The value of post-operative chemotherapy after chemoradiotherapy in patients with high-risk locally advanced rectal cancer-results from the RAPIDO trial

BACKGROUND

Pre-operative chemoradiotherapy (CRT) rather than radiotherapy (RT) has resulted in fewer locoregional recurrences (LRRs), but no decrease in distant metastasis (DM) rate for patients with locally advanced rectal cancer (LARC). In many countries, patients receive post-operative chemotherapy (pCT) to improve oncological outcomes. We investigated the value of pCT after pre-operative CRT in the RAPIDO trial.

PATIENTS AND METHODS

Patients were randomised between experimental (short-course RT, chemotherapy and surgery) and standard-of-care treatment (CRT, surgery and pCT depending on hospital policy). In this substudy, we compared curatively resected patients from the standard-of-care group who received pCT (pCT+ group) with those who did not (pCT- group). Subsequently, patients from the pCT+ group who received at least 75% of the prescribed chemotherapy cycles (pCT ≥75% group) were compared with patients who did not receive pCT (pCT-/- group). By propensity score stratification (PSS), we adjusted for the following unbalanced confounders: age, clinical extramural vascular invasion, distance to the anal verge, ypT stage, ypN stage, residual tumour, serious adverse event (SAE) and/or readmission within 6 weeks after surgery and SAE related to pre-operative CRT. Cumulative probability of disease-free survival (DFS), DM, LRR and overall survival (OS) was analysed by Cox regression.

RESULTS

In total, 396/452 patients had a curative resection. The number of patients in the pCT+, pCT >75%, pCT- and pCT-/- groups was 184, 112, 154 and 149, respectively. The PSS-adjusted analyses for all endpoints demonstrated hazard ratios between approximately 0.7 and 0.8 (pCT+ versus pCT-), and 0.5 and 0.8 (pCT ≥75% versus pCT-/-). However, all 95% confidence intervals included 1.

CONCLUSIONS

These data suggest a benefit of pCT after pre-operative CRT for patients with high-risk LARC, with approximately 20%-25% improvement in DFS and OS and 20%-25% risk reductions in DM and LRR. Compliance with pCT additionally reduces or improves all endpoints by 10%-20%. However, differences are not statistically significant.

In vitro discovery of promising anti-cancer drug combinations using iterative maximisation of a therapeutic index

In vitro-based search for promising anti-cancer drug combinations may provide important leads to improved cancer therapies. Currently there are no integrated computational-experimental methods specifically designed to search for combinations, maximizing a predefined therapeutic index (TI) defined in terms of appropriate model systems. Here, such a pipeline is presented allowing the search for optimal combinations among an arbitrary number of drugs while also taking experimental variability into account. The TI optimized is the cytotoxicity difference (in vitro) between a target model and an adverse side effect model. Focusing on colorectal carcinoma (CRC), the pipeline provided several combinations that are effective in six different CRC models with limited cytotoxicity in normal cell models. Herein we describe the identification of the combination (Trichostatin A, Afungin, 17-AAG) and present results from subsequent characterisations, including efficacy in primary cultures of tumour cells from CRC patients. We hypothesize that its effect derives from potentiation of the proteotoxic action of 17-AAG by Trichostatin A and Afungin. The discovered drug combinations against CRC are significant findings themselves and also indicate that the proposed strategy has great potential for suggesting drug combination treatments suitable for other cancer types as well as for other complex diseases.

Differences in trial knowledge and motives for participation among cancer patients in phase 3 clinical trials

While participants in clinical oncology trials are essential for the advancement of cancer therapies, factors decisive for patient participation have been described but need further investigation, particularly in the case of phase 3 studies. The aim of this study was to investigate differences in trial knowledge and motives for participation in phase 3 clinical cancer trials in relation to gender, age, education levels and former trial experience. The results of a questionnaire returned from 88 of 96 patients (92%) were analysed using the Mann-Whitney U-test. There were small, barely relevant differences in trial knowledge among patients when stratified by gender, age or education. Participants with former trial experience were less aware about the right to withdraw. Male participants and those aged ≥65 years were significantly more motivated by a feeling of duty, or by the opinions of close ones. Men seem more motivated than women by external factors. With the awareness that elderly and single male participants might be a vulnerable group and participants with former trial experience are less likely to be sufficiently informed, the information consent process should focus more on these patients. We conclude that the informed consent process seems to work well, with good results within most subgroups.

