTx/RTx (5-fluorouracil, cisplatin, 36 Gy) were compared with those with primary surgery for pT3 tumors. Therapy response after CTx/RTx was evaluated using 'Cologne Regression Grade' (minor response: >or=10% vital residual tumor cells (VRTCs), major response: <10% VRTC or pathologic complete response). Prognosis was evaluated for adenocarcinoma (AC) and squamous cell carcinoma (SCC).

RESULTS

Of 297 patients, 52% were SCC and 48% AC. In all, 192 patients underwent CTx/RTx, 100 (65%) SCC and 92 (64%) AC (nonsignificant). In SCC group 51% and in AC group 29% achieved major response (P < 0.01). Patients with major response had a 2-year survival rate (2y-SR) of 78% versus those with minor response or without CTx/RTx, with a 2y-SR of 45% (P = 0.001). Examining patients with major response exclusively, the prognosis of AC (2y-SR 85%) is better than that of SCC (2y-SR 54%) (P < 0.01).

CONCLUSION

This retrospective study concludes that in esophageal tumors, response to and prognosis after neo-adjuvant CTx/RTx vary according to histology.

The effects of preoperative chemotherapy on isolated tumour cells in the blood and bone marrow of gastric cancer patients

Recent studies in breast cancer suggest that monitoring the isolated tumour cells (ITC) may be used as a surrogate marker to evaluate the efficacy of systemic chemotherapy. In the present study, we have investigated the effects of preoperative chemotherapy on ITC in the blood and bone marrow of patients with potentially resectable gastric cancer. After sorting out the CD45-positive cells, the presence of ITC defined as cytokeratin-positive cells was examined before and after preoperative chemotherapy. The patients received two courses of preoperative chemotherapy with cisplatin (100 mg m⁻², day 1) and 5-fluorouracil (1000 mg m⁻², days 1–5), administered every 28 days. Fourteen of 32 (44%) patients initially diagnosed with ITC in blood and/or bone marrow were found to be negative (responders) after preoperative chemotherapy (P<0.01). The incidence of ITC in bone marrow was also significantly (P<0.01) reduced from 97 (31 of 32) to 53% (17 of 32). The difference between patients positive for ITC in the blood before (n=7, 22%) and after (n=5, 16%) chemotherapy was statistically insignificant. The overall 3-year survival rates were 32 and 49% in the responders and non-responders, respectively (P=0.683). These data indicate that preoperative chemotherapy can reduce the incidence of ITC in patients with gastric cancer.

Regional lymph node metastases; a singular manifestation of the process of clinical metastases in cancer: contemporary animal research and clinical reports suggest unifying concepts

Research results from laboratory animals and human clinical reports provide insight into cancer cell disseminations and elaborate the complex metastatic cascade of cells into both regional lymph nodes and other distant organs. Critical appraisal of clinical trials indicates that lymph node metastases are themselves non-lethal, but indicate prognosis, confirming laboratory conclusions. Distant vital organ metastases can be resected with long term survival in highly selective situations, demonstrating metastatic specificity in oligometastatic disease. Appreciating lymphatic system embryology, anatomy, and physiology is necessary for understanding lymph node metastases. The primary lymphatic system function was to return interstitial fluid to the circulation. Later evolutionary insertion of lymphocyte collections in lymph nodes interrupting lymph flow completed a system of analyzing external antigens to enable adaptive immunologic responses. Human cancers seldom elicit major immunological responses; they are not generally "foreign" enough. Therefore, lymphatic metastases have little meaning in evolutionary terms. Organ specificity of both lymphatic and distant metastases occurs as metastatic cells lie dormant, but grow selectively only in liver, lung, bone, or lymph nodes. These organ specific metastatic cells have little ability to produce different organ site clinical metastases. Thus, laboratory findings and clinical correlations emphasize that surgical lymph node removal should be de-emphasized or omitted. More physiological approaches to the highly manipulable multi-step processes of clinical metastases arising from host microenvironments will eventually prevail.

The effect of neoadjuvant chemotherapy on lymph node micrometastases in squamous cell carcinomas of the thoracic esophagus

BACKGROUND

Neoadjuvant chemotherapy (NACT) has been postulated but not yet proven to eradicate micrometastases and improve the prognosis of patients with advanced esophageal squamous cell carcinomas (ESCC). Cytokeratin immunohistochemistry of the lymph nodes of ESCC revealed immunohistochemical micrometastases (IHM) and cytokeratin deposits (CD), which are hyalinized denucleated particles considered to be cadavers of carcinoma cells. Successful chemotherapy should convert cancer cells from IHM to CD and improve the status of ESCC patients from systemic disease to regional disease.

