Abstract 3358: PLCRC-PROVENC3: assessing the prognostic value of post-surgery liquid biopsy cell-free circulating tumor DNA in stage III colon cancer patients

Introduction: Surgery followed by adjuvant chemotherapy (ACT) is standard of care in stage III colon cancer. However, 50% of the patients would be cured by surgery alone and are being overtreated, while 30-35% will experience a recurrence despite adjuvant treatment, resulting in only 15-20% of the patients benefitting from ACT. Therefore, there is a need for prognostic biomarkers to better stratify this group of patients for ACT decisions. Recent observational and interventional studies in non-metastatic colon cancer have shown that detection of cell-free circulating tumor DNA (ctDNA) in blood after surgery is highly prognostic for development of recurrence. Hence, ctDNA analysis is a promising approach to guide treatment decisions in stage III colon cancer, but studies with large well-defined patient cohorts are needed to prove clinical utility.

Aim: Determine the prognostic value of ctDNA in stage III colon cancer patients treated with ACT to reduce futile treatment.

Methods: 241 stage III colon cancer patients treated with ACT were included in the prospective observational study “PROVENC3” (PROgnostic Value of Early Notification by Ctdna in Colon Cancer stage 3), a substudy of the Prospective Dutch Colorectal Cancer cohort (PLCRC). The PLCRC infrastructure accrued patients with colorectal cancer in 23 participating hospitals in the Netherlands. After informed consent, blood was collected pre-surgery, post-surgery, post-ACT and every six months up to 3 years. Tumor-informed detection of ctDNA was performed through integrated whole genome sequencing (WGS) analyses of formalin-fixed paraffin-embedded tumor tissue DNA (80x), germline DNA (40x), and plasma cell-free DNA (30x).

Results: Patient accrual was completed in 2021, with a median follow-up of 35.6 months. In total, 1090 blood samples have been collected to date. Analytical studies demonstrated a limit of detection of the test of 0.005% ctDNA utilizing contrived reference models derived from six independent cell lines, with a specificity of 99.6% across 119 noncancerous donor plasma specimens. From the PROVENC3 study, ctDNA analyses are ongoing for pre-surgery (n=68) and post-surgery (n=241 patients) blood samples. Preliminary results demonstrated a ctDNA detection rate of 93.4% pre-surgery and 17.1% post-surgery, which was associated with disease recurrence. Final analysis will enable determination of: 1) the proportion of ctDNA-positive/negative patients after surgery and the corresponding recurrence rates; 2) the prognostic value of post-surgery ctDNA; and 3) the lead time between post-surgery ctDNA detection and recurrence.

Future Perspective: Ultimately, the results of this study will be used to model and design a ctDNA-guided interventional trial in stage III colon cancer patients, to reduce futile ACT and its associated side-effects.

Citation Format: Carmen Rubio-Alarcon, Steven L. Ketelaars, Ingrid A. Franken, Sietske C. van Nassau, Dave E. van der Kruijssen, Suzanna J. Schraa, Theodora C. Linders, Pien Delis-van Diemen, Maartje Alkemade, Anne Bolijn, Marianne Tijssen, Margriet Lemmens, Miranda van Dongen, Mirthe Lanfermeijer, Annegien Broeks, Lana Meiqari, Linda J. Bosch, Victor E. Velculescu, Amy Greer, Samuel V. Angiuoli, Andrew Georgiadis, David Riley, James R. White, Christopher Greco, Liam Cox, Daan van den Broek, Cornelis J. Punt, Veerle M. Coupé, Miriam Koopman, Jeanine Roodhart, Gerrit A. Meijer, Mark Sausen, Geraldine R. Vink, Remond J. Fijneman. PLCRC-PROVENC3: assessing the prognostic value of post-surgery liquid biopsy cell-free circulating tumor DNA in stage III colon cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3358.

Abstract 519: Clinical impact ofKRASG12, G13, Q61, K117 and A146 mutations in patients with colorectal liver metastases

Introduction: The distribution of KRAS mutation variants across tumor types is not uniform. The KRAS A146 mutation is predominantly seen in colorectal cancer (CRC) patients. Here, we evaluated how clinical features like tumor load and overall survival differ between metastatic CRC (mCRC) patients carrying distinct somatic KRAS G12, G13, Q61, K117 or A146 mutations.

Methods: 419 CRC patients with initially unresectable liver-limited metastases, who participated in the multicenter CAIRO5 prospective clinical trial, were evaluated for tumor tissue KRAS mutation status. For the subgroup of patients who carried a KRAS mutation and were treated with bevacizumab and doublet or triplet chemotherapy (N=156), clinical outcome was evaluated and pretreatment tumor burden was quantified as liquid biopsy circulating tumor DNA (ctDNA) mutant allele fraction (MAF) and as total tumor volume (TTV) on CT imaging. The MAF, TTV and overall survival were compared between patients harboring different KRAS mutation variants.

Results: Of the 156 patients with a KRAS mutated tumor, most carried a KRAS G12 mutation (N=112, 71.8%), followed by mutations in G13 (N=15, 9.6%), A146 (N=12, 7.7%), Q61 (N=9, 5.8%) and K117 (N=5, 3.2%). High plasma ctDNA levels were observed for patients carrying a KRAS A146 mutation versus those with a KRAS G12 mutation, with a median MAF of 48% versus 19%, respectively. Radiological TTV revealed this difference to be associated with a higher tumor load in patients harboring a KRAS A146 mutation (median TTV 672 cm3 (A146) versus 74 cm3 (G12), p=0.036). Moreover, KRAS A146 mutation carriers showed inferior overall survival compared to patients with mutations in KRAS G12 (median 10.7 versus 26.4 months; HR=2.5; p=0.003), and the multivariable Cox regression analysis showed that the KRAS alteration was the only independent prognostic factor for overall survival.

Conclusion and Relevance: This study revealed that within mCRC patients A146 is the third most common KRAS mutation variant, and mCRC patients carrying a KRAS A146 mutation represent a distinct molecular subtype of patients with high tumor burden and poor clinical outcome. This highlights the importance of testing CRC for all KRAS mutations in routine clinical care and shows the opportunity for personalized treatment beyond detecting the presence of a KRAS mutation by taking the specific KRAS mutation variant into account.

Citation Format: Iris van 't Erve, Nina J. Wesdorp, Jamie E. Medina, Leonardo Ferreira, Alessandro Leal, Joost Huiskens, Karen Bolhuis, Jan-Hein T. van Waesberghe, Rutger-Jan Swijnenburg, Daan van den Broek, Victor E. Velculescu, Geert Kazemier, Cornelis J. Punt, Gerrit A. Meijer, Remond J. Fijneman. Clinical impact ofKRASG12, G13, Q61, K117 and A146 mutations in patients with colorectal liver metastases [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 519.

Abstract 2224: DELFI as a real-time treatment response assessment for patients with cancer

Introduction: Measurement of tumor-derived DNA molecules in the plasma (ctDNA) has become a useful tool to determine the overall tumor burden in patients with cancer. The ctDNA burden may change over time, decreasing after treatment response and increasing with development of resistance to therapy. Monitoring the dynamics of ctDNA burden over the course of treatment with a rapid, non-invasive test enables physicians to make timely treatment decisions. Using the DNA evaluation of fragments for early interception (DELFI) approach, we have developed the DELFI Monitoring Score (DMS) to longitudinally assess ctDNA burden during therapy of cancer patients.

Methods: We performed low coverage whole genome sequencing on 302 cfDNA libraries of 76 treatment-naive metastatic colorectal cancer (mCRC) patients with at least one blood draw prior to and after treatment initiation. Mutations in KRAS, NRAS, or BRAF were independently measured by digital droplet PCR (ddPCR) for all timepoints evaluated. We trained a Bayesian regression model with the mutant allele fraction (MAF) of KRAS, NRAS, or BRAF as response and fragmentation-related features as predictors as well as a random intercept. To avoid overfitting and assess generalizability, we used cross-validation, wherein each patient’s samples were held out of the dataset and a model was trained on the samples of all other patients to generate predictions for the held-out samples. Patients with DMS below and above a detectability threshold at the first blood draw post-treatment (between 4-12 weeks) were classified as molecular responders and non-responders, respectively. Progression-free survival outcomes, defined as time to progression by RECIST 1.1 or death, were evaluated using a Kaplan-Meier estimator in these two groups.

Results: Molecular responders based on DMS assessment experienced longer progression-free survival than molecular non-responders (p < 0.01), similar to a MAF-based approach. Additionally, in the 43 patients for whom the MAF of the KRAS, NRAS, or BRAF variants was 0% at the first blood draw post-treatment, we observed further separation on progression-free survival by the DELFI Monitoring Score (p = 0.014).

Conclusions: We developed a novel quantitative measure of ctDNA burden using cell-free DNA fragmentation patterns that is estimable from low coverage whole genome sequencing. The DMS appears to be useful for measuring ctDNA burden and enabling a non-invasive approach to treatment monitoring, as it distinguishes therapeutic responses in a mCRC cohort. Our ability to detect differences in progression-free survival among patients with undetectable ddPCR MAFs suggests that DMS may be more sensitive and predictive than conventional mutation-based approaches for treatment response monitoring.

Citation Format: Keith Lumbard, Laurel A. Keefer, Iris van't erve, Jacob Carey, Bryan Chesnick, Denise Butler, Michael Rongione, Cornelis J. Punt, Nicholas C. Dracopoli, Remond J. Fijneman, Gerrit A. Meijer, Robert B. Scharpf, Victor E. Velculescu, Alessandro Leal. DELFI as a real-time treatment response assessment for patients with cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2224.

Neoadjuvant Chemoradiotherapy Versus Upfront Surgery for Resectable and Borderline Resectable Pancreatic Cancer: Long-Term Results of the Dutch Randomized PREOPANC Trial

PURPOSE

The benefit of neoadjuvant chemoradiotherapy in resectable and borderline resectable pancreatic cancer remains controversial. Initial results of the PREOPANC trial failed to demonstrate a statistically significant overall survival (OS) benefit. The long-term results are reported.