Drug screen in patient cells suggests quinacrine to be repositioned for treatment of acute myeloid leukemia

To find drugs suitable for repositioning for use against leukemia, samples from patients with chronic lymphocytic, acute myeloid and lymphocytic leukemias as well as peripheral blood mononuclear cells (PBMC) were tested in response to 1266 compounds from the LOPAC¹²⁸⁰ library (Sigma). Twenty-five compounds were defined as hits with activity in all leukemia subgroups (<50% cell survival compared with control) at 10 μM drug concentration. Only one of these compounds, quinacrine, showed low activity in normal PBMCs and was therefore selected for further preclinical evaluation. Mining the NCI-60 and the NextBio databases demonstrated leukemia sensitivity and the ability of quinacrine to reverse myeloid leukemia gene expression. Mechanistic exploration was performed using the NextBio bioinformatic software using gene expression analysis of drug exposed acute myeloid leukemia cultures (HL-60) in the database. Analysis of gene enrichment and drug correlations revealed strong connections to ribosomal biogenesis nucleoli and translation initiation. The highest drug–drug correlation was to ellipticine, a known RNA polymerase I inhibitor. These results were validated by additional gene expression analysis performed in-house. Quinacrine induced early inhibition of protein synthesis supporting these predictions. The results suggest that quinacrine have repositioning potential for treatment of acute myeloid leukemia by targeting of ribosomal biogenesis.

Hope for a cure and altruism are the main motives behind participation in phase 3 clinical cancer trials

It is necessary to carry out randomised clinical cancer trials (RCTs) in order to evaluate new, potentially useful treatments for future cancer patients. Participation in clinical trials plays an important role in determining whether a new treatment is the best therapy or not. Therefore, it is important to understand on what basis patients decide to participate in clinical trials and to investigate the implications of this understanding for optimising the information process related to study participation. The aims of this study were to (1) describe motives associated with participation in RCTs, (2) assess if patients comprehend the information related to trial enrolment, and (3) describe patient experiences of trial participation. Questionnaires were sent to 96 cancer patients participating in one of nine ongoing clinical phase 3 trials at the Department of Oncology, Uppsala University Hospital in Sweden. Eighty-eight patients completed the questionnaire (response rate 92%); 95% of these were patients in adjuvant therapy and 5% participated in clinical trials on palliative care. Two main reasons for participation were identified: personal hope for a cure and altruism. Patients show adequate understanding of the information provided to them in the consent process and participation entails high patient satisfaction.

Intraoperative hyperthermic versus postoperative normothermic intraperitoneal chemotherapy for colonic peritoneal carcinomatosis: a case-control study

BACKGROUND

Cytoreductive surgery and intraperitoneal chemotherapy has improved prognosis in patients with peritoneal carcinomatosis. The main modes of intraperitoneal chemotherapy treatment are peroperative hyperthermic intraperitoneal chemotherapy (HIPEC) and normothermic sequential postoperative intraperitoneal chemotherapy (SPIC). The aim of this study was to compare HIPEC and SPIC with respect to overall survival, disease-free survival, morbidity, and mortality in patients with peritoneal carcinomatosis from colon cancer.

PATIENTS AND METHODS

A matched case-control study was conducted in patients with surgical macroscopic complete removal of carcinomatosis; matching was according to the peritoneal cancer index score. Thirty-two patients were included, 16 in each group (HIPEC and SPIC). Overall survival, disease-free survival, morbidity, mortality, and clinicopathological parameters were compared.

RESULTS

Median overall survival was 36.5 months in the HIPEC group and 23.9 months in the SPIC group (P = 0.01). Median disease-free survival for these groups was 22.8 (HIPEC) and 13.0 months (SPIC; P = 0.02). Morbidity was not statistically different, 19% in SPIC and 37% in HIPEC. Postoperative mortality was observed in one patient in each group.