METHODS

Cytokeratin immunostaining of surgically removed lymph nodes was performed for 107 patients with node-positive ESCC, including 32 patients without preoperative treatment (Surgery group) and 75 patients undergoing NACT using CDDP, doxorubicin hydrochroride, and 5-fluorouracil (NACT group). Cytokeratin-positive staining was done for serial hematoxylin-eosin-stained sections and classified as pathologic metastasis, IHM, or CD.

RESULTS

CD was observed less frequently in the Surgery group than in the NACT group (6% vs 43%, P < .0001), whereas IHM was more frequent in the former (47% vs 24%, P = .019). IHM was a poor prognostic factor in both groups, whereas CD was a favorable one in the NACT group. The effect of chemotherapy on IHM was classified as eradicated, IHM(-)/CD(+); persistent, IHM(+)/CD(+); no effect, IHM(+)/CD(-); or not informative, IHM(-)/CD(-). This classification correlated well with the clinical response of the primary neoplasm, number of pathologic metastases, and postoperative survival (3-year survival rates: 78%, 18%, 0%, and 38%). IHM/CD was found to be an independent prognostic factor together with the number of pathologic metastases in the multivariate analysis.

CONCLUSIONS

Disappearance of IHM and the emergence of CD suggest the eradication of micrometastases by NACT. The clinical benefit of NACT was apparent for IHM(-)/CD(+) patients with node-positive ESCC.

Regional lymph node metastases, a singular manifestation of the process of clinical metastases in cancer: contemporary animal research and clinical reports suggest unifying concepts

The multistep complex metastatic cascade in cancer has been extensively studied in recent years. In addition, the concept of metastatic organ specificity has been elaborated. Histological studies in clinical situations have become far more sophisticated, enabling the frequent discovery of minor collections of cells in bone marrow and lymph nodes. Pertinent clinical evidence of the selective nodal metastatic pattern exists in differentiated thyroid cancer in younger, low-risk patients, yet none of the published risk group definitions indicate that lymph node metastases have a relationship to thyroid cancer survival. This unique clinical situation with very frequent nodal metastases but excellent survival is replicated in carcinoid cancers of the gastrointestinal tract. The lymph node metastatic frequency without distant organ metastases in these two human cancers help cement the understanding gained from laboratory and animal research regarding metastatic specificity and hopefully will help place the role of lymph node metastases generally and their surgical removal on a more scientifically and logically based understanding. More broadly, the elaboration of the frequency of metastatic cell dissemination to distant organs as well as lymph nodes, and comprehension of the metastatic cascade with metastatic specificity may reorient our understanding of the evolution from metastatic cells to clinical metastatic disease. Additionally, these concepts reemphasize that lymph node metastases are indicators, not governors, of distant metastases and survival, and add the assumption that metastatic tumor cells and tumor cell clusters, and perhaps even micrometastases in other organs, are themselves only indicators and not governors of distant metastases and survival in human cancers since they represent dormant metastases prior to their host microenvironmental changes that, on rare occasions, lead to angiogenesis and clinical metastases. Thus, the future may allow us to abandon some aspects of our surgical or systemic attack on clinical cancer metastases, such as lymph node removal or use of toxic chemotherapy, but open the door to more physiological and hopefully less traumatic approaches to the highly manipulable multistep genetic and physiological process of metastatic development. The future biological models of clinical cancer behavior will have to incorporate aspects of understanding the intricate metastatic cascade, and particularly the host microenvironmental factors that permit or prevent progressive growth of dormant cells or cell clusters to clinical metastases.