METHODS

In this multicenter, phase III trial, patients with resectable and borderline resectable pancreatic cancer were randomly assigned (1:1) to neoadjuvant chemoradiotherapy or upfront surgery in 16 Dutch centers. Neoadjuvant chemoradiotherapy consisted of three cycles of gemcitabine combined with 36 Gy radiotherapy in 15 fractions during the second cycle. After restaging, patients underwent surgery followed by four cycles of adjuvant gemcitabine. Patients in the upfront surgery group underwent surgery followed by six cycles of adjuvant gemcitabine. The primary outcome was OS by intention-to-treat. No safety data were collected beyond the initial report of the trial.

RESULTS

Between April 24, 2013, and July 25, 2017, 246 eligible patients were randomly assigned to neoadjuvant chemoradiotherapy (n = 119) and upfront surgery (n = 127). At a median follow-up of 59 months, the OS was better in the neoadjuvant chemoradiotherapy group than in the upfront surgery group (hazard ratio, 0.73; 95% CI, 0.56 to 0.96; P = .025). Although the difference in median survival was only 1.4 months (15.7 months v 14.3 months), the 5-year OS rate was 20.5% (95% CI, 14.2 to 29.8) with neoadjuvant chemoradiotherapy and 6.5% (95% CI, 3.1 to 13.7) with upfront surgery. The effect of neoadjuvant chemoradiotherapy was consistent across the prespecified subgroups, including resectable and borderline resectable pancreatic cancer.

CONCLUSION

Neoadjuvant gemcitabine-based chemoradiotherapy followed by surgery and adjuvant gemcitabine improves OS compared with upfront surgery and adjuvant gemcitabine in resectable and borderline resectable pancreatic cancer.

Abstract 540: Molecular response evaluation of patients with metastatic colorectal cancer using circulating tumor DNA

Introduction: Patients with colorectal cancer with unresectable and isolated liver metastases (CRLM) are mostly treated with chemotherapy and targeted treatments like anti-epidermal growth factor receptor (EGFR) monoclonal antibody therapy. Clinical response evaluation of systemic treatment is performed by radiological CT imaging, which can detect disease progression. However, CT imaging does not always give information about the viability of the tumor tissue nor does it constitute the genomic changes of the tumor, i.e. development of sub-clones following the pressure of treatment. Cell-free circulating tumor DNA (ctDNA) derived from liquid biopsies is a minimally invasive biomarker that has great potential for tumor detection and is present in relatively high levels in the plasma of patients with CRLM. Liquid biopsy ctDNA allows for longitudinal follow-up and gives the possibility to track intratumor heterogeneity caused by different sub-clones without a repeated tumor biopsy. Here, we aim to assess the use of molecular profiling using serial liquid biopsies as a biomarker for treatment response evaluation.

Methods: Tumor tissue obtained prior to treatment as well as longitudinal liquid biopsies were collected from patients with CRLM who participated in a prospective clinical trial with CRC and were treated with panitumumab and doublet chemotherapy. Liquid biopsy ctDNA was isolated and analyzed by targeted sequencing using a panel of 33-genes, allowing to map dynamic molecular changes during treatment. ctDNA sequencing results were corrected for germline variants and clonal hematopoiesis variants by using targeted sequencing data of patient-matched tumor tissue DNA and white blood cell (WBC) genomic DNA, respectively. ‘Molecular response' was defined as the elimination of more than 95% of ctDNA after treatment compared to the measurement before treatment initiation. Detection of disease progression by ctDNA was compared to CT imaging.

Results: At present, 110 longitudinal plasma samples as well as WBC genomic DNA and tumor tissue DNA are analyzed from a cohort of 33 patients. Currently, we are expanding the number of patients and samples. Molecular responders to treatment showed a significantly longer overall survival than non-responders (median 51 vs 25 months; p=0.033; HR=3.7). In addition, significantly earlier detection of disease progression was observed using ctDNA compared to radiological imaging (median difference of 4.8 months; p=0.006).

Conclusion: Serial plasma ctDNA analyses in patients with mCRC provide a minimally-invasive tool for longitudinal treatment response evaluation of dynamic genomic alterations and creates an opportunity for patient subset selection for possible adaptation of the treatment regimen.

Citation Format: Iris van 't Erve, Jamie E. Medina, Alessandro Leal, Eniko Papp, Karen Bolhuis, John K. Simmons, Samuel Angiuoli, Cornelis J. Punt, Gerrit A. Meijer, Victor E. Velculescu, Remond J. Fijneman. Molecular response evaluation of patients with metastatic colorectal cancer using circulating tumor DNA [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 540.

Abstract 708: Limited release of circulating tumor DNA into the systemic circulation by peritoneal metastases from colorectal cancer

Introduction: Circulating tumor DNA (ctDNA) from plasma is a promising biomarker. Patients with metastatic colorectal cancer (CRC) often have high ctDNA levels compared to other cancer types. However, it is unclear whether this is also the case for patients with peritoneal metastases from CRC.

Aim: To compare the propensity of ctDNA shedding by isolated liver metastases and isolated peritoneal metastases from CRC.

Methods: Plasma was collected from 100 CRC patients (64% male, mean age of 60 [SD=10] years) with isolated unresectable liver metastasis (CRC-LM). Plasma and ascites were obtained from 20 CRC patients (60% male, mean age of 63 [SD=9.8] years) with isolated unresectable peritoneal metastases (CRC-PM). All liquid biopsies were obtained prior to treatment and cell-free DNA was isolated using the QIAsymphony (Qiagen, Germany) and assessed by droplet digital PCR (ddPCR; Bio-Rad, Hercules, USA). Patients with a KRAS or BRAF tumor tissue mutation were suited for plasma ctDNA ddPCR analysis, and were detected in 57 CRC-LM (57%) and 11 CRC-PM (55%) patients. The ability to shed ctDNA into the circulation was evaluated by comparing KRAS/BRAF mutation status in plasma and ascites with the mutation status based on tumor tissue. Regarding liquid biopsies, mutant allele fraction (MAF) and mutant copies per ml input (MTc/ml) were reported.

Results: Tissue mutations could be confirmed in plasma in 93% of CRC-LM and only 20% of CRC-PM patients, whereas mutations were detected in ascites in 100% of CRC-PM patients. The MAF and MTc/ml were both significantly lower in CRC-PM plasma ctDNA (median MAF=0.28% and MTc/ml=21) compared to CRC-LM plasma ctDNA (median MAF=18.9% and MTc/ml= 1758; P<0.0001). In addition, the MAF and MTc/ml were significantly higher in CRC-PM ascites ctDNA (median MAF=16.4%, MTc/ml=305) compared to plasma ctDNA (median MAF=0.28%, MTc/ml=21; P<0.0001).

Conclusion: To our knowledge, this is the first study showing a comprehensive comparison of tissue, blood and ascites derived genomic information in patients with CRC and extensive isolated peritoneal metastases. This study concludes that isolated peritoneal metastases from CRC is a malignancy with distinct clinical and biological characteristics, which should be taken into account when considering the clinical utility of ctDNA in different metastatic setting of CRC. To detect genomic alterations, the blood circulation is the preferred source of ctDNA in case of CRC liver metastases, whereas ascites offers an alternative to plasma in patients with peritoneal metastases, which might be suitable as diagnostic, prognostic, predictive or disease monitoring biomarker.

Citation Format: Iris van 't Erve, Koen P. Rovers, Alexander Constantinides, Karen Bolhuis, Emma C. Wassenaar, Robin J. Lurvink, Clément J. Huysentruyt, Petur Snaebjornsson, Daan van den Broek, Tineke E. Buffart, Niels F. Kok, Gerrit A. Meijer, Cornelis J. Punt, Onno Kranenburg, Ignace H. de Hingh, Remond J. Fijneman. Limited release of circulating tumor DNA into the systemic circulation by peritoneal metastases from colorectal cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 708.

Abstract 3096: Liquid biopsy cell-free circulating tumor DNA as prognostic biomarker for stage III colon cancer patients

Introduction: Stage III colon cancer patients undergo surgery followed by adjuvant chemotherapy (ACT) according to clinical guidelines. However, 50% would be cured by surgery alone and are being overtreated, while 30-35% will relapse despite adjuvant treatment. This means that only 15-20% of the patients benefit from ACT. Therefore, there is a need for better prognostic biomarkers to stratify patients for ACT. Detection of cell-free circulating tumor DNA (ctDNA) in blood after surgery is indicative of minimal residual disease and highly prognostic for disease recurrence. Hence, detecting liquid biopsy ctDNA is a promising approach to guide treatment decisions in stage III colon cancer.

Aim: Determine prognostic value of ctDNA in stage III colon cancer patients treated with ACT in order to reduce futile treatment.

Methods: 315 stage III colon cancer patients treated with ACT will be included in the prospective observational study “PROVENC3” (PROgnostic Value of Early Notification by Ctdna in Colon Cancer stage 3). The Prospective Dutch Colorectal Cancer Cohort (PLCRC) infrastructure organizes accrual of colorectal cancer patients in more than 50 hospitals in the Netherlands, among which 25 hospitals that accrue patients for PROVENC3. If informed consent is provided, blood is collected at baseline, post-surgery, post-ACT and every six months up to 3 years, and shipped to a central location. Tumor-informed detection of mutations in ctDNA will be performed by combined analysis of targeted sequencing of a panel of >30 genes in cfDNA (PGDx elio plasma test) and a panel of >500 genes in DNA from formalin-fixed paraffin-embedded tumor tissue (PGDx elio tissue complete assay). The clinical, pathological, and molecular data will be handled according to the FAIR (findable, accessible, interoperable and reusable) principles and integrated in cBioPortal.