CONCLUSION

HIPEC was associated with improved overall survival and disease-free survival compared with SPIC at similar morbidity and mortality, suggesting that HIPEC is the treatment of choice in colonic peritoneal carcinomatosis.

The initial change in tumor size predicts response and survival in patients with metastatic colorectal cancer treated with combination chemotherapy

BACKGROUND

To determine whether the change in tumor diameters at the first follow-up computed tomography (CT) examination after baseline examination (first change) correlates with outcome in patients with metastatic colorectal cancer (mCRC) treated with combination chemotherapy.

PATIENTS AND METHODS

The first change was analyzed in a multicenter randomized phase III trial (Nordic VI, N = 567) comparing first-line irinotecan with either bolus or infused 5-fluorouracil. Cox proportional hazards multiple regression model and Kaplan-Meier survival analyses after correction for guarantee-time bias were carried out to evaluate correlations between first change, objective response according to RECIST 1.0, progression-free survival (PFS), and overall survival (OS).

RESULTS

The hazard ratios for PFS and OS decreased along with first change. A decrease between 10% and <30%, albeit RECIST does not regard this as a partial response, was a positive prognostic factor for PFS and OS. Patients who had new lesions or unequivocal progression of nonmeasurable lesions had a worse prognosis than those with only an increase in size of >20%.

CONCLUSIONS

The change in tumor size at the first follow-up CT is strongly prognostic for PFS and OS in mCRC.

An explorative study on the clinical utility of baseline and serial serum tumour marker measurements in advanced upper gastrointestinal cancer

The value of early tumour marker changes during palliative chemotherapy in patients with upper gastrointestinal adenocarcinoma (UGIA) is unclear. Seventy-three patients with advanced UGIA were randomised to receive 45 mg/m2 docetaxel or 180 mg/m2 irinotecan with 5-FU/leucovorin. After every 2nd course the patients were crossed over to the other regimen. Serum was sampled before start of chemotherapy and every 2nd week during 8 weeks for CEA, TPA, TPS, CA72-4, CA19-9 and CA242 measurements. Eighteen patients (25%) had partial response (PR) and 21 patients had stable disease for at least 4 months (SD4). All baseline marker levels, except CA72-4, correlated with time to progression and survival. Patients with normal levels, except CA72-4, also had more clinical responses (PR+SD4) than patients with elevated values. Tumour marker changes early during treatment provided modest predictive information for tumour response and survival. A model combining baseline level, the change and the interaction between them gave the best prediction of outcome, however, insignificantly better than baseline level for all markers except CA242. Baseline tumour marker levels provide prognostic information for patients with UGIA on palliative chemotherapy. Early changes generally failed to provide accurate information for tumour response and survival.

EGFR, HER2 and HER3 expression in primary colorectal carcinomas and corresponding metastases: Implications for targeted radionuclide therapy

Members of the epidermal growth factor receptor, EGFR, family are interesting as targets for radionuclide therapy using targeting agents labeled with α- or β-emitting radionuclides, especially when EGFR-positive colorectal carcinomas, CRC, are resistant to EGFR inhibiting agents like cetuximab and various tyrosine kinase inhibitors. The expression of EGFR, HER2 and HER3 was therefore analyzed in CRC samples from primary tumors, corresponding lymph node metastases and, in a few cases, liver metastases. The expression of HER2 and EGFR was scored from immunohistochemical preparations using the HercepTest criteria 0, 1+, 2+ or 3+ for cellular membrane staining while HER3 expression was scored as no, weak or strong cytoplasm staining. Material from 60 patients was analyzed. The number of EGFR 2+ or 3+ positive primary tumors was 16 out of 56 (29%) and for lymph node metastases 8 out of 56 (14%) whereas only one out of nine (11%) liver metastases were positive. Thus, there was lower EGFR positivity in the metastases. Only one among 53 patients was strongly HER2 positive and this in both the primary tumor and the metastasis. Eight out of 49 primary tumors (16%) were strongly HER3 positive and the corresponding numbers for lymph node metastases were 9 out of 49 (18%) and for liver metastases 2 out of 9 (22%). The observed number of strongly EGFR positive cases was somewhat low but EGFR might be, for the cases with high EGFR expression in metastases, a target for radionuclide therapy. HER2 seems not to be of such interest due to rare expression, neither HER3 due to mainly expression in the cytoplasm. The requirements for successful EGFR targeted radionuclide therapy are discussed, as well as patient inclusion criteria related to radionuclide therapy.