[Minimal residual tumor in gastrointestinal carcinoma. Relevance to prognosis and oncologic surgical consequences]

Isolated tumor cells as a consequence of minimal residual disease are often not detectable by routine diagnostic procedures. However, before or after surgery, isolated tumor cells in lymph nodes, the peritoneal cavity, blood, or bone marrow can frequently be identified by immunohistochemical or molecular methods. Failure to reveal the presence of such cells results in under-staging of tumor patients and may constitute the source of unexpected tumor recurrence after radical surgery. These facts emphasize the importance of isolated tumor cells at least as a surrogate marker. The frequency of appearance of isolated tumor cells in different organ systems also depends on the type of primary tumor. Developments in modern detection methods have led to increasing sensitivity but at the expense of specificity. Isolated tumor cells demonstrate remarkable heterogeneity with respect to proliferative potential and tumorigenicity. This characteristic is also reflected by a striking variability in the expression of various genes conditioning the aforementioned biological behavior. Unfortunately there is also remarkable heterogeneity in methods used for sampling and processing patient material as well as for the enrichment and detection of isolated tumor cells. Despite the ongoing controversies concerning detection methods and biological significance of isolated tumor cells, several clinical trials providing data supporting the prognostic relevance of minimal residual disease should also be considered for gastrointestinal carcinoma. In future this finding should be integrated in the planning of trials in surgical oncology, and "minimal residual disease" should receive stronger attention as a stratification criterion in such clinical studies.

Prognostic Value of Cytokeratin-Positive Bone Marrow Cells of Gastric Cancer Patients

BACKGROUND

Epithelial cells in the bone marrow of patients with gastric cancer suggest tumor dissemination; however, their prognostic implications are controversial. We prospectively evaluated the correlation of bone marrow findings, recurrence rate, and disease-free survival after long-term follow-up.

METHODS

Bone marrow were aspirated from both iliac crests and stained with monoclonal cytokeratin (CK)-18 antibody in 209 patients before their initial operation. Patients were followed up for a median of 56 months.

RESULTS

Overall, 39 (19%) of 209 patients and 15 (14%) of 109 R0-resected patients had CK-positive cells. CK-positive patients had more local, regional, and distant recurrence than CK-negative patients (P < .05). We found a significantly shorter disease-free survival (P < .05) in the patients with >2 CK-positive cells per 2 x 10(6) bone marrow cells (mean, 35 months) than in patients with <or=2 CK-positive cells per 2 x 10(6 )bone marrow cells (mean, 70 months) or in patients with no CK-positive cells (mean, 86 months). Multivariate analysis confirmed that >2 CK-positive cells per 2 x 10(6) bone marrow cells was an independent prognostic factor for tumor-related death (P < .05).

CONCLUSIONS

Not only the mere presence of CK-positive epithelial cells in bone marrow, but also the cell number, correlates with prognosis. Our findings suggest that classifying CK-positive bone marrow cells in these patients will facilitate future studies.

Prognostic factors in adenocarcinoma of the esophagus or gastroesophageal junction

The incidence of adenocarcinoma of the esophagus is rising rapidly in Western Europe and North America. It is an aggressive disease with early lymphatic and hematogenous dissemination. TNM cancer staging systems predict survival on the basis of the anatomic extent of the tumor. However, the adequacy of the current TNM staging system for adenocarcinoma of the esophagus or gastroesophageal junction (GEJ) is questioned repeatedly. Numerous prognostic factors have been described, but are not included in the TNM system. This review describes clinical parameters, aspects of operative technique, response to preoperative chemoradiotherapy therapy, complications and established pathologic determinants found in the resection specimen that have a prognostic impact. Furthermore, their potential application in the clinical setting in patients with adenocarcinoma of the esophagus or GEJ is discussed. Future directions to improve staging systems are given.

Impact of disseminated tumor cells in gastrointestinal cancer

The detection of epithelial cells by sensitive immunological and molecular methods in blood, lymph nodes or bone marrow of gastrointestinal cancer patients may open a new approach to clinical metastasis research. The phenotypic and genomic characterization of these cells is of great value in the prediction of the further course of the disease and the monitoring of response to treatment. In addition, the role of ultrastaging in blood, lymph nodes and bone marrow of cancer patients for the indication of multimodal therapy is discussed in this review. The impact of prognostic or predictive factors for new treatment protocols in patients with gastrointestinal cancer was evaluated as well as the correlation with clinical factors.

Adenocarcinoma of the esophagus and cardia: a review of the disease and its treatment

BACKGROUND

Over the past 50 years there has been a remarkable change in the epidemiology of esophageal cancer. Previously rare, adenocarcinoma of the esophagus and gastroesophageal junction is now the most common esophageal cancer, and in the United States the incidence is increasing faster than that of any other malignancy. Surveillance in patients with Barrett's esophagus is identifying adenocarcinoma at an earlier, more curable stage in many patients, and at the same time new endoscopic and surgical options are available for the therapy of these localized tumors.