Results and future directions: Around 125 patients and 400 blood samples included to date. Once sequencing data are obtained we will determine: 1) the proportion of ctDNA-positive and ctDNA-negative patients after surgery and the corresponding recurrence rates; 2) the prognostic value of ctDNA pre-surgery; and 3) the lead time between ctDNA detection and recurrence. Ultimately, the results of this study will be used to model and design an ethically acceptable and cost-effective ctDNA-guided interventional trial, to reduce futile ACT and its associated side-effects in stage III colon cancer patients.

Citation Format: Carmen Rubio Alarcón, Dave E. van der Kruijssen, Lana Meiqari, Linda J. Bosch, John K. Simmons, Victor E. Velculescu, Daan van den Broek, Cornelis J. Punt, Veerle M. Coupé, Miriam Koopman, Gerrit A. Meijer, Geraldine R. Vink, Remond J. Fijneman. Liquid biopsy cell-free circulating tumor DNA as prognostic biomarker for stage III colon cancer patients [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3096.

Abstract 6487: Circulating tumor cells, tumor- and endothelium- derived extracellular vesicles, but not circulating endothelial cells associate with poor prognosis in colorectal cancer

Elevated tumor-derived EV (tdEV) and Circulating Tumor Cell (CTC) load in patients with metastatic cancer is associated with poor clinical outcome. In this study, we investigated whether endothelium-derived extracellular vesicles (edEVs) can be detected in the blood of metastatic colorectal cancer (mCRC) patients and whether there is an association with prognosis.

The open-source ACCEPT software was used to enumerate edEVs, tdEVs and other objects from digitally stored CellSearch® images obtained after Circulating Endothelial Cell (CEC) and CTC enrichment from blood of 395 mCRC patients, before the initiation of a new therapy. Patients had participated in the prospective phase III CAIRO2 study. ACCEPT classified objects, CTC and CEC counts and patient information were used in univariable and multivariable analysis to determine their relation with Progression-Free Survival (PFS) and Overall Survival (OS).

edEVs are present in blood of mCRC patients at 5-10 fold higher frequencies than CECs. A significantly shorter PFS and OS was observed for patients with ≥ 3 CTCs/ 7.5 mL, ≥ 40 tdEVs/ 7.5 mL and ≥ 287 edEVs/ 4.0 mL. The Hazard Ratio HR (95% CI) of PFS for increased CTCs, tdEVs and edEVs was 1.4 (1.1-1.9), 2.0 (1.5-2.6) and 1.7 (1.2-2.5), respectively. Similarly, the HR of OS for increased CTCs, tdEVs and edEVs was 2.2 (1.7-3.0), 2.7 (2.0-3.5) and 2.1 (1.5-2.8), respectively. There was no cut-off value for CECs leading to a dichotomization of patients with a significant HR. Both tdEVs and edEVs remained significant predictors of OS in multivariable analysis.

edEVs and tdEVs are independent prognostic factors for OS in mCRC patients.

Funded by the NWO Applied and Engineering Sciences Cancer-ID project #14190.

Citation Format: Afroditi Nanou, Linda Mol, Miriam Koopman, Cornelis J. Punt, Leon W. Terstappen. Circulating tumor cells, tumor- and endothelium- derived extracellular vesicles, but not circulating endothelial cells associate with poor prognosis in colorectal cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6487.

Preoperative Chemoradiotherapy Versus Immediate Surgery for Resectable and Borderline Resectable Pancreatic Cancer: Results of the Dutch Randomized Phase III PREOPANC Trial

PURPOSE

Preoperative chemoradiotherapy may improve the radical resection rate for resectable or borderline resectable pancreatic cancer, but the overall benefit is unproven.

PATIENTS AND METHODS

In this randomized phase III trial in 16 centers, patients with resectable or borderline resectable pancreatic cancer were randomly assigned to receive preoperative chemoradiotherapy, which consisted of 3 courses of gemcitabine, the second combined with 15 × 2.4 Gy radiotherapy, followed by surgery and 4 courses of adjuvant gemcitabine or to immediate surgery and 6 courses of adjuvant gemcitabine. The primary end point was overall survival by intention to treat.

RESULTS

Between April 2013 and July 2017, 246 eligible patients were randomly assigned; 119 were assigned to preoperative chemoradiotherapy and 127 to immediate surgery. Median overall survival by intention to treat was 16.0 months with preoperative chemoradiotherapy and 14.3 months with immediate surgery (hazard ratio, 0.78; 95% CI, 0.58 to 1.05; P = .096). The resection rate was 61% and 72% (P = .058). The R0 resection rate was 71% (51 of 72) in patients who received preoperative chemoradiotherapy and 40% (37 of 92) in patients assigned to immediate surgery (P < .001). Preoperative chemoradiotherapy was associated with significantly better disease-free survival and locoregional failure-free interval as well as with significantly lower rates of pathologic lymph nodes, perineural invasion, and venous invasion. Survival analysis of patients who underwent tumor resection and started adjuvant chemotherapy showed improved survival with preoperative chemoradiotherapy (35.2 v 19.8 months; P = .029). The proportion of patients who suffered serious adverse events was 52% versus 41% (P = .096).

CONCLUSION

Preoperative chemoradiotherapy for resectable or borderline resectable pancreatic cancer did not show a significant overall survival benefit. Although the outcomes of the secondary end points and predefined subgroup analyses suggest an advantage of the neoadjuvant approach, additional evidence is required.

Abstract 4464: Tumor-derived extracellular vesicles in blood of metastatic breast, colorectal, prostate, and non-small cell lung cancer patients associate with worse survival

Circulating Tumor Cell (CTC) counts, as determined by the CellSearch® system, associate with poor overall survival (OS) in castration-resistant prostate cancer (CRPC), breast, colorectal and non-small cell lung (NSCLC) cancer patients. The cut-offs used to discriminate between patients with favorable and unfavorable prognoses are 5 CTCs / 7.5 mL of blood for breast and CRPC, 3 for colorectal and 1 for NSCLC. The low numbers of CTCs frequently limit the accurate discrimination of patients into favorable or unfavorable prognosis groups. We previously reported the presence of CK+, DNA-, CD45- tumor-derived extracellular vesicles (tdEVs) in ~20x higher frequencies in CRPC patients and showed their equivalence to CTC counts in predicting clinical outcome. In this study, we explored the presence of tdEVs in the blood of metastatic CRPC, breast, colorectal, and NSCLC patients, determined the association of tdEVs with OS and whether they aid in stratifying patients with favorable CTC counts. Digitally stored CellSearch® system images obtained from previously reported studies from 190 CRPC, 450 colorectal, 179 breast and 117 NSCLC patients before the initiation of a new treatment were used to enumerate tdEVs automatically using the open-source ACCEPT software. tdEV counts highly correlated with CTC counts in all cancer types (Spearman’s Rho tests p&lt;0.001) and were present at 0-280-fold (Mean 20, SD 25) higher frequencies. A cut-off tdEV value of 23 (median +2SD of 93 healthy donors) was used to dichotomize patients into favorable and unfavorable groups. Kaplan-Meier analyses showed associations of CTCs and tdEVs with OS with hazard ratios (HRs) of 2.4 & 2.1 in CRPC, 2.7 & 2.1 in breast, 2.3 & 2.0 in colorectal and 1.6 & 2.0 in NSCLC, respectively. 52% of the 43% CRPC patients with favorable CTC counts had elevated tdEVs; 53% of the 50% breast cancer patients with favorable CTC counts had elevated tdEVs; 46% of the 72% colorectal cancer patients with favorable CTC counts had elevated tdEVs and 3% of the 75% NSCLC patients with favorable CTC counts had unfavorable tdEVs. CRPC, colorectal and breast cancer patients with favorable CTC counts could be further stratified using tdEV counts (log-rank tests p &lt; 0.05). CTC and tdEV counts equally predict OS n the different cancer types studied. Use of tdEVs in patients with favorable CTC counts can further stratify patients and thereby contribute to clinical decision making. Funded by the NWO Applied and Engineering Sciences Cancer-ID project #14190, the EUFP7 CTCTrap project #305341 and the EU IMI CANCER-ID project # 115749-1.

Citation Format: Afroditi Nanou, Leonie L. Zeune, Sanne de Wit, Craig M. Miller, Cornelis J. Punt, Harry J. Groen, Daniel F. Hayes, Johann S. de Bono, Leon W. Terstappen. Tumor-derived extracellular vesicles in blood of metastatic breast, colorectal, prostate, and non-small cell lung cancer patients associate with worse survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4464.

Abstract 1588: Liquid biopsy analyses of cell-free circulating tumor DNA as predictive and prognostic biomarker for colorectal cancer patients with metastatic disease

Background: Most colorectal cancer (CRC) deaths are caused by metastatic disease (mCRC). Therapeutic approaches include treatment with monoclonal antibodies (mAbs) against EGFR and VEGF. There is an urgent clinical need to stratify mCRC patients for optimal treatment. Cell-free circulating tumor DNA (ctDNA) derived from blood plasma is expected to improve stratification by early detection of therapy resistance and disease progression.

Aim: The general aim of this study is to advance towards clinical implementation of ctDNA-based tests as molecular biomarkers to improve disease management of mCRC patients. We will investigate added value of liquid biopsy ctDNA-based gene mutation analyses compared to: 1) tissue-based tests for RAS mutation status as determined in standard clinical care setting; and 2) monitoring of disease progression by computed tomography (CT) imaging.

Methods: CAIRO5 is a multicenter, randomized, phase 3 clinical trial of the Dutch Colorectal Cancer Group (DCCG) and includes patients with initially unresectable, liver-only mCRC, as confirmed by a central panel of liver surgeons/radiologists based on CT imaging. This study involves nation-wide longitudinal collection of liquid biopsies (blood samples) using cell-save tubes and CT imaging from up to 564 patients. Hotspot mutations in ctDNA will be analyzed by droplet digital PCR (ddPCR), and mutations in a panel of genes by targeted error correction sequencing (TEC-seq). Clinical, imaging, biobanking, and molecular data will be collected using standardized data fields and data formats and integrated for querying and viewing in tranSMART, making use of the national Health-RI research IT infrastructure.

