Undervalued criteria in the evaluation of multimodal trials for upper GI cancers.

Global economies and their health systems face a huge challenge from cancer: 1 in 3 women and 1 in 2 men will develop cancer in their lifetime. In the less developed countries, the volume of cancer patients will overwhelm the existing healthcare systems. Even in developed regions, patients with upper gastrointestinal (GI) cancer usually present with locally advanced tumors that their prognosis is poor. A detailed knowledge of anatomy, embryology, epidemiology, tumor classifications and tumor growth is key understanding and evaluating the relevant research. We review undervalued criteria necessary to evaluate the response to multimodal therapy for upper GI cancers.

Epidermal growth factor receptor (EGFR) is an independent adverse prognostic factor in esophageal adenocarcinoma patients treated with cisplatin-based neoadjuvant chemotherapy.

Neoadjuvant platin-based therapy is accepted as a standard therapy for advanced esophageal adenocarcinoma (EAC). Patients who respond have a better survival prognosis, but still a significant number of responder patients die from tumor recurrence. Molecular markers for prognosis in neoadjuvantly treated EAC patients have not been identified yet. We investigated the epidermal growth factor receptor (EGFR) in prognosis and chemotherapy resistance in these patients. Two EAC patient cohorts, either treated by neoadjuvant cisplatin-based chemotherapy followed by surgery (n=86) or by surgical resection (n=46) were analyzed for EGFR protein expression and gene copy number. Data were correlated with clinical and histopathological response, disease-free and overall survival. In case of EGFR overexpression, the prognosis for neoadjuvant chemotherapy responders was poor as in non-responders. Responders had a significantly better disease-free survival than non-responders only if EGFR expression level (p=0.0152) or copy number (p=0.0050) was low. Comparing neoadjuvantly treated patients and primary resection patients, tumors of non-responder patients more frequently exhibited EGFR overexpression, providing evidence that EGFR is a factor for indicating chemotherapy resistance. EGFR overexpression and gene copy number are independent adverse prognostic factors for neoadjuvant chemotherapy-treated EAC patients, particularly for responders. Furthermore, EGFR overexpression is involved in resistance to cisplatin-based neoadjuvant chemotherapy.

Is preoperative chemotherapy followed by surgery the appropriate treatment for signet ring cell containing adenocarcinomas of the esophagogastric junction and stomach?

BACKGROUND: Recent data suggest primary resection as the preferable approach in patients with signet ring cell gastric cancer (SRC). The aim of our retrospective exploratory study was to evaluate the influence of SRC on prognosis and response in esophagogastric adenocarcinoma treated with neoadjuvant chemotherapy. METHODS: A total of 723 locally advanced esophagogastric adenocarcinomas (cT3/4 N any) documented in a prospective database from two academic centers were classified according to the WHO definition for SRC (more than 50 % SRC) and analyzed for their association with response and prognosis after neoadjuvant treatment. RESULTS: A total of 235 tumors (32.5 %) contained SRC. Median survival of SRC was 26.3 compared with 46.6 months (p < 0.001) for non-SRC. SRC were significantly associated with female gender, gastric localization, advanced ypT and R1/2 categories, and lower risk of surgical complications and anastomotic leakage (each p < 0.001). Clinical (21.1 vs. 33.7 %, p = 0.001) and histopathological response (less than 10 % residual tumor: 16.3 vs. 28.9 %, p < 0.001) were significantly less frequent in SRC. Clinical response (p = 0.003) and complete histopathological response (pCR) (3.4 %) (p = 0.003) were associated with improved prognosis in SRC. Clinical response, surgical complications, ypTN categories, but not SRC were independent prognostic factors in forward Cox regression analysis in R0 resected patients. Risk of peritoneal carcinomatosis was increased (p < 0.001), while local (p = 0.015) and distant metastases (p = 0.02) were less frequent than in non-SRC. CONCLUSIONS: Prognosis of SRC is unfavorable. Although response to neoadjuvant chemotherapy is rare in SRC, it is associated with improved outcome. Thus, chemotherapy might not generally be abandoned in SRC. A stratification based on SRC should be included in clinical trials.

