Second-line systemic therapy for metastatic colorectal cancer

Mitotherapy prevents peripheral neuropathy induced by oxaliplatin in mice

Oxaliplatin (OXA) is an antineoplastic agent used for the treatment of cisplatin-resistant tumours, presenting lower incidence of nephrotoxicity and myelotoxicity than other platinum-based drugs. However, OXA treatment is highly associated with painful peripheral neuropathy, a well-known and relevant side effect caused by mitochondrial dysfunction. The transfer of functional exogenous mitochondria (mitotherapy) is a promising therapeutic strategy for mitochondrial diseases. We investigated the effect of mitotherapy on oxaliplatin-induced painful peripheral neuropathy (OIPN) in male mice. OIPN was induced by i.p. injections of oxaliplatin (3 mg/kg) over 5 consecutive days. Mechanical (von Frey test) and cold (acetone drop test) allodynia were evaluated between 7 and 17 days after the first OXA treatment. Mitochondria was isolated from donor mouse livers and mitochondrial oxidative phosphorylation was assessed with high resolution respirometry. After confirming that the isolated mitochondria were functional, the organelles were administered at the dose of 0.5 mg/kg of mitochondrial protein on days 1, 3 and 5. Treatment with OXA caused both mechanical and cold allodynia in mice that were significant 7 days after the initial injection of OXA and persisted for up to 17 days. Mitotherapy significantly prevented the development of both sensory alterations, and attenuated body weight loss induced by OXA. Mitotherapy also prevented spinal cord ERK1/2 activation, microgliosis and the increase in TLR4 mRNA levels. Mitotherapy prevented OIPN by inhibiting neuroinflammation and the consequent cellular overactivity in the spinal cord, presenting a potential therapeutic strategy for pain management in oncologic patients undergoing OXA treatment.

Mitomycin C and capecitabine: An additional option as an advanced line therapy in patients with metastatic colorectal cancer

BACKGROUND

In recent years survival of patients with metastatic colorectal cancer (mCRC), though still limited, has improved significantly; clearly, when the disease becomes refractory to standard regimens, additional treatment options are needed. Studies have shown that mitomycin C (MMC), an antitumor antibiotic, and capecitabine, a precursor of 5-fluorouracil, may act synergistically in combination. The efficacy of MMC/capecitabine has been demonstrated in the first-line setting, but only a few small studies have tested it in the advanced-line setting, with contradictory results.

AIM

To summarize our experience using MMC/capecitabine as an advanced line treatment for mCRC.

METHODS

A retrospective study was conducted at a tertiary medical center including all patients with histologically proven mCRC who were treated with MMC/capecitabine after at least two previous lines of standard chemotherapy in 2006-2020. Data on patient demographics and past medical history, laboratory, pathological, and radiological factors, and treatment and survival were collected from the files. Survival analyses were performed using the Kaplan-Meier method. The association of patient and tumor characteristics with treatment effectiveness and toxicity was evaluated with univariate and multivariate proportional hazard Cox regression analyses. P ≤ 0.05 was considered statistically significant.

RESULTS

The cohort consisted of 119 patients of median age 64 years (range 37-85). Patients received a median of 2 MMC/capecitabine cycles (range 0.5-9.0). Thirty-four patients (28.6%) experienced grade ≥ 3 toxicity, including 2 (1.7%) with grade 4; there was no drug-related mortality. The objective response rate was 0.8%, and the disease control rate, 24.4%. Median progression-free survival (PFS) was 2.1 mo (range 0.2-20.3), and median overall survival, 4.8 mo (range 0.2-27.5). The 6-month overall survival rate was 44%; 8.7% of patients remained progression-free. Factors associated with longer PFS were lower gamma-glutamyl transferase level (P = 0.030) and primary tumor location in the left colon (P = 0.017). Factors associated with longer overall survival were lower gamma-glutamyl transferase level (P = 0.022), left-colon tumor location (P = 0.044), low-to-moderate histological grade (P = 0.012), Eastern Cooperative Oncology Group performance status 0-1 (P = 0.036), and normal bilirubin level (P = 0.047).

CONCLUSION

MMC/capecitabine is an active, available, and relatively safe regimen for use beyond standard lines of therapy in mCRC. Several clinical and laboratory parameters can identify patients more likely to benefit.

