Impact of KRAS, BRAF and microsatellite instability status after cytoreductive surgery and HIPEC in a national cohort of colorectal peritoneal metastasis patients.

BACKGROUND: Patients with metastatic colorectal cancer (mCRC) carrying BRAF (mutBRAF) or KRAS mutation (mutKRAS) have an inferior prognosis after liver or lung surgery, whereas the prognostic role in the context of peritoneal metastasis (PM) after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has been less investigated. METHODS: In total, 257 patients with non-appendiceal PM-CRC were included from the Norwegian National Unit for CRS-HIPEC. RESULTS: In total, 180 patients received CRS-HIPEC with Mitomycin C, 77 patients received palliative surgery only. In the CRS-HIPEC group, mutBRAF was found in 24.7%, mutKRAS 33.9% and double wild-type 41.4% without differences in survival. MSI was found in 29.3% of mutBRAF cases. Patients with mutBRAF/MSI had superior 5-year survival compared to mutBRAF with MSS (58.3% vs 25.2%, P = 0.022), and better 3-year disease-free survival (DFS) compared to mutKRAS (48.6% vs 17.2%, P = 0.049). Peritoneal Cancer Index and the number of lymph node metastasis were prognostic for OS, and the same two, location and gender prognostic for DFS in multivariate analysis. CONCLUSIONS: PM-CRC with CRS-HIPEC patients has a surprisingly high proportion of mutBRAF (24.7%). Survival was similar comparing mutBRAF, mutKRAS and double wild-type cases, whereas a small subgroup with mutBRAF and MSI had better survival. Patients with mutBRAF tumours and limited PM should be considered for CRS-HIPEC.

Physical exercise during adjuvant chemotherapy for colorectal cancer-a non-randomized feasibility study.

BACKGROUND: Colorectal cancer (CRC) is the third most common cancer worldwide, and a large proportion of the patients receive adjuvant oxaliplatin-based chemotherapy. Most of these experience chemotherapy-induced peripheral neuropathy (CIPN), affecting quality of life. Evidence to advise exercise to reduce CIPN is limited. The primary aim of this study was to investigate the feasibility of an exercise intervention and data collection among CRC patients during adjuvant chemotherapy. MATERIAL AND METHODS: This non-randomized feasibility study included CRC patients admitted to adjuvant chemotherapy to an intervention consisting of supervised aerobic endurance, resistance, and balance exercises twice a week at the hospital in addition to home-based exercise once a week. A physiotherapist supervised the patients, and the intervention lasted throughout the period of adjuvant chemotherapy (12-24 weeks). Participants performed physical tests and filled in questionnaires at baseline, 3, 6, 9, and 12 months. RESULTS AND CONCLUSION: Nineteen (63%) of 30 invited patients consented. A major barrier to recruit or consent to participation was long travel distance to the hospital. The completion rate of questionnaires and physical tests were near 100%. Seven participants dropped out, five before the intervention started. Median attendance to supervised exercise was 85%. There were no serious adverse events related to the intervention. Except for a planned higher intensity of endurance exercise, we found the intervention feasible and safe. Based on experiences in this study, some adjustments have been made for an upcoming randomized trial, including the supervised exercise taking place close to participants' homes. TRIAL REGISTRATION: NCT03885817, March 22, 2019, retrospectively registered.

Identification of serum microRNA profiles in colon cancer.

BACKGROUND: microRNAs (miRNAs) exist in blood in an apparently stable form. We have explored whether serum miRNAs can be used as non-invasive early biomarkers of colon cancer. METHODS: Serum samples from 30 patients with colon cancer stage IV and 10 healthy controls were examined for the expression of 375 cancer-relevant miRNAs. Based on the miRNA profile in this study, 34 selected miRNAs were measured in serum from 40 patients with stage I-II colon cancer and from 10 additional controls. RESULTS: Twenty miRNAs were differentially expressed in serum from stage IV patients compared with controls (P<0.01). Unsupervised clustering revealed four subgroups; one corresponding mostly to the control group and the three others to the patient groups. Of the 34 miRNAs measured in the follow-up study of stage I-II patients, 21 showed concordant expression between stage IV and stage I-II patient. Based on the profiles of these 21 miRNAs, a supervised linear regression analysis (Partial Least Squares Regression) was performed. Using this model we correctly assigned stage I-II colon cancer patients based on miRNA profiles of stage IV patients. CONCLUSION: Serum miRNA expression profiling may be utilised in early detection of colon cancer.