Interactions of zoospores of Ulva linza with arginine-rich oligopeptide monolayers

We recently reported on the strong interactions of zoospores of the green alga, Ulva linza with an arginine-rich oligopeptide self-assembled monolayer (SAM) [Biofouling 2008, 24, 303-312], where the arginine-rich peptide induced not only high spore settlement, but also a form of abnormal settlement, or "pseudo-settlement", whereby a proportion of spores do not go through the normal process of surface exploration, adhesive exocytosis, and loss of flagella. Further, it was demonstrated that both the total number of settled spores and the fraction of pseudosettled spores were related to the surface density of the arginine-rich peptide. Here we present a further investigation of the interactions of zoospores of Ulva with a set of oligomeric, de novo designed, arginine-rich peptides, specifically aimed to test the effect of peptide primary structure on the interaction. Via variations in the peptide length and by permutations in the amino acid sequences, we gain further insight into the spore-surface interactions. The interpretation of the biological assays is supported by physicochemical characterization of the SAMs using infrared spectroscopy, ellipsometry, and contact angle measurements. Results confirm the importance of arginine residues for the anomalous pseudosettlement, and we found that settlement is modulated by variations in both the total length and peptide primary structure. To elucidate the causes of the anomalous settlement and the possible relation to peptide-membrane interactions, we also compared the settlement of the "naked" zoospores of Ulva (which present a lipoprotein membrane to the exterior without a discrete polysaccharide cell wall), with the settlement of diatoms (unicellular algae that are surrounded by a silica cell wall), onto the peptide SAMs. Cationic SAMs do not notably affect settlement (attachment), adhesion strength, or viability of diatom cells, suggesting that the effect of the peptides on zoospores of Ulva is mediated via specific peptide-membrane interactions.

Early prediction of response to first-line chemotherapy by sequential [18F]-2-fluoro-2-deoxy-D-glucose positron emission tomography in patients with advanced colorectal cancer

BACKGROUND

To evaluate [(18)F]-2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET), for early evaluation of response to palliative chemotherapy and for prediction of long-term outcome, in patients with metastatic colorectal cancer (mCRC).

PATIENTS AND METHODS

In a randomized trial, patients with mCRC received irinotecan-based combination chemotherapy. FDG-PET was carried out before treatment and after two cycles in 51 patients at two centers. Visual changes in tumor FDG uptake and changes measured semi-automatically, as standard uptake values (SUVs), were compared with radiological response after four and eight cycles.

RESULTS

The mean baseline SUV for all tumor lesions per patient was higher in nonresponders than in responders (mean 7.4 versus 5.6, P = 0.02). There was a strong correlation between metabolic response (changes in SUV) and objective response (r = 0.57, P = 0.00001), with a sensitivity of 77% and a specificity of 76%. There was no significant correlation between metabolic response and time to progression (P = 0.5) or overall survival (P = 0.1).

CONCLUSIONS

Although metabolic response assessed by FDG-PET reflects radiological tumor volume changes, the sensitivity and specificity are too low to support the routine use of PET in mCRC. Furthermore, PET failed to reflect long-term outcome and can, thus, not be used as surrogate end point for hard endpoint benefit.

Postoperative adverse events and long-term survival after cytoreductive surgery and intraperitoneal chemotherapy

BACKGROUND

Peritoneal carcinomatosis (PC) is fatal without special combined cytoreductive surgery (CRS) and intraperitoneal chemotherapy (IPC). This study was designed to identify factors that may increase the risk of postoperative morbidity and mortality from combined CRS and IPC interventions for PC. Survival based on primary tumour type and extent of surgery is reported.

METHODS

Between May 1991 and November 2004, 123 patients were treated with CRS and IPC for PC. Based on the National Cancer Institute Common Toxicity Criteria for grade 3 and 4, data on 30 days postoperative morbidity and 90 days mortality were analysed.