Involvement of Met receptor pathway in aggressive behavior of colorectal cancer cells induced by parathyroid hormone-related peptide

BACKGROUND

Parathyroid hormone-related peptide (PTHrP) plays a key role in the development and progression of many tumors. We found that in colorectal cancer (CRC) HCT116 cells, the binding of PTHrP to its receptor PTHR type 1 (PTHR1) activates events associated with an aggressive phenotype. In HCT116 cell xenografts, PTHrP modulates the expression of molecular markers linked to tumor progression. Empirical evidence suggests that the Met receptor is involved in the development and evolution of CRC. Based on these data, we hypothesized that the signaling pathway trigged by PTHrP could be involved in the transactivation of Met and consequently in the aggressive behavior of CRC cells.

AIM

To elucidate the relationship among PTHR1, PTHrP, and Met in CRC models.

METHODS

For in vitro assays, HCT116 and Caco-2 cells derived from human CRC were incubated in the absence or presence of PTHrP (1-34) (10^-8 M). Where indicated, cells were pre-incubated with specific kinase inhibitors or dimethylsulfoxide, the vehicle of the inhibitors. The protein levels were evaluated by Western blot technique. Real-time polymerase chain reaction (RT-qPCR) was carried out to determine the changes in gene expression. Wound healing assay and morphological monitoring were performed to evaluate cell migration and changes related to the epithelial-mesenchymal transition (EMT), respectively. The number of viable HCT116 cells was counted by trypan blue dye exclusion test to evaluate the effects of irinotecan (CPT-11), oxaliplatin (OXA), or doxorubicin (DOXO) with or without PTHrP. For in vivo tests, HCT116 cell xenografts on 6-wk-old male N:NIH (S)_nu mice received daily intratumoral injections of PTHrP (40 μg/kg) in 100 μL phosphate-buffered saline (PBS) or the vehicle (PBS) as a control during 20 d. Humanitarian slaughter was carried out and the tumors were removed, weighed, and fixed in a 4% formaldehyde solution for subsequent treatment by immunoassays. To evaluate the expression of molecular markers in human tumor samples, we studied 23 specimens obtained from CRC patients which were treated at the Hospital Interzonal de Graves y Agudos Dr. José Penna (Bahía Blanca, Buenos Aires, Argentina) and the Hospital Provincial de Neuquén (Neuquén, Neuquén, Argentina) from January 1990 to December 2007. Seven cases with normal colorectal tissues were assigned to the control group. Tumor tissue samples and clinical histories of patients were analyzed. Paraffin-embedded blocks from primary tumors were reviewed by hematoxylin-eosin staining technique; subsequently, representative histological samples were selected from each patient. From each paraffin block, tumor sections were stained for immunohistochemical detection. The statistical significance of differences was analyzed using proper statistical analysis. The results were considered statistically significant at P < 0.05.