Results: The nation-wide multi-center logistics for longitudinal blood sample collection and plasma processing has been established, with participation of more than 40 Dutch hospitals. At present (Nov 2017), over 220 patients have been included from whom more than 550 blood samples and 330 CT images were obtained. Proof of concept for the validity of this workflow was obtained by successful subjection of 11 plasma samples to ctDNA mutation analysis by TEC-seq (Phallen et al., 2017).

Discussion: Implementation of ctDNA-based tests as molecular biomarkers to improve disease management of mCRC patients requires collection of information from large, well-defined studies with longitudinal patient follow-up. This translational research project will provide the data that are needed to determine cost-effectiveness analysis of ctDNA mutation analyses by health technology assessment, yielding recommendations for clinical implementation of ctDNA applications.

Citation Format: Iris van 't Erve, Jillian Phallen, Karen Bolhuis, Joost Huiskens, Nicole C. van Grieken, Veerle Coupé, Annegien Broeks, Daan van den Broek, Alessandro Leal, Victor E. Velculescu, Cornelis J. Punt, Gerrit A. Meijer, Remond J. Fijneman. Liquid biopsy analyses of cell-free circulating tumor DNA as predictive and prognostic biomarker for colorectal cancer patients with metastatic disease [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1588.

Abstract CT089: The Dutch Oncology Research Platform (DORP), a national infrastructure for investigator-initiated multicenter clinical cancer research

Background Investigator-initiated clinical cancer research (IICCR) contributes in a major way to improved prognosis of cancer patients. However, increased complexity of legislation and regulation, lack of uniformity in local procedures among participating hospitals, and increasing demands on monitoring seriously endanger IICCR, since insufficient staff/funding is available to meet these requirements. In addition, better characterization of patient subgroups requiring specific treatments hamper the feasibility of randomized studies with classic design, and calls for innovative study designs. In The Netherlands, tumor-specific research groups exist for almost every tumor type, which however have different levels of professionalization, but which all face the same problems. This seriously hampers future development of IICCR.

Methods A national infrastructure (DORP) has been developed to facilitate IICCR. DORP has 3 pillars: statistical support, monitoring, and project management. DORP provides statistical and logistic support in protocol development according to up-to-date standards, and, once financial support for the conduct of the study (i.e. datamanagement) has been obtained, provides support for monitoring and project management. The latter includes implementation of the study in participating hospitals, and administrative/financial management of the study. DORP statisticians will develop innovative trial designs that provide more feasible alternatives to classic phase 3 studies in small subgroups of patients, and DORP project managers will aim to harmonize local study procedures in hospitals in order to speed up study initiation.

Results The DORP initiative has been received with great enthousiasm among stakeholders (i.e. research groups, patient advocacy groups, large trial offices, professional and hospital organisations, insurance companies). DORP has recently received a 6.5 million euro starting grant from the Dutch Cancer Society (KWF Kankerbestrijding), which has allowed to established DORP as a cooperation in which all stakeholders participate. A total of approx. 30 statisticians, monitors and project managers will be recruited and will be employed at institutions with established expertise in the respective fields. A director has been commissioned by the board. Trial development with DORP support has been initiated in January 2018.

Conclusion The objective of DORP is more trials, for more patients, of better quality, that are timely completed. DORP may internationally provide an example for IICCR support.

Citation Format: Cornelis J. Punt. The Dutch Oncology Research Platform (DORP), a national infrastructure for investigator-initiated multicenter clinical cancer research [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT089.

Perioperative systemic therapy for resectable colorectal peritoneal metastases: Sufficient evidence for its widespread use? A critical systematic review

BACKGROUND/PURPOSE

Despite its widespread use, no randomised studies have investigated the value of perioperative systemic therapy as adjunct to cytoreduction and HIPEC for colorectal peritoneal metastases. This systematic review evaluated the available evidence, which consists of non-randomised studies only.

METHODS

A systematic search identified studies that investigated the influence of neoadjuvant, adjuvant, or perioperative systemic therapy on overall survival (OS).

RESULTS

The 11 included studies (n=1708) were clinically heterogeneous and subject to selection bias. Studies on neoadjuvant systemic therapy revealed OS benefit (n=3), no OS benefit (n=1), and superiority of chemotherapy with bevacizumab vs. chemotherapy (n=2). Studies on adjuvant systemic therapy showed no OS benefit (n=3). Studies on perioperative systemic therapy demonstrated OS benefit (n=1), and superiority of modern vs. conventional systemic therapy(n=1).

CONCLUSION

Significant limitations of available evidence question the widespread use of perioperative systemic therapy in this setting, stress the need for randomised studies, and impede conclusions regarding optimal timing and regimens. Included studies may suggest a survival benefit of neoadjuvant systemic therapy.

Survival of patients with colorectal peritoneal metastases is affected by treatment disparities among hospitals of diagnosis: A nationwide population-based study

BACKGROUND

In the Netherlands, surgery for peritoneal metastases of colorectal cancer (PMCRC) is centralised, whereas PMCRC is diagnosed in all hospitals. This study assessed whether hospital of diagnosis affects treatment selection and overall survival (OS).

METHODS

Between 2005 and 2015, all patients with synchronous PMCRC without systemic metastases were selected from the Netherlands Cancer Registry. Treatment was classified as cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC), systemic therapy or other/no treatment. Hospitals of diagnosis were classified as: (1) non-teaching or academic/teaching hospital and (2) HIPEC centre or referring hospital. Referring hospitals were further classified based on the frequency of CRS/HIPEC as high-, medium- or low-frequency hospital. Multivariable regression analyses were used to assess the independent influence of hospital categories on the likelihood of CRS/HIPEC and OS.

RESULTS

A total of 2661 patients, diagnosed in 89 hospitals, were included. At individual hospital level, CRS/HIPEC and systemic therapy ranged from 0% to 50% and 6% to 67%, respectively. Hospital of diagnosis influenced the likelihood of CRS/HIPEC: 33% versus 13% for HIPEC centres versus referring hospitals (odds ratio (OR) 3.66 [2.40-5.58]) and 11% versus 17% for non-teaching hospitals versus academic/teaching hospitals (OR 0.60 [0.47-0.77]). Hospital of diagnosis affected median OS: 14.1 versus 9.6 months for HIPEC centres versus referring hospitals (hazard ratio (HR) 0.82 [0.67-0.99]) and 8.7 versus 11.5 months for non-teaching hospitals versus academic/teaching hospitals (HR 1.15 [1.06-1.26]). Compared with diagnosis in medium-frequency referring hospitals, median OS was increased in high-frequency referring hospitals (12.6 months, HR 0.82 [0.73-0.91]) and reduced in low-frequency referring hospitals (8.1 months, HR 1.12 [1.01-1.24]).

CONCLUSION

Treatment disparities among hospitals of diagnosis and their impact on survival indicate suboptimal treatment selection for PMCRC.

Practical and Robust Identification of Molecular Subtypes in Colorectal Cancer by Immunohistochemistry

PURPOSE

Recent transcriptomic analyses have identified four distinct molecular subtypes of colorectal cancer with evident clinical relevance. However, the requirement for sufficient quantities of bulk tumor and difficulties in obtaining high-quality genome-wide transcriptome data from formalin-fixed paraffin-embedded tissue are obstacles toward widespread adoption of this taxonomy. Here, we develop an immunohistochemistry-based classifier to validate the prognostic and predictive value of molecular colorectal cancer subtyping in a multicenter study.

EXPERIMENTAL DESIGN

Tissue microarrays from 1,076 patients with colorectal cancer from four different cohorts were stained for five markers (CDX2, FRMD6, HTR2B, ZEB1, and KER) by immunohistochemistry and assessed for microsatellite instability. An automated classification system was trained on one cohort using quantitative image analysis or semiquantitative pathologist scoring of the cores as input and applied to three independent clinical cohorts.

RESULTS

This classifier demonstrated 87% concordance with the gold-standard transcriptome-based classification. Application to three validation datasets confirmed the poor prognosis of the mesenchymal-like molecular colorectal cancer subtype. In addition, retrospective analysis demonstrated the benefit of adding cetuximab to bevacizumab and chemotherapy in patients with RAS wild-type metastatic cancers of the canonical epithelial-like subtypes.

CONCLUSIONS

This study shows that a practical and robust immunohistochemical assay can be employed to identify molecular colorectal cancer subtypes and uncover subtype-specific therapeutic benefit. Finally, the described tool is available online for rapid classification of colorectal cancer samples, both in the format of an automated image analysis pipeline to score tumor core staining, and as a classifier based on semiquantitative pathology scoring. Clin Cancer Res; 23(2); 387-98. ©2016 AACR.

MicroRNA-143 is a putative predictive factor for the response to fluoropyrimidine-based chemotherapy in patients with metastatic colorectal cancer

Approximately half of the colorectal cancer (CRC) patients develop metastatic disease. Fluoropyrimidine-based chemotherapy forms the backbone of treatment in these patients. However, the response to this therapy varies between individuals. Therefore, an important challenge in CRC research is to identify biomarkers that are predictive of this response. In this study, we explored the potential of miRNAs, and the miRNA producing protein Dicer, as biomarkers that can predict chemo-sensitivity to fluoropyrimidine chemotherapy in patients with metastatic colorectal cancer (mCRC). We analyzed the levels of 22 miRNAs and the Dicer protein in primary tumors from patients with mCRC who were treated with first-line capecitabine monotherapy within the CAIRO trial of the Dutch Colorectal Cancer Group. Correlation between the expression status of miRNAs or Dicer in primary tumors and the progression free survival (PFS) were investigated. Patients with low expression of miR-143 in their primary tumor had increased median PFS compared to those with high expression of miR-143. Furthermore, FXYD3, an ion transport regulator and a putative target of miR-143, also showed an association with PFS. These findings warrant further studies to investigate the relationship between miR-143, FXYD3 and fluoropyrimidines, and the clinical utility of miR-143 as biomarker.