Predictive and prognostic factors for treatment and survival in 305 patients with advanced gastrointestinal neuroendocrine carcinoma (WHO G3): the NORDIC NEC study.

BACKGROUND: As studies on gastrointestinal neuroendocrine carcinoma (WHO G3) (GI-NEC) are limited, we reviewed clinical data to identify predictive and prognostic markers for advanced GI-NEC patients. PATIENTS AND METHODS: Data from advanced GI-NEC patients diagnosed 2000-2009 were retrospectively registered at 12 Nordic hospitals. RESULTS: The median survival was 11 months in 252 patients given palliative chemotherapy and 1 month in 53 patients receiving best supportive care (BSC) only. The response rate to first-line chemotherapy was 31% and 33% had stable disease. Ki-67<55% was by receiver operating characteristic analysis the best cut-off value concerning correlation to the response rate. Patients with Ki-67<55% had a lower response rate (15% versus 42%, P<0.001), but better survival than patients with Ki-67≥55% (14 versus 10 months, P<0.001). Platinum schedule did not affect the response rate or survival. The most important negative prognostic factors for survival were poor performance status (PS), primary colorectal tumors and elevated platelets or lactate dehydrogenase (LDH) levels. CONCLUSIONS: Advanced GI-NEC patients should be considered for chemotherapy treatment without delay.PS, colorectal primary and elevated platelets and LDH levels were prognostic factors for survival. Patients with Ki-67<55% were less responsive to platinum-based chemotherapy, but had a longer survival. Our data indicate that it may not be correct to consider all GI-NEC as one single disease entity.

Performance of clinical guidelines compared with molecular tumour screening methods in identifying possible Lynch syndrome among colorectal cancer patients: a Norwegian population-based study.

BACKGROUND: The aim of this study was to assess the performance of the Revised Bethesda Guidelines (RBG) and the accuracy of the Amsterdam II criteria (AM II) in identifying possible Lynch syndrome (LS) compared with the results of molecular tumour testing. METHODS: Tumours from 336 unselected colorectal cancer patients were analysed by three molecular tests (namely microsatellite instability (MSI), BRAF mutation and methylation of mismatch-repair genes), and patients were classified according to the RBG and AM II criteria. RESULTS: A total of 87 (25.9%) patients fulfilled the RBG for molecular tumour analyses (MSI and/or immunohistochemistry), and the AM II identified 8 (2.4%) patients as having possible LS. Molecular tests identified 12 tumours (3.6%) as probable LS. The RBG identified 6 of the 12 patients (sensitivity 50%), whereas 5 of the 8 patients who fulfilled the AM II criteria were not likely to be LS, based on molecular tests (predictive value of positive test, 38%). INTERPRETATION: Assuming a fairly high accuracy of molecular testing, the performance of the RBG in identifying patients with possible LS was poor, and the AM II criteria falsely identified a large proportion as having possible LS. This favours the use of molecular testing in the diagnosis of possible LS.

Awareness of heredity in colorectal cancer patients is insufficient among clinicians: a Norwegian population-based study.

OBJECTIVE: The assessment of family history and medical data is crucial in identifying families with Lynch syndrome (LS). Among consecutive colorectal cancer (CRC) patients, we aimed at identifying all patients with a hereditary predisposition, and to study a possible discrepancy with assessments made by the responsible clinicians. METHOD: All consecutively diagnosed patients with CRC from two Norwegian hospitals were included, and information on family history was collected in a detailed interview. We assessed information in medical records, and tumours were examined for LS-associated histopathological features. RESULTS: Among 562 patients, there was no documentation of family history in 388 (69.0%) medical records, and in 174 (31.0%) patients, there was no clinical assessment of the information that was collected on family history. Based on detailed interviews and extended pathological examination, we found that 137 (24.4%) of the 562 patients could be classified as possible LS according to the Revised Bethesda Guidelines (RBG); and that 46 (33.6%) of these patients could be identified by family history alone. CONCLUSION: Family history and relevant information in patient records can identify patients with possible LS. However, clinicians often fail to include information on hereditary factors and to assess relevant data in medical records. Familial CRC is therefore not acknowledged, and genetic counselling is not offered.

