Low microsatellite instability: A distinct instability type in gastric cancer?

PURPOSE

We recently showed that low microsatellite instability (MSI-L) is associated with a good response to platinum/5-fluorouracil (5-FU) neoadjuvant chemotherapy (CTx) in gastric cancer. The purpose of this study was to characterize the instability pattern and to investigate an association of MSI-L tumors with mutations in genes of DNA repair pathways and with total tumor mutation burden (TMB).

METHODS

MSI patterns were compared between 67 MSI high (-H) and 35 MSI-L tumors. Whole-exome sequencing was performed in 34 microsatellite stable (MSS) and 20 MSI-L tumors after or without neoadjuvant CTx.

RESULTS

Of the 35 MSI-L tumors, 33 tumors had instability at a dinucleotide repeat marker. In the homologous recombination (HR) pathway, 10 of the 34 (29%) MSS and 10 of the 20 (50%) MSI-L tumors showed variants (p = 0.154). In the DNA damage tolerance pathway, 6 of the 34 (18%) MSS and 7 of the 20 (35%) MSI-L tumors had variants (p = 0.194). The HR deficiency score was similar in both tumor groups. TMB was significantly higher in MSI-L compared to MSS tumors after CTx (p = 0.046). In the MSS and MSI-L tumors without CTx no difference was observed (p = 1.00).

CONCLUSION

MSI-L due to instability at dinucleotide repeat markers was associated with increased TMB after neoadjuvant CTx treatment, indicating sensitivity to platinum/5-FU CTx. If confirmed in further studies, this could contribute to refined chemotherapeutic options including immune-based strategies for GC patients with MSI-L tumors.

Age-dependent benefit of neoadjuvant treatment in adenocarcinoma of the esophagus and gastroesophageal junction: a multicenter retrospective observational study of young versus old patients

OBJECTIVES

The objective was to provide evidence for age-dependent use of neoadjuvant treatment by clinical comparisons of young (lower quartile, <56.6 years) versus old (upper quartile, >71.3 years) patients with esophageal and esophagogastric-junction adenocarcinoma.

BACKGROUND

Neoadjuvant treatment is the standard of care for locally advanced and node-positive EAC. However, the effect of age on oncological outcomes is disputable as they are underrepresented in treatment defining randomized controlled trials.

METHODS

Patients with EAC undergoing esophagectomy between 2001 and 2022 were retrospectively analyzed from three centers. Patients having distant metastases or clinical UICC-stage I were excluded. Cox proportional hazards regression was used to identify the variables associated with survival benefit.

RESULTS

Neoadjuvant treatment was administered to 185/248 (74.2%) young and 151 out of 248 (60.9%) elderly patients ( P =0.001). Young age was associated with a significant overall survival (OS) benefit (median OS: 85.6 vs. 29.9 months, hazard ratio 0.62, 95% CI: 0.42-0.92) after neoadjuvant treatment versus surgery alone. In contrast, elderly patients did only experience a survival benefit equaling the length of neoadjuvant treatment itself (median OS: neoadjuvant 32.8 vs. surgery alone 29.3 months, hazard ratio 0.89, 95% CI: 0.63-1.27). Despite the clear difference in median OS benefit, histopathological regression was similar ((Mandard-TRG-1/2: young 30.7 vs. old 36.4%, P= 0.286). More elderly patients had a dose reduction or termination of neoadjuvant treatment (12.4 vs. 40.4%, P <0.001).

CONCLUSION

Old patients benefit less from neoadjuvant treatment compared to younger patients in terms of gain in OS. Since they also experience more side effects requiring dose reduction, upfront surgery should be considered as the primary treatment option in elderly patients.

Pattern and time point of relapse in locally advanced esophagogastric adenocarcinoma after multimodal treatment: implications for a useful structured follow-up

PURPOSE

Despite improvements in multimodal treatment of locally advanced esophagogastric adenocarcinoma, the majority of patients still relapses. The impact of structured follow-up for early detection of recurrence is unclear and controversially discussed.

METHODS

Patients with locally advanced esophagogastric adenocarcinoma having received neoadjuvant/perioperative chemotherapy followed by tumor resection between 2009 and 2021, underwent a structured follow-up including three-monthly imaging during the first 2 years, followed by semiannual and annual examinations in year 3-4 and 5, respectively. Clinical outcome including pattern and time point of relapse was analyzed.

RESULTS

Two hundred fifty-seven patients were included in this analysis. In 50.2% (n = 129) of patients, recurrent disease was diagnosed, with the majority (94.6%) relapsing within the first 2 years. The most common site of relapse were lymph node metastases followed by peritoneal carcinomatosis and hepatic and pulmonary metastases. 52.7% of patients presented with symptoms at the time of relapse. Cumulative risk and time point of relapse differed significantly between patient with a node-positive tumor (ypN+) after neoadjuvant treatment (high-risk group) and patients with node-negative primary tumor (ypN0) (low-risk group). High-risk patients had a significantly inferior disease-free survival (DFS) and overall survival (OS) with 11.1 and 29.0 months, respectively, whereas median DFS and OS were not reached for the low-risk group.

CONCLUSIONS

The risk of relapse differs significantly between high- and low-risk patients. Only a part of relapses is associated with clinical symptoms. An individualized follow-up strategy is recommended for high- and low-risk patients considering the individual risk of relapse.

Microsatellite instability and sex-specific differences of survival in gastric cancer after neoadjuvant chemotherapy without and with taxane: An observational study in real world patients

PURPOSE

To investigate the prognostic role of microsatellite instability (MSI) in association with sex of patients treated with platinum/fluoropyrimidine neoadjuvant chemotherapy (CTx) with or without a taxane-containing compound.

METHODS

Of the 505 retrospectively analyzed patients with gastric or gastroesophageal adenocarcinoma, 411 patients were treated without taxane and 94 patients with a taxane-containing compound. MSI was determined using standard assays.

RESULTS

Females demonstrated a better overall survival (OS) than males in the non-taxane group (HR, 0.59; 95% CI 0.41-0.86; p = 0.005), whereas no significant difference was found in the taxane group (HR 1.22; 95% CI 0.55-2.73, p = 0.630). MSI-High (-H) was associated with a better prognosis in both groups (without taxane: HR 0.56; 95% CI 0.33-0.97; p = 0.038; with taxane: HR 0.28; 95% CI 0.04-2.02, p = 0.204). In the non-taxane group, female MSI-H patients showed the best OS (HR 0.18, 95% CI 0.05-0.73; p = 0.016), followed by the female microsatellite stable (MSS) (HR 0.67, 95% CI 0.46-0.98, p = 0.040) and the male MSI-H group (HR 0.76; 95% CI 0.42-1.37, p = 0.760) taken the male MSS group as reference. In the taxane group, female and male MSI-H patients demonstrated the best OS (female MSI-H: HR 0.05, 95% CI 0.00-240.46; male MSI-H: HR 0.45, 95% CI 0.61-3.63, p = 0.438), whereas the female MSS group showed a decreased OS (HR 1.39 95% CI 0.62-3.12, p = 0.420) compared to male MSS patients.

