The identification of candidate effective combination regimens for pancreatic cancer using the histoculture drug response assay.

The prognosis for patients with pancreatic cancer is extremely poor, as they are resistant to first line chemotherapy. The long-term goal of this study was to identify effective combination chemotherapy for pancreatic cancer using pancreatic cancer surgical specimens in the histoculture drug response assay (HDRA) based on three-dimensional culture of tumour fragments, which maintains nature tumour histology in vitro. From 2015 to 2017, the HDRA was performed with tumour specimens from 52 pancreatic cancer patients from Asan Medical Hospital. First, combination drug regimens showed higher drug efficacy and less patient variation than single drugs. Initially, 5-Fluorouracil(5-FU)/Belotecan/Oxaliplatinum and Tegafur/Gimeracil (TS-1)/Oxaliplatinum/Irinotecan were found to be effective. Second, we were able to correlate the efficacy of some drugs with tumour stage. Third, when designing new combination regimens containing 5-FU or gemcitabine, we could identify more effective drug combinations. This is the first study to demonstrate usefulness of the HDRA for pancreatic cancer. Using this technique, we could identify novel candidate combination drug regimens that should be effective in treating pancreatic cancer.

A Single Low Dose of Eribulin Regressed a Highly Aggressive Triple-negative Breast Cancer in a Patient-derived Orthotopic Xenograft Model.

BACKGROUND/AIM: In the present study, the breast cancer patient-derived orthotopic xenograft (PDOX) model was used to identify an effective drug for a highly aggressive triple negative breast cancer (TNBC). MATERIALS AND METHODS: The TNBC tumor from a patient was implanted in the right 4th inguinal mammary fat pad of nude mice to establish a PDOX model. Three weeks later, 19 mice were randomized into the untreated-control group (n=10) and the eribulin treatment group (n=9, eribulin, 0.3 mg/kg, i.p., day 1). RESULTS: On day 8, eribulin significantly inhibited tumor volume compared to the control group (p<0.01). Eribulin regressed tumors in 3 mice (33.3%) and apparently eradicated them in 6 mice (66.7%). At day 14, tumor regrowth was observed in 2 mice of the eribulin group, which was undetectable on day 8. However, 44.4% (4 out of 9) of the mice in the eribulin group were tumor-free on day 14. CONCLUSION: A single low-dose eribulin was efficacious on a highly aggressive TNBC. The breast cancer PDOX model can be used to identify highly effective drugs for TNBC.

Genetic and metabolic comparison of orthotopic and heterotopic patient-derived pancreatic-cancer xenografts to the original patient tumors.

Tumors from 25 patients with pancreatic cancer were used to establish two patient-derived xenograft (PDX) models: orthotopic PDX (PDOX) and heterotopic (subcutaneous) PDX (PDHX). We compared gene expression by immunohistochemistry, single-nucleotide polymorphism (SNP), DNA methylation, and metabolite levels. The 4 cases, of the total of 13 in which simultaneous PDHX & PDOX models were established, were randomly selected. The molecular-genetic characteristics of the patient's tumor were well maintained in the two PDX models. SNP analysis demonstrated that both groups were more than 90% identical to the original patient's tumor, and there was little difference between the two models. DNA methylation of most genes was similar among the two models and the original patients tumor, but some gene sets were hypermethylated the in PDOX model and hypomethylated in the PDHX model. Most of the metabolites had a similar pattern to those of the original patient tumor in both PDX tumor models, but some metabolites were more prominent in the PDOX and PDHX models. This is the first simultaneous molecular-genetic and metabolite comparison of patient tumors and their tumors established in PDOX and PDHX models. The results indicate high fidelity of these critical properties of the patient tumors in the two models.

Prospective Clinical Correlation of the Histoculture Drug Response Assay for Ovarian Cancer.