Interim endoscopy results during neoadjuvant therapy for gastric cancer correlate with histopathological response and prognosis.

BACKGROUND: Neoadjuvant chemotherapy for locally advanced gastric cancer leads to major histopathological response in less than 30 % of patients. Data on interim endoscopic response assessment do not exist. This exploratory prospective study evaluates early endoscopy after 50 % of the chemotherapy as predictor for later response and prognosis. METHODS: Forty-seven consecutive patients were included (45 resected; 33 R0 resections). All patients received baseline endoscopy and CT scans, after 50 % of their chemotherapy (EGD-1, CT-1) and after completion of chemotherapy (EGD-2, CT-2). Interim endoscopic response (EGD-1) was assessed after having received 50 % (6 weeks) of the planned 12 weeks of neoadjuvant chemotherapy. Post-chemotherapy response was clinically assessed by a combination of CT scan (CT-2) and endoscopy (EGD-2). Histopathological response was determined by a standardized scoring system (Becker criteria). Endoscopic response was defined as a reduction of >75 % of the tumor mass. RESULTS: Twelve patients were responders at EGD-1 and 13 at EGD-2. Nine patients (19.1 %) were clinical responders and 7 patients (15.6 %) were histopathological responders after chemotherapy. Specificity, accuracy, and negative predictive value of the interim EGD-1 for subsequent histopathological response were 31/38 (82 %), 36/47 (76 %), and 31/33 (93 %); and for recurrence or death, 28/30 (93.3 %), 38/47 (80.9 %), and 28/35 (80.0 %). Response at EGD-1 was significantly associated with histopathological response (p = 0.010), survival (p < 0.001), and recurrence-free survival (p = 0.009). CONCLUSIONS: Interim endoscopy after 6 weeks predicts response and prognosis. Therefore, tailoring treatment according to interim endoscopic assessment could be feasible, but the findings of this study should be validated in a larger patient cohort.

Factors predicting prognosis and recurrence in patients with esophago-gastric adenocarcinoma and histopathological response with less than 10 % residual tumor.

PURPOSE: Neoadjuvant treatment is an accepted standard approach for treating locally advanced esophago-gastric adenocarcinomas. Despite a response of the primary tumor, a significant percentage dies from tumor recurrence. The aim of this retrospective exploratory study from two academic centers was to identify predictors of survival and recurrence in histopathologically responding patients. METHODS: Two hundred thirty one patients with adenocarcinomas (esophagus: n = 185, stomach: n = 46, cT3/4, cN0/+, cM0) treated with preoperative chemotherapy (n = 212) or chemoradiotherapy (n = 19) followed by resection achieved a histopathological response (regression 1a: no residual tumor (n = 58), and regression 1b < 10 % residual tumor (n = 173)). RESULTS: The estimated median overall survival was 92.4 months (5-year survival, 56.6 %) for all patients. For patients with regression 1a, median survival is not reached (5-year survival, 71.6 %) compared to patients with regression 1b with 75.3 months median (5-year survival, 52.2 %) (p = 0.031). Patients with a regression 1a had lymph node metastases in 19.0 versus 33.7 % in regression 1b. The ypT-category (p < 0.001), the M-category (p = 0.005), and the type of treatment (p = 0.04) were found to be independent prognostic factors in R0-resected patients. The recurrence rate was 31.7 % (n = 66) (local, 39.4 %; peritoneal carcinomatosis, 25.7 %; distant metastases, 50 %). Recurrence was predicted by female gender (p = 0.013), ypT-category (p = 0.007), and M-category (p = 0.003) in multivariate analysis. CONCLUSION: Response of the primary tumor does not guarantee recurrence-free long-term survival, but histopathological complete responders have better prognosis compared to partial responders. Established prognostic factors strongly influence the outcome, which could, in the future, be used for stratification of adjuvant treatment approaches. Increasing the rate of histopathological complete responders is a valid endpoint for future clinical trials investigating new drugs.