CONCLUSION

OS in gastric/gastroesophageal cancer after CTx might depend on sex and MSI status and may differ between patients treated with or without a taxane compound in the chemotherapeutic regimen.

Clinical Characteristics and Oncological Outcomes of Surgically Treated Early-Onset Gastric Adenocarcinoma - a Retrospective Cohort Study

Introduction: The incidence of early-onset gastric adenocarcinoma (patients <50 years, EOGA) is rising. Tumors in younger patients are associated with prognostically unfavorable features. The impact of EOGA on patient survival, however, remains unclear. The aim of this study is to evaluate early-onset age as a prognostic factor compared to late-onset gastric adenocarcinoma (LOGA, >50years) in a surgical cohort and assess treatment options. Methods: We analyzed 738 patients (129 early-onset/609 late-onset) operated in curative intent from 2002 to 2021. Data was extracted from a prospectively managed database of an academic tertiary referral hospital. Differences in perioperative as well as oncological outcomes were calculated by chi-square test. Cox regression analysis was performed to assess disease-free survival (DFS) and overall survival (OS). Results: EOGA patients were more often treated with neoadjuvant therapy (62.8% vs. 43.7%, p<0.001) and extended surgical resections e.g. through additional resections (36.4% vs. 26.8%, p=0.027). EOGA was more often metastasized into regional lymph nodes (pN+ 67.4% vs. 55.3%, p=0.012) and to distant sites (pM+: 23.3% vs. 12.0%, p=0.001) and was more often poorly differentiated (G3/G4: 91.1% vs. 67.2%, p<0.001). There were no significant differences in overall complication rates (31.0% vs. 36.6%, p=0.227). Survival analysis showed shorter DFS (median DFS 25.6 months vs. not reached, p=0.006) but similar OS (median OS: 50.5 months vs. not reached, p=0.920) in EOGA compared to LOGA. Conclusions: This analysis confirmed that EOGA is associated with more aggressive tumor characteristics. Early-Onset was not a prognostic factor in the multivariate analysis. EOGA patients may be more capable to undergo intensive multimodal therapy including perioperative chemotherapy and extended surgery.

Outcome and prognostic factors in patients undergoing salvage therapy for recurrent esophagogastric cancer after multimodal treatment

PURPOSE

Perioperative systemic treatment has significantly improved the outcome in locally advanced esophagogastric cancer. However, still the majority of patients relapse and die. Data on the optimal treatment after relapse are limited, and clinical and biological prognostic factors are lacking.

METHODS

Patients with a relapse after neoadjuvant/perioperative treatment and surgery for esophagogastric cancer were analyzed using a prospective database. Applied treatment regimens, clinical prognostic factors and biomarkers were analyzed.

RESULTS

Of 246 patients 119 relapsed. Among patients with a relapse event, those with an early relapse (< 6 months) had an inferior overall survival (OS 6.3 vs. 13.8 months, p < 0.001) after relapse than those with a late relapse (> 6 months). OS after relapse was longer in patients with a microsatellite-unstable (MSI) tumor. Systemic treatment was initiated in 87 patients (73% of relapsed pat.); among those OS from the start of first-line treatment was inferior in patients with an early relapse with 6.9 vs. 10.0 months (p = 0.037). In 27 patients (23% of relapsed pat.), local therapy (irradiation or surgical intervention) was performed due to oligometastatic relapse, resulting in a prolonged OS in comparison to patients without local therapy (median OS 35.2 months vs. 7.8 months, p < 0.0001). Multivariate analysis confirmed the prognostic benefit of the MSI status and a local intervention.

CONCLUSION

Patients relapsing after multimodal treatment have a heterogeneous prognosis depending on the relapse-free interval (if systemic treatment applied), extent of metastatic disease as well as MSI status. The benefit of additional local intervention after relapse should be addressed in a randomized trial.

Perioperative chemotherapy with 5-FU, leucovorin, oxaliplatin, and docetaxel (FLOT) for esophagogastric adenocarcinoma: ten years real-life experience from a surgical perspective

PURPOSE

According to the results of FLOT4 trial, perioperative FLOT chemotherapy improved overall survival (OS) in locally advanced, resectable esophagogastric adenocarcinoma (EGA) compared to perioperative ECF/ECX. We report real-life data 10 years after introduction of perioperative FLOT at our institution.

METHODS

Survival of 356 consecutive EGA patients (cT3/4 and/or cN + and/or cM1) who underwent curative surgical resection was retrospectively analysed from a prospective database. A total of 263 patients received preoperative chemotherapy according to FLOT protocol and 93 patients received an epirubicin/platinum/5FU-based regimen (EPF). Propensity score matching (PSM) according to pretretment characteristics was performed to compensate for heterogeneity between groups.

RESULTS

Median OS did not differ between groups (FLOT/EPF 52.1/46.4 months, p = 0.577). After PSM, survival was non-significantly improved after FLOT compared to EPF (median OS not reached/46.4 months, p = 0.156). Perioperative morbidity and mortality did not differ between groups. Histopathologic response rate was 35% after FLOT and 26% after EPF (p = 0.169). R0 resection could be achieved more frequently after FLOT than after EPF (93%/79%, p = 0.023).

CONCLUSION

Overall survival after perioperative FLOT followed by surgery is comparable to clinical trials. However, collective real-life application of FLOT failed to provide a significant survival benefit compared to EPF. In clinical reality, patient selection is triggered by age, comorbidity, tumor localization, and clinical tumor stage. Yet matched analyses support FLOT4 trial findings.

Mechanical stretching and chemical pyloroplasty to prevent delayed gastric emptying after esophageal cancer resection-a meta-analysis and review of the literature

BACKGROUND

Delayed gastric emptying (DGE) occurs in up to 40% of patients after esophageal resection and prolongs recovery and hospital stay. Surgically pyloroplasty does not effectively prevent DGE. Recently published methods include injection of botulinum toxin (botox) in the pylorus and mechanical interventions as preoperative endoscopic dilatation of the pylorus. The aim of this study was to investigate the efficacy of those methods with respect to the newly published Consensus definition of DGE.

METHODS

A systematic literature search using CENTRAL, Medline, and Web of Science was performed to identify studies that described pre- or intraoperative botox injection or mechanical stretching methods of the pylorus in patients undergoing esophageal resection. Frequency of DGE, anastomotic leakage rates, and length of hospital stay were analyzed. Outcome data were pooled as odd's ratio (OR) or mean difference using a random-effects model. Risk of bias was assessed using the Robins-I tool for non-randomized trials.