Identification of novel neuroendocrine-specific tumour genes.

Neuroendocrine tumours (NETs) comprise a heterogenous group of malignancies with an often unpredictable course, and with limited treatment options. Thus, new diagnostic, prognostic, and therapeutic markers are needed. To shed new lights into the biology of NETs, we have by cDNA transcript profiling, sought to identify genes that are either up- or downregulated in NE as compared with non-NE tumour cells. A panel of six NET and four non-NET cell lines were examined, and out of 12 743 genes examined, we studied in detail the 200 most significantly differentially expressed genes in the comparison. In addition to potential new diagnostic markers (NEFM, CLDN4, PEROX2), the results point to genes that may be involved in the tumorigenesis (BEX1, TMEPAI, FOSL1, RAB32), and in the processes of invasion, progression and metastasis (MME, STAT3, DCBLD2) of NETs. Verification by real time qRT-PCR showed a high degree of consistency to the microarray results. Furthermore, the protein expression of some of the genes were examined. The results of our study has opened a window to new areas of research, by uncovering new candidate genes and proteins to be further investigated in the search for new prognostic, predictive, and therapeutic markers in NETs.

Reversal of multidrug resistance by lipophilic drugs.

The phenomenon of multidrug resistance implies that a wide spectrum of structurally and functionally unrelated chemotherapeutic drugs are recognized and processed by the molecular system which protects multidrug-resistant (MDR) cells against lipophilic cytotoxic drugs. This suggests that lipophilic agents with low toxicity may also be recognized and processed by this molecular system. At high concentrations these agents might saturate the system, thereby reversing multidrug resistance. In support of this hypothesis, 19 (73%) of 26 arbitrarily chosen lipophilic drugs were in this study found to increase the accumulation of actinomycin D in MDR WEHI 164 cells. The most potent of these drugs were also shown to sensitize these cells to the cytotoxic effect of actinomycin D and doxorubicin. There was a good correlation between the ability of the lipophilic drugs to induce an increased accumulation of actinomycin D in MDR cells and their ability to sensitize these cells to the cytotoxic effect of chemotherapeutic drugs. The ability to reverse drug resistance appeared to be additive, since increased accumulation of actinomycin D was also obtained by combining low concentrations of various lipophilic drugs. This may be a way to reduce the in vivo toxic effect of the lipophilic drugs yet still obtain a reversal of drug resistance. When MDR cells were exposed to lipophilic drugs which reversed drug resistance, the synergistic cytotoxic effect of actinomycin D and tumor necrosis factor was obtained at reduced actinomycin D concentrations.

Identification of novel growth factor-responsive genes in neuroendocrine gastrointestinal tumour cells.

Targeting growth-regulatory pathways is a promising approach in cancer treatment. A prerequisite to the development of such therapies is characterisation of tumour growth regulation in the particular tumour cell type of interest. In order to gain insight into molecular mechanisms underlying proliferative responses in neuroendocrine (NE) gastrointestinal (GI) tumours, we investigated gene expression in human carcinoid BON cells after exposure to gastrin, hepatocyte growth factor (HGF), pituitary adenylate cyclase-activating polypeptide or epidermal growth factor. We particularly focused on gastrin- and HGF-induced gene expression, and identified 95 gastrin- and 101 HGF-responsive genes. The majority of these genes are known mediators of processes central in tumour biology, and a number of them have been associated with poor prognosis and metastasis in cancer patients. Furthermore, we identified 12 genes that were regulated by all four factors, indicating that they may be universally regulated during NE GI tumour cell proliferation. Our findings provide useful hypotheses for further studies aimed to search for new therapeutic targets as well as tumour markers in NE GI tumours.

