Modeling efficacy of bevacizumab treatment for metastatic colon cancer

Clinical Factors Affecting Bevacizumab Efficacy With and Without Conventional Chemotherapy in Metastatic Colon Cancer

PURPOSE

Bevacizumab (BZ) combined with first line chemotherapy (CC) has shown good clinical outcomes in metastatic colorectal cancer (mCRC). Overall survival (OS) and/or progression free survival in mCRC patients receiving BZ with or without 5FU-based CC is thought to be affected by clinical and morphological factor(s).

PATIENTS AND METHODS

We reviewed retrospective medical records of all consecutive mCRC patients treated with BZ with or without CC at tertiary care center between 2003 and 2009 out of which149 patients (m = 77, f = 72) were eligible.

RESULTS

Our study population had a mean age at diagnosis of 63.5 years (SD = 11) with median follow-up period of 19.4 months. On initial radiological evaluation following BZ therapy, 56 patients (m = 31, f = 25) had complete or partial response categorized as "early responders." Remaining patients (m = 46, f = 47) who were either stable or showed progressive disease were categorized as "non-responders." Fifty percent among early responders and 60% among non-responders [relative risk (RR) 0.67 (95% confidence interval (CI), 0.43-1.06)] demonstrated disease progression on follow up. There was a slightly better OS among early responders compared to non-responders (median 21.5 months days versus 16.8 months, P = 0.07). Cox regression analysis suggested male sex (RR 0.65, 95% CI, 0.43-0.98), hematochezia (RR 0.63, 95% CI, 0.4-0.98), resectable primary tumor (RR 0.42, 95% CI, 0.24-0.72) and resectable metastatic mass (RR 0.32, 95% CI, 0.14-0.74) were found to be associated with longer OS. Abdominal pain (RR 1.76, 95% CI, 1.1-2.8), accompanying diabetes (RR 1.76, 95% CI, 1.09-2.85), and unexplained weight loss (RR 2.73, 95% CI, 1.73-4.29) were associated with poor OS.

CONCLUSIONS

Better OS among mCRC patients with resectable primary and metastatic tumors was seen. This is the first study to demonstrate slightly better outcome in males and negative influence of diabetes on outcome in mCRC treated with BZ.

CT Perfusion Imaging Can Predict Patients' Survival and Early Response to Transarterial Chemo-Lipiodol Infusion for Liver Metastases from Colorectal Cancers

Objective

To prospectively evaluate the performance of computed tomography perfusion imaging (CTPI) in predicting the early response to transarterial chemo-lipiodol infusion (TACLI) and survival of patients with colorectal cancer liver metastases (CRLM).

Materials and Methods

Computed tomography perfusion imaging was performed before and 1 month after TACLI in 61 consecutive patients. Therapeutic response was evaluated on CT scans 1 month and 4 months after TACLI; the patients were classified as responders and non-responders based on 4-month CT scans after TACLI. The percentage change of CTPI parameters of target lesions were compared between responders and non-responders at 1 month after TACLI. The optimal parameter and cutoff value were determined. The patients were divided into 2 subgroups according to the cutoff value. The log-rank test was used to compare the survival rates of the 2 subgroups.

Results

Four-month images were obtained from 58 patients, of which 39.7% were responders and 60.3% were non-responders. The percentage change in hepatic arterial perfusion (HAP) 1 month after TACLI was the optimal predicting parameter (p = 0.003). The best cut-off value was -21.5% and patients who exhibited a ≥ 21.5% decrease in HAP had a significantly higher overall survival rate than those who exhibited a < 21.5% decrease (p < 0.001).

Conclusion

Computed tomography perfusion imaging can predict the early response to TACLI and survival of patients with CRLM. The percentage change in HAP after TACLI with a cutoff value of -21.5% is the optimal predictor.