RESULTS

Out of 391 articles seven retrospective studies described patients that underwent preventive botulinum toxin injection and four studies described preventive mechanical stretching of the pylorus. DGE was not affected by injection of botox (OR 0.87, 95% confidence interval [CI] 0.37-2.03, P = 0.75), whereas mechanical stretching resulted in significant reduction of DGE (OR 0.26, 95% CI 0.14-0.5, P < 0.0001).

CONCLUSION

Mechanical stretching of the pylorus, but not injection of botox reduces DGE after esophageal cancer resection. A newly developed consensus definition should be used before the conduction of a large-scale randomized-controlled trial.

Expression of Angiogenic Proteins in Tumor and Stroma Affects Survival in Patients With Gastric Cancer

BACKGROUND

Gastric cancer is one of the most frequent malignancies worldwide. Angiogenic growth factors play a crucial role in mediating the crosstalk between cancer cells and the surrounding microenvironment. In this exploratory study, we investigate the impact of angiogenic proteins within the tumor cell or stroma compartment on survival of patients with gastric cancer.

MATERIALS AND METHODS

In 29 patients, tumor and stromal compartments were separated using laser capture microdissection. Angiogenic protein expression was measured using a bead-based immunoassay and correlated with tumor stage and overall survival.

RESULTS

Overall survival was significantly shorter in patients with a high stroma concentration of vascular endothelial growth factor (VEGF)-A (23.5 (±17.6) versus 33.6 (±21.0) mo; P = 0.009) and stem cell factor (22.2 (±18.5) versus 33.6 (±21.8) mo; P = 0.01) compared with patients with a low stroma concentration. High stromal VEGF-D showed a trend toward worse survival (26.8 (±22.0) versus 37.2 (±19.0) mo; P = 0.09). We did not observe any significant correlation between tumor-specific expression of angiogenic cytokines and survival.

CONCLUSIONS

This translational study highlights the difference in clinical impact between tumor and stromal expression of angiogenic proteins. Compartment-specific concentrations of VEGF-A and stem cell factor affect the clinical prognosis and help to identify the best therapy for patients with gastric cancer.

Neoadjuvant Therapy Improves Outcomes in Locally Advanced Signet-Ring-Cell Containing Esophagogastric Adenocarcinomas

BACKGROUND

Only a few studies have analyzed multimodal treatment concepts in the subgroup of signet-ring-cell containing upper gastrointestinal (GI) cancer. Recent retrospective, multicentric data favor primary resection without neoadjuvant chemotherapy for gastric signet-ring-cell containing carcinomas (SRCs). We compared the outcomes of primarily resected carcinomas with neoadjuvantly treated, locally advanced esophagogastric SRCs.

METHODS

A total of 310 patients with esophagogastric SRC-staged cT3/4/Nany/Many from a prospective unicentric database were included in this study; 192 (61.9%) received neoadjuvant therapy (NEO group) and 118 (38.1%) were primarily resected (RES group).

RESULTS

Overall, 128 (41.3%) patients presented with adenocarcinoma of the esophagogastric junction (AEG) and 182 (58.7%) presented with gastric cancer. Neoadjuvant therapy was significantly associated with resection in curative intent (NEO: 91.1%; RES: 75.4%; P = 0.001), improved (y)pT category (P = 0.035), improved (y)pN category (P < 0.001), and R0 resections (curative intent cohort: 76.0% in NEO vs. 60.7% in RES; P = 0.010), among others, but not with postoperative complications. Overall survival was significantly improved by neoadjuvant treatment {median survival 28.5 months (95% confidence interval [CI] 14.4-39.6) vs. RES: 14.9 months (10.6-17.5); P < 0.001}, as well as in subgroups (AEG and gastric tumors, R0-resected patients, and patients with and without relevant comorbidities). Independent prognostic factors were neoadjuvant therapy (hazard ratio [HR] 0.66; P = 0.023), pT4 category (HR 1.71; P = 0.041), pN2 category (HR 1.86; P = 0.013), pN3 category (HR 2.40; P < 0.001), pM1 category (HR 1.95; P = 0.003), age > 70 years (HR 1.79; P = 0.006), gastric localization (HR 0.69; P = 0.032), American Society of Anesthesiologists classification 3/4 (HR 1.71; P = 0.004), and incomplete resection R1/2 (HR 1.6; P = 0.014).

CONCLUSIONS

Our results demonstrate a survival advantage for advanced-stage esophagogastric SRC patients by neoadjuvant treatment.

Postoperative follow-up programs improve survival in curatively resected gastric and junctional cancer patients: a propensity score matched analysis

BACKGROUND

To date there is no evidence that more intensive follow-up after surgery for esophagogastric adenocarcinoma translates into improved survival. This study aimed to evaluate the impact of standardized surveillance by a specialized center after resection on survival.

METHODS

Data of 587 patients were analyzed who underwent curative surgery for esophagogastric adenocarcinoma in our institution. Based on their postoperative surveillance, patients were assigned to either standardized follow-up (SFU) by the National Center for Tumor Diseases (SFU group) or individual follow-up by other physicians (non-SFU group). Propensity score matching (PSM) was performed to compensate for heterogeneity between groups. Groups were compared regarding clinicopathological findings, recurrence, and impact on survival before and after PSM.

RESULTS

Of 587 patients, 32.7% were in the SFU and 67.3% in the non-SFU group. Recurrence occurred in 39.4% of patients and 92.6% within the first 3 years; 73.6% were treated, and of those 17.1% underwent resection. In recurrent patients overall and post-recurrence survival (OS/PRS) was influenced by diagnostic tools (p < 0.05), treatment (p ≤ 0.001), and resection of recurrence (p ≤ 0.001). Standardized follow-up significantly improved OS (84.9 vs. 38.4 months, p = 0.040) in matched analysis and was an independent positive predictor of OS before and after PSM (p = 0.034/0.013, respectively).

CONCLUSION

After PSM, standardized follow-up by a specialized center significantly improved OS. Cross-sectional imaging and treatment of recurrence were associated with better outcome. Regular follow-up by cross-sectional imaging especially during the first 3 years should be recommended by national guidelines, since early detection might help select patients for treatment of recurrence and even resection in few designated cases.

Inflammatory cytokines are associated with response and prognosis in patients with esophageal cancer

Background

Esophageal cancer is often marked by aggressive tumor growth and poor prognosis. Patient groups who benefit from perioperative therapy are not yet defined. The tumor microenvironment and circulating factors as possible predictors of response and prognosis gain interest. This study aimed to investigate cytokines in patients’ serum and tumor tissue with regard to response and prognosis.