Prediction of response and prognosis by a score including only pretherapeutic parameters in 410 neoadjuvant treated gastric cancer patients.

BACKGROUND: Response to neoadjuvant chemotherapy is an independent prognostic factor in locally advanced gastric cancer. However, no prospectively tested pretherapeutic parameters predicting response and/or survival in gastric cancer are available in clinical routine. METHODS: We evaluated the prognostic significance of various clinical pathologic parameters in 410 patients who were treated with neoadjuvant chemotherapy followed by gastrectomy. Clinical and histopathologic response evaluation was performed by using standardized criteria. A prognostic score was created on the basis of the variables identified in the multivariate analysis. RESULTS: Three pretherapeutic parameters were identified as positive predictive factors for response and prognosis: tumor localization in the middle third of the stomach (P=0.001), well-differentiated tumors (P=0.001), and intestinal tumor type according to Laurén classification (P=0.03). A prognostic index was constructed, dividing the patients into three risk groups: low (n=73), intermediate (n=274), and high (n=63). The three groups had significantly different clinical (P=0.007) and histopathologic response rates (P=0.001) and survival times, with a median survival time that was not reached in the low-risk group, 39.2 months in the intermediate-risk group, and 20.5 months in the high-risk group. The corresponding 5-year survival rates were 65.3, 41.2, and 21.2% (P<0.001), respectively. CONCLUSIONS: A simple scoring system based on three clinicopathologic parameters accurately predicts response and prognosis in neoadjuvant treated gastric cancer. This system provides additional useful information that could be applied to select gastric cancer patients pretherapeutically for different treatment approaches. Prospective testing of the score in an independent patient cohort is warranted.

Molecular imaging of proliferation and glucose utilization: utility for monitoring response and prognosis after neoadjuvant therapy in locally advanced gastric cancer.

BACKGROUND: Metabolic imaging of gastric cancer is limited due to the 30% of primary tumors that are not (18)F-fluorodeoxyglucose (FDG) avid. In contrast, the proliferation marker (18)F-fluorothymidine (FLT) has been shown to visualize also non-FDG-avid gastric tumors. In this study we tested whether FLT-positron emission tomography (PET) can improve the predictive potential of molecular imaging for assessing response to neoadjuvant therapy in gastric cancer compared with FDG-PET. METHODS: 45 patients with gastric cancer underwent FDG- and FLT-PET before and 2 weeks after initiation of chemotherapy. FDG/FLT-PET findings and Ki67 immunohistochemistry were correlated with clinical and histopathological response and survival. RESULTS: 14 patients had non-FDG-avid tumors, whereas all tumors could be visualized by FLT-PET. No significant association of clinical or histopathological response with any of the analyzed metabolic parameters [initial standardized uptake value (SUV), SUV after 2 weeks, change of SUV for FDG/FLT] was found. Univariate Cox regression analysis for Ki67 and metabolic parameters revealed significant prognostic impact for survival only for FLT SUV(mean) day 14 (p=0.048) and Ki67 (p=0.006). Multivariate Cox regression analysis (including clinical response, Lauren type, ypN category, and FLT SUV(mean) day 14) revealed Lauren type and FLT SUV(mean) day 14 as the only significant prognostic factors (p=0.006, p=0.002). CONCLUSIONS: FLT uptake 2 weeks after initiation of therapy was shown to be the only imaging parameter with significant prognostic impact. Neither FLT-PET nor FDG-PET were correlated with histopathological or clinical response. However, these data must be interpreted with caution due to the single-center trial study design, relatively short follow-up, poor response rates, and unfavorable prognosis.

Association of the VEGF 936C>T polymorphism with FDG uptake, clinical, histopathological, and metabolic response in patients with adenocarcinomas of the esophagogastric junction.