[Multiple drug resistance--theoretical and clinical aspects]. / Multimedikamentresistens--teoretiske og kliniske aspekter.

A major problem in the treatment of cancer is clinical resistance to chemotherapeutic drugs. Multi-drug resistance (MDR) is a well-studied experimental phenomenon which seems to play an important role in clinical resistance to drugs. Tumour cells selected for resistance to a "natural product" anticancer drug display crossresistance to a variety of structurally and functionally unrelated anticancer drugs. Such resistant cells accumulate and retain less drug than retained by their drug sensitive counterparts. This lower grade of accumulation is most likely mediated by P-glycoprotein, an integral membrane protein which functions as an energy-dependent efflux pump. It has now become clear that several lipophilic agents can reverse MDR both in vitro and in vivo. Clinical trials with such modulators (chemosensitizers) have already given promising results.

[Therapeutic failure of antineoplastic agents. Extracellular and cellular causes]. / Behandlingssvikt ved bruk av cytostatika. Ekstracellulaere og cellulaere årsaker.

Chemotherapy plays an important role in the treatment of cancer. However, the drug regimens used today can only offer a cure to a small fraction of cancer patients. The article reviews the factors that limit the effect of chemotherapeutic treatment of cancer. The major cause of failure of chemotherapeutic treatment is the presence of resistant tumour cells. In addition to the various changes that may occur in tumour cells, various other factors may limit the "effective concentration" of a drug delivered to the site of the tumour, and thereby affect the overall clinical response to therapy.

[Interleukins--important signal substances for T-lymphocytes]. / Interleukiner--viktige signalsubstanser for T-lymfocytter.

The immune system plays an important role in defence against infections, and probably also in defence against cancer. The various white blood cells are the actors in the immune system. Important effector cells are the T-lymphocytes, which are responsible for the cellular immune response. Interleukins are proteins which act as signal substances between leukocytes. Many of the interleukins play an important role in the activation, growth, proliferation and differentiation of T-lymphocytes. This article describes the various interleukins and their effects on the T-lymphocytes.

Effect of pyridoxine on tumor necrosis factor activities in vitro.

Clinical trials with tumor necrosis factor (TNF) as an antitumor agent have so far given rather disappointing results. In this study we show that the naturally occurring vitamin B6 compound, pyridoxine, enhances TNF-induced cytolysis of three subclones of a mouse fibrosarcoma cell line (WEHI 164). The degree of pyridoxine-induced enhancement of TNF cytotoxicity seems to be dependent on the cells sensitivity to TNF, as the enhancement was much more pronounced in the relatively TNF resistant subclone act-R(cl.12)-WEHI 164, than in the very TNF sensitive subclone WEHI 164 clone 13. Furthermore, our study shows that pyridoxine, in contrast to its enhancing effect on TNF-induced cytotoxicity, rather inhibits TNF-induced growth of human FS-4 fibroblasts. Pyridoxine also enhances lymphotoxin (LT)-induced tumor cell killing and inhibits LT-induced fibroblast growth. Pyridoxine is a relatively non-toxic agent in vivo. Our results suggest that a combination of TNF and pyridoxine may be more efficient than TNF alone, in the treatment of cancer patients.

Reversal of drug resistance by erythromycin: erythromycin increases the accumulation of actinomycin D and doxorubicin in multidrug-resistant cells.

Development of resistance to one type of lipophilic chemotherapeutic drug often leads to resistance to other, structurally unrelated, lipophilic drugs. This suggests that non-toxic lipophilic agents may interfere with and reverse drug resistance by saturating the pathway through which multidrug-resistant (MDR) cells protect themselves against cytotoxic drugs. The lipophilic antibiotic, erythromycin, can significantly reverse the resistance of MDR WEHI 164 murine fibrosarcoma cells to the chemotherapeutic drugs, doxorubicin and actinomycin-D. The MDR cells showed an approximately 10-fold higher expression of the P-glycoprotein than the drug-sensitive parental cells from which the resistant cells were derived. The accumulation of actinomycin-D and doxorubicin was much lower in the drug-resistant cells than in the sensitive parental cells. The concentrations of erythromycin which reversed the drug resistance of the MDR cells increased the accumulation of actinomycin-D and doxorubicin in these cells to a level comparable to that observed in the sensitive parental cells. Our data suggest that erythromycin reverses drug resistance by saturating the drug-binding sites on the P-glycoprotein, thereby reducing the capacity of this protein to pump drugs out of resistant cells. Some of our MDR cells have also become more resistant to tumour necrosis factor (TNF). However, erythromycin did not reverse TNF resistance, suggesting that the mechanisms of multi-drug and TNF resistance are different. TNF did not influence drug accumulation in MDR cells.