Oil-in-water biocompatible microemulsion as a carrier for the antitumor drug compound methyl dihydrojasmonate

Methyl dihydrojasmonate (MJ) has been studied because of its application as an antitumor drug compound. However, as MJ is a poorly water-soluble compound, a suitable oil-in-water microemulsion (ME) has been studied in order to provide its solubilization in an aqueous media and to allow its administration by the parenteral route. The ME used in this work was characterized on the pseudo-ternary phase diagram by dynamic light scattering and rheological measurements. Regardless of the drug presence, the droplet size was directly dependent on the oil/surfactant (O/S) ratio. Furthermore, the drug incorporation into the ME significantly increased the ME diameter, mainly at low O/S ratios. The rheological evaluation of the systems showed that in the absence of drug a Newtonian behavior was observed. On the other hand, in the presence of MJ the ME systems revealed pseudoplastic behavior, independently of the O/S ratio. The in vivo studies demonstrated that not only was the effect on the tumor inhibition inversely dependent on the MJ-loaded ME administered dose, but also it was slightly higher than the doxorubicin alone, which was used as the positive control. Additionally, a small antiangiogenic effect for MJ-loaded ME was found at doses in which it possesses antitumor activity. MJ revealed to be nontoxic at doses higher than 350 mg/kg, which was higher than the dose that provides tumor-inhibition effect in this study. Because the MJ-loaded ME was shown to have anticancer activity comparable to doxorubicin, the ME described here may be considered a suitable vehicle for parenteral administration of MJ.

Morpholino-Mediated Isoform Modulation of Vascular Endothelial Growth Factor Receptor-2 (VEGFR2) Reduces Colon Cancer Xenograft Growth

Angiogenesis plays a key role in tumor growth. Vascular endothelial growth factor (VEGF) is a pro-angiogenic that is involved in tumor angiogenesis. When VEGF binds to membrane-bound vascular endothelial growth factor receptor 2 (mVEGFR2), it promotes angiogenesis. Through alternative polyadenylation, VEGFR2 is also expressed in a soluble form (sVEGFR2). sVEGFR2 sequesters VEGF and is therefore anti-angiogenic. The aim of this study was to show that treatment with a previously developed and reported antisense morpholino oligomer that shifts expression from mVEGFR2 to sVEGFR2 would lead to reduced tumor vascularization and growth in a murine colon cancer xenograft model. Xenografts were generated by implanting human HCT-116 colon cancer cells into the flanks of NMRI nu/nu mice. Treatment with the therapeutic morpholino reduced both tumor growth and tumor vascularization. Because the HCT-116 cells used for the experiments did not express VEGFR2 and because the treatment morpholino targeted mouse rather than human VEGFR2, it is likely that treatment morpholino was acting on the mouse endothelial cells rather than directly on the tumor cells.

Personalized medicine in metastatic colorectal cancer treated with anti-epidermal growth factor receptor agents: a future opportunity?

Treatment options for colorectal cancer have increased substantially in the past decade, with the introduction of novel biological therapies targeting cancer-specific molecules leading to significantly improved outcomes. Despite access to these treatments, we are not yet in an era where we can fully personalize treatment choices for patients with colorectal cancer. A number of prognostic and predictive markers have been identified that appear to be directly related to sensitivity to targeted therapies, such as those against epidermal growth factor receptor. However, the sensitivities of individual tumors toward different biological agents appear to be more complex. It seems that a more complete molecular signature of the tumor must be taken into account when making individual treatment choices. In the absence of having fully elucidated the influence of these prognostic or predictive markers, other surrogate markers of early treatment success may be useful in determining whether to continue treatment with a particular agent. In this review, we discuss the role of molecular markers in choosing appropriate treatment for the individual patient, along with the use of measuring the depth of response to a particular agent to assist decisions on whether to continue therapy in colorectal cancer.