Results

Median survival between SCC and AC was not different (published previously). Lower levels of CCL11 (Eotaxin-1) and CXCL10 (IP-10) in the tumor tissue were associated with a better prognosis (p = 0.022; p = 0.002). In the AC subgroup higher concentrations of TGF-β3 in serum and corresponding tumor tissue were associated with adverse prognosis (p = 0.035; p = 0.006). An association with histopathological response was found for IL-12(p70) and CXCL10 in patients’ sera (p = 0.041; p = 0.032). The tissue levels of TGF-β1 and TGF-β2 were significantly lower in histopathological responders than in nonresponders (p = 0.033; p = 0.007). A similar trend was seen for TGF-β3, without statistical significance (p = 0.097).

Materials and Methods

Preoperative serum samples and corresponding tumor tissue (n = 54), only serum (n = 20) or only tissue (n = 4) were collected from patients undergoing surgery for cT3/4 esophageal squamous cell cancer (SCC) (n = 34) and adenocarcinoma (AC) (n = 44). All samples were taken after neoadjuvant treatment. All patients received perioperative chemo(radio)therapy. Cytokine levels of 17 different cytokines were measured by multiplex immunoassay and correlated with clinicopathological factors.

Conclusions

Two chemokines (CCL11 and CXCL10) in posttherapeutic tumor tissue were associated with prognosis in patients with esophageal cancer, lower levels indicating a better prognosis. Lower levels of TGF-β were associated with better response and prognosis in patients with AC.

[Gastric stump carcinoma: frequency, treatment, complications and prognosis]

BACKGROUND

Gastric stump carcinoma develops in the gastric remnant after partial gastrectomy. While the frequency of gastric cancer is declining, the incidence of gastric stump carcinoma has remained stable due to the long latency period. As the surgical treatment of gastric ulcers by partial gastrectomy has become much less important, more and more gastric stump carcinomas develop after oncological resection.

AIM

This study compared the surgical therapy of gastric stump carcinoma with the therapy of primary gastric cancer.

MATERIAL AND METHODS

From 2001 to 2014 a total of 24 patients were surgically treated for gastric stump carcinoma in the University Hospital of Heidelberg. In the same time 428 patients underwent resection due to primary gastric cancer. Both groups were analyzed and compared with a focus on preoperative therapy, intraoperative differences, complications and overall survival.

RESULTS

Patients with gastric stump carcinoma were older at disease onset (68 years vs. 62 years, p = 0.003). Compared with primary gastric cancer, patients with gastric stump carcinoma were more often suspected of having lymph node (cN+) involvement (51.4 % vs. 41.7 %, p < 0.001) but neoadjuvant therapy was applied less often (48.7 % vs. 14.3 %, p < 0.01). For resection of gastric stump carcinoma, extended resections were more often necessary (54.5 % vs. 28.2 %, p < 0.001). There were no significant differences in mean overall survival between the two patient groups (64.4 months vs. 45.8 months, p = 0.34) CONCLUSION: Despite the differences described, the treatment of gastric stump carcinoma does not essentially differ from that of primary gastric cancer. Carcinomas of the gastric stump are more often locally advanced and in our opinion a neoadjuvant therapy should be applied analogue to gastric cancer even if evidence-based data on this point are limited.

Surgical strategies in true adenocarcinoma of the esophagogastric junction (AEG II): thoracoabdominal or abdominal approach?

BACKGROUND

The optimal surgical approach for adenocarcinoma directly at the esophagogastric junction (AEG II) is still under debate. This study aims to evaluate the differences between right thoracoabdominal esophagectomy (TAE) (Ivor-Lewis operation) and transhiatal extended gastrectomy (THG) for AEG II.

METHODS

From a prospective database, 242 patients with AEG II (TAE, n = 56; THG, n = 186) were included and analyzed according to characteristics and perioperative morbidity and mortality and overall survival (chi-square, Mann-Whitney U, log-rank, Cox regression).

RESULTS

Groups were comparable at baseline with exception of age. Patients older than 70 years were more frequently resected by THG (p = 0.003). No differences in perioperative morbidity (p = 0.197) and mortality (p = 0.711) were observed, including anastomotic leakages (p = 0.625) and pulmonary complications (p = 0.494). There was no significant difference in R0 resection (p = 0.719) and number of resected lymph nodes (p = 0.202). Overall median survival was 38.4 months. Survival after TAE was significantly longer than after THG (median OS not reached versus 33.6 months, p = 0.02). Multivariate analysis revealed pN-category (p < 0.001) and type of surgery (p = 0.017) as independent prognostic factors. The type of surgery was confirmed as prognostic factor in locally advanced AEG II (cT 3/4 or cN1), but not in cT1/2 and cN0 patients.

CONCLUSIONS

Our single-center experience suggests that patients with (locally advanced) AEG II tumors may benefit from TAE compared to THG. For further evaluation, a randomized trial would be necessary.

Prognostic impact of nodal status and therapeutic implications

The prognostic impact of lymph node (LN) metastases in gastric cancer is generally accepted. In primarily resected patients the pN-category and LN ratio are independent prognostic factors. Number of involved LNs, number of resected LNs, lymphangiosis and micrometastases also influence the prognosis significantly. To guarantee a proper D2 lymphadenectomy (LAD) at least 25 LNs according to the German S3 guidelines for the treatment of gastric cancer should be removed. Also in neoadjuvantly treated patients the ypN-category and LN ratio play an important prognostic role, despite the fact that UICC staging system was development based only on primarily resected patients. The role of response of LNs in neoadjuvantly treated patients is still unclear and needs further investigation. It seems to be less important than the response of the primary tumor. Limited data exists, suggesting that preoperative treatment might reduce the number of LNs involved and improve ypN-category. Due to further development in gastric cancer like laparoscopic resection and effective perioperative treatment in locally advanced tumor the role and the prognostic impact of LAD is again in the focus of discussion.

Immediate tumor resection in patients with locally advanced gastroesophageal adenocarcinoma with nonresponse to chemotherapy after 4 weeks of treatment versus resection after completion of chemotherapy (OPTITREAT trial, DRKS00004668): study protocol for a randomized controlled pilot trial

Background

Neoadjuvant chemotherapy is a standard of care for patients with adenocarcinoma of the esophagus and stomach in Europe, but still only 20–40 % respond to therapy and the critical issue; how to treat nonresponding patients is still unclear. So far, there is no randomized trial evaluating the impact of early termination of neoadjuvant chemotherapy and immediate tumor resection in nonresponding patients with locally advanced gastroesophageal cancer on postoperative outcome. With this exploratory pilot trial, we want to get first estimates about the effect of discontinuation of chemotherapy with the aim to plan and conduct a further definitive trial.