RESULTS

By Western blot analysis and using total Met antibody, we found that PTHrP regulated Met expression in HCT116 cells but not in Caco-2 cells. In HCT116 cells, Met protein levels increased at 30 min (P < 0.01) and at 20 h (P < 0.01) whereas the levels diminished at 3 min (P < 0.05), 10 min (P < 0.01), and 1 h to 5 h (P < 0.01) of PTHrP treatment. Using an active Met antibody, we found that where the protein levels of total Met decreased (3 min, 10 min, and 60 min of PTHrP exposure), the status of phosphorylated/activated Met increased (P < 0.01) at the same time, suggesting that Met undergoes proteasomal degradation after its phosphorylation/activation by PTHrP. The increment of its protein level after these decreases (at 30 min and 20 h) suggests a modulation of Met expression by PTHrP in order to improve Met levels and this idea is supported by our observation that the cytokine increased Met mRNA levels at least at 15 min in HCT116 cells as revealed by RT-qPCR analysis (P < 0.05). We then proceeded to evaluate the signaling pathways that mediate the phosphorylation/ activation of Met induced by PTHrP in HCT116 cells. By Western blot technique, we observed that PP1, a specific inhibitor of the activation of the proto-oncogene protein tyrosine kinase Src, blocked the effect of PTHrP on Met phosphorylation (P < 0.05). Furthermore, the selective inhibition of the ERK 1/2 mitogen-activated protein kinase (ERK 1/2 MAPK) using PD98059 and the p38 MAPK using SB203580 diminished the effect of PTHrP on Met phosphorylation/activation (P < 0.05). Using SU11274, the specific inhibitor of Met activation, and trypan blue dye exclusion test, Western blot, wound healing assay, and morphological analysis with a microscope, we observed the reversal of cell events induced by PTHrP such as cell proliferation (P < 0.05), migration (P < 0.05), and the EMT program (P < 0.01) in HCT116 cells. Also, PTHrP favored the chemoresistance to CPT-11 (P < 0.001), OXA (P < 0.01), and DOXO (P < 0.01) through the Met pathway. Taken together, these findings suggest that Met activated by PTHrP participates in events associated with the aggressive phenotype of CRC cells. By immunohistochemical analysis, we found that PTHrP in HCT116 cell xenografts enhanced the protein expression of Met (0.190 ± 0.014) compared to tumors from control mice (0.110 ± 0.012; P < 0.05) and of its own receptor (2.27 ± 0.20) compared to tumors from control mice (1.98 ± 0.14; P < 0.01). Finally, assuming that the changes in the expression of PTHrP and its receptor are directly correlated, we investigated the expression of both Met and PTHR1 in biopsies of CRC patients by immunohistochemical analysis. Comparing histologically differentiated tumors with respect to those less differentiated, we found that the labeling intensity for Met and PTHR1 increased and diminished in a gradual manner, respectively (P < 0.05).

CONCLUSION

PTHrP acts through the Met pathway in CRC cells and regulates Met expression in a CRC animal model. More basic and clinical studies are needed to further evaluate the PTHrP/Met relationship.

Contribution of "complete response to treatment" to survival in patients with unresectable metastatic colorectal cancer: A retrospective analysis

BACKGROUND

The aim of the study is to reveal the contribution of complete response (CR) to treatment to overall survival (OS) in patients with unresectable metastatic colorectal cancer. In addition, to evaluate progression-free survival (PFS) in patients who attained CR to treatment and to examine the clinicopathologic features of the patient group with CR.

METHODS

This article is a retrospective chart review. Patients diagnosed with metastatic colorectal cancer were divided into two groups. The systemic treatment was compared with the patients who received a full response according to the Response Evaluation Criteria in Solid Tumors (RECIST1.1) and those who did not attain CR (progression partial response and stable response) in terms of both PFS and OS data, and the effect of attaining CR to treatment on prognosis was evaluated.

RESULTS

A total of 222 patients were included in the study. 202 of 222 patients could be evaluated in terms of complete response. All data from their files were tabulated and analyzed retrospectively. The mean age of diagnosis of the study group was 60.13 ± 12.52 years. The total number of patients who attained CR to treatment was 31 (15.3%); 171 (84.6%) patients did not attain CR. Patients who had a CR had longer median PFS times than patients who did not have a CR (15.2 vs. 7.4 months, P<0.001). Patients who had CR had longer median survival times than patients who did not have a CR (39.2 vs. 16.9 months, P<0.001). In subgroup patients who underwent primary surgery, the number of patients who attained CR was statistically higher compared with the number of patients who did not attain CR (p<0.001). Complete response was less common in the presence of liver metastasis and bone metastasis (p = 0.041 and p = 0.046, respectively), had a negative prognostic effect. In other words, 89.1% of patients with liver metastasis, 100.0% of patients with bone metastasis, and 88.7% of those who died did not have a CR to the treatment. According to multivariate analysis, CR to treatment, primary surgery, first-line chemotherapy (combination compared with fluoropyrimidine), and no bone metastasis were found to be predictors for OS.

CONCLUSION

Providing CR with systemic treatment in patients with unresectable metastatic colorectal cancer (mCRC) contributes to prognosis. The primary resection in our secondary acquisitions from the study, the number of metastatic regions and the combination therapy regimens also contributed to the prognosis.