PURPOSE: The MUNICON trial confirmed prospectively the usefulness of early response evaluation by 2-deoxy-2-[F-18]fluoro-D-glucose-positron emission tomography (FDG-PET) . Metabolic responders (R) showed initially a higher FDG uptake compared with nonresponders (p = 0.018). An association of the vascular endothelial growth factor (VEGF) 936C>T polymorphism and FDG uptake was reported for breast cancer. Therefore, we investigated the VEGF 936C>T polymorphism for an association with response and survival. PROCEDURES: The study was based on 110 patients included in the MUNCON trial (103 male, seven female; 75 AEG I, 35 AEG II, event-free survival (EFS) median 21.1 ± 4.6 months). Response was significantly associated with EFS. The VEGF 936C>T polymorphism was determined by PCR and restriction fragment length polymorphism analysis. For analysis, the T-variants were combined. RESULTS: One hundred two patients were evaluable. Seventy-two patients showed the CC, 24 the CT, and six the TT genotype. Median EFS was 29.3 months for CC and 11.7 months for CT/TT (p = 0.04). No association of the genotypes (CC or CT/TT) with the SUV or response was found. Multivariate analysis revealed histopathological regression (p = 0.003) and genotype (p = 0.04) as independent prognostic factors. A combination of genotype and PET response (Gen-PET) defines three prognostic groups early in the course of treatment (p = 0.002). Cox regression analysis including clinical and histopathological response and Gen-PET reveals Gen-PET as independent prognostic factor (p = 0.003). CONCLUSION: The VEGF 936C>T polymorphism is a prognostic factor in patients undergoing neoadjuvant chemotherapy, although it is not associated with FDG uptake and response. The combination of metabolic response and VEGF 936C>T polymorphism defines three different prognostic groups. These findings need to be confirmed prospectively. This study has been registered in the European Clinical Trials Database as trial 2007-003356-11.

Prognostic significance of free peritoneal tumor cells in the peritoneal cavity before and after neoadjuvant chemotherapy in patients with gastric carcinoma undergoing potentially curative resection.

BACKGROUND: Free peritoneal tumor cells (FPTCs) are an independent prognostic factor in patients undergoing curative resection for gastric carcinoma. Whether neoadjuvant chemotherapy (NAC) can eliminate FPTCs in the peritoneal lavage remains unclear. The aim of the study was to determine the effect of NAC on FPTCs. METHODS: From 1994 to 2000, data from a total of 61 patients with resectable gastric cancer were analyzed. Peritoneal cytology was performed before NAC at laparoscopy and at tumor resection. A minimum of 6 weeks of NAC, consisting of cisplatin, folinic acid, and fluorouracil, was administered. FPTCs were detected immunohistochemically with Ber-EP4 antibody. RESULTS: No FPTCs could be detected in 42 patients (69%), compared to 19 (31%) with FPTCs before NAC. During chemotherapy, 10 (24%) of 42 patients developed FPTCs, and 7 (37%) of 19 patients reverted from positive to negative. Patients who became FPTC negative (n = 7) showed an improved median survival (36.1 months) and a longer 2-year survival (71.4%) compared to FPTC-positive patients before and after NAC (n = 12), with a median survival of 9.2 months and a 2-year survival rate of 25%. In contrast, patients who reverted from FPTC negative to positive during NAC (n = 10) had a median survival of 18.5 months and a 2-year survival of only 20%. Multivariate analysis identified ypN category and FPTC change as independent prognostic factors. CONCLUSIONS: NAC for patients with positive cytology could lead to FPTC negativity in a subset of patients and improve their prognosis. However, NAC might be a risky strategy for almost one-quarter of patients whose disease develops positive cytology.

Immunohistochemical detection of receptor tyrosine kinases c-kit, EGF-R, and PDGF-R in colorectal adenocarcinomas.