Methods/design

OPTITREAT is designed as a single-center, randomized controlled pilot trial with two parallel study groups. Four weeks after starting neoadjuvant chemotherapy in all patients, clinical response will be assessed by endoscopy and endosonographic ultrasound. Then, nonresponding patients (n = 84) will be randomized in a 1:1 ratio to intervention group with stopping chemotherapy and immediate tumor resection or control group with completion of chemotherapy before surgery. Outcome measures are overall survival, R0 resection rate, perioperative morbidity and mortality, histopathological response, and quality of life. Statistical analysis will be based on the intention-to-treat population. Due to the study design as an explorative pilot trial, no formal sample size calculation was performed. The planned total sample size of 120 patients is considered ethical and large enough to show the feasibility and safety of the concept. First data on differences between the study groups in the defined endpoints will also be generated.

Discussion

Individualized therapy is of utmost interest in the treatment of locally advanced gastroesophageal adenocarcinoma as less than half of the patients show objective response to current chemotherapy regimens. The findings of the OPTITREAT trial will help to get first data about clinical response evaluation followed by immediate tumor resection in nonresponding patients after 4 weeks of neoadjuvant chemotherapy. Based on the results of this pilot study, a future confirmatory trial will be planned to prove efficacy and evaluate significance.

Trial registration

German Clinical Trial Register number: DRKS00004668

Surgery of gastric cancer and esophageal cancer: Does age matter?

INTRODUCTION

In the past, elderly patients with upper GI cancers were excluded from surgery or multimodal treatment only due to their advanced age. In an aging society this way of patient selection seems to be questionable. The aim of this retrospective exploratory study was to investigate how patients with upper GI cancer over the age of 70 years differ from younger patients in the postoperative course and which parameters influence overall survival in older patient populations.

PATIENTS AND METHODS

From 2002 to 2012 1,005 patients underwent resection of esophageal or gastric cancer at the University of Heidelberg. 272 patients were older than 70 years and analyzed in subgroups (70-74 years: n = 146; 75-79 years: n = 82; 80 years or older: n = 44). Patients older than 70 years were compared to patients under 70 years (n = 733) with focus on differences in patients characteristics and outcome. Statistical analyses were made retrospectively on a prospective database.

RESULTS

Fewer older patients were treated neoadjuvantly (< 70 years: 41.5%; > 70 years: 24.7%, P < 0.001) and extended resection (abdominothoracic approach) was applied less frequently compared to patients under 70 years (< 70 years: 38.9%; > 70 years: 19.9%, P < 0.001). The pNM-category (HR 1.41/2.56) and R-status (HR 1.78) remain the most important predictive factor for survival (all < 0.001). Female patients had a longer survival than men over the age of 70 (84.9 vs. 23.5 months, P < 0.01). Patients over 80 years had a significant shortened overall survival (> 80 years: 16.7 vs. < 70 years: 37.4 months) compared to the other subgroups (P < 0.001) and a significant increased in-hospital mortality (> 80 years: 20.5% vs. < 70 years: 6.0%, P = 0.002).

CONCLUSIONS

An exclusion from surgical therapy due to advanced age in general seems not to be justified. However, the decision for a surgical resection in patients over 80 years should be made with caution. pNM-categories and R0-resection remain the most important predictive factors for overall survival in all subgroups. No survival benefit for neoadjuvant treatment in patients over 70 years was found, while women survived longer than men. However, the decision concerning a (radio) chemotherapy should be made individually in each patient.

Serum microRNA profiles as prognostic or predictive markers in the multimodality treatment of patients with gastric cancer

Despite the implementation of multimodality treatment strategies, the persistently poor prognosis of gastric cancer patients is predominantly caused by the lack of predictive markers for response assessment in the neoadjuvant setting, preventing individualized therapy. Therefore, the identification of novel predictive and prognostic markers for application in the multimodality treatment of gastric cancer patients is required. The aim of the present study was to characterize the serum microRNA (miRNA/miR) profile of gastric cancer patients undergoing multimodality therapy to identify possible prognostic and predictive markers. The study consisted of 32 patients with gastric cancer who had undergone either primary surgical resection (n=14) or neoadjuvant therapy followed by surgical resection (n=18). Histopathological regression was defined as a major histopathological response when the resected specimens contained <10% vital residual tumor cells. Intratumoral miRNA was isolated from pre-operative or post-neoadjuvant blood serum samples. Initially, microarray analyses were performed in six of the patients that received neoadjuvant treatment (three responders versus three non-responders), to assess the amplification profile of dysregulated miRNAs. Based on these findings, possible predictive or prognostic markers were validated in all study patients by performing single reverse transcription-polymerase chain reaction (RT-PCR) analysis. Depending on the extent of the histopathological regression, a differential miRNA expression profile was identified in the microarray analyses. Based on the amplification profile, miR-21, miR-29a and miR-221 were selected for additional validation. However, the single RT-PCR measurements of the three selected miRNAs did not exhibit any prognostic or predictive value in the patients treated with primary resection or neoadjuvant therapy and resection. Thus, the current pilot study failed to identify a prognostic or predictive value in selected miRNAs using single RT-PCR measurements, however, the microarray results revealed a differential microRNA expression profile depending on the histopathological regression. The findings of the present study may have been affected by the small sample size.

Post-therapeutic response evaluation by a combination of endoscopy and CT scan in esophagogastric adenocarcinoma after chemotherapy: better than its reputation

BACKGROUND

Neoadjuvant chemotherapy is an accepted standard of care for locally advanced esophagogastric cancer. As only a subgroup benefits, a response-based tailored treatment would be of interest. The aim of our study was the evaluation of the prognostic and predictive value of clinical response in esophagogastric adenocarcinomas.

METHODS

Clinical response based on a combination of endoscopy and computed tomography (CT) scan was evaluated retrospectively within a prospective database in center A and then transferred to center B. A total of 686/740 (A) and 184/210 (B) patients, staged cT3/4, cN0/1 underwent neoadjuvant chemotherapy and were then re-staged by endoscopy and CT before undergoing tumor resection. Of 184 patients, 118 (B) additionally had an interim response assessment 4-6 weeks after the start of chemotherapy.

RESULTS

In A, 479 patients (70%) were defined as clinical nonresponders, 207 (30%) as responders. Median survival was 38 months (nonresponders: 27 months, responders: 108 months, log-rank, p < 0.001). Clinical and histopathological response correlated significantly (p < 0.001). In multivariate analysis, clinical response was an independent prognostic factor (HR for death 1.4, 95% CI 1.0-1.8, p = 0.032). In B, 140 patients (76%) were nonresponders and 44 (24%) responded. Median survival was 33 months, (nonresponders: 27 months, responders: not reached, p = 0.003). Interim clinical response evaluation (118 patients) also had prognostic impact (p = 0.008). Interim, preoperative clinical response and histopathological response correlated strongly (p < 0.001).

CONCLUSION

Preoperative clinical response was an independent prognostic factor in center A, while in center B its prognostic value could only be confirmed in univariate analysis. The accordance with histopathological response was good in both centers, and interim clinical response evaluation showed comparable results to preoperative evaluation.