Involvement of parathyroid hormone-related peptide in the aggressive phenotype of colorectal cancer cells

Colorectal cancer (CRC) remains one of the leading causes of mortality from malignant diseases worldwide. In general terms, CRC presents high heterogeneity due to the influence of different genetic and environmental factors; also, the neoplastic cells are strongly influenced by the extracellular matrix and several surrounding cells, known together as the tumor microenvironment (TME). Bidirectional communication takes place between the tumor and the TME through the release of autocrine and paracrine factors. Parathyroid hormone-related peptide (PTHrP) is a cytokine secreted by a wide variety of tissues and is able to regulate several cellular functions both in physiological as well as in pathological processes. It exerts its effects as a paracrine/autocrine factor, although its mode of action is mainly paracrine. It has been shown that this peptide is expressed by several tumors and that the tumor secretion of PTHrP is responsible for the malignant humoral hypercalcemia. Eight years ago, when our research group started studying PTHrP effects in the experimental models derived from intestinal tumors, the literature available at the time addressing the effects of PTHrP on colorectal tumors was limited, and no articles had been published regarding to the paracrine action of PTHrP in CRC cells. Based on this and on our previous findings regarding the role of PTH in CRC cells, our purpose in recent years has been to explore the role of PTHrP in CRC. We analyzed the behavior of CRC cells treated with exogenous PTHrP, focalizing in the study of the following events: Survival, cell cycle progression and proliferation, migration, chemoresistance, tumor-associated angiogenesis, epithelial to mesenchymal transition program and other events also associated with invasion, such us the induction of cancer stem cells features. This work summarizes the major findings obtained by our investigation group using in vitro and in vivo CRC models that evidence the participation of PTHrP in the acquisition of an aggressive phenotype of CRC cells and the molecular mechanisms involved in these processes. Recently, we found that this cytokine induces this malignant behavior not only by its direct action on these intestinal cells but also through its influence on cells derived from TME, promoting a communication between CRC cells and surrounding cells that contributes to the molecular and morphological changes observed in CRC cells. These investigations establish the basis for our next studies in order to address the clinical applicability of our findings. Recognizing the factors and mechanisms that promote invasion in CRC cells, evasion to the cytotoxic effects of current CRC therapies and thus metastasis is decisive for the identification of new markers with the potential to improve early diagnosis and/or to predict prognosis, to predetermine drug resistance and to provide treatment guidelines that include targeted therapies for this disease.

Efficacy of Herbal Medicines Intervention for Colorectal Cancer Patients With Chemotherapy-Induced Gastrointestinal Toxicity - a Systematic Review and Meta-Analysis

Purpose: Chemotherapy-induced gastrointestinal (CIGI) toxicity affects the quality of life of patients with colorectal cancer (CRC) and the clinical application of treatment drugs. This review aims to evaluate the efficacy of traditional herbal medicines (HMs) in alleviating symptoms of CIGI toxicity (including nausea and vomiting, anorexia, diarrhea, constipation, oral mucositis, abdominal pain, and abdominal distension), and to explore further individual herb or herbal combinations in alleviating the CIGI toxicity.

Methods: Nine electronic databases were screened from 2010 to 2020. Twenty-two randomized controlled trials with a total of 1,995 patients evaluating the complementary efficacy of HMs with chemotherapy compared with chemotherapy-alone were included. Further, sensitivity analyses of orally administered multi-ingredient HM interventions were explored based on the composition of HM interventions.

Results: The meta-analysis showed that HM treatment combined with chemotherapy significantly alleviated the overall CIGI toxicity (RR = 0.78 [0.72, 0.84], p < 0.001, I² = 44%), nausea and vomiting (RR = 0.74 [0.66, 0.82], p < 0.001, I² = 35%), diarrhea (P = 0.02, RR = 0.64, 95% CI = 0.44–0.93, I² = 50%), oral mucositis (RR = 0.65 [0.48, 0.88], P = 0.005, I² = 24%), and abdominal distension (RR = 0.36 [0.18, 0.73], P = 0.004, I² = 0%). However, no statistically significant effects of HMs were shown in studies with a double-blind design for CIGI toxicity. Based on the ingredients of the HMs, further sensitivity analyses identified five herbs [Glycyrrhiza uralensis Fisch., Atractylodes macrocephala Koidz., Astragalus membranaceus (Fisch.) Bge., Codonopsis pilosula (Franch.) Nannf., and the pericarp of Citrus reticulata Blanco.] that were associated with significant reductions in CIGI toxicity.