Long term follow up of the EORTC 18952 trial of adjuvant therapy in resected stage IIB-III cutaneous melanoma patients comparing intermediate doses of interferon-alpha-2b (IFN) with observation: Ulceration of primary is key determinant for IFN-sensitivity

BACKGROUND

We report on the long term outcome of the EORTC 18952 adjuvant interferon (IFN) trial in 1388 resected stage IIB/III melanoma patients and identify key predictive factors for outcome.

METHODS

We analysed outcome of the EORTC 18952 trial (4 weeks of IFN, 10 MU, 5 times/week for 4 weeks followed by 12 months IFN at 10 MU, 3 times/week versus followed by 24 months IFN at 5 MU 3 times/week versus observation) regarding relapse-free survival (RFS), distant metastasis-free interval/survival (DMFI/DMFS), and overall survival (OS), and analysed potential predictive factors of outcome.

FINDINGS

At a median follow-up of 11 years, the comparison of IFN 13 months versus IFN 25 months versus observation yielded estimated hazard ratios (HR) for RFS of 0.94 versus 0.84 (p = 0.06); for DMFI 0.95 versus 0.82 (p = 0.027); for DMFS 0.95 versus 0.84 (p = 0.07); and for OS 0·95 versus 0.84 (p = 0.08), respectively. The impact of treatment was greatest in the ulceration group, whereas in patients with non-ulcerated primaries the impact was null (HR ≥ 1.0). In patients with ulcerated melanoma the HR for IFN 13 months versus 25 months versus observation were for: RFS 0.82 (p = 0.16) versus 0.61 (p = 0.0008); DMFS 0.76 (p = 0.06) versus 0.57 (p = 0.0003); OS 0.80 (p = 0.13) versus 0.59 (p = 0.0007). In stage IIB/III-N1 (microscopic nodal involvement only) patients with ulcerated melanoma the HR estimates were for: RFS 0.85 versus 0.62; DMFS 0.80 versus 0.56; OS 0.77 versus 0.54.

CONCLUSIONS

This long term report of the EORTC 18952 trial demonstrates the superiority of the 25-month IFN schedule and defines ulceration of the primary as the overriding predictive factor for IFN-sensitivity.

Neo-adjuvant chemotherapy followed by surgery versus surgery alone in high-risk patients with resectable colorectal liver metastases: the CHARISMA randomized multicenter clinical trial

Background

Efforts to improve the outcome of liver surgery by combining curative resection with chemotherapy have failed to demonstrate definite overall survival benefit. This may partly be due to the fact that these studies often involve strict inclusion criteria. Consequently, patients with a high risk profile as characterized by Fong’s Clinical Risk Score (CRS) are often underrepresented in these studies. Conceptually, this group of patients might benefit the most from chemotherapy. The present study evaluates the impact of neo-adjuvant chemotherapy in high-risk patients with primary resectable colorectal liver metastases, without extrahepatic disease. Our hypothesis is that adding neo-adjuvant chemotherapy to surgery will provide an improvement in overall survival (OS) in patients with a high-risk profile.

Methods/Design

CHARISMA is a multicenter, randomized, phase III clinical trial. Patients will be randomized to either surgery alone (standard treatment, arm A) or to 6 cycles of neo-adjuvant oxaliplatin-based chemotherapy, followed by surgery (arm B). Patients must be ≥ 18 years of age with liver metastases of histologically confirmed primary colorectal carcinoma. Patients with extrahepatic metastases are excluded. Liver metastases must be deemed primarily resectable. Only patients with a CRS of 3–5 are eligible. The primary study endpoint is OS. Secondary endpoints are progression free survival (PFS), quality of life, morbidity of resection, treatment response on neo-adjuvant chemotherapy, and whether CEA levels can predict treatment response.

Discussion

CHARISMA is a multicenter, randomized, phase III clinical trial that will provide an answer to the question if adding neo-adjuvant chemotherapy to surgery will improve OS in a well-defined high-risk patient group with colorectal liver metastases.

Trial registration

The CHARISMA is registered at European Union Clinical Trials Register (EudraCT), number: 2013-004952-39, and in the “Netherlands national Trial Register (NTR), number: 4893.

Relationship among circulating tumor cells, CEA and overall survival in patients with metastatic colorectal cancer

BACKGROUND

We previously reported results of a prospective trial evaluating the significance of circulating tumor cells (CTCs) in patients with metastatic colorectal cancer (mCRC). This secondary analysis assessed the relationship of the CTC number with carcinoembryonic antigen (CEA) and overall survival.

PATIENTS AND METHODS

Patients with mCRC had CTCs measured at baseline and specific time points after the initiation of new therapy. Patients with a baseline CEA value ≥ 10 ng/ml and CEA measurements within ± 30 days of the CTC collection were included.

RESULTS

We included 217 patients with mCRC who had a CEA value of ≥ 10 ng/ml. Increased baseline CEA was associated with shorter survival (15.8 versus 20.7 months, P = 0.012). Among all patients with a baseline CEA value of ≥ 25 ng/ml, patients with low baseline CTCs (<3, n = 99) had longer survival than those with high CTCs (≥ 3, n = 58; 20.8 versus 11.7 months, P = 0.001). CTCs added prognostic information at the 3-5- and 6-12-week time points regardless of CEA. In a multivariate analysis, CTCs at baseline but not CEA independently predicted survival and both CTCs and CEA independently predicted survival at 6-12 weeks.

CONCLUSIONS

This study demonstrates that both CEA and CTCs contribute prognostic information for patients with mCRC.

Phase III trial comparing adjuvant treatment with pegylated interferon Alfa-2b versus observation: prognostic significance of autoantibodies--EORTC 18991

PURPOSE

Conflicting data have been reported concerning the prognostic value of autoimmune antibodies in patients with melanoma treated with adjuvant interferon alfa-2b (IFN). We evaluated the prognostic significance of autoantibodies in the European Organisation for Research and Treatment of Cancer 18991 trial, comparing long-term administration of pegylated IFN (PEG-IFN) with observation.

PATIENTS AND METHODS

Anticardiolipin, antithyroglobulin, and antinuclear antibodies were determined by enzyme-linked immunosorbent assays in 296 patients before random assignment and every 6 months after random assignment for up to 5 years. Prognostic impact of autoantibodies on recurrence-free survival (RFS) was assessed using the following three Cox models: a model that considered autoantibody appearance as a time-independent variable (model 1); a model that considered a patient to be autoantibody positive from the first positive test (model 2); and a model in which the most recent autoantibody test was used to define the status of the patient (model 3).

RESULTS

Patients who were autoantibody negative at baseline were analyzed (n = 220). Occurrence of autoantibodies during follow-up was higher in the PEG-IFN-treated patients (18% in the observation arm v 52% in the PEG-IFN arm). Autoantibody appearance was of prognostic importance by using model 1 (hazard ratio [HR] = 0.56; 95% CI, 0.36 to 0.87; P = .01). However, when guarantee-time bias was taken into account using model 2 (HR = 1.19; 95% CI, 0.75 to 1.88; P = .46) or method 3 (HR = 1.14; 95% CI, 0.71 to 1.83; P = .59), significance was lost. Results were similar when treatment groups were analyzed separately.

CONCLUSION

Appearance of autoimmune antibodies is neither a prognostic nor a predictive factor for improved outcome in patients with melanoma treated with PEG-IFN.

Predictive and prognostic markers for the outcome of chemotherapy in advanced colorectal cancer, a retrospective analysis of the phase III randomised CAIRO study

We have tested several biomarkers [dihydropyrimidine dehydrogenase (DPD), orotate phosphoribosyl transferase (OPRT), thymidine phosphorylase (TP), thymidylate synthase (TS) and excision cross-complementing gene (ERCC1)] for their prognostic and predictive value in relation to the outcome of chemotherapy in tumour tissues of 556 advanced colorectal cancer (ACC) patients who were randomised between sequential treatment and combination treatment in the CApecitabine, IRinotecan, Oxaliplatin (CAIRO) study. DPD expression showed a statistically significant predictive value for combination treatment with capecitabine plus irinotecan with low versus high values resulting in an improved median progression-free survival (PFS) and median overall survival (OS) of 8.9 (95% confidence interval (CI) 8.3-9.9) versus 7.2 months (95% CI 6.5-8.1, p=0.006), and 21.5 months (95% CI 17.9-26.5) versus 16.9 months (95% CI 13.0-19.1, p=0.04), respectively. In the overall patient population a high OPRT expression in stromal cells was a favourable prognostic parameter for OS, with 21.5 months (95% CI 17.9-27.3) versus 17.2 months (95% CI 15.1-18.6, p=0.036), respectively. A similar effect was observed for PFS. In a multivariate analysis that included known prognostic factors these results remained significant and also showed that a high OPRT expression in tumour cells was an unfavourable prognostic parameter for PFS and OS. In conclusion, in this largest study on capecitabine with or without irinotecan to date we found a predictive value of DPD expression. Our results on the prognostic value of OPRT expression warrant further studies on the role of stromal cells in the outcome of treatments. The divergent results of ours and previous studies underscore the complexity of these biomarkers and currently prevent the routine use of these markers in daily clinical practice.