PURPOSE: The selective inhibition of tyrosine kinases is a promising strategy in the treatment of several human malignancies. This study aimed to clarify expression patterns of therapeutically addressable receptor tyrosine kinases in colorectal cancer. MATERIALS AND METHODS: In this study, we used tissue arrays to analyze 263 specimen of colorectal carcinoma for the expression of the tyrosine kinases c-kit (CD117), epidermal growth factor receptor (EGF-R), and platelet-derived growth factor receptor (PDGF-R). Staining patterns were then correlated with tumor stage and survival. RESULTS: Five tumors (1.9%) showed a strong expression of c-kit (CD117), while in 40 samples (15.2%), a weak/intermediate expression was observed. Positive staining did not correlate with histopathological parameters although a trend toward a better survival of c-kit-positive patients was observed. No positivity for PDGF-R was observed in 263 samples of colorectal carcinomas. Positive EGF-R expression was identified in 39 cases (15.2%), whereas 218 samples (84.8%) stained negative. CONCLUSIONS: Our study confirms that expression of the tyrosine kinases c-kit and PDGF-R are rare in colorectal carcinomas and do not correlate with tumor stage.

Prognostic significance of histopathological tumor regression after neoadjuvant chemotherapy in esophageal adenocarcinomas.

We evaluated histomorphological findings in 92 surgical resection specimens of locally advanced esophageal adenocarcinomas after neoadjuvant cisplatin-based chemotherapy. Tumor response to neoadjuvant chemotherapy was determined using a system encompassing three tumor regression grades based on the estimation of the percentage of residual tumor tissue of the primary tumor site in relation to the macroscopically identifiable previous tumor bed. The significance of this system was validated by correlation of the tumor regression grades with the corresponding clinicopathological characteristics and patient survival. Seven patients (7%) had complete tumor regression (grade tumor regression grade 1), 48 patients (52%) had subtotal or partial tumor regression (tumor regression grade 2: 1-50% residual tumor), and 37 patients (40%) had minimal or no regression (tumor regression grade 3: >50% residual tumor). Tumor regression was significantly associated with posttreatment complete tumor resection status (UICC R0 status; P=0.016), tumor category (UICC pT category; P<0.001), and with the absence of either lymph node metastases (P=0.001) or lymphatic invasion (P<0.001). Survival analysis showed a significant prognostic relevance of the applied regression system in univariate (P<0.001) and multivariate analyses as a single independent factor (P=0.024). We conclude that the effect of preoperative chemotherapy in esophageal adenocarcinomas can be assessed by the determination of histological tumor regression, providing highly valuable prognostic information, which may even exceed the prognostic impact of the current TNM classification of these tumors. Therefore, we strongly recommend the implementation of a standardized tumor regression grading system in pathological reports of esophageal adenocarcinomas treated by neoadjuvant chemotherapy.

Long-term outcome of endoscopic therapy in patients with bile duct injury after cholecystectomy.

BACKGROUND AND AIM: Bile duct lesions, including leaks and strictures, are immanent complications of open or laparoscopic cholecystectomy. Endoscopic procedures have gained increasing potential as the treatment of choice in the management of postoperative bile duct injuries. METHODS: Between January 1996 and December 2006, 44 patients with biliary leakages and 12 patients with biliary strictures after cholecystectomy were identified by analyzing the endoscopic retrograde cholangiopancreatography database, clinical records, and cholangiograms. The long-term follow up of endoscopic treatment in biliary lesions after cholecystectomy was evaluated by this retrospective study. RESULTS: In 34 of 35 patients (97%) with peripheral bile duct leakages, endoscopic therapy was successful. Transpapillary endoprothesis and/or nasobiliary drainage were removed after 31 (5-399) days. After stent removal, the median follow-up period was 81 (11-137) months. In patients with central bile duct leakages, the success rate after median 90 (4-145) days of endoscopic therapy was 66.7% (6/9 patients). The median follow up after stent removal in six successfully treated patients was 70 (48-92) months. Eleven of 12 patients (91.6%) with bile duct strictures had successfully completed stent therapy. The follow-up period of this patient group was 99 (53-140) months. CONCLUSIONS: Endoscopic treatment of bile duct lesions after cholecystectomy is effective, particularly in patients with peripheral bile duct leakages and bile duct strictures. Therefore, it should be the first-line therapy used in these patients. Although endoscopic management is less successful in patients with central bile duct leakages, an attempt is warranted.