Vascular Endothelial Growth Factor in Colonic Cancer, Ulcerative Colitis and Colonic Adenoma: An Immunohistochemical Study

BACKGROUND: Colon cancer is one of the most common malignancies worldwide. Colonic adenoma and ulcerative colitis (UC) are important precancerous lesions. Vascular Endothelial Growth Factor (VEGF) is a well-known pro-angiogenic factor plays important role in physiologic and pathologic conditions and in neovascularization in cancer and hence becomes a potential target for anti-angiogenic cancer therapy.AIM: This study investigated VEGF immunohistochemical expression in colon cancer and its precancerous lesions. MATERIAL AND METHODS:  Paraffin blocks from two hospitals were collected in a year: Colon cancer: 20 cases, colonic adenoma: 15 cases, UC: 15 cases and 5 controls from normal mucosa. VEGF was assessed immunohistochemically using a primary anti-VEGF antibody (VG1, Dako, Denemark).RESULTS: Median age was 49 years (range 31-52) in cancer, 40 years (range 31-52) in adenomas and 33 years (range 27-43) in UC. VEGF expression was negative in control, significantly strongly positive in 90% of colonic adenocarcinoma (p= 0.001), significantly positive in adenomas (p= 0.002) - the weak positivity significantly seen in mild dysplasia (p= 0.001) - and significantly positive in 73.3% of UC cases (p=0.022).CONCLUSION: The significant increase in positivity of VEGF in precancerous to cancerous lesions may point to its potential role in the pathogenesis and progression of colonic neoplasia.

Perfusion CT best predicts outcome after radioembolization of liver metastases: a comparison of radionuclide and CT imaging techniques

OBJECTIVE

To determine the best predictor for the response to and survival with transarterial radioembolisation (RE) with (90)yttrium microspheres in patients with liver metastases.

METHODS

Forty consecutive patients with liver metastases undergoing RE were evaluated with multiphase CT, perfusion CT and (99m)Tc-MAA SPECT. Arterial perfusion (AP) from perfusion CT, HU values from the arterial (aHU) and portal venous phase (pvHU) CT, and (99m)Tc-MAA uptake ratio of metastases were determined. Morphologic response was evaluated after 4 months and available in 30 patients. One-year survival was calculated with Kaplan-Meier curves.

RESULTS

We found significant differences between responders and non-responders for AP (P < 0.001) and aHU (P = 0.001) of metastases, while no differences were found for pvHU (P = 0.07) and the (99m)Tc-MAA uptake ratio (P = 0.40). AP had a significantly higher specificity than aHU (P = 0.003) for determining responders to RE. Patients with an AP >20 ml/100 ml/min had a significantly (P = 0.01) higher 1-year survival, whereas an aHU value >55 HU did not discriminate survival (P = 0.12). The Cox proportional hazard model revealed AP as the only significant (P = 0.02) independent predictor of survival.

CONCLUSION

Compared to arterial and portal venous enhancement and the (99m)Tc-MAA uptake ratio of liver metastases, the AP from perfusion CT is the best predictor of morphologic response to and 1-year survival with RE.

KEY POINTS

• Perfusion CT allows for calculation of the liver arterial perfusion. • Arterial perfusion of liver metastases differs between responders and non-responders to RE. • Arterial perfusion can be used to select patients responding to RE.

Advances and Prospects in Cancer Immunotherapy

Cancer immunotherapy is a promising and effective treatment modality for patients with cancers. Cytokine, anticytokine, and antibody therapies appear to be effective in treating various forms of cancer. The human papillomavirus vaccine is protective for cervical cancer, and this discovery has paved the way to the development of cancer vaccines for other forms of virus-associated cancers such as liver cancer and Merkel cell carcinoma. Clinical trials have demonstrated that adoptive cell therapy using tumor-infiltrating lymphocytes can induce tumor regression in approximately 75% of metastatic melanoma patients, suggesting the possibility of using similar technique to effectively treat breast, lung, and renal cancers in the near future. Besides, genetically engineered T cells transduced with genes encoding specific T cell receptors and chimeric antigen receptors have been shown effective in the treatment of cancer patients. These studies suggest that combination therapies are superior choices in cancer immunotherapy for patients.