Conclusion: A statistically significant effect of HMs combined with chemotherapy on alleviating the overall CIGI toxicity, nausea and vomiting, diarrhea, oral mucositis, or abdominal distension is only shown in studies without a double-blind design. Further well-designed, double-blinded, large-scaled randomized controlled trials (RCTs) are warranted to comprehensively evaluate the treatment efficacy. Further clinical research that includes the five herbs with chemotherapy for patients, the safety of the combinations of these herbs, and the potential synergistic effects of these combinations of herbs should be conducted.

USP11 induce resistance to 5-Fluorouracil in Colorectal Cancer through activating autophagy by stabilizing VCP

Chemotherapy plays an important role in the treatment of patients with colorectal cancer (CRC). However, the resistance to chemotherapy severely affects the prognosis of CRC patients and the mechanisms are still poorly understood. Our study investigated the role of ubiquitin-specific protease 11 (USP11) in CRC chemotherapy and found that USP11 could induce resistance to 5-fluorouracil by activating autophagy. A series of in vitro and in vivo experiments revealed that USP11 promoted autophagy through AMPK/Akt/mTOR pathway via stabilizing valosin-containing protein (VCP). Overall, our study demonstrated that USP11 might be valuable to predict the chemotherapeutic sensitivity and improve the prognosis of CRC patients.

An appraisal of emerging second line therapies for metastatic colorectal cancer

INTRODUCTION

Despite a significant improvement in overall survival over the last 15 years, colorectal cancer remains a major public health problem worldwide. Much effort has been made to develop an optimal choice of first-line treatments, but after progression the therapeutic possibilities and the criteria for choice are different.

AREAS COVERED

The purpose of this literature review is to discuss the different possibilities of second-line treatment and to specify the criteria for choice. Biological subgroups requiring specific therapeutic decisions will be described. We conducted a systematic review for randomized controlled trials published since 1995. A non-exhaustive review of published phase II studies, cohort studies, and international guidelines was also given and future leads were discussed.

EXPERT OPINION

Some choices of second-line treatments are a direct result of the option chosen in the first line. Others are necessary because of the biological specificity of the tumor: immunotherapy for tumors with microsatellite instability, or the combination encorafenib cetuximab for mutated BRAF-V600E tumors. In many other circumstances, there are several options that require extensive involvement of multidisciplinary boards and the patient in the final therapeutic decision.

Individualized prediction of survival benefit from primary tumor resection for patients with unresectable metastatic colorectal cancer

Background

The impact of primary tumor resection (PTR) on the prognosis of unresectable metastatic colorectal cancer (mCRC) patients remains debatable. We aimed to develop several prognostic nomograms which could be useful in predicting whether patients might benefit from PTR or not.

Methods

Patients diagnosed as mCRC without resected metastasis were identified from the Surveillance Epidemiology and End Results database and randomly assigned into two groups: a training cohort (6369 patients) and a validation cohort (2774 patients). Univariate and multivariable Cox analyses were performed to identify the independent predictors and construct nomograms that could independently predict the overall survival (OS) of unresectable mCRC patients in PTR and non-PTR groups, respectively. The performance of these nomograms was assessed by the concordance index (C-index), calibration curves, and decision curve analysis (DCA).

Results

Based on the result of univariate and multivariable Cox analyses, two nomograms were respectively constructed to predict the 1-year OS rates of unresectable mCRC patients when receiving PTR and not. The first one included age, gender, tumor grade, proximal colon, N stage, CEA, chemotherapy, radiotherapy, histology type, brain metastasis, liver metastasis, lung metastasis, and bone metastasis. The second nomogram included age, race, tumor grade, primary site, CEA, chemotherapy, brain metastasis, and bone metastasis. These nomograms showed favorable sensitivity with the C-index range of 0.700–0.725. The calibration curves and DCAs also exhibited adequate fit and ideal net benefits in prognosis prediction and clinical application.

Conclusions

These practical prognosis nomograms could assist clinicians in making appropriate treatment decisions to effectively manage the disease.