The predictive value of metabolic response to preoperative radiochemotherapy in locally advanced rectal cancer measured by PET/CT.

BACKGROUND: To evaluate the value of positron emission tomography using fluorodeoxyglucose and computer tomography scan (FDG-PET/CT) for prediction of histopathological response of preoperative radiochemotherapy (RCTX) in patients with rectal carcinoma. METHODS: Thirty patients with uT3 rectal carcinoma were examined by FDG-PET/CT at baseline, 14 days after initiation, and after completion of preoperative RCTX. The FDG decreases seen with PET scanning from baseline to day 14 (early metabolic response) and after completion of therapy (late metabolic response) were compared with histopathological tumor response. One patient denied surgery after RCTX. RESULTS: The mean (+/-SD) reduction of tumor FDG uptake in histopathologically responding compared to non-responding tumors was -44.3% (+/-20.1%) versus -29.6% (+/-13.1%) (p = 0.085) at day 14 and -66.0% (+/-20.3%) versus -48.3% (+/-23.4%) (p = 0.040) after completion of RCTX. Best differentiation of histopathological tumor response was achieved by a cut-off value of 35% reduction of initial FDG uptake at day 14 and 57.5% after completion of therapy. Applying the cut-off values as a criterion for metabolic response, histopathological response was predicted with a sensitivity of 74% (14/19) at day 14 and 79% (15/19) after completion of therapy. The positive predictive value for early metabolic response was 82% (14/17) and for late metabolic response was 83% (15/18). Histopathological evidence of accumulated peritumoral inflammation cells was associated with a minor FDG decrease in five histopathologically responding patients, and influenced the results with negative predictive values of 58% (7/12) and 64% (7/11) at the early and late time points, respectively. CONCLUSIONS: Metabolic response to a preoperative RCTX using FDG-PET/CT in rectal cancer patients can be correlated with histopathological response, but FDG uptake of peritumoral inflammation cells limited the results and led to false negative results.

Procalcitonin ratio indicates successful surgical treatment of abdominal sepsis.

BACKGROUND: On-demand relaparotomy has been associated with a slightly decreased mortality compared to planned relaparotomy in the surgical treatment of secondary peritonitis. On-demand relaparotomy must be performed without delay to detect progressing sepsis early, before the onset of multiorgan failure. The aim of the study was to evaluate procalcitonin (PCT) as a parameter for early detection of progressing sepsis after operative treatment of the infective source. METHODS: In 104 consecutive patients with secondary peritonitis, PCT serum levels were monitored on postoperative days 1 and 2 after initial operative elimination of the septic focus. The PCT ratio between postoperative days 1 and 2 was calculated and correlated to the success of the initial intervention. The latter was considered inadequate if relaparotomies were necessary to eliminate the intraabdominal infection. RESULTS: Using classification and regression tree analysis, a cutoff could be calculated at 1.03 for the PCT ratio of postoperative day 1 to day 2. Lesser values indicated unsuccessful elimination of the septic source, whereas values above 1.03 represented successful operative treatment of the septic focus. Unsuccessful treatment of the septic process could be detected with a specificity of 63% and a sensitivity of 95%. CONCLUSION: The PCT ratio appears to be a valuable aid in deciding if further relaparotomies are necessary after initial operative treatment of an intraabdominal septic focus.

Prognosis of patients with colorectal cancer is associated with lymph node ratio: a single-center analysis of 3,026 patients over a 25-year time period.

