Correlation of ADC value with pathologic indexes in colorectal tumor homografts in Balb/c mouse

The relationship between the apparent diffusion coefficient and the Ki-67 proliferation index in intracranial solitary fibrous tumor/hemangiopericytoma

This study evaluated the value of the apparent diffusion coefficient (ADC) in distinguishing grade II and III intracranial solitary fibrous tumors/hemangiopericytomas and explored the correlation between ADC and Ki-67. The preoperative MRIs of 37 patients treated for solitary fibrous tumor/hemangiopericytoma (grade II, n = 15 and grade III, n = 22) in our hospital from 2011 to October 2020 were retrospectively analyzed. We compared the difference between the minimum, average, maximum, and relative ADCs based on tumor grade and examined the correlation between ADC and Ki-67. Receiver operating characteristic curve analysis was used to analyze the diagnostic efficiency of the ADC. There were significant differences in the average, minimum, and relative ADCs between grade II and III patients. The optimal cutoff value for the relative ADC value to differentiate grade II and III tumors was 0.998, which yielded an area under the curve of 0.879. The Ki-67 proliferation indexes of grade II and III tumors were significantly different, and the average (r =  - 0.427), minimum (r =  - 0.356), and relative (r =  - 0.529) ADCs were significantly negatively correlated with the Ki-67 proliferation index. ADC can be used to differentiate grade II and III intracranial solitary fibrous tumors/hemangiopericytomas. Our results can be used to formulate a personalized surgical treatment plan before surgery.

Correlations between intravoxel incoherent motion (IVIM) parameters and histological findings in rectal cancer: preliminary results

Our purpose was to correlate different intravoxel incoherent motion (IVIM), histopathological and clinical parameters in rectal cancer. 17 patients with histologically proven rectal cancer investigated on a 3.T device were included into the study. DWI was performed using a multi-slice single-shot echo-planar imaging sequence with b values of 0, 50, 200, 500 and 1000 s/mm.² A polygonal region of interest was drawn within the tumors on every b image. The following parameters were retrieved from IVIM: apparent diffusion coefficient (ADC), true diffusion (D), pseudo diffusion coefficient (D*), perfusion factor (f), and relative perfusion f·D*. In every case, cell count, nucleic areas, proliferation index KI 67, and microvessel density were estimated on histopathological specimens. Pearson's correlation coefficient was used to analyze the association between the parameters. ADC correlated well with KI 67 index and D tended to correlate with cell count and KI 67. ADC and D tended to correlate with total nucleic area. The perfusion factor f correlated well with stained vessel area, total vessel area, and vessel count. D* and fD* correlated with mean vessel diameter. Distant metastasized tumors had higher D* and fD* values. IVIM parameter reflected different clinical and histopathological features in rectal cancer.

Use of non-invasive imaging to monitor response to aflibercept treatment in murine models of colorectal cancer liver metastases

The liver is the most frequent metastatic site in colorectal cancer (CRC), and relevant orthotopic in vivo models are needed to study the efficacy of anticancer drugs in the metastatic setting. A challenge when utilizing such models is monitoring tumor growth during the experiments. In this study, experimental liver metastases were established in nude mice by splenic injection of the CRC cell lines HT29 and HCT116, and the mice were treated with the antiangiogenic drug aflibercept. Tumor growth was monitored using magnetic resonance imaging (MRI) and bioluminescence imaging (BLI). Aflibercept treatment was well tolerated and resulted in increased animal survival in HCT116, but not in HT29, while inhibited tumor growth was observed in both models. Treatment efficacy was monitored with high precision using MRI, while BLI detected small-volume disease with high sensitivity, but was less accurate in end-stage disease. Apparent diffusion coefficient (ADC) values obtained by diffusion weighted MRI (DW-MRI) were highly predictive of treatment response, with increased ADC corresponding well with areas of necrosis observed by histological evaluation of aflibercept-treated xenografts. The results showed that the efficacy of the antiangiogenic drug aflibercept varied between the two models, possibly reflecting unique growth patterns in the liver that may be representative of human disease. Non-invasive imaging, especially MRI and DW-MRI, can be used to effectively monitor tumor growth and treatment response in orthotopic liver metastasis models.

Fluorouracil-based preoperative chemoradiotherapy with or without oxaliplatin for stage II/III rectal cancer: a 3-year follow-up study

BACKGROUND

Fluorouracil-based preoperative chemoradiotherapy has become the standard treatment for stage II/III rectal cancer. In order to improve the overall survival (OS) and disease-free survival (DFS), we added oxaliplatin to the standard treatment, and compared the effectiveness of these two treatment patterns.

METHODS

A total of 206 patients enrolled in the prospective study had histologically confirmed rectal cancer of clinical stage II/III during July 2007 to July 2010. They were randomized into the experimental group received oxaliplatin and capecitabine in combination with radiotherapy, and the control group received capecitabine in combination with radiotherapy. All patients received surgery in 6-10 weeks after chemoradiotherapy and adjuvant chemotherapy with mFOLFOX6. The primary endpoints were DFS and OS, and the secondary endpoints included toxicity, compliance, and histopathological response.

RESULTS

The 3-year OS in the experimental group and the control group was 90.29% vs. 86.41% (P>0.05), and the 3-year DFS was 80.58% vs. 69.90% (P>0.05). The pathological complete remission (pCR) rates were 23.30% and 19.42%, respectively (P=0.497). The 3-year local recurrence rates were 4.85% vs. 5.83% (P=0.694), and the 3-year distant metastasis rates were 16.50% and 28.16%, respectively (P=0.045). There were no significant differences in most grade 3-4 toxicities between two groups, however, grade 3-4 diarrhea occurred in 16.50% (17/103) of the experimental group, compared with 6.80% (7/103) of the control group (P=0.030). Also, the total grade 3-4 acute toxicity showed a significant difference (10.68% vs. 21.36%, P=0.037).

CONCLUSIONS

The experimental treatment did not lead significantly improved OS and DFS, and thus longer follow-up is warranted for our patient cohort. Adding oxaliplatin to capecitabine-based preoperative chemoradiotherapy can significantly reduce metastasis, but has only minimal impact on local recurrence. Although grade 3-4 toxicity rate increased (primarily gastrointestinal toxicity), patients can stand to be followed up with allopathic treatment.

Biomarkers in preclinical cancer imaging

In view of the trend towards personalized treatment strategies for (cancer) patients, there is an increasing need to noninvasively determine individual patient characteristics. Such information enables physicians to administer to patients accurate therapy with appropriate timing. For the noninvasive visualization of disease-related features, imaging biomarkers are expected to play a crucial role. Next to the chemical development of imaging probes, this requires preclinical studies in animal tumour models. These studies provide proof-of-concept of imaging biomarkers and help determine the pharmacokinetics and target specificity of relevant imaging probes, features that provide the fundamentals for translation to the clinic. In this review we describe biological processes derived from the “hallmarks of cancer” that may serve as imaging biomarkers for diagnostic, prognostic and treatment response monitoring that are currently being studied in the preclinical setting. A number of these biomarkers are also being used for the initial preclinical assessment of new intervention strategies. Uniquely, noninvasive imaging approaches allow longitudinal assessment of changes in biological processes, providing information on the safety, pharmacokinetic profiles and target specificity of new drugs, and on the antitumour effectiveness of therapeutic interventions. Preclinical biomarker imaging can help guide translation to optimize clinical biomarker imaging and personalize (combination) therapies.