Early morphological change for predicting outcome in metastatic colorectal cancer after regorafenib

New response evaluation criteria using early morphological change in imatinib treatment for patients with gastrointestinal stromal tumor

BACKGROUND

The introduction of molecularly targeted drugs, including imatinib, has greatly improved the prognosis of gastrointestinal stromal tumor (GIST), and based on the different response image, the methods of response evaluation have been established for GISTs. Furthrmore, the best response evaluation using them has been reported to be associated with progression-free survival (PFS) in imatinib treatment. However, since it is more important to predict the clinical outcomes of imatinib treatment in "early treatment phase", new predicting factor in earlier stage is desired to work out the whole strategy of each patient. Early morphological change (EMC) was previously reported as a predictive marker for molecularly targeted drugs in metastatic colorectal cancer. The purpose of the present study was to verify the efficacy of EMC in predicting the outcome in patients with GIST receiving imatinib at early evaluation.

METHODS

We retrospectively reviewed 66 patients. EMC in computed tomography (CT) image was evaluated, and the patients were categorized into two groups: active MR (morphological response) (+) group and active MR (-) group. We investigated the association between the presence of active MR and clinical outcomes.

RESULTS

Forty-five patients had active MR ( +). The median progression-free survival (PFS) in patients with/without active MR was 49/23 months (P = 0.0039).

CONCLUSION

The evaluation criteria based on EMC could be a sensitive method to predict the clinical outcome of imatinib treatment for patients with unresectable GIST.

Practical considerations in the use of regorafenib in metastatic colorectal cancer

Over the past 20 years, management of patients with metastatic colorectal cancer (mCRC) has improved considerably, leading to increased overall survival and more patients eligible for third- or later-line therapy. Currently, two oral therapies are recommended in the third-line treatment of mCRC, regorafenib and trifluridine/tipiracil. Selecting the most appropriate treatment in the third-line setting poses different challenges compared with treatment selection at earlier stages. Therefore, it is important for physicians to understand and differentiate between available treatment options and to communicate the benefits and challenges of these to patients. In this narrative review, practical information on regorafenib is provided to aid physicians in their decision-making and patient communications in daily practice. We discuss the importance of appropriate patient selection and adverse events management through close patient monitoring and dose adjustments to ensure patients stay on treatment for longer and receive as much benefit as possible. We also highlight key physician-patient communication points to facilitate shared decision-making.

Imaging and clinical correlates with regorafenib in metastatic colorectal cancer

In colorectal cancer (CRC), imaging is important in determining tumor stage, selecting treatment strategies, and in assessing response to therapy. However, some challenges remain with established imaging techniques, such as computed tomography, and with some commonly used response criteria, such as Response Evaluation Criteria in Solid Tumors, which measures change in size of several target lesions instead of change in tumor morphology or metabolic function. In addition, these assessments are not typically conducted until after 8 weeks of treatment, meaning that potential non-responders are often not identified in a timely manner. Regorafenib, an oral tyrosine kinase inhibitor indicated for the treatment of metastatic CRC, blocks the activity of several protein kinases involved in angiogenesis, oncogenesis, metastasis, and tumor immunity. Timely differentiation of regorafenib responders from non-responders using appropriate imaging techniques that recognize not only changes in tumor size but also changes in tumor density or vasculature, may reduce unnecessary drug-related toxicity in patients who are unlikely to respond to treatment. This review discusses the latest developments in computed tomography, magnetic resonance imaging, and positron emission tomography tumor imaging modalities, and how these aid in identifying patients with metastatic CRC who are responders or non-responders to regorafenib treatment.