Recombinant tumour necrosis factor (TNF) fixed to cell monolayers retains its cytotoxic and growth-stimulatory activity. Evidence that internalization of TNF is not necessary for induction of biological effects.

Recombinant human tumour necrosis factor (rTNF) retained its cytotoxic activity after being fixed with paraformaldehyde to adherent cell monolayers. The cytotoxicity appeared to be mainly due to fixed rTNF and not to any free soluble rTNF that could have leaked out from the fixed rTNF cell preparations. The fixed rTNF cell preparations also stimulated the growth of human diploid fibroblasts, under conditions where little growth-stimulatory activity was found in suspension. These results indicate that TNF may exert its effect on target cells without internalization, perhaps through a receptor-mediated process that may alter the levels of a second messenger within the target cells. This signal transduction does not appear to involve cAMP or cGMP, since we were unable to detect significant changes in the levels of these two second messengers in TNF-exposed WEHI 164 clone 13 cells.

Effect of erythromycin and tumour necrosis factor on the drug resistance of multidrug-resistant cells: reversal of drug resistance by erythromycin.

WEHI 164 murine fibrosarcoma cells were rendered multidrug-resistant (MDR) by culture in the presence of actinomycin D. In addition to resistance to actinomycin D, the cells acquired resistance to doxorubicin, mitomycin, vincristine and cycloheximide. The fact that development of resistance to one type of lipophilic chemotherapeutic drug also results in resistance to other structurally unrelated lipophilic drugs suggests that non-toxic lipophilic agents may interfere with drug resistance by saturating the pathway by which MDR-cells inhibit drug cytotoxicity. We show that the antibiotic erythromycin significantly reverses the resistance of MDR WEHI 164 cells to doxorubicin and actinomycin D. In addition to cross-resistance to chemotherapeutic drugs, 3 out of 4 actinomycin D-resistant WEHI 164 cell lines also showed higher resistance to tumour necrosis factor (TNF) than the parental WEHI 164 cells. However, whereas verapamil, a calcium antagonist known to reverse multidrug-resistance, rendered resistant cells more sensitive to chemotherapeutic drugs, it protected the cells from killing by TNF, suggesting that drug resistance and TNF resistance may not be directly connected. A synergistic cytotoxic effect of TNF and actinomycin D was obtained on both the parental and the MDR cells. However, higher concentrations of TNF and actinomycin D were required to obtain a cytotoxic effect in the MDR cells, reflecting actinomycin D and TNF resistance in these cells.

Evidence that tumour necrosis factor (TNF) is not constitutively present in vivo. The association of TNF with freshly isolated monocytes reflects a rapid in vitro production.

Tumour necrosis factor (TNF) cytotoxic activity has been shown not to be present in detectable amounts in the serum of healthy humans, but it may be found in some patients with meningococcal disease. In this study we investigated whether TNF is constitutively present in vivo on or within monocytes. TNF was detected on freshly isolated paraformaldehyde-fixed monocytes from both healthy individuals and cancer patients. No significant difference was found between the two groups. TNF appeared first 40-60 min after in vitro monocyte adherence, which is the same time as it took TNF to appear extracellularly after the exposure of in vitro cultured monocytes to lipopolysaccharide (LPS). This indicates that TNF associated with freshly isolated monocytes was synthesized in vitro. The inducing signal may be monocyte contact with plastic. Exposure of whole blood to LPS immediately after vein puncture was followed by about twice as rapid TNF release as that observed with in vitro cultured monocytes. The release was inhibited by cycloheximide but not by actinomycin D, indicating that the TNF detected did not represent TNF present in vivo. This is consistent with the fact that no TNF cytotoxic activity was detected in blood cell extracts. However, TNF-mRNA may have been present in vivo. Thus, the available evidence indicates that TNF is not constitutively expressed in vivo.