The histoculture drug response assay (HDRA) has been correlated clinically to a number of cancer types (please see Chaps. 7 - 11 of the present volume). The present chapter reviews the clinical trials of the HDRA for ovarian cancer. A prospective clinical trial of the HDRA for advanced epithelial ovarian cancer (AEOC) was performed at Asan Medical Center, Seoul, Korea. The clinical trial compared the efficacy of first-line therapy paclitaxel and carboplatinum in the HDRA and the clinical response for the patients whose tumors were tested in the HDRA. A series of patients (104) were treated with adjuvant combination chemotherapy of paclitaxel and carboplatinum after primary cytoreductive surgery. Tumor fragments were cultured on Gelfoam® and tested with paclitaxel and carboplatinum and evaluated with the MTT endpoint. Patients were categorized into two groups as either sensitive to both drugs (SS) or not sensitive to one or both drugs (R) based on HDRA results. The recurrence rate was much lower in the SS group compared to the R group, 29.2% vs. 69.8%, respectively. The SS group had a significantly longer progression-free survival compared to the R group, 34.0 months vs. 16.0 months, respectively. In another clinical trial, the HDRA was performed on 85 cases of ovarian cancer and 97% were evaluable. HDRA results were correlated to clinical response of 15 patients who received cisplatinum-based therapy that included doxorubicin and cyclophosphamide (CAP therapy). The true-positive rate was 88%, the true-negative rate was 86%, the sensitivity was 88%, the specificity was 86%, and the accurate prediction rate was 87% when HDRA results were compared to the response of the treated patients.

Development and Applicability of Integrative Tumor Response Assays for Metastatic Colorectal Cancer.

AIM: The present study investigated how well the results of integrative tumor-response assay (ITRA) compared to those of clinical response to chemotherapy in patients with metastatic colorectal cancer (CRC). PATIENTS AND METHODS: A total of 129 patients with metastatic CRC were prospectively enrolled. ITRA consisted of two sequential histoculture drug-response assays (HDRAs). First-stage HDRAs were performed using 5-fluorouracil with leucovorin and oxaliplatin (FX), or with irinotecan (FR). Second-stage HDRAs (ITRA) were performed for cells surviving after the first-stage HDRA, using FX, FR, and their combinations with bevacizumab and cetuximab. RESULTS: Among 129 patients, 42 (32.6%) completed second-line chemotherapy, results that correlated with those of ITRA. The accuracy of ITRA for predicting response to second-line chemotherapy was 61.9% (26/42), with a sensitivity of 44.4% (8/18) and a specificity of 75% (18/24). CONCLUSION: Despite its relatively low accuracy, ITRA might be a useful technique for predicting therapeutic efficacy and selecting for appropriate first-line and second-line anticancer regimens for patients.

Surgical and Oncological Factors Affecting the Successful Engraftment of Patient-derived Xenografts in Pancreatic Ductal Adenocarcinoma.

BACKGROUND: To effectively use pancreatic cancer patient-derived xenograft (PDX) models in translational research, successful PDX engraftment of surgical specimens in immune-deficient mice is needed. MATERIALS AND METHODS: A total of 102 patients underwent pancreatic cancer resection using various procedures. Tumor tissue from all patents was implanted subcutaneously into mice. Tumor engraftment and growth in mice were determined. Engraftment was tested for correlation with operation type, time, tumor size, and oncogene expression using immunohistoculture. RESULTS: Multivariate analysis showed that a tumor size of more than 3.5 cm in the patient was a significant factor related to successful PDX engraftment. In contrast, there was no correlation of engraftment with surgical procedure, time needed to remove the specimen, tumor differentiation, lymph node metastasis, and protein expression of p53, Receptor tyrosine-protein kinase erbB-2 (CERBB2), or deleted in pancreatic carcinoma locus 4 (DPC4). CONCLUSION: A minimum tumor size in the patient is an important factor for successful tumor engraftment.

Independence of cytotoxic drug sensitivity profiles and receptor subtype of invasive ductal breast carcinoma demonstrated by the histoculture drug response assay (HDRA).

AIM: Breast cancer can be divided into four subtypes: luminal-A, luminal-B, HER-2 enriched and triple negative breast cancer (TNBC) by the presence or absence of receptors. Each subtype has a typical clinical behavior and prognosis. Many chemotherapeutic agents are used clinically for breast cancer. The histoculture drug response assay (HDRA) is used for selection of effective chemotherapeutic agents for individual patients Materials and Methods: In the present study, the HDRA was used for eleven frequently-used single-agent or combinations on the four subtypes of breast cancer in order to determine the correlation of drug sensitivity profile and breast-cancer subtype. Fifty invasive ductal breast carcinoma patients who underwent cancer surgery and adjuvant chemotherapy between January 2012 and January 2013 had their tumors analyzed in the HDRA. Age, gender, height and weight, tumor-nodes-metastasis (TNM) stage, immunohistochemical (IHC profiles, breast-cancer subtypes and HDRA results were recorded. RESULTS: The inhibition rate (IR) of each agent or combination for each breast-cancer subtype was determined. Drug to drug IRs were statistically distinct in all subtypes (p<0.05) but no correlation between response to chemotherapeutic agents and breast-cancer subtype was found (p=0.851 by two-way ANOVA test). CONCLUSION: The clear difference between average sensitivity of the chemotherapeutic agents tested and lack of correlation with breast-cancer subtype suggest the importance of individualized treatment for breast-cancer patients.