METHODS

This article is a review of the epidemiology, diagnosis, staging, and treatment options for esophageal and gastroesophageal junction adenocarcinoma.

RESULTS

The epidemiology, prognosis, patterns of lymphatic metastasis, and survival for esophageal and gastroesophageal junction adenocarcinoma suggest that these tumors are similar. New options for therapy, as well as the results of surgical resection with and without chemoradiotherapy, are reviewed.

CONCLUSIONS

Surveillance programs for Barrett's are identifying patients with early, curable adenocarcinoma of the esophagus or gastroesophageal junction. Therapy for more advanced tumors hinges on local control of the disease and the eradication of systemic metastases.

Esophageal Carcinoma: Current Controversial Topics

Worldwide, esophageal carcinoma is a common gastrointestinal cancer with a high mortality. The incidence of adenocarcinoma of the esophagus is increasing in the western world, but squamous cell carcinoma remains dominant in the underdeveloped parts of the world. Both types of esophageal carcinoma remain equally virulent. Currently, there are no optimal preventative screening programs available and most patients present with advanced or metastatic disease. Although many options are available for improving diagnostic accuracy, a single method has not displayed significant advantages over the others. In addition, selecting a superior treatment regimen has not surfaced. Preferred resection techniques exist, but one method has not illustrated improvements in survival over the others. A lack of improved survival rates with single modality therapies has led to a multi modality approach. However, developments in neoadjuvant and adjuvant therapies have led to mixed conclusions. Collectively, past studies have not shown an optimal neoadjuvant or adjuvant regimen in terms of survival benefit. This review highlights existing staging modalities and treatment regimens for esophageal carcinoma, in an effort to illustrate the controversial nature surrounding its management.

Detection of circulating oesophageal squamous cancer cells in peripheral blood and its impact on prognosis

BACKGROUND

Many studies have attempted to detect cancer cells using the reverse transcription-polymerase chain reaction (RT-PCR) for specific mRNAs. None has examined the correlation between the presence of circulating oesophageal cancer cells in peripheral blood and long-term outcome.

METHODS

Blood samples were obtained on admission, and before, during and after operation from 70 patients with squamous oesophageal cancer who had complete clinicopathological records and who underwent curative oesophagectomy between June 1997 and June 2000. RT-PCR for mRNA encoding squamous cell carcinoma antigen (SCCA mRNA) was used to detect oesophageal cancer cells in peripheral blood.

RESULTS

Twenty-three patients (33 per cent) were positive for SCCA mRNA on admission and 17 of these patients developed recurrent disease. SCCA mRNA on admission correlated with the depth of tumour invasion (P < 0.001) and with venous invasion (P < 0.001). Eleven of 24 patients with a positive intraoperative result were positive for SCCA mRNA only during operation, of whom seven also developed recurrence.

CONCLUSION

RT-PCR for SCCA mRNA can detect oesophageal cancer cells in peripheral blood. The presence of such cells in blood samples obtained on admission or during operation is a useful predictor of outcome in patients with oesophageal squamous cell carcinoma.

Prevalence of bone marrow micrometastases in esophagogastric cancer patients with and without neoadjuvant chemoradiotherapy

BACKGROUND

Bone marrow micrometastases are present in a high proportion of patients undergoing curative resection for esophagogastric cancer. The incorporation of preoperative systemic therapies into these patients' treatment is widely practiced. This study investigates the effect of neoadjuvant chemoradiotherapy (CRT) on the incidence of micrometastases and the viability of detected tumor cells.

MATERIALS AND METHODS

Rib bone marrow was obtained from patients (n = 106) in three centers, who were selected for potentially curative resection. Patients received neoadjuvant CRT plus surgery (n = 55), or surgery alone (n = 51). To detect micrometastases, mononuclear cells were isolated from fresh marrow and immediately stained immunohistochemically with an anti-cytokeratin-18 antibody using the APAAP technique. Tumor cell viability was assessed by immunohistochemical staining of marrow cell cultures for cytokeratin-positive cells.

RESULTS

Micrometastases were detected in fresh marrow in 42% (23/55) of patients who received neoadjuvant CRT plus surgery, and in 67% (34/51) of patients treated with surgery alone. Viable tumor cells were demonstrated in 10 of 18 marrow cultures from CRT plus surgery cases. In this patient subset, combination of results of staining fresh and cultured marrow significantly increased micromet detection to 78%.