Nomograms for Prediction of Molecular Phenotypes in Colorectal Cancer

Background

Colorectal cancer (CRC) patients with different molecular phenotypes, including microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and somatic mutations in BRAF and KRAS gene, vary in treatment response and prognosis. However, molecular phenotyping under adequate quality control in a community-based setting may be difficult. We aimed to build the nomograms based on easily accessible clinicopathological characteristics to predict molecular phenotypes.

Methods

Three hundred and six patients with pathologically confirmed stage I-IV CRC were included in the cohort. The assays for MSI, CIMP, and mutations in BRAF and KRAS gene were performed using resected tumor samples. The candidate predictors were identified from clinicopathological variables using multivariate Logistic regression analyses to construct the nomograms that could predict each molecular phenotype.

Results

The incidences of MSI, CIMP, BRAF mutation and KRAS mutation were 25.3% (72/285), 2.5% (7/270), 3.4% (10/293), and 34.8% (96/276) respectively. In the multivariate Logistic analysis, poor differentiation and high neutrophil/lymphocyte ratio (NLR) were independently associated with MSI; poor differentiation, high NLR and high carcinoembryonic antigen/tumor size ratio (CSR) were independently associated with CIMP; poor differentiation, lymphovascular invasion and high CSR were independently associated with BRAF mutation; poor differentiation, proximal tumor, mucinous tumor and high NLR were independently associated with KRAS mutation. Four nomograms for MSI, CIMP, BRAF mutation and KRAS mutation were developed based on these independent predictors, the C-indexes of which were 61.22% (95% CI: 60.28–62.16%), 95.57% (95% CI: 95.20–95.94%), 83.56% (95% CI: 81.54–85.58%), and 69.12% (95% CI: 68.30–69.94%) respectively.

Conclusion

We established four nomograms using easily accessible variables that could well predict the presence of MSI, CIMP, BRAF mutation and KRAS mutation in CRC patients.

Bivariate network meta-analysis for surrogate endpoint evaluation

Surrogate endpoints are very important in regulatory decision making in healthcare, in particular if they can be measured early compared to the long-term final clinical outcome and act as good predictors of clinical benefit. Bivariate meta-analysis methods can be used to evaluate surrogate endpoints and to predict the treatment effect on the final outcome from the treatment effect measured on a surrogate endpoint. However, candidate surrogate endpoints are often imperfect, and the level of association between the treatment effects on the surrogate and final outcomes may vary between treatments. This imposes a limitation on methods which do not differentiate between the treatments. We develop bivariate network meta-analysis (bvNMA) methods, which combine data on treatment effects on the surrogate and final outcomes, from trials investigating multiple treatment contrasts. The bvNMA methods estimate the effects on both outcomes for all treatment contrasts individually in a single analysis. At the same time, they allow us to model the trial-level surrogacy patterns within each treatment contrast and treatment-level surrogacy, thus enabling predictions of the treatment effect on the final outcome either for a new study in a new population or for a new treatment. Modelling assumptions about the between-studies heterogeneity and the network consistency, and their impact on predictions, are investigated using an illustrative example in advanced colorectal cancer and in a simulation study. When the strength of the surrogate relationships varies across treatment contrasts, bvNMA has the advantage of identifying treatment comparisons for which surrogacy holds, thus leading to better predictions.

Multicenter open-label randomized phase II study of second-line panitumumab and irinotecan with or without fluoropyrimidines in patients with KRAS wild-type metastatic colorectal cancer (PACIFIC study)

This phase II clinical trial compared the efficacy and safety of second-line irinotecan and panitumumab treatment (IRI + Pmab) with that of irinotecan, fluoropyrimidines and panitumumab treatment (control) in patients with KRAS wild-type mCRC. The primary endpoint was progression-free survival. In addition, early predictive markers of treatment efficacy were explored. Eighty patients were planned to be recruited. Due to a slow accrual rate, only 48 patients were recruited from 2012 to 2016, of which 23 were allocated to the control group and 25 were allocated to the IRI + Pmab group. The median progression-free survival was 254 days (95% confidence interval, 159-306) for control, and 190 days (95% confidence interval, 159-213) for IRI + Pmab (log-rank test, P = 0.26). The response rate without confirmation was 21.7% (5/23) for control and 40.0% (10/25) for IRI + Pmab. Neutropenia, leukopenia, and anorexia were the most common Grade 3/4 adverse events, and several early drop-outs from the treatment protocol were observed in the control group. As for the biomarkers, carcinoembryonic antigen and lactate dehydrogenase (LDH) smoothly declined immediately after the initial dosing in patients with a partial response or stable disease. After starting treatment, LDH-1 and - 2 increased, while LDH-4 and - 5 decreased, irrespective of tumor response. However, exceptions were frequent. In conclusion, this study failed to prove the safety and efficacy of irinotecan and panitumumab treatment due to insufficient patient accrual. Although LDH and its isozymes changed after initiation of treatment, their ability to predict the tumor response may not surpass that of carcinoembryonic antigen levels.The University Hospital Medical Information Network Clinical Trial Registry: UMIN000007658.