Involvement of tumor necrosis factor in cytotoxicity mediated by human monocytes.

Human monocytes cultured in a specially prepared medium free of lipopolysaccharide (LPS) constitutively produced a small, though significant, amount of tumor necrosis factor (TNF). Upon addition of LPS, the amount produced remained constant until the LPS concentration reached 1-10 ng/ml, whereupon the production of TNF dramatically increased, eventually becoming 100-fold greater than when the LPS concentration was below 1 ng/ml. Priming the monocytes with recombinant interferon-gamma (rIFN-gamma) before LPS exposure resulted in a 2- to 10-fold increase in TNF production, the highest relative increase being obtained at lower LPS concentrations and in the absence of LPS. Monocyte-produced TNF appears to be the effector molecule in monocyte-mediated killing of some target cell types, since antiserum against recombinant TNF inhibited killing of both actinomycin D-treated and untreated WEHI 164 cells by human monocytes. However, it also appears that TNF may not in all cases be an effector molecule in monocyte-mediated killing, since cytolysis of K562 cells mediated by IFN-gamma/LPS-activated monocytes was not inhibited by antiserum against recombinant TNF. Antiserum which was raised against a monocyte-derived cytotoxic factor and which neutralized recombinant TNF did, however, inhibit monocyte-mediated cytolysis of K562 cells, suggesting that an extracellular factor, perhaps related to TNF, was also involved in monocyte-mediated killing of K562 cells. A TNF-like activity was associated with the monocyte surface membrane, since paraformaldehyde-fixed monocytes expressed cytotoxic activity which was neutralized by antiserum against recombinant TNF. Fixed monocytes activated with rIFN-gamma in addition to LPS before fixation were generally more cytotoxic than those exposed to LPS alone, and those exposed to LPS were much more cytotoxic than those not exposed to LPS. Thus it is possible that high local TNF concentrations may be generated near the target cell upon direct contact between effector and target cells, and that also monocyte-associated TNF may in this way be involved in monocyte-mediated cytotoxicity.

A flow cytometric and immunofluorescence microscopic study of tumor necrosis factor production and localization in human monocytes.

The production and localization of tumor necrosis factor (TNF) in human monocytes were investigated by using monoclonal and polyclonal antibodies against recombinant human TNF together with flow cytometry and immunofluorescence microscopy. Lipopolysaccharide (LPS) induced a rapid and transient accumulation of TNF in perinuclear vesicles which was detected 20 min after the addition of LPS. The fluorescence intensity of the vesicles peaked at 40 min of LPS exposure, concomitantly with the release of TNF into the medium. Thus, our results indicate that the secretion of TNF is typical for secretory proteins as it involves passage through the secretory apparatus. Additional studies demonstrated that plasma membrane-associated TNF could not be detected in live monocytes not exposed to LPS. However, after 90 min with LPS, a small population of monocytes expressed membrane-associated TNF, and by 24 hr approximately 50% of the monocytes displayed TNF on the plasma membrane. Furthermore, our results indicate that plasma membrane-associated TNF does not represent released TNF bound back to its own receptor. Thus, our findings support the view that TNF exists as a surface trans-membrane protein in LPS-stimulated monocytes.

Lymphotoxin-induced growth stimulation of diploid human fibroblasts in the presence and absence of gamma interferon.

In the present study we investigated the effect of lymphotoxin (LT) on the growth of human diploid fibroblasts, in the presence and absence of gamma interferon (IFN-gamma). Recombinant LT (rLT) had a growth stimulatory effect on diploid human FS-4 fibroblasts. This growth-stimulatory effect was reduced in the presence of recombinant IFN-gamma (rIFN-gamma). LT thus has a similar effect on diploid fibroblasts as tumour necrosis factor (TNF).