CONCLUSIONS

A significant proportion of patients with esophagogastric cancer have disseminated viable tumor cells at time of surgery, irrespective of pre-operative treatment. The use of marrow culture in parallel with fresh marrow staining may increase the detection of micrometastases. The persistence of tumor cells resistant to systemic therapy may explain why these regimens fail in a majority of patients.

Minimal residual disease in gastric cancer

In curatively resected gastric cancer, the incidence of distant relapse is as high as 30%. Although the most important factor contributing to the local control of the tumor is the microscopic tumor-free margin of the surgical resection, the occurrence of distant metastases is in many cases due to preoperative or perioperative tumor cell dissemination. In addition to the established TNM staging system, disseminated tumor cells may serve as independent prognostic factors influencing patient outcome after curative surgery. Basically, in gastric cancer three compartments have been identified in which single tumor cells may be shed: lymph nodes, peritoneal cavity, and bone marrow. Assessment of resected regional lymph nodes with monoclonal antibodies directed against cytokeratin antigens leads to an upstaging in comparison with conventional histology. Nodal micrometastases detected by immunohistochemistry result in an upstaging of up to 36% of patients. However, their prognostic significance remains controversial. Local dissemination of tumor cells in the peritoneal cavity determines the outcome in advanced gastric cancer and diffuse-type carcinoma. Patients with negative peritoneal washings seem to have a more favorable prognosis. Moreover, with the use of these diagnostic tools, patient subpopulations may be identified which profit from intraperitoneal therapy regimens. Diffuse hematogenous tumor cell dissemination into the bone marrow has been shown to be a prognostic factor in several studies. In our own population of 180 gastric cancer patients, bone marrow cells were screened immunohistochemically with a monoclonal antibody directed against cytokeratin 18 (CK18). In 95 patients (53%), CK2-posititve cells were detected. In a multivariate analysis, the independence of the presence of three or more disseminated tumor cells per 10(6) mononuclear cells was proven to be a prognostic factor in patients with intestinal-type tumors, pT1/2 status, and pN0 status. In conclusion, the TNM status only partially reflects the actual extent of systemic disease in patients with resected gastric cancer. The assessment of minimal residual disease is valuable in estimating the prognosis in many patients. In the future, staging systems will have to not only include TNM data but also provide specific information on biological properties of residual cancer cells in order to establish more exact prognostic estimates and provide patients with an individually tailored multimodal treatment.

Bone marrow micrometastases predict early post-operative recurrence following surgical resection of oesophageal and gastric carcinoma

AIM

Tumour cells in the bone marrow of patients with gastrointestinal cancer may detect patients at higher risk of disease recurrence and death following potentially curative surgery.

METHODS

Immunocytochemistry using the monoclonal antibody Ber-EP4, which detects tumour cells from squamous and adenocarcinomas was used. In preliminary spiking experiments to define sensitivity, tumour cells were detected in blood at 10(3)/ml. Bone marrow samples from 74 patients with oesophago-gastric cancer and from 14 control patients was examined.

RESULTS

27 (36.5%) patients with cancer and one control patient had stained cells present in their bone marrow at the time of resection. During the follow up period (mean 14 months), relapse and disease-specific death were commoner in patients whose marrow contained tumour cells. Multivariate analysis confirmed bone marrow micrometastasis as an independent prognostic variable for both recurrence and survival.

CONCLUSIONS

Bone marrow immunocytochemistry using Ber-EP4 may identify those patients at highest risk of early relapse following RO resection of oesophageal or gastric cancer.

Detection of bone marrow micrometastasis in gastric cancer patients by immunomagnetic separation

BACKGROUND

Micrometastasis to the bone marrow can predict widespread disease and a poor prognosis of cancer patients after surgery. The purpose of this study was to evaluate the clinical significance of detecting micrometastasis in the bone marrow of gastric cancer patients.

METHODS

Bone marrow and peripheral blood samples were obtained from 53 gastric cancer patients at the time of surgery. These samples were enriched by immunomagnetic separation and immunostained with an anti-cytokeratin antibody. Expression of vascular endothelial growth factor and erbB-2/HER2 was examined in the primary tumors.