Potential therapeutic targets for growth arrest of colorectal cancer cells exposed to PTHrP

Although PTHrP is implicated in several cancers, its role in chemoresistance is not fully elucidated. We found that in CRC cells, PTHrP exerts proliferative and protective effects and induces cell migration. The aim of this work was to further study the effects of PTHrP in CRC cells. Herein we evidenced, for the first time, that PTHrP induces resistance to CPT-11 in Caco-2 and HCT116 cells; although both cell lines responded to the drug through different molecular mechanisms, the chemoresistance by PTHrP in these models is mediated through ERK, which in turn is activated by PCK, Src and Akt. Moreover, continue administration of PTHrP in nude mice xenografts increased the protein levels of this MAPK and of other markers related to tumorigenic events. The understanding of the molecular mechanisms leading to ERK 1/2 activation and the study of ERK targets may facilitate the development of new therapeutic strategies for CRC treatment.

Second-line chemotherapy in patients with advanced or recurrent biliary tract cancer: a single center, retrospective analysis of 294 cases

Purpose The survival benefit of first-line chemotherapy (CT1) for biliary tract cancer (BTC) is now established but the role of second-line chemotherapy (CT2) has not been fully elucidated yet. Methods Consecutive advanced BTC patients receiving CT1 between 2000 and 2016 were retrospectively studied. We investigated the safety and efficacy of CT2, prognostic factors for residual survival after CT1, and explored subgroups who would benefit from CT2. Results Among 294 patients receiving CT1 for advanced BTC, CT2 was given in 139 patients (47%). CT2 provided a response rate of 4%, a disease control rate of 52%, a median progression-free survival of 2.8 and overall survival of 7.7 months, respectively. CT2 was associated with longer residual survival after CT1 (hazard ratio [HR] 0.61, p < 0.01), as well as PS of 0-1 (HR 0.53, p < 0.01), best response to CT1 of PD (HR 1.46, p = 0.01), and CEA ≥5.0 ng/mL (HR 1.69, p < 0.01). The effects of CT2 were homogeneous across almost all subgroups but were more prominent in patients with age ≥ 70 years (HR 0.32, p for interaction =0.02), CA19-9 ≥ 200 IU/mL (HR 0.41, p for interaction = 0.08) and CEA ≥5.0 ng/mL (HR 0.41, p for interaction = 0.06). Conclusions The introduction rate of CT2 was 47%. Although the efficacy of CT2 was modest in terms of tumor response, it was associated with better survival. Further investigations are necessary both to develop more effective regimens and to select patients who will benefit from CT2.

Inter-operator variability and source of errors in tumour response assessment for hepatocellular carcinoma treated with sorafenib

OBJECTIVES

To assess the inter-operator concordance and the potential sources of discordance in defining response to sorafenib in hepatocellular carcinoma (HCC).

METHODS

All patients who received sorafenib between September 2008 and February 2015 were scrutinised for this retrospective study. Images were evaluated separately by three radiologists with different expertise in liver imaging (operator 1, >10 years; operator 2, 5 years; operator 3, no specific training in liver imaging), according to: response evaluation radiological criteria in solid tumours (RECIST) 1.1, modified RECIST (mRECIST) and response evaluation criteria in cancer of the liver (RECICL).