Progression-free survival is accurately predicted in patients treated with chemotherapy for epithelial ovarian cancer by the histoculture drug response assay in a prospective correlative clinical trial at a single institution.

This study aimed to prospectively correlate clinical outcomes of advanced epithelial ovarian cancer (AEOC), with the results of in vitro chemosensitivity testing of taxol and carboplatin using the in vitro histoculture drug response assay (HDRA). A total of 104 patients with AEOC were treated with combination chemotherapy of taxol and carboplatin after primary cytoreductive surgery between 2007 and 2012 at the Asan Medical Center, Seoul, Korea. To compare chemosensitivity in the HDRA with clinical response, all patients were first categorized into two groups as either sensitive to both taxol and carboplatin (SS), or not sensitive to one or both drugs (R) based on HDRA results. The recurrence rate was much lower in the SS group compared to the R group; 29.2% vs 69.8%, respectively (p=0.02). The SS group had a significantly longer progression-free survival compared to the R group, 34.0 months vs 16.0 months, respectively (p=0.025). These results demonstrate that the HDRA prospectively correlates to clinical outcome from chemotherapy and that treatment regimens can be individualized based on the HDRA.

Applicability of histoculture drug response assays in colorectal cancer chemotherapy.

AIM: The present study, using the histoculture drug response assay (HDRA) compared chemosensitivity with the clinical response of a treatment regime in patients with advanced colorectal cancer (CRC). PATIENTS AND METHODS: A total of 324 patients with primary CRC were prospectively enrolled. HDRAs were performed using seven combinations of anticancer drugs, including 5-fluorouracil with leucovorin (FL), FL with oxaliplatin (FOLFOX), irinotecan (FOLFIRI), and their combinations with bevacizumab and cetuximab. RESULTS: Among 324 HDRA results, tumor inhibition rates of regimes using FOLFOX (34.2-39.2%) were higher than those using FOLFIRI (24.2-32.7%, p<0.001). Out of 86 evaluated chemotherapeutic regimes, the correlation rate of HDRA to the clinical effect of chemotherapy was calculated to be 66.3% (57/86), with a 72.7% (40/55) sensitivity and a 54.7% (17/31) specificity. CONCLUSION: HDRA might be a feasible and useful technique for predicting therapy efficacy and selecting the appropriate anticancer regime for individual patients, notwithstanding its low accuracy.

In vitro chemosensitivity using the histoculture drug response assay in human epithelial ovarian cancer.

The choice of chemotherapeutic drugs to treat patients with epithelial ovarian cancer has not depended on individual patient characteristics. We have investigated the correlation between in vitro chemosensitivity, as determined by the histoculture drug response assay (HDRA), and clinical responses in epithelial ovarian cancer. Fresh tissue samples were obtained from 79 patients with epithelial ovarian cancer. The sensitivity of these samples to 11 chemotherapeutic agents was tested using the HDRA method according to established methods, and we analyzed the results retrospectively. HDRA showed that they were more chemosensitive to carboplatin, topotecan and belotecan, with inhibition rates of 49.2%, 44.7%, and 39.7%, respectively, than to cisplatin, the traditional drug of choice in epithelial ovarian cancer. Among the 37 patients with FIGO stage III/IV serous adenocarcinoma who were receiving carboplatin combined with paclitaxel, those with carboplatin-sensitive samples on HDRA had a significantly longer median disease-free interval than patients with carboplatin-resistant samples (23.2 vs. 13.8 months, p < 0.05), but median overall survival did not differ significantly (60.4 vs. 37.3 months, p = 0.621). In conclusion, this study indicates that HDRA could provide useful information for designing individual treatment strategies in patients with epithelial ovarian cancer.