Adjuvant interferon-alpha for melanoma revisited: news from old and new studies

Currently the data from 12 randomised phase III trials investigating the role of interferon-alpha (IFNalpha) in patients with stage II-III high-risk melanoma are available. The most prominent differences between these trials concern the dose of IFNalpha, the duration of IFNalpha administration, and the stage of disease. Some of these trials have not yet reached maturity, but despite this the positive results from some immature trials have attracted considerable attention. When only data from mature trials is considered, one may conclude that the use of high-dose IFNalpha does prolong disease-free survival (DFS) but not overall survival (OS). Combined data from low-dose IFNalpha trials does not suggest a benefit in either DFS or OS. A trial with intermediate-dose IFNalpha is still immature. Therefore currently the routine use of IFNalpha cannot be recommended outside the scope of clinical trials.

Phase I and pharmacokinetic study of E7070, a novel sulfonamide, given at a daily times five schedule in patients with solid tumors. A study by the EORTC-early clinical studies group (ECSG)

BACKGROUND

E7070 is a novel antitumor sulfonamide which blocks the cell in G1 phase. A phase I study was initiated to investigate the toxicity, maximum tolerated dose (MTD), and pharmacokinetics of this compound when administered intravenously at a daily times five schedule once every three weeks.

PATIENTS AND METHODS

Patients with solid tumors not amenable to standard forms of therapy were eligible. E7070 was administered to cohorts of 3-6 patients per dose level, the starting dose was 10 mg/m2/day. Dose escalation was performed according to a Fibonacci-like scheme.

RESULTS

Thirty-three patients entered the study. At E7070 doses of 200 and 160 mg/m2/day dose-limiting toxicities occurred, which consisted of febrile neutropenia, thrombocytopenia. diarrhea, skin folliculitis, asthenia, and stomatitis. The pharmacokinetic profile of E7070 at this schedule is non-linear with increasing dose. A partial response was observed in a patient with heavily pretreated breast cancer. Disease stabilizations and some minor responses were also documented.

CONCLUSIONS

Myelosuppression is the predominant toxicity of E7070. Clinical efficacy with E7070 was observed. The recommended dose for further studies at this daily times five schedule is 130 mg/m2/day.

Phase I and pharmacokinetic study of the orally administered farnesyl transferase inhibitor R115777 in patients with advanced solid tumors

R115777 is a novel selective inhibitor of farnesyl transferase, an enzyme that is involved in the proliferation of the malignant cell type. This study was designed to determine the toxicity, maximal tolerated dose and pharmacokinetics of R115777 when given orally b.i.d. for 28 days followed by 1-2 weeks of rest. Patients with advanced solid tumors for whom no standard therapy was available could enter the study. The starting dose of R115777 was 200 mg/dose and inter- as well as intra-patient dose escalations were performed with increments of 100 mg/dose. Nine patients entered the study and received in total 23 treatment cycles. A dose of 300 mg b.i.d. proved feasible with grade 4 neutropenia occurring in one of six patients who completed the first treatment cycle. Other toxicities were infrequent. Pharmacokinetic analysis demonstrated that peak plasma concentrations of 881+/-393 ng/ml were reached within 1-5 h. No accumulation of R115777 was observed over a 28-day period. The study was terminated based on these results together with the observation from a related phase I study in which higher doses of R115777 were associated with the frequent occurrence of grade 3-4 myelosuppression. We conclude that the recommended dose of R115777 given for 28 days followed by 1-2 weeks of rest is 300 mg b.i.d. Myelosuppression is the dose-limiting toxicity.

[Interferon for adjuvant therapy in melanoma; although approved, not indicated]

The Dutch melanoma group reconsidered their 1997 consensus statement on treatment of melanoma because new studies on adjuvant treatment with interferon(IFN)-alpha have been published. These have resulted in its registration for stage IIa; for stage IIb/III IFN-alpha was already registered. Overall survival should be the main endpoint of adjuvant clinical studies, especially when treatment is associated with toxicity. Since a benefit has not been unequivocally demonstrated in melanoma with Breslow thickness > 1.5 mm and/or regional lymph node metastases, there is no need to change the Dutch consensus statement. Drug registration authorities and medical professionals should cooperate more closely.

Dendritic cell-based vaccines: from mouse models to clinical cancer immunotherapy

B and T lymphocytes are the effectors of specific immunity. However, their function is critically dependent on dendritic cells (DC). DC are professional antigen presenting cells that both initiate and modulate the immune response. The recent breakthrough in the generation of DC from their progenitors has stimulated research on DC in both fundamental and clinical immunology. Objective immune response induction has now been reported in clinical studies using DC. In this review we discuss the development and potential of DC-based vaccines to induce antitumor immunity.

Analysis of melanoma cells in peripheral blood by reverse transcription-polymerase chain reaction for tyrosinase and MART-1 after mononuclear cell collection with cell preparation tubes: a comparison with the whole blood guanidinium isothiocyanate RNA isolation method

Melanoma cell detection in peripheral blood by tyrosinase reverse transcription-polymerase chain reaction (RT-PCR) is usually performed on RNA isolated from whole blood using a guanidinium isothiocyanate (GITC)/phenol extraction method or from Ficoll Hypaque isolated mononuclear cells. The first method contains environmentally harmful reagents, and the second is laborious in the preanalytical steps. Cell preparation tubes (CPTs) are ready-to-use Ficoll Hypaque-based tubes that avoid the time-consuming and critical loading on Ficoll Hypaque. We examined whether CPTs can be used to determine melanoma cell dissemination in peripheral blood. We first investigated whether melanoma cells were retained in the mononuclear cell layer. All six morphologically different melanoma cell lines studied in the spiking experiments were retained in the upper layer. In further experiments, we were able to detect low dilutions of added SK-MEL-28 cells more consistently after nested RT-PCR for tyrosinase or MART-1 in the RNA isolated from mononuclear cells from CPTs than from RNA isolated with the GITC method. In addition, RNA was extracted from paired blood samples from 24 analysable stage III and stage IV melanoma patients and analysed for the presence of tyrosinase and MART-1 RNA using both the CPT/RNeasy and the whole blood/GITC method. The quality of the CPT/RNeasy RNA was better than the RNA isolated from whole blood with GITC/phenol. However, the RT-PCR results were less unequivocal: MART-1 mRNA was more often detected with CPTIRNeasy compared with whole blood/GITC (six versus three), whereas tyrosinase mRNA was found less often in CPT/RNeasy RNA (two versus eight). Taken together these results suggest that the CPT isolation method is suitable for the isolation of mononuclear cells, including melanoma cells.

[Immunology in medical practice. XXV. Use of dendritic cells in the immunotherapy of cancer]

Dendritic cells are among the most efficient antigen-presenting cells of our immune system and they play a crucial role in immunity reactions such as the activation of T and B cells and the induction or maintenance of tolerance. New culture methods allow us to generate dendritic cells in sufficient numbers for further studies and for the preparation of antigen-loaded dendritic cells for clinical application in cancer patients. In animal studies immunization with antigen-loaded dendritic cells offered protection from growth of injected tumour cells. In experimental clinical studies in cancer patients with e.g. metastatic renal carcinoma, melanoma and B cell lymphoma some lasting remissions were observed after administration of antigen-loaded dendritic cells. Side effects were minor. Unanswered questions on tumour vaccines with antigen-loaded dendritic cells concern specific matters, such as optimal culture methods and antigen loading, and general matters, such as dose, frequency, duration and route of administration. Also, no method is currently available by which the in vivo immune response can be measured accurately.

Melanoma-inhibiting activity (MIA) mRNA is not exclusively transcribed in melanoma cells: low levels of MIA mRNA are present in various cell types and in peripheral blood

The detection of minimal amounts of melanoma cells by tyrosinase reverse transcription polymerase chain reaction (RT-PCR) is seriously hampered by false negative reports in blood of melanoma patients with disseminated melanoma. Therefore, additional assays which make use of multiple melanoma markers are needed. It has been shown that introduction of multiple markers increases the sensitivity of detection. Melanoma inhibitory activity (MIA) is one such melanoma-specific candidate gene. To test the specificity of MIA PCR, we performed 30 and 60 cycles of PCR with two different sets of MIA specific primers on 19 melanoma and 16 non-melanoma cell lines. MIA mRNA was detected in 16 out of 19 melanoma cell lines and in seven out of 16 non-melanoma cell lines after 30 cycles of PCR. However, MIA mRNA could be detected in all cell lines after 60 cycles of PCR. Also, in 14 out of 14 blood samples of melanoma patients, five out of six blood samples of non-melanoma patients and in seven out of seven blood samples of healthy volunteers, MIA mRNA was detected after 60 cycles of PCR, whereas no MIA PCR product could be detected in any of the blood samples after 30 cycles of PCR. We conclude that low levels of MIA transcripts are present in various normal and neoplastic cell types. Therefore, MIA is not a suitable marker gene to facilitate the detection of minimal amounts of melanoma cells in blood or in target organs of the metastatic process.

Biodistribution and vaccine efficiency of murine dendritic cells are dependent on the route of administration

Dendritic cells (DCs) are professional antigen-presenting cells, well equipped to initiate an immune response. Currently, tumor antigen-derived peptide loaded DCs are used in clinical vaccination in cancer patients. However, the optimal dose and route of administration of a DC vaccine still remain to be determined. Using indium-111-labeled DCs, we investigated whether the route of administration does affect the biodistribution of DCs in lymphoid organs and whether it influences the outcome of DC vaccination in the B16 mouse melanoma tumor model. The results demonstrate that i.v. injected DCs mainly accumulate in the spleen, whereas s.c. injected DCs preferentially home to the T-cell areas of the draining lymph nodes. Using tyrosinase-related protein-2-derived peptide-loaded DC vaccination in a fully autologous B16 melanoma tumor model, we observed a delay in tumor growth, improved survival as well as increased antitumor cytotoxic T-cell reactivity after s.c. vaccination as compared to i.v. vaccination. These data demonstrate that optimal induction of antitumor reactivity against the autologous melanocyte differentiation antigen tyrosinase-related protein-2-derived peptide occurs after s.c. vaccination and correlates with the preferential accumulation of DCs in the T-cell areas of lymph nodes.