RESULTS

Grade 3-4 adverse events were observed in 51 patients (41%) and were associated with stoma formation, duration of surgery, peroperative blood loss and peritoneal cancer index (PCI). Excision, or electrocautery evaporation, of tumour from small bowel surface was correlated to bowel morbidity. Five patients had treatment-related mortality (4%) within 90 days. Survival was associated with macroscopic radical surgery, prior surgical score, PCI and primary tumour type.

CONCLUSIONS

CRS and IPC for PC are associated with high morbidity and mortality. However, in light of the potential benefit indicated by long-term survival, the adverse event from this treatment is considered acceptable.

Heterogeneous activity of cytotoxic drugs in patient samples of peritoneal carcinomatosis

AIMS

To investigate if the pattern of cytotoxic drug sensitivity in vitro in patient samples of peritoneal carcinomatosis (PC) is supportive to the current standardized approach for drug selection for perioperative intraperitoneal chemotherapy (IPC).

METHODS

The cytotoxic effect of cisplatin, oxaliplatin, irinotecan, 5-fluorouracil, mitomycin-C, doxorubicin and melphalan was investigated in vitro on tumour cells from 223 patient tumour samples of different PC origins.

RESULTS

Considerable differences in cytotoxic drug sensitivity between tumour types of the PC entity and within each tumour type were observed. Cisplatin showed high cross-resistance with oxaliplatin but low cross-resistance with doxorubicin and irinotecan. No cross-resistance was found between irinotecan and doxorubicin. The dose-response relationships for melphalan and irinotecan in individual samples showed great variability.

CONCLUSIONS

The activity in vitro of cytotoxic drugs commonly used in IPC for PC is very heterogeneous. Efforts for individualizing drug selection for PC patients undergoing IPC seem justified.

Anomalous settlement behavior of Ulva linza zoospores on cationic oligopeptide surfaces

Identification of settlement cues for marine fouling organisms opens up new strategies and methods for biofouling prevention, and enables the development of more effective antifouling materials. To this end, the settlement behaviour of zoospores of the green alga Ulva linza onto cationic oligopeptide self-assembled monolayers (SAMs) has been investigated. The spores interact strongly with lysine- and arginine-rich SAMs, and their settlement appears to be stimulated by these surfaces. Of particular interest is an arginine-rich oligopeptide, which is effective in attracting spores to the surface, but in a way which leaves a large fraction of the settled spores attached to the surface in an anomalous fashion. These 'pseudo-settled' spores are relatively easily detached from the surface and do not undergo the full range of cellular responses associated with normal commitment to settlement. This is a hitherto undocumented mode of settlement, and surface dilution of the arginine-rich peptide with a neutral triglycine peptide demonstrates that both normal and anomalous settlement is proportional to the surface density of the arginine-rich peptide. The settlement experiments are complemented with physical studies of the oligopeptide SAMs, before and after extended immersion in artificial seawater, using infrared spectroscopy, null ellipsometry and contact angle measurements.

Population analysis of the pharmacokinetics and the haematological toxicity of the fluorouracil-epirubicin-cyclophosphamide regimen in breast cancer patients

PURPOSE

The aims of the study were (a) to characterise the pharmacokinetics (PK), including inter-individual variability (IIV) and inter-occasion variability (IOV) as well as covariate relationships and (b) to characterise the relationship between the PK and the haematological toxicity of the component drugs of the fluorouracil (5-FU)-epirubicin (EPI)-cyclophosphamide (CP) regimen in breast cancer patients.

PATIENTS AND METHODS

Data from 140 breast cancer patients, either within one of different studies or in routine clinical management, were included in the analyses. The patients were all treated with the fluorouracil-epirubicin-cyclophosphamide (FEC) regimen every third week for 3-12 courses, either in standard doses, i.e. 600/60/600 mg/m(2) of 5-FU, EPI and CP, respectively, or according to a dose escalation/reduction protocol (tailored dosing). PK data were available from 84 of the patients, whereas time-courses of haematological toxicity were available from 87 patients. The data analysis was carried out using mixed effects models within the NONMEM program.