Multicenter Cohort Study to Assess the Association between Changes on Imaging and Outcome after Regorafenib Treatment (KSCC1603)

<b><i>Background:</i></b> Molecular targeted drugs having angiogenesis-inhibiting properties allow the induction of necrosis inside tumors. We retrospectively investigated the relationship between changes on imaging associated with regorafenib (REGO) and treatment outcomes using real-world data. <b><i>Patients and Methods:</i></b> The eligibility criteria included an ECOG PS of 0–1, a starting dose of 120 or 160 mg/day of REGO, and a duration of treatment of at least 35 days. Regarding changes on imaging, cavitation in lung lesions (CLL), morphologic response of liver lesions (MRL), and change of liver metastasis density (CLD) were evaluated. <b><i>Results:</i></b> We finally screened 671 cases, and 226 cases were eligible. In total, 172 and 145 patients had lung and liver metastases, respectively. Among the patients with lung metastasis, CLL was found in 69 patients (40.0%). The median progression-free survival (PFS) of the patients with and those without CLL was 3.2 and 2.4 months, respectively (hazard ratio [HR] = 0.758; 95% confidence interval [CI]: 0.529–1.087), and the median overall survival (OS) of these groups was 10.5 and 8.9 months, respectively (HR = 0.862; 95% CI: 0.579–1.285). MRL and CLD of liver metastasis were analyzed in 145 and 90 patients, respectively. The median OS with and without MRL was 8.9 and 8.2 months, respectively, whereas the median OS with and without CLD was 11.6 and 7.7 months, respectively (HR = 0.523; 95% CI: 0.275–0.992). <b><i>Conclusion:</i></b> CLL may predict PFS but not OS among patients with lung metastasis. CLD was predictive of favorable outcomes for REGO in patients with liver metastasis.

[Radiologic response assessment in metastatic colorectal cancers]

The increasing indications of cytostatic biotherapies and the improvement in metastatic surgery have profoundly changed the management of metastatic colorectal cancer (mCRC) patients. Then the development of prognostic and predictive scores would be useful to stratify the treatments. Tumor radiological measurement is crucial to estimate treatment efficacy, and to predict pathological response and survival, and this parameter is included when a prognostic score is developed. But the standard size-based radiologic criteria, the Response Evaluation Criteria in Solid Tumors (RECIST), was designed ten years ago to assess tumor volume reduction after cytotoxic chemotherapy only. Nowadays, this method may be insufficient for mCRC patients. The aim of this review is to describe the different radiological assessments evaluated in mCRC, and to underline their correlations with patient's survival and pathologic response. A better knowledge of these radiological measurements would help to better integrate them in prospective trials, and in the prognostic and predictive scores. The choice of radiological measurement could be discussed regarding patient's situation, combining different approaches, and assessing tumoral mass quantification.

Clinical Implications of Decreased Computed Tomography Value after Ramucirumab in Advanced Gastric Cancer

OBJECTIVES

This study aimed to evaluate whether a decrease of computed tomography (CT) value for tumors serves as a predictive marker in patients with advanced gastric cancer (aGC) who have undergone chemotherapy with vascular epithelial growth factor receptor 2 inhibitor (ramucirumab).

METHOD

We retrospectively analyzed 44 patients with aGC who received taxane alone (TAX arm; n = 33), ramucirumab alone, or ramucirumab in combination with taxane (RAM arm; n = 11) as second-line or later chemotherapy between July 2010 and October 2016. In all patients, tumor size and tumor CT value were evaluated at two timepoints: pretreatment and first evaluation. We calculated the change of the tumors' CT value. The associations of these factors with tumor response, progression-free survival (PFS), and overall survival were investigated.

RESULTS

Ten (90.9%) of 11 patients in the RAM arm and 18 (54.5%) of 33 patients in the TAX arm showed decreased CT values. The rate of CT value change in the RAM arm (median -32.80%, range -53.63 to 6.84%) was higher than that in the TAX arm (median -0.44%, range -37.47 to 40.64%; p = 0.0005). When using the median value of CT value change as a cut-off, PFS was significantly longer in patients with a high rate of CT value change (decrease ≥32.80%) than in those with a low rate (decrease <32.80%) in the RAM arm (median 292 and 112 days; p = 0.045), while no significant difference of this kind was found in the TAX arm (median 91 and 125 days; p = 0.45).