RESULTS

The overall response concordance between the more expert operators was good, irrespective of the criteria (RECIST 1.1, ĸ = 0.840; mRECIST, ĸ = 0.871; RECICL, ĸ = 0.819). Concordance between the less expert operator and the other colleagues was lower. The most evident discordance was in target lesion response assessment, with expert operators disagreeing mostly on lesion selection and less expert operators on lesion measurement. As a clinical correlate, overall survival was more tightly related with "progressive disease" as assessed by the expert compared to the same assessment performed by operator 3.

CONCLUSIONS

Decision on whether a patient is a responder or progressor under sorafenib may vary among different operators, especially in case of a non-specifically trained radiologist. Regardless of the adopted criteria, patients should be evaluated by experienced radiologists to minimise variability in this critical instance.

KEY POINTS

• Inter-operator variability in the assessment of response to sorafenib is poorly known. • The concordance between operators with expertise in liver imaging was good. • Target lesions selection was the main source of discordance between expert operators. • Concordance with non-specifically trained operator was lower, independently from the response criteria. • The non-specifically trained operator was mainly discordant in measurements of target lesions.

Two novel SHP-1 agonists, SC-43 and SC-78, are more potent than regorafenib in suppressing the in vitro stemness of human colorectal cancer cells

Signal transducer and activator of transcription 3 (STAT3) has been shown to play a critical role in the maintenance of cancer stem cells (CSCs). Hence, the inhibition of STAT3 signaling has been suggested to be a viable therapeutic approach for cancers. Moreover, the efficacy of combinations of chemotherapeutic drugs and napabucasin, a small-molecule STAT3 inhibitor, have been assessed in various clinical trials, including those involving patients with metastatic colorectal cancer (CRC).

Two recently developed small-molecule STAT3 inhibitors, SC-43 and SC-78, which can stimulate SHP-1 to inactivate STAT3, were found to have anti-tumor activity. In this study, the inhibitory effects of SC-43, SC-78, and regorafenib (a reference drug) on cell viability, STAT3 phosphorylation, and various stemness properties [e.g., sphere-forming and soft agar colony-forming abilities, CD133⁺/CD44⁺ (stem cell-like) subpopulations, and the expression of several CSC markers] were examined for both HCT-116 and HT-29 human CRC cells. We found that SC-43 and SC-78 but not regorafenib inhibited constitutive and IL-6-induced STAT3 phosphorylation in HCT-116 and HT-29 cells, respectively. Moreover, SC-43 and SC-78 were more potent than regorafenib in suppressing the stemness properties (except stem cell-like subpopulations) of these cells. As expected, SHP-1 knockdown almost completely abolished the suppressive effects of SC-43 and SC-78 on the sphere formation in both cell lines. Furthermore, SC-43 and SC-78 showed synergistic inhibitory effects with oxaliplatin and/or irinotecan on sphere formation. Overall, our results suggest that SC-43 and SC-78 are potent STAT3 inhibitors that may potentially be used in combination therapy for CRC.

The paradigm of tumor shrinkage and rapid liver remnant hypertrophy for conversion of initially unresectable colorectal liver metastasis: a case report and literature review

Background

For colorectal liver metastasis (CRLM) patients, hepatic resection is currently the sole cure offering the chance of long-term survival. Tumor shrinkage and planned liver remnant hypertrophy are the two key strategies for conversion of initially unresectable CRLM. First conducted in 2012, associated liver partition and portal vein ligation for staged hepatectomy (ALPPS) allows rapid liver growth. As a means to induce hypertrophy, portal vein embolization (PVE) has been widely applied before extending hepatectomy. Recently, Peng et al. present a new approach of terminal branches portal vein embolization (TBPVE), offering an efficient way to amplify FLR and making chances for surgery in 2 weeks.

Case presentation

We reported a 61-year-old woman with synchronous hepatic metastasized carcinoma of the colon sigmoideum underwent TBPVE after 6 cycles of neoadjuvant therapy in order to perform a planned right trisectionectomy. Rapid liver remnant hypertrophy and remarkable tumor shrinkage were achieved, and laparoscopic sigmoidectomy and right trisectionectomy were successfully performed. The postsurgical course was uneventful and 7 months of recurrence-free survival have been witnessed.

Conclusions

The dual tactics of tumor shrinkage and planned rapid liver remnant hypertrophy will make concerted efforts to further increase the clinical candidacy for curative resection, which are valuable for further investigation.