Anti-angiogenic activity of VXM01, an oral T-cell vaccine against VEGF receptor 2, in patients with advanced pancreatic cancer: A randomized, placebo-controlled, phase 1 trial

VEGFR-2 is expressed on tumor vasculature and a target for anti-angiogenic intervention. VXM01 is a first in kind orally applied tumor vaccine based on live, attenuated Salmonella bacteria carrying an expression plasmid, encoding VEGFR-2. We here studied the safety, tolerability, T effector (Teff), T regulatory (Treg) and humoral responses to VEGFR2 and anti-angiogenic effects in advanced pancreatic cancer patients in a randomized, dose escalation phase I clinical trial. Results of the first 3 mo observation period are reported. Locally advanced or metastatic, pancreatic cancer patients were enrolled. In five escalating dose groups, 30 patients received VXM01 and 15 placebo on days 1, 3, 5, and 7. Treatment was well tolerated at all dose levels. No dose-limiting toxicities were observed. Salmonella excretion and salmonella-specific humoral immune responses occurred in the two highest dose groups. VEGFR2 specific Teff, but not Treg responses were overall increased in vaccinated patients. We furthermore observed a significant reduction of tumor perfusion after 38 d in vaccinated patients together with increased levels of serum biomarkers indicative of anti-angiogenic activity, VEGF-A, and collagen IV. Vaccine specific Teff responses significantly correlated with reductions of tumor perfusion and high levels of preexisting VEGFR2-specific Teff while those showing no antiangiogenic activity had low levels of preexisting VEGFR2 specific Teff, showed a transient early increase of VEGFR2-specific Treg and reduced levels of VEGFR2-specific Teff at later time points - pointing to the possibility that early anti-angiogenic activity might be based at least in part on specific reactivation of preexisting memory T cells.

Association of angiogenic factors with prognosis in esophageal cancer

Background

Despite multimodal therapy esophageal cancer often presents with poor prognosis. To improve outcome, tumor angiogenesis and anti-angiogenic therapeutic agents have recently gained importance. However, patient subgroups who benefit from anti-angiogenic therapy are not yet defined. In this retrospective exploratory study we investigated 9 angiogenic factors in patients’ serum and tissue samples with regard to their association with clinicopathological parameters, prognosis and response in patients with locally advanced preoperatively treated esophageal cancer.

Methods

From 2007 to 2012 preoperative serum and corresponding tumor tissue (n = 54), only serum (n = 20) or only tumor tissue (n = 4) were collected from esophageal squamous cell carcinoma (SCC) (n = 34) and adenocarcinoma of the esophagogastric junction (AEG) (n = 44) staged cT3/4NanyM0/x after preoperative chemo(radio)therapy. Angiogenic cytokine levels in both tissue and serum were measured by multiplex immunoassay.

Results

Median survival in all patients was 28.49 months. No significant difference was found in survival between SCC and AEG (p = 0.90). 26 patients were histopathological responders. Histopathological response was associated with prognosis (p = 0.05).

Angiogenic factors were associated with the following clinicopathological factors: tumor tissue expression of Angiopoietin-2 and Follistatin was higher in SCC compared to AEG (p = 0.022 and p = 0.001).

High HGF and Follistatin expression in the tumor tissue was associated with poor prognosis in all patients (p = 0.037 and p = 0.036). No association with prognosis was found in the patients’ serum. Neither patients’ serum nor tumor tissue showed an association between angiogenic factors and response to neoadjuvant therapy.

Conclusion

Two angiogenic factors (HGF and Follistatin) in posttherapeutic tumor tissue are associated with prognosis in esophageal cancer patients. Biological differences of AEG and SCC with respect to angiogenesis were evident by the different expression of 2 angiogenic factors. Results are promising and should be pursued prospectively, optimally sequentially pre- and posttherapeutically.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1120-5) contains supplementary material, which is available to authorized users.

[Salvage surgery in esophageal cancer : Feasibility in patients after definitive radiochemotherapy (> 50 Gy)]

BACKGROUND

Salvage surgery as an additional therapy option is currently discussed for an increasing number of patients with esophageal cancer after definitive radio(chemo)therapy after tumor progression, recurrence or on explicit request of the patient.

OBJECTIVES

The objective of this study was an analysis of the surgical option of salvage esophagectomy after definitive radiation in patients with esophageal cancer. Additionally the current literature on this topic was evaluated.

MATERIAL AND METHODS

A total of 92 patients with esophageal cancer from a prospective database were included in this study who underwent esophagectomy either after neoadjuvant radio(chemo)therapy (< 50 Gy) or definitive radio(chemo)therapy (> 50 Gy) between 2002 and 2012. The analysis was performed retrospectively.

RESULTS

The median survival of the two groups of patients was not significantly different after initial diagnosis with 24.2 months (95 % CI 0.0-51.93) for patients undergoing definitive radio(chemo)therapy and 30.7 months (95 % CI 9.3-52.2) for patients after neoadjuvant therapy (p = 0.96). Both patient groups showed no differences in pretherapeutic characteristics and response to radio(chemo)therapy. Postoperative complications and perioperative mortality were not different.

DISCUSSION

Salvage esophagectomy is now an additional treatment option after definitive radio(chemo)therapy in patients with esophageal cancer. In preselected patients with tumor recurrence, progression or with a strong wish for surgical therapy, salvage surgery should be discussed in interdisciplinary tumor boards after exclusion of distant metastases.

Metastatic esophagogastric adenocarcinomas (EGA): Treatment, prognosis, and pretherapeutic selection options

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Background: Nowadays an increasing number of patients (pts.) with metastatic disease (MD) are discussed in interdisciplinary tumor boards. Preliminary results of the FLOT-3 study suggest a benefit for pts. with limited MD after resection compared to pts. with chemotherapy (CTx) only. Own published data suggest that a subgroup of pts. may benefit from surgery (ESJO, 2013). Primary objective of this retrospective explorative study was the outcome of pts. with resected metastatic EGA and the evaluation of our preoperative prognosis score (PPS) in a larger patients`series. Methods: From 2001-2012 123/800 EGA were classified as cM1 either confirmed intraoperatively as pM1 or confirmed by imaging during follow-up. Response evaluation was performed clinically by endoscopy and CT-scan, histopathologically by the Becker regression score. The PPS for pts. treated with CTx contains grading, clinical response and presumed R-category. Analysis was performed retrospectively from a prospective database. Results: M1 sites (70 AEG, 53 gastric cancer): 27 liver, 43 distant lymph nodes, 16 peritoneum, 10 lung, 6 others, 21 multiple. 11 (9%) were only explored, the rest resected. 49/112 (40%) had multivisceral resections. 63/112 (56%) were completely resected (R0). 72 had preoperative CTx, 51 primary resection. 26 (21%) were classified as clinical responder, 16 (13%) as histopathological responder, 30 (42%) as subgroup with improved prognosis by the PPS. The median survival was 20.0 months (m.). Survival was significantly increased by resection, a complete resection and a preoperative CTx (primary resection: 11m., after CTx: 30 m.)(all p=0.001), but not by multivisceral resection, number or type of metastases or localization of the primary tumor. In pts. who had preoperative CTx, clinical response and the PPS (21 m. versus 66 m., p=0.005) significantly influenced survival. In R0 pts. preoperative CTx (p=0.03), clinical response and the PPS remained prognostic (both p=0.001). Conclusions: A primary resection without preoperative CTx is not appropriate for metastatic EGA. Subgroups of pts. with limited metastatic spread may be selected for surgery using the PPS. Prospective randomized studies are required.