OBJECTIVE: We examined the prognostic impact of lymph node ratio (relation of tumor-infiltrated to resected lymph nodes) in comparison to the pN category and other prognostic factors in patients with colorectal cancer. SUMMARY BACKGROUND DATA: Although the high prognostic impact of lymph node metastases and the total number of lymph nodes to be resected are well established, studies still report large differences in lymph node numbers. The lymph node ratios relevant for prognosis are not clearly defined and not routinely reported. METHODS: We analyzed the clinical and histopathological data of 3026 patients with colorectal cancer at a single surgical center over a 25-year time period (1982-2006). RESULTS: One thousand seven hundred sixty-three colon and 1263 rectal carcinomas were documented. The rate of curative resection was 77.4% and the median number of resected lymph nodes was 16. The optimal cut-off values for prognostic differentiation of LNRs were statistically calculated as 0.17, 0.41, and 0.69. The 5-year overall survival of patients without lymph node metastases was 87%. Patients with lymph node metastases had 5-year overall survival rates of 60.6%, 34.4%, 17.6%, and 5.3% with increasing LNRs (P < 0.001). Multivariate survival analysis identified both the LNR and the pN category, the number of resected lymph nodes, the patient's age, the tumor location (colon vs. rectum), the pT category, the pM status, the R status, the tumor grade, and the year of operation as independent prognostic factors. The LNR had better prognostic value than the pN category (P < 0.05). The analysis of the subgroup of patients separated into colon and rectal cancer patients confirmed the identified LNRs as independent prognostic factors (P < 0.001). CONCLUSIONS: The defined cut-off values of LNRs were strong independent prognostic factors for colorectal cancer patients and should be calculated for risk group stratification.

Early metabolic response evaluation by fluorine-18 fluorodeoxyglucose positron emission tomography allows in vivo testing of chemosensitivity in gastric cancer: long-term results of a prospective study.

PURPOSE: We prospectively evaluated the predictive value of positron emission tomography using fluorine-18 fluorodeoxyglucose (FDG-PET) for in vivo testing of chemosensitivity in locally advanced gastric cancer using an a priori definition of metabolic response (a decrease of >35% of the standard uptake value). The goal of the study was the definition of biologically different groups of patients prior to or early during induction therapy, with special emphasis on FDG non-avid tumors. EXPERIMENTAL DESIGN: Based on our data, which was published in 2003, at least 36 patients with metabolic response or FDG non-avid tumors had to be recruited for an analysis of the group of FDG non-avid tumors with sufficient statistical power. Seventy-one patients (32 metabolic nonresponders, 17 metabolic responders, and 22 patients with FDG non-avid tumors) underwent FDG-PET at baseline. In FDG-avid tumors, FDG-PET was repeated 14 days after the initiation of chemotherapy. RESULTS: Metabolic responders (17 of 49) showed a high histopathologic response rate (69%) and a favorable prognosis (median survival not reached), whereas metabolic nonresponders (32 of 49) had a poor prognosis (median survival, 24.1 months) and showed a histopathologic response in 17%. The histopathologic response rate (24%) for FDG-PET non-avid patients showed no significant difference compared with FDG-avid nonresponders (P=0.72). Survival of FDG non-avid patients was 36.7 months (not significantly different from FDG-avid nonresponders, 24.1 months, P=0.46). CONCLUSION: In locally advanced gastric cancer, three different metabolic groups exist. Response and survival was predicted by PET in FDG-avid tumors. Metabolic response assessment was not possible in FDG non-avid tumors; however, due to unfavorable outcome, therapy modification might also be considered in FDG non-avid tumors.

The new credo: induction chemotherapy in locally advanced gastric cancer: consequences for surgical strategies.