Phase I and pharmacologic study of oral (PEG-1000) 9-aminocamptothecin in adult patients with solid tumors

PURPOSE

9-Amino-20(S)-camptothecin (9-AC) is a specific inhibitor of topoisomerase-I. Recently, a bioavailability of approximately 48% for the oral PEG-1000 formulation was reported. We conducted a phase I and pharmacokinetic study of the oral PEG-1000 formulation of 9-AC to define the maximum-tolerated dose, toxicity profiles, pharmacokinetic-dynamic relationships, and preliminary antitumor activity in patients with solid tumors.

PATIENTS AND METHODS

Patients were treated with oral (PEG-1000) 9-AC given once a day for 7 or 14 days at doses ranging from 0.25 to 1.1 mg/m(2)/d; cycles were repeated every 21 days. For pharmacokinetic analysis, plasma sampling was performed on days 1 and 6 or 8 of the first course using a validated high-performance liquid chromatographic assay.

RESULTS

Thirty patients were entered onto the study; three patients were not assessable for toxicity and response. Twenty-seven patients received a total of 89 courses. The dose-limiting toxicities (DLTs) were myelosuppression and diarrhea at a dose of 1.1 mg/m(2)/d for 14 days. Pharmacokinetics showed a substantial interpatient variation of the area under the plasma concentration-time curve (AUC) of 9-AC. The intrapatient variability was extremely small. A significant correlation was observed between the percentage decrease in WBC count and the AUC of 9-AC lactone (r(2) = 0.86). One partial response was noted in a patient with metastatic colorectal cancer.

CONCLUSION

DLTs in this phase I study of oral 9-AC daily for 14 days every 21 days were myelosuppression and diarrhea. The recommended dose for phase II studies is 0.84 mg/m(2)/d. In view of the substantial interpatient variability in AUC and the availability of a limited sampling model, a pharmacokinetic guided phase II study should be considered.

Prediction of the systemic exposure to oral 9-amino-20(S)-camptothecin using single-sample analysis

The purpose of this study was to develop and validate limited-sampling strategies for prediction of the area under the plasma-concentration time curves (AUCs) of the lactone and total (i. e., lactone plus carboxylate) forms of the novel topoisomerase-I inhibitor 9-amino-20(S)-camptothecin (9-AC). Complete pharmacokinetic curves for both drug species were obtained from 32 patients who received the drug orally in a clinical phase I setting at dose levels ranging from 0.25 to 1.10 mg/m2. The concentrations of the lactone and carboxylate forms of 9-AC in plasma were measured by HPLC. Using data from 20 randomly selected patients, forward-stepwise multivariate regression analysis was used to generate modeling strategies incorporating data from one, two, or three plasma samples. The simultaneous optimal prediction of both 9-AC lactone and 9-AC total AUCs was obtained with sample time points at 0.33, 3.0, and 11.0 h after drug dosing. Validation of the models on an independent data set comprising data of the remaining 12 patients demonstrated that 9-AC lactone and 9-AC total AUCs could be predicted sufficiently unbiased and precise using one and two time points: [AUC (ng. h/ml) = 7.103*C3 + 4.333] for 9-AC lactone and [AUC (ng. h/ml) = 9.612*C3 + 13.77*C11 - 44.11] for 9-AC total, where C3 and C11 represent the 9-AC plasma concentrations in ng/ml at 3 and 11 h after drug dosing. Application of the proposed models will be valuable in the determination of 9-AC population pharmacokinetics and permits treatment optimization for patients on the basis of individual pharmacokinetic characteristics through restricted drug monitoring in clinical routines.

Reproducibility of detection of tyrosinase and MART-1 transcripts in the peripheral blood of melanoma patients: a quality control study using real-time quantitative RT-PCR

In recent years, large discrepancies were described in the success rate of the tyrosinase reverse transcription polymerase chain reaction (RT-PCR) for detecting melanoma cells in the peripheral blood of melanoma patients. We present a quality control study in which we analysed the reproducibility of detection of tyrosinase and MART-1 transcripts in 106 blood samples from 68 melanoma patients (mainly stages III and IV). With this study, we aimed to improve insight in the reproducibility of a RT-PCR for the detection of (minimal) amounts of circulating melanoma cells. We performed two reverse transcriptions on each mRNA sample and performed tyrosinase and MART-1 nested PCRs in duplicate per cDNA sample. Thus, four tyrosinase and four MART-1 measurements were performed per blood sample. In our study, the majority of blood samples was negative for tyrosinase (80%) or MART-1 (66%). Only four samples were positive in all four determinations for tyrosinase and seven for MART-1. Variable results (1-3 times positive results) were obtained for tyrosinase and MART-1 in 16% and 27% respectively. MART-1 PCR had a better performance than tyrosinase PCR. Sensitivity increased when both markers were used. We reasoned that the low number of melanoma marker PCR-positive blood samples can be explained by differences in mRNA quality. By using real-time quantitative PCR, we found that this was not the case: amplification of porphobilinogen deaminase (PBGD), a low copy household gene, was not different in blood samples in which a melanoma marker was not detected from groups in which this marker was detected more or less consistently (1-4 times). When applying real-time quantitative PCR for tyrosinase and MART-1, we found that a low amount of SK-MEL-28 cell equivalents was present in the blood of melanoma patients, with a higher number of equivalents in the group with a consistently positive result. We conclude that low reproducibility of a repeated assay for the detection of circulating melanoma cells is not caused by differences in mRNA quality between the samples, but due to low numbers of amplifiable target mRNA molecules in the mRNA sample. Use of more than one marker and repetition of the assay will increase the probability of finding positive PCR results.

Phase I study of Carzelesin (U-80,244) given (4-weekly) by intravenous bolus schedule

Carzelesin is a cyclopropylpyrroloindole analogue which acts as a DNA-sequence-specific alkylating agent. In this phase I study, Carzelesin was given as a 4-weekly 10 min i.v. infusion to 51 patients with advanced solid tumours. Patients received a median of two courses (range 1-5) at one of nine dose levels: 24, 48, 96, 130, 150, 170, 210, 250 and 300 microg m(-2). According to NCI-CTC criteria, non-haematological toxicities (grade 1/2) included fever, nausea and vomiting, mucositis and anorexia, none of which was clearly dose related. The dose-limiting toxicity was haematological and consisted mainly of neutropenia and to a lesser extent thrombocytopenia. From the dose level 150 microg m(-2), the haematological toxicity (particularly thrombocytopenia) was delayed in onset, prolonged and cumulative in some patients. In several courses, double WBC nadirs occurred. The maximum tolerated dose for a single course was 300 microg m(-2). From the dose level 170 microg m(-2), the intended dose intensity could not be delivered to most patients receiving > 2 courses owing to cumulative haematological toxicity. The dose level with the best dose intensity for multiple courses was 150 microg m(-2). The pharmacokinetics of Carzelesin and its metabolites (U-76,073; U-76,074) have been established in 31 patients during the first course of treatment using a HPLC method. Carzelesin exhibited linear pharmacokinetics. The concentration of U-76,074 (active metabolite) extended above the lower limit of quantitation (1 ng ml(-1)) for short periods of time and only at the higher dose levels. There was no relationship between neutropenia and the AUC of the prodrug Carzelesin, but the presence of detectable plasma levels of the active metabolite U-76,074 was usually associated with a substantial decrease in ANC values.

Clinical activity and benefit of irinotecan (CPT-11) in patients with colorectal cancer truly resistant to 5-fluorouracil (5-FU)

The aim of this prospective study was to assess the efficacy, clinical benefit and safety of CPT-11 (irinotecan) in patients with stringently-defined 5-fluorouracil-resistant metastatic colorectal cancer (CRC). 107 patients with documented progression of metastatic CRC during 5-FU were treated with CPT-11 350 mg/m2 once every 3 weeks in a multicentre phase II study. Tumour response and toxicity were assessed using WHO criteria. Changes in performance status (PS), weight and pain were also measured. The WHO response rate was 13/95 (13.7%, 95% CI 7.5% to 22.3%) eligible patients with a median duration of response of 8.5 months (37 weeks, range: 18-53+). There was also a high rate of disease stabilisation (44.2%) with a median duration of 4.8 months. The probability of being free of progression at 4 months was 50%. Median survival from first administration of CPT-11 was 10.4 months or 45 weeks (range: 3-66+ weeks). There was weight stabilisation or gain in 81% (73/90) of patients, a favourable outcome in PS in 91% (82/90) (improvement of WHO PS 2 or stabilisation of PS 0-1), and pain relief in 54% (26/48). There were no toxic deaths. Neutropenia was short-lasting and non-cumulative. Diarrhoea grade > or = 3 occurred in 7% of cycles and 28/107 (26%) of patients. CPT-11 350 mg/m2 once every 3 weeks has an encouraging degree of activity in progressive metastatic CRC truly resistant to 5-FU with a relatively high rate of tumour growth control translated into clinical benefit. The toxicity profile of CPT-11 is becoming better understood and has been considerably improved.

Randomised trial of irinotecan plus supportive care versus supportive care alone after fluorouracil failure for patients with metastatic colorectal cancer

BACKGROUND

In phase II studies, irinotecan is active in metastatic colorectal cancer, but the overall benefit has not been assessed in a randomised clinical trial.

METHODS

Patients with proven metastatic colorectal cancer, which had progressed within 6 months of treatment with fluorouracil, were randomly assigned either 300-350 mg/m2 irinotecan every 3 weeks with supportive care or supportive care alone, in a 2:1 ratio.