In vitro chemosensitivity of gastric adenocarcinomas to histone deacetylase inhibitors, compared to established drugs.

BACKGROUND/AIMS: This study was performed to determine the efficacy of histone deacetylase inhibitors in gastric cancer, together with other established regimens. METHODOLOGY: The chemosensitivities of 93 gastric cancer patients to established drugs, and three histone deacetylase inhibitors (SAHA, PXD101, and a novel candidate, CG-2) were evaluated using the histoculture drug response assay. RESULTS: Tumor growth inhibition rates were the highest with cisplatin, followed by PXD101, taxol, docetaxel, and TS-1, in descending order. The response rates were 41.9-68.8%, and 37.6-47.3%, respectively, at an inhibition rate cutoff value of 30%. Synergistic activity was evident with most combinations of established drugs and histone deacetylase inhibitors. Diffuse- or mixed-type carcinomas on Lauren classification were closely associated with increased chemosensitivity to TS-1 (p = 0.044). Node-positive and "other than tubular type" tumors on WHO classification were chemosensitive to cisplatin (p = 0.011 and 0.014, respectively). CG-2 chemosensitivity was markedly associated with low preoperative CA724 level (< or = 4 U/ml) (p = 0.046). CONCLUSIONS: This in vitro chemosensitivity assay validates the comparable chemo-response of gastric cancers to histone deacetylase inhibitors and established drugs, indicating considerable therapeutic efficacy of these agents. Additionally, a number of clinicopathological parameters are significantly associated with specific regimens.

Chemosensitivity of uterine cervical cancer demonstrated by the histoculture drug response assay.

Uterine cervical cancer is a leading cause of cancer-related death in the female population worldwide. In vitro chemosensitivity test is important to find effective drugs in uterine cervical cancer that requires the established chemotherapeutic strategies. The purpose of this study is to investigate the chemosensitivity of uterine cervical cancer using the histoculture drug response assay (HDRA). Sixty-five fresh tumor tissues were obtained from patients with cervical cancer: 47 squamous cell carcinomas, 11 adenocarcinomas, and 7 adenosquamous cell carcinomas. The median age was 44 years (range, 25-74 years), and the median follow-up duration was 26.3 months (range, 1.6-52.7 months). The clinical stage by the International Federation of Gynecologists and Obstetricians (FIGO) was stage I of 80.0% (52/65) and stage IIA of 13.8% (9/65). The inhibition rates of ten chemotherapeutic agents against these cancer tissues were tested using the HDRA method according to established methods. Five agents were evaluated as sensitive drugs in cervical cancer with inhibition rates of greater than 30%: 41.0% for carboplatin, 35.0% for cisplatin, 33.8% for paclitaxel, 41.4% for belotecan, and 49.2% for topotecan. Especially, carboplatin combined with paclitaxel showed an inhibition rate of 54.0%, which was higher than any other single agent. However, there were no noticeable differences in chemosensitivity according to histopathologic types and FIGO stage. Despite such limitation, the HDRA may be a promising chemosensitivity test to predict an effective drug for each patient. The HDRA could provide useful information that is invaluable for the design of individualized treatments in patients with cervical cancer.

Preliminary study of chemosenstivity tests in osteosarcoma using a histoculture drug response assay.

BACKGROUND: The clinical efficacy of chemotherapy is strongly correlated with the histoculture drug response assay (HDRA) in various types of cancers. However, there have been no previous reports on its use in osteosarcoma. MATERIALS AND METHODS: Thirty-six fresh samples of human osteosarcoma were evaluated by the HDRA method in order to determine its possible usefulness in the treatment of this cancer. All the materials were obtained either during biopsy or surgical excision at our hospital, between January 2003 and October 2005. RESULTS: A significant inhibition rate in primary biopsies was observed with Adriamycin (ADM) (47.3+/-15.3%); Cisplatin (CDDP) (36.3+/-22.3%); and Carboplatin (CBP) (50.5+/-23.3%); treatment. ADM and CBP demonstrated a statistically significant increase in inhibition rates compared to the other drugs. CONCLUSION: Even though the HDRA method has many limitations, it might be a feasible and useful technique for selecting and predicting the efficacy of anticancer drugs for osteosarcoma patients.