Is primary surgery without preoperative chemotherapy the best treatment option for signet ring cell esophagogastric adenocarcinomas?

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Background: Recent retrospective multicentric data favor a primary resection without neoadjuvant chemotherapy for signet ring cell (SRC) gastric cancer. Aim of this retrospective exploratory study is the comparison of primary resected with neoadjuvantly treated locally advanced SRC esophagogastric adenocarcinomas (EGA) in respect of outcome. Methods: From 2002-2012 200/646 resected EGA were classified as SRC by WHO classification (more than 50% signet ring cells) and staged cT3/4 Nany M0/x. Clinical response evaluation was based on endoscopy and CT-scan and histopathological regression was based on the Becker score (<10% residual tumor cells: responder). UICC 7th was used. Analysis was retrospectively from a prospective data base. Results: 103 were treated by preoperative chemotherapy (CTx), 97 were primary resected. 73 (37%) had AEG, 127 (63%) gastric cancer. Postoperative CTx was delivered in 62/103 (60%) of the patients with preoperative CTx and in 51/97 (53%) of the primary resected patients (p=0.28). In-hospital mortality was 4.5% (9/200). 20 (20%) were classified as clinical, 15 (8%) as histopathological responders. Preoperative CTx was significantly associated with worse pretherapeutic cT- (p=0.005) and cN- (p=0.008) categories, but subsequent lower (y)pN-category (p=0,001) and improved lymphnode ratio (p=0.001). Overall survival was significantly improved after preoperative CTx compared to primary resection (median survival 30.2 versus 17.6 months, p=0.001). Median survival of responding patients is not reached, median survival of nonresponder was 24.4 months (identical for clinical and histopathological responders) compared to 17.6 months in primary resected patients (p=0.002). The positive prognostic effect of preoperative CTx was significantly higher in AEG (p=0.004) compared to gastric cancer (p=0.067). In the 119 completely resected patients the survival was significantly improved by preoperative CTx (p=0.005), but it was no independent prognostic factor. Conclusions: A pre/periopative CTx seems also to be justified in SRC EGA. Relevant limitations are the retrospective and non-randomized design.

A multifactorial histopathologic score for the prediction of prognosis of resected esophageal adenocarcinomas after neoadjuvant chemotherapy

BACKGROUND

For esophageal adenocarcinoma treated with neoadjuvant chemotherapy, postoperative staging classifications initially developed for non-pretreated tumors may not accurately predict prognosis. We tested whether a multifactorial TNM-based histopathologic prognostic score (PRSC), which additionally applies to tumor regression, may improve estimation of prognosis compared with the current Union for International Cancer Control/American Joint Committee on Cancer (UICC) staging system.

PATIENTS AND METHODS

We evaluated esophageal adenocarcinoma specimens following cis/oxaliplatin-based therapy from two separate centers (center 1: n = 280; and center 2: n = 80). For the PRSC, each factor was assigned a value from 1 to 2 (ypT0-2 = 1 point; ypT3-4 = 2 points; ypN0 = 1 point; ypN1-3 = 2 points; ≤ 50 % residual tumor/tumor bed = 1 point; >50 % residual tumor/tumor bed = 2 points). The three-tiered PRSC was based on the sum value of these factors (group A: 3; group B: 4-5; group C: 6) and was correlated with patients' overall survival (OS).

RESULTS

The PRSC groups showed significant differences with respect to OS (p < 0.0001; hazard ratio [HR] 2.2 [95 % CI 1.7-2.8]), which could also be demonstrated in both cohorts separately (center 1 p < 0.0001; HR 2.48 [95 % CI 1.8-3.3] and center 2 p = 0.015; HR 1.7 [95 % CI 1.1-2.6]). Moreover, the PRSC showed a more accurate prognostic discrimination than the current UICC staging system (p < 0.0001; HR 1.15 [95 % CI 1.1-1.2]), and assessment of two goodness-of-fit criteria (Akaike Information Criterion and Schwarz Bayesian Information Criterion) clearly supported the superiority of PRSC over the UICC staging.

CONCLUSION

The proposed PRSC clearly identifies three subgroups with different outcomes and may be more helpful for guiding further therapeutic decisions than the UICC staging system.

Prognostic impact of lymph node involvement and the extent of lymphadenectomy (LAD) in adenocarcinoma of the esophagogastric junction (AEG)

BACKGROUND

The prognostic importance of lymph node (LN) involvement for patients with adenocarcinoma of the esophagogastric junction (AEG) is well-known. In the latest edition of the UICC staging system, the number of metastatic LNs was taken into account, while the extent of lymphadenectomy (LAD) remains unaddressed. Removal of at least six LNs is recommended, but there is no defined minimum number as to classify as (y)pN0. We examined the prognostic value of the number of positive LNs, number of LNs removed, and LN ratio (LNR) in order to determine the influence of an adequate LAD on overall survival (OS).

METHODS

We analyzed data of 316 patients with AEG treated in our institution (2001-2011) regarding clinicopathological data, treatment, morbidity, mortality, and long-term prognosis. Univariate and multivariate analysis was performed using Cox regression to evaluate the prognostic impact of(y)pN category, number of LNs removed and LNR.

RESULTS

OS decreased with higher count of positive LNs (p < 0.001) and higher LNR (p < 0.001). Whether >6, >15, or >30 LNs were removed did not influence OS, neither in the entire study population nor within individual (y)pT or (y)pN categories. Multivariate analysis revealed LNR (p < 0.001) besides M category (p = 0.015) and tracheotomy during the postoperative course (p = 0.005) as independent predictors of OS.

CONCLUSION

The classification according to the number of involved LNs in the latest edition of the UICC staging system improves prognostication in patients with AEG. The importance of an adequate LAD is shown by the high prognostic relevance of the LNR rather than the absolute number of LNs removed.

Preoperative therapy of esophagogastric cancer: the problem of nonresponding patients

INTRODUCTION

Preoperative treatment is nowadays standard for locally advanced esophagogastric cancer in Europe. Surprisingly, little attention has been paid to nonresponders so far. The aim of our retrospective exploratory study was the comparison of responder, nonresponder, and primary resected patients in respect of outcome considering the tumor entity.