FINDINGS

189 patients were allocated irinotecan and supportive care and 90 supportive care alone. The mean age of the participants was 58.8 years; 181 (65%) were men and 98 (35%) were women. WHO performance status was 0 in 79 (42%) patients, 1 in 77 (41%) patients, and 2 in 32 (17%) patients. Tumour-related symptoms were present in 134 (71%) patients and weight loss of more than 5% was seen in 15 (8%) patients. With a median follow-up of 13 months, the overall survival was significantly better in the irinotecan group (p=0.0001), with 36.2% 1-year survival in the irinotecan group versus 13.8% in the supportive-care group. The survival benefit, adjusted for prognostic factors in a multivariate analysis, remained significant (p=0.001). Survival without performance-status deterioration (p=0.0001), without weight loss of more than 5% (p=0.018), and pain-free survival (p=0.003) were significantly better in the patients given irinotecan. In a quality-of-life analysis, all significant differences, except on diarrhoea score, were in favour of the irinotecan group.

INTERPRETATION

Our study shows that despite the side-effects of treatment, patients who have metastatic colorectal cancer, and for whom fluorouracil has failed, have a longer survival, fewer tumour-related symptoms, and a better quality of life when treated with irinotecan than with supportive care alone.

Response rate and prognostic factors of recurrent oligodendroglioma treated with procarbazine, CCNU, and vincristine chemotherapy. Dutch Neuro-oncology Group

OBJECTIVES

To determine the response rate and factors correlated with response of oligodendroglial tumors to procarbazine, lomustine (CCNU), and vincristine (PCV) chemotherapy.

DESIGN

Retrospective, observational multicenter study.

METHODS

Patients treated with PCV or intensified PCV chemotherapy for a recurrent oligodendroglial tumor after surgery and radiation therapy with measurable disease were retrospectively evaluated for response. A 50% reduction in cross-sectional enhancing tumor area was considered a partial response. Stabilized or responding patients received six cycles of PCV unless unacceptable toxicity occurred.

RESULTS

Fifty-two patients were included; median time to progression (MTP) for the entire group was 10 months. In 17% of patients a complete response (MTP, 25 months) was obtained, and in 46% a partial response (MTP, 12 months) was obtained. Median overall survival was 20 months. Although treatment was discontinued for toxicity in seven patients, it was generally well tolerated. The intensified PCV regimen was more toxic. Patients initially presenting with seizures and patients with tumor necrosis in histologic specimens had a better response rate in contrast to patients who had their first relapse within 1 year of first treatment (surgery and radiation therapy).

CONCLUSIONS

Oligodendroglial tumors are chemosensitive, but most patients will have relapsed after 12 to 16 months. New studies must aim at improving initial treatment and second-line chemotherapy.

Results of interleukin-2-based treatment in advanced melanoma: a case record-based analysis of 631 patients

PURPOSE

In patients with stage IV melanoma, durable responses have been reported with treatment regimens that involve high-dose interleukin-2 (IL-2). We analyze long-term results of 631 melanoma patients from 12 institutions who had received IL-2 alone, in combination with interferon alfa 2a or 2b (IFNalpha), or with cytotoxic drugs.

METHODS

Case records that contained pretreatment parameters, response data, and updated survival information were collected. After univariate analysis, the multivariate evaluation of the impact of pretreatment parameters on response and survival was performed by logistic regression and Cox's regression, respectively.

RESULTS

Patients were divided into four groups according to treatment: IL-2 alone (n=117), IL-2 and chemotherapy (n=49), IL-2 and IFNalpha (n=153), and IL-2, chemotherapy, and IFNalpha (n=312). The median survival of all patients was 10.5 months and the 2- and 5-year survival rates were 19.9% and 10.4%, respectively. Independent prognostic factors for response and survival were entirely different, treatment group being the only significant factor for response, and serum lactate dehydrogenase (LDH), metastatic site, and performance predicting survival. The addition of IFNalpha to IL-2 was associated with prolonged survival, but the effect of additional chemotherapy was less obvious.

CONCLUSION

Serum LDH, metastatic site, and performance status are useful stratification factors for randomized trials in metastatic melanoma. The improved long-term survival rates observed in melanoma patients treated with IL-2/IFNalpha-containing regimens are notable in contrast to the reported 5-year survival rates of 2% to 6% achieved with chemotherapy, but because selection bias cannot be ruled out, the impact of IL-2, as well as all other components of the treatment regimens, on survival needs to be confirmed in prospective randomized trials.

New drugs in the treatment of colorectal carcinoma

BACKGROUND

Treatment with 5-fluorouracil (5-FU) plus leucovorin has been the unofficial standard therapy for patients with colorectal carcinoma (CRC) for more than a decade; however, the optimal dose and schedule remain a matter of debate. Recently several new drugs have shown activity in this disease. These include irinotecan (CPT-11); oxaliplatin; the thymidylate synthase inhibitors raltitrexed, uracil/tegafur (UFT), capecitabine, and S-1; the biochemical modulators trimetrexate and 5-ethynyluracil; and the monoclonal antibody 17-1A.

METHODS

The results of clinical trials with these and other new agents, as well as their current status and main characteristics, were reviewed.

RESULTS

Several of these agents, some with a novel mechanism of action, show promising activity in CRC. In combination with 5-FU and leucovorin, trimetrexate showed encouraging response rates in Phase II studies. Other interesting agents include capecitabine, UFT, and S-1. The biochemical modulator 5-ethynyluracil may allow the oral administration of 5-FU; however, results of Phase II clinical trials are not yet available. CPT-11 is in the most advanced stage of development and, based on consistent data generated in extensive Phase II studies, currently appears to be a reasonable choice for 5-FU-resistant or refractory disease. Another promising agent is oxaliplatin, which showed activity as first-line and second-line treatment.

CONCLUSIONS

Several new agents have shown promise in the treatment of CRC, and changes in the standard treatment of advanced or high risk CRC appear likely in the near future.

Pharmacokinetics and bioavailability of oral 9-aminocamptothecin capsules in adult patients with solid tumors

Preclinical studies indicate enhanced antitumor activity of 9-amino-20(S)-camptothecin (9-AC) when it is administered in a manner that provides prolonged systemic exposure. In view of this observation, the pharmacokinetics and oral bioavailability of 9-AC polyethylene glycol 1000 capsules were evaluated in 12 patients with solid tumors. Patients were randomized to receive either 1.5 mg/m2 9-AC p.o. on day 1 and 1.0 mg/m2 9-AC i.v. on day 8 or vice versa. Serial plasma samples were collected up to 55 h after dosing and analyzed for 9-AC by liquid chromatography. Plasma concentrations of the lactone and carboxylate forms of 9-AC rapidly reached an equilibrium, with the active lactone accounting for < 10% of total drug at the terminal disposition phase. The drug demonstrated peak levels at 1.2 h and an overall bioavailability of 48.6+/-17.6% (range, 24.5-80.4%), indicating significant systemic exposure to the drug, which may enable chronic oral treatment.

5-Fluorouracil in colorectal cancer: rationale and clinical results of frequently used schedules

Colorectal cancer is one of the most frequent cancers in the western world. Approximately half of the patients will die of their disease because of metastases. The most active cytotoxic agent used to date is 5-fluorouracil (5-FU). However, clinical responses are achieved only in a minority of patients. Based on the current knowledge of the mechanism of action of 5-FU, many attempts have been made to improve the clinical results. These include the use of biochemical modulators and different methods of administration, and these are the subject of this review. Specifically, of five different modulators, i.e. leucovorin, methotrexate, interferon-alpha, N-(phosphonacetyl)-L-aspartate and trimetrexate glucuronate, the biochemical background and the clinical results obtained with these modulators are discussed. In order to get more insight, an overview of the 5-FU metabolism has been given. In addition, the different methods of systemic administration of 5-FU as well as possible mechanisms underlying 5-FU resistance are described.

A clinical pharmacokinetics study of carzelesin given by short-term intravenous infusion in a phase I study

We investigated the pharmacokinetic behavior of carzelesin in 31 patients receiving this drug by 10-min intravenous infusion in a Phase I clinical trial, which was conducted at institutions in Nijmegen (institution 1) and Brussels (institution 2). The dose steps were 24, 48, 96, 130, 150, 170, 210, 250, and 300 microg/m2. Carzelesin is a cyclopropylpyrroloindole prodrug that requires metabolic activation via U-76,073 to U-76,074. The lower limit of quantitation (LLQ) of the high-performance liquid chromatography (HPLC) method used in this study was 1 ng/ml for the parent drug and its metabolic products. Carzelesin was rapidly eliminated from plasma (elimination half-life 23 +/- 9 min; mean value +/- SD). At all dose levels, U-76,073 was found as early as in the first samples taken after the start of the infusion. However, the concentration of U-76,074 exceeded the LLQ for only short periods and only at the higher dose levels. Although the plasma levels of all three compounds were well above the respective IC50 values obtained by in vitro clonogenic assays, they were much lower than those observed in a preclinical study in mice. There was a substantial discrepancy in the mean plasma clearance observed between patients from institution 1 (7.9 +/- 2.1 l h[-1] m[-2]) and those from institution 2 (18.4 +/- 13.6 l h[-1] m[-2]; P = 0.038), probably reflecting problems with drug administration in the latter institution. The results recorded for patients in institution 1 indicated that the AUC increased proportionately with increasing doses. There was a good correlation between the maximal plasma concentration and the AUC, enabling future monitoring of drug exposure from one timed blood sample. Urinary excretion of carzelesin was below 1% of the delivered dose.

The use of interferon-alpha in the treatment of cutaneous melanoma: a review

During the past few years significant progress has been made in the treatment of cutaneous melanoma. These developments often involve the use of interferon-alpha (IFNalpha). Promising results have been reported in high risk patients using adjuvant treatment with high dose IFNalpha. A confirmatory trial of high dose IFNalpha and several adjuvant trials using low or intermediate dose IFNalpha are ongoing, and currently a standard regimen cannot be defined. High response rates have been reported in patients with metastatic disease with combination chemoimmunotherapy schedules. Randomized trials have to be performed in order to demonstrate a survival benefit over less toxic regimens. In this paper the current status of IFNalpha in the treatment of cutaneous melanoma is reviewed.