Perioperative chemotherapy in stage II and stage III gastric cancer is now accepted as a standard of care in the Western world. Two randomized phase III studies have shown improved survival for patients with induction chemotherapy followed by surgery compared with surgery alone. It is generally accepted that patients who respond to induction therapy have a significantly improved survival compared with that in nonresponding patients. Unfortunately no prospectively tested markers predicting response and/or prognosis are available for clinical practice. In adenocarcinomas of the esophagogastric junction (AEG), fluorodeoxyglucose-positron emission tomography (FDG-PET) prospectively was established as a surrogate predicting response and prognosis. The MUNICON (Metabolic response evalUatioN for Individualisation of neoadjuvant Chemotherapy in oesOphageal and oesophagogastric adeNocarcinoma) I study confirmed prospectively the usefulness of early metabolic response evaluation and showed the feasibility of a PET-guided treatment algorithm. These findings are an important step forward in the tailoring of multimodal treatment in accordance with tumor biology. In gastric cancer, we have analyzed FDG-PET in a prospective study. In gastric cancer the issue is more complicated, because about 30% of gastric cancers cannot be visualized with sufficient contrast for quantification. Insufficient FDG uptake is mostly associated with diffuse-type gastric cancer with signet ring cells and mucinous content. In FDG-avid patients, FDG-PET can be used for response evaluation, comparable to that in AEG. The prognosis of FDG-nonavid patients is similar to that in metabolic nonresponders. The addition of new tracers such as fluorothymidine may increase the sensitivity of PET in the future. Treatment concepts such as immediate resection after only 2 weeks of induction therapy with or without adjuvant treatment could be considered in metabolic nonresponders, or modified chemotherapy regimens, possibly including biologically targeted drugs, could be considered in those with FDG-nonavid tumors.

Microarray-based prediction of tumor response to neoadjuvant radiochemotherapy of patients with locally advanced rectal cancer.

BACKGROUND & AIMS: Neoadjuvant chemoradiotherapy has become a standard treatment of locally advanced rectal carcinomas, even though the responsiveness varies from complete response to resistance. The aim of the study was to evaluate the capacity of gene expression signatures to identify responders and nonresponders pretherapeutically. METHODS: By using microarray technology we generated gene expression profiles of 43 biopsy specimens of locally advanced rectal carcinomas. The transcription profile then was compared with histopathologic response and used to identify a set of genes discriminating responders from nonresponders. RESULTS: We identified a gene expression signature of 42 genes, mostly encoding proteins that either play a role in the nucleus, such as the transcription factor ETS2, or are associated with transport function, such as the solute carrier SLC35E1, or the regulation of apoptosis, such as caspase-1. In leave-one-out cross-validation the correct classification of a responder was 71%, the specificity of the analysis for a correct classification of a nonresponder was 86%. By applying an additional statistical method of 200 successive splittings into training and test data sets we generated an individual prediction accuracy measure for each predicted response. CONCLUSIONS: Our study shows that pretherapeutic prediction of response of rectal carcinomas to neoadjuvant chemoradiotherapy is feasible, and may represent a new valuable and practical tool of therapeutic stratification.

Correlation of CK-20-positive cells in peripheral venous blood with serum CEA levels in patients with colorectal carcinoma.

Tumor cell dissemination appears to be an early event in tumor progression, and tumor cells can be detected in peripheral venous blood at the time of the operation. Although cytokeratin 20 (CK-20) is not specifically expressed by colorectal carcinomas, it represents a widely used marker for the detection of colorectal tumor cells. We used the combination of density centrifugation and CK-20 real-time reverse transcription polymerase chain reaction to detect CK-20-positive cells in the peripheral venous blood of 37 patients with colorectal carcinoma. Detection rates were compared to serum levels of the tumor markers carcinoembryonic antigen (CEA), carbohydrate antigen CA 19-9, and cancer antigen CA 125. The prognostic impact was assessed by the overall survival and by univariate and multivariate analysis. Overall, CK-20-positive cells in peripheral venous blood were detected in 11 of 37 (29.7%) patients. CK-20-positive patients showed a significantly higher mean serum CEA level (90.3 ng/ml) than the 4.1 ng/ml found in the CK-20-negative group (p = 0.03). CEA levels also correlated with CK-20 copy numbers. No significant correlation was observed for CA 19-9 or CA 125. CK-20-negative patients showed a trend toward better survival (p = 0.08). In the univariate analysis, CA 19-9, CEA, tumor size, lymph node status, grading, the presence of distant metastases, and resection status reached significant prognostic levels, whereas the detection of CK-20-positive cells showed only a prognostic trend (p = 0.06). Multivariate analysis failed to identify independent prognostic parameters. Here we report the correlation of CK-20-positive cells in peripheral venous blood with the serum CEA level of patients with colorectal cancer, which may represent a potential marker of the tumor load.