CONCLUSIONS

Patients with aGC treated with ramucirumab experienced a significant decrease of CT value of tumors and had an association between the rate of CT value change and PFS. Our study suggests that CT value changes of tumors may be a predictor for the efficacy of ramucirumab in aGC.

Regorafenib: A Review in Metastatic Colorectal Cancer

Regorafenib (Stivarga^®) is an oral small-molecule multiple kinase inhibitor. It is indicated worldwide for patients with metastatic colorectal cancer (mCRC). In the EU and USA it is indicated for patients with mCRC who have been previously treated with, or are not considered candidates for available therapies, including fluoropyrimidine-based chemotherapy, an anti-VEGF therapy and, if RAS wild-type, an anti-EGFR therapy. In Japan, it is indicated for the treatment of unresectable, advanced/recurrent CRC. The addition of regorafenib to best supportive care prolonged median overall survival (OS; by up to 2.5 months) and progression-free survival (PFS; by up to 1.5 months) relative to the addition of placebo in double-blind phase 3 studies (CORRECT and CONCUR) in patients with mCRC who had progressed after failure of standard therapy. Health-related quality of life was not adversely affected with regorafenib relative to placebo. A large open-label phase 3 study (CONSIGN) and several large real-world studies supported the efficacy of regorafenib in this setting. Regorafenib had a generally manageable tolerability profile, which was consistent with the profile of a typical small-molecule multiple kinase inhibitor. Treatment-related adverse events (AEs), mostly of mild or moderate severity, were reported in the majority of patients receiving regorafenib, with dermatological toxicities and liver enzyme elevations among the most common AEs. Although identification of biomarkers/parameters predicting efficacy outcomes with regorafenib will help to individualize therapy, current evidence indicates that regorafenib is a valuable treatment option for patients with refractory mCRC who have a very poor prognosis.

Design, synthesis and antiproliferative evaluation of novel sulfanilamide-1,2,3-triazole derivatives as tubulin polymerization inhibitors

Microtubule as an important target in the cancer therapy was used to design novel tubulin polymerization inhibitors. Sulfanilamide-1,2,3-triazole hybrids were designed by a molecular hybridization strategy and their antiproliferative activity against three selected cancer cell lines (BGC-823, MGC-803 and SGC-7901) were evaluated. All sulfanilamide-1,2,3-triazole hybrids displayed potent inhibitory activity against all cell lines. In particular, compound 10b showed the most excellent inhibitory effect against MGC-803 cells, with an IC₅₀ value of 0.4 μM. Cellular mechanism studies elucidated that 10b induced apoptosis by decreasing the expression level of Bcl-2 and Parp and increasing the expression level of BAX. 10b inhibited the epithelial-mesenchymal transition process by up-regulating E-cadherin and down-regulating N-cadherin. Furthermore, the tubulin polymerization inhibitory activity in vitro of 10b was 2.4 μM. In vivo anticancer assay, 10b effectively inhibited MGC-803 xenograft tumor growth without causing significant loss of body weight. These sulfanilamide-1,2,3-triazole hybrids as potent tubulin polymerization inhibitors might be used as promising candidates for cancer therapy.

Antiproliferative Phenothiazine Hybrids as Novel Apoptosis Inducers against MCF-7 Breast Cancer

We designed a series of novel phenothiazine-1,2,3-triazole hybrids by the molecular hybridization strategy and evaluated their antiproliferative activity against three cancer cell lines (MDA-MB-231, MDA-MB-468 and MCF-7). For the structure-activity relationships, the importance of 1,2,3-triazole and substituents on phenyl ring was explored. Among these phenothiazine-1,2,3-triazole hybrids, compound 9f showed the most potent inhibitory effect against MCF-7 cells, with an IC₅₀ value of 0.8 μM. Importantly, compound 9f could induce apoptosis against MCF-7 cells by regulating apoptosis-related proteins (Bcl-2, Bax, Bad, Parp, and DR5). These potent phenothiazine-1,2,3-triazole hybrids as novel apoptosis inducers might be used as antitumor agents in the future.