PATIENTS AND METHODS

From 2001-2011, 607 patients with locally advanced esophagogastric carcinoma (adenocarcinoma of the esophagogastric junction (AEG), n = 293; squamous cell cancer (SCC), n = 111; gastric cancer, n = 203) after preoperative treatment (n = 281) or primary resection (n = 326) were included. Histopathological response evaluation (Becker criteria) was available for 263.

RESULTS

A total of 76/263 (28.9 %) were responders (<10 % residual tumor). There was an association of response with increased R0 resections (p < 0.001) but also with a higher complication rate (p = 0.008) compared to nonresponse and primary surgery. Mortality was not influenced. Increased R0 resections after response were confirmed in every tumor entity (AEG, p = 0.010; SCC, p = 0.023; gastric cancer, p = 0.006). Median survival was best for responders with 43.5 months [95 % confidence interval (CI), 27.9-59.1], followed by nonresponders with 24.3 months (95 % CI, 21.6-27.0) and primary resected patients with 20.8 months (95 % CI, 17.7-23.9; p = 0.002). AEG (p = 0.012) and gastric cancer (p = 0.017) revealed identical results, but in the subgroup of SCC, the survival of nonresponders (median, 11.6 months; 95 % CI, 6.9-16.3) was even worse than for primary resected patients (median, 23.8 months; 95 % CI, 1.7-46.0; p = 0.012).

CONCLUSION

The histopathological response rate was low. Generally, nonresponding patients with AEG or gastric cancer seem not to have a disadvantage compared to primary resected patients, but nonresponders with SCC have a worse prognosis, which strengthens the demand for a critical patient selection in surgery for this tumor entity.

Tumor cell quantification and normalized multi-gene expression analysis of micrometastatic cells in blood and bone marrow of cancer patients: introduction of the embedded tumor cell calibrator technique

Abstract #5029

Background: The purpose of this study was the validation of a new preanalytical enrichment and molecular detection method using embedded tumor cell calibrators (ETC) for process control, relative tumor cell enumeration and quantitative gene expression analysis of circulating tumor cells (CTC) in breast cancer patients.&#x2028; Methods: Samples from every patient were devided in native probes and matched calibrator probes containing either 2, 4 or 8 breast carcinoma tumor cells (ETC). The high affinity antibodies BM7 (MUC-1) and VU1D9 (EpCAM) were used for immunomagnetic tumor cell enrichment in 10 mL of peripheral EDTA-blood of patients with primary and metastatic breast cancer. Mononuclear cells from bone marrow of patients with primary breast cancer were analysed in parallel by standardized cytospin immunocytology techniques (2x106 cells) and by the immunobead enrichment technique (1x107 cells). Separated cells were lysed and used for mRNA isolation and c-DNA synthesis. A real-time quantitative RT-PCR approach for the tumor identifier cytokeratin 19 (CK19) and mammaglobin 1 (MG1) and the surrogate markers HER-2, survivin (Sur), prostate-specific ets factor (PSE), CXCR4, Nanog, CD276 and FGFR2 was established using primers and FAM-labeled TaqMan probes selected with the UniversalProbeLibrary system (Roche AG, Basel, CH).&#x2028; Results: Positivity rate of ETC controlled realtime RT-PCR on the basis of CK19 and MG1 was 6.9% in 205 patients with primary breast cancer and 61.1% in patients with metastatic disease. Clonal selection or conversion from a HER2 negative (histology) to a HER2 positive phenotype was determined by qRT-PCR in 21 from 73 (28.8%) patients. During a 18 months follow-up of 92 patients with primary breast cancer, multimarker positivity was determined in 10 patients, and in three of these patients early metastasis was clinically confirmed. Tumor cell detection rate in bone marrow on the basis of&#x2028; 1x107 cells was 10.5% (11/104) while cytology at the level of 2x106 cells resulted in a positivity rate of only 1% (1/104).&#x2028; Conclusion: For the first time we describe embedded tumor cells (ETC) as internal calibrators for accurate process control and normalization of the complex techniques of the immunobead separation and the quantitative RT-PCR technique. Tumor cell quantification was performed with the tumor identifiers CK19 and MG1, while corresponding expression levels of surrogate markers were determined on the basis of spiked calibrator cells. The ETC technique improved monitoring and gene expression analysis of disseminated tumor cells in peripheral blood and bone marrow significantly.&#x2028; Characterization of clinically relevant markers from the networks of apoptosis (Sur, PSE), tumor related/induced angiogenesis (CD276), growth factor receptors (HER-2, FGFR2) and cytostatica resistence (ABCG2) may improve early detection of metastasis, monitoring of treatment regimes and prediction of (new) therapeutic targets.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5029.

Quantitative multimarker analysis in circulating tumor cells of patients with breast cancer

1021

Background: The purpose of this study was clinical application of new methods for quantitative gene expression analysis of circulating tumor cells (CTC) in breast cancer patients. Methods: The high affinity antibodies BM7 (MUC-1) and VU1D9 (EpCAM) were used for immunomagnetic tumor cell enrichment in 10 mL of peripheral EDTA-blood of patients with primary breast cancer (n=167) and metastatic disease (n=131). Separated cells were lysed and used for mRNA isolation and c-DNA synthesis. The breast carcinoma- associated markers MUC1 and EpCAM were determined by conventional RT-PCR. The markers cytokeratin 19 (CK19), mammaglobin 1, survivin, HER-2, CXCR4 and prostate-specific ets factor (PSE) were amplified by real-time quantitative RT-PCR using primers and FAM-labeled TaqMan probes selected with the UniversalProbeLibrary system (Roche AG, Basel, CH). The β-actin transcript served as internal process quality control. Specificity of the RT-PCR was confirmed by examination of blood of healthy donors. Results: Sensitivity for every single transcript was adjusted to 2 tumor cells per 5 ml blood. Tumor-associated transcripts were detected in 31 of 167 (18.5%) patients with primary breast cancer. The marker with the highest incidence of 81% was MUC1. Patients with metastatic disease (n=131) had a positivity rate of 56% and were characterized by multiple marker expression. During a 12 (9–15) months follow-up of 81 patients with primary breast cancer, multimarker positivity was determined in 10 patients, and in three of these patients early metastasis was clinically confirmed. In patients with metastatic disease the CK19 positive CTCs co-expressed either survivin, PSE, CXCR4 or HER2 in more than 70% of the cases. Conclusion: Using a combination of preanalytical immunomagnetic tumor cell enrichment, followed by a multigene quantitative RT- PCR approach, we describe a sensitive detection system for rare circulating breast carcinoma cells. By quantitative expression analysis, survivin, PSE, CXCR4 and HER2 together with CK19 were identified as reliable markers for early detection of metastasis and for prediction of risk of recurrence. The marker panel can be extended further to match patients to best drugs and to predict treatment benefits.

No significant financial relationships to disclose.