RESULTS

Cytokeratin-positive cancer cells were observed in the bone marrow of 16 (30%) of 53 patients. Among them, two patients also had cancer cells in the peripheral blood. The presence of bone marrow micrometastasis was correlated with the depth of invasion and lymph node metastasis but was not associated with peritoneal dissemination. Detection of bone marrow micrometastasis was not correlated with vascular endothelial growth factor or HER2 expression in the primary tumors. Four patients with micrometastasis had recurrence in the liver or lungs, but this did not occur in patients without micrometastasis.

CONCLUSIONS

Detection of cancer cells in the bone marrow might be an indicator of postoperative hematogenous metastasis in gastric cancer patients.

Cytokeratin deposits in lymph nodes show distinct clinical significance from lymph node micrometastasis in human esophageal cancers

BACKGROUND

Cytokeratin immunostaining is the most common method used to identify micrometastatic cancer cells from the lymph nodes. However, contamination with hyalinized cytokeratin particles, frequently observed in the lymph nodes of esophageal cancer patients, can lead to misinterpretation of cytokeratin immunostaining.

MATERIALS AND METHODS

Cytokeratin immunostaining (AE1/AE3) of surgically removed lymph nodes was performed for 41 cases of node-negative, but locally advanced (T3, T4), esophageal cancer patients. Cytokeratin immunoreactivity (CK) was classified as micrometastasis (MM) or cytokeratin deposit (CD) by the presence or absence of tumor nuclei in serial sections given hematoxylin-eosin staining.

RESULTS

CK (+) was observed in 18 patients (44%), including 11 with MM (+) (27%) and 10 with CD (+) (24%). There was no correlation between MM and CD, and neither was associated with clinicopathological factors, except for a high incidence of preoperative chemotherapy in CD (+) patients. The presence of CK did not affect postoperative survival of esophageal cancer patients at this limited stage, showing a 5-year survival rate of 57% for CK (+) and 64% for CK (-) (P = 0.6064). Interestingly, patients with MM (+) showed poorer prognosis than MM (-) (5-year survival: 28% vs 79%, P = 0.0188), while CD (+) patients tended to display better prognosis than CD (-) ones (5-year survival: 78% vs 56%, P = 0.1860).

CONCLUSIONS

Evaluation by cytokeratin immunostaining of lymph nodes requires careful discrimination of CD from MM, in order to allow MM to be used as a prognostic factor for esophageal cancer patients.

The presence of bone marrow cytokeratin-immunoreactive cells does not predict outcome in gastric cancer patients

The independent prognostic significance of isolated tumour cells in bone marrow is still a matter of debate. This study evaluated the possible association of bone marrow micrometastases with tumour progression and prognosis in patients affected by gastric cancer. Bone marrow aspirates from both iliac crests were obtained from 114 consecutive patients operated on for gastric cancer. The specimens were stained with monoclonal antibody CAM 5.2 which reacts predominantly with cytokeratin filaments 8 and 19. Among 114 cases analysed, 33 cases (29%) had cytokeratine-positive cells in the bone marrow. There was no significant relationship between the presence of bone marrow micrometastases and site, depth of tumour invasion, lymph node metastases, presence of metastases. Patients with cytokeratine-positive cells had a trend towards a diffuse type histology (P=0.06). Among the 88 curatively resected patients, median survivals were 40 months and 36 months for cytokeratine-negative and cytokeratine-positive subsets respectively (P=0.9). Recurrence of the disease was observed in 39 cases (44.3%); 11 of 24 (45.8%) in the cytokeratine-positive subset and 28 of 64 (43.7%) in the cytokeratine-negative subset. In conclusion in our experience the presence of cytokeratine-positive cells in the bone marrow of curatively resected gastric cancer patients did not affect outcome and its independent prognostic significance remains to be proven before its official acceptance in the TNM classification.

Minimal residual disease in gastrointestinal cancer

Tumor progression after curative resection of gastrointestinal carcinomas is probably caused by pre- or intraoperative tumor cell dissemination. Disseminated tumor cells are generally detected by immunohistochemistry- or PCR-based molecular-biology methods. A consensus on which is the most adequate detection method has not yet been found, which makes the comparison of data difficult. The prognostic relevance of disseminated cells has been shown, at least in part, for esophageal, gastric, pancreatic, and colonic cancer. The data regarding hepatocellular cancer is conflicting. This article gives a critical review of tumor cell detection in gastrointestinal cancer.