RESULTS

The PK of 5-FU, EPI and 4-hydroxy-cyclophosphamide (4-OHCP), the active metabolite of CP, were described with a one-compartment model with saturable elimination, a three-compartment linear model and a two-compartment linear model, respectively. No clinical significant correlation was found between PK across drugs. The unexplained variability in clearance was found to be less within patients, between courses (inter-occasion variability, IOV) than between patients (inter-individual variability, IIV) for EPI and 5-FU. For 4-OHCP, however, the IIV diminished by approximately 45% when significant covariates were included and the final population model predicts an IIV that is equal to IOV. Significant covariates for elimination capacity parameters were serum albumin (5-FU, EPI and 4-OHCP), creatinine clearance (5-FU), bilirubin (EPI) and body surface area (BSA) (4-OHCP). Elimination capacity of 5-FU and EPI was not related to BSA and for none of the studied drugs did body weight explain the PK variability. The time-course of haematological toxicity after treatment was well described by a semi-physiological model that assumes additive haematological toxicity between CP and EPI with negligible contribution from 5-FU. The influence of G-CSF could be incorporated into the model in a mechanistic manner as shortening the maturation time to 43% of the normal duration and increasing the mitotic activity to 269% of normal activity.

CONCLUSIONS

The models presented describe the dose-concentration-toxicity relationships for the FEC therapy and may provide a basis for implementation and comparison of different individualisation strategies based on covariates, therapeutic drug monitoring and/or pharmacodynamic (PD) feedback. The PD model extends on previous semi-mechanistic models in that it also takes G-CSF administration into account.

Identification of molecular mechanisms for cellular drug resistance by combining drug activity and gene expression profiles

Acquired drug resistance is a major problem in cancer treatment. To explore the genes involved in chemosensitivity and resistance, 10 human tumour cell lines, including parental cells and resistant subtypes selected for resistance against doxorubicin, melphalan, teniposide and vincristine, were profiled for mRNA expression of 7400 genes using cDNA microarray technology. The drug activity of 66 cancer agents was evaluated on the cell lines, and correlations between drug activity and gene expression were calculated and ranked. Hierarchical clustering of drugs based on their drug–gene correlations yielded clusters of drugs with similar mechanism of action. Genes correlated with drug sensitivity and resistance were imported into the PathwayAssist software to identify putative molecular pathways involved. A substantial number of both proapoptotic and antiapoptotic genes such as signal transducer and activator of transcription 1, mitogen-activated protein kinase 1 and focal adhesion kinase were found to be associated to drug resistance, whereas genes linked to cell cycle control and proliferation, such as cell division cycle 25A and signal transducer of activator of transcription 5A, were associated to general drug sensitivity. The results indicate that combined information from drug activity and gene expression in a resistance-based cell line panel may provide new knowledge of the genes involved in anticancer drug resistance and become a useful tool in drug development.

Cellular drug sensitivity in MLL-rearranged childhood acute leukaemia is correlated to partner genes and cell lineage

Rearrangements in the 11q23 region, the site of the mixed lineage leukaemia (MLL) gene, are found in both childhood acute myeloid (AML) and lymphoblastic (ALL) leukaemia. We studied the in vitro drug resistance by the fluorometric microculture cytotoxicity assay (FMCA) in 132 children with AML and 178 children with ALL (aged 0-17 years). In AML, children with t(9;11) (n = 10) were significantly more sensitive to cytarabine (P < 0.001) and doxorubicin (P = 0.005) than non-11q23 rearranged patients (n = 108). Children with other 11q23 rearrangements (n = 14) differed less from non-rearranged children. The 'AML-profile' common to all three groups included relative resistance to glucocorticoids and vincristine. In ALL, children with 11q23 rearrangement (n = 22) were significantly more sensitive to cytarabine (P = 0.026) than children without 11q23 rearrangement (n = 156), also after stratification for white blood cell count. In conclusion, the findings indicate that the cellular drug resistance is correlated to both the cell lineage and the type of 11q23 rearrangement. High cellular sensitivity to cytarabine and doxorubicin might explain the excellent treatment results in children with AML and t(9;11). The present study supports the strategy of contemporary protocols to include high-dose cytarabine in the treatment of 11q23-positive patients both in AML and ALL.