Collagen gel droplet-embedded culture drug sensitivity test (CD-DST) predicts the effect of adjuvant chemotherapy on pancreatic cancer.

PURPOSE: We evaluated the clinical effectiveness of collagen gel droplet-embedded culture drug sensitivity tests (CD-DSTs) in predicting the efficacy of adjuvant chemo-therapeutic treatments for pancreatic cancer (PC). METHODS: The clinicopathological characteristics and prognoses of 22 PC patients who underwent CD-DST after pancreatectomy at Tohoku University between 2012 and 2016 were analyzed retrospectively. Eligibility criteria were resectable or borderline resectable PC, successful evaluation for 5-fluorouracil sensitivity by CD-DST, treatment with S-1 adjuvant chemotherapy, and no preoperative chemotherapy. RESULTS: The rate of successful evaluation by CD-DST was 52.3% in PC. The optimal T/C ratio, defined as the ratio of the number of cancer cells in the treatment group (T) to that in the control group (C), for 5-fluorouracil was 85% using receiver operating characteristic curve analysis. The sensitive group (T/C ratio < 85%; n = 11) had a better recurrence-free survival rate than the resistant group (T/C ratio ≥ 85%; n = 11; P = 0.029). A Cox proportional hazards regression model demonstrated that sensitivity to 5-fluorouracil was an independent predictor of recurrence on multivariate analysis (hazard ratio 3.28; 95.0% CI 1.20-9.84; P = 0.020). CONCLUSIONS: CD-DSTs helped to predict PC recurrence after S-1 adjuvant chemotherapy.

Patient-Derived Ex Vivo Cultures and Endpoint Assays with Surrogate Biomarkers in Functional Testing for Prediction of Therapeutic Response.

Prediction of therapeutic outcomes is important for cancer patients in order to reduce side effects and improve the efficacy of anti-cancer drugs. Currently, the most widely accepted method for predicting the efficacy of anti-cancer drugs is gene panel testing based on next-generation sequencing. However, gene panel testing has several limitations. For example, only 10% of cancer patients are estimated to have druggable mutations, even if whole-exome sequencing is applied. Additionally, even if optimal drugs are selected, a significant proportion of patients derive no benefit from the indicated drug treatment. Furthermore, most of the anti-cancer drugs selected by gene panel testing are molecularly targeted drugs, and the efficacies of cytotoxic drugs remain difficult to predict. Apart from gene panel testing, attempts to predict chemotherapeutic efficacy using ex vivo cultures from cancer patients have been increasing. Several groups have retrospectively demonstrated correlations between ex vivo drug sensitivity and clinical outcome. For ex vivo culture, surgically resected tumor tissue is the most abundant source. However, patients with recurrent or metastatic tumors do not usually undergo surgery, and chemotherapy may be the only option for those with inoperable tumors. Therefore, predictive methods using small amounts of cancer tissue from diagnostic materials such as endoscopic, fine-needle aspirates, needle cores and liquid biopsies are needed. To achieve this, various types of ex vivo culture and endpoint assays using effective surrogate biomarkers of drug sensitivity have recently been developed. Here, we review the variety of ex vivo cultures and endpoint assays currently available.

Role of Collagen Gel Droplet-Embedded Culture-Drug Sensitivity Testing (CD-DST) for Assessing the Sensitivity of Gastric Cancer to Chemotherapy Drugs Combined with Other Cancer Therapeutic Drugs.

BACKGROUND: Chemosensitivity tests have long been a widely discussed research topic. Our group performed collagen gel droplet-embedded culture-drug sensitivity testing (CD-DST) of patients with advanced gastric cancer during the period from December 2012 to December 2017. To verify how CD-DST should be used, we invested correlations of sensitivities to cisplatin (CDDP), docetaxel (DOC), paclitaxel (PTX), and CPT11 with clinical outcome. METHODS: Patients with advanced gastric cancer underwent gastrectomy with lymph node dissection at Nippon Medical School Tama Nagayama Hospital, and surgical samples were retrospectively examined by CD-DST to assess chemosensitivity. The patients later received adjuvant chemotherapy as standard adjuvant therapy or chemotherapy. The CD-DST test was not performed for S-1 because it is commonly used in chemotherapy for gastric cancer. Although oxaliplatin has also recently become a key drug for advanced gastric cancer, it had not been adopted for gastric cancer in 2012, so CD-DST testing was not performed. The χ2 test was used for all statistical analyses. A p-value of <0.05 was assumed to indicate statistical significance. Three-year survival rates were estimated using the Kaplan-Meier method, and the log-rank test was used to compare the obtained curves. RESULTS: Of the tumors from gastric cancer patients, 67.0% (77/115) could be cultured. The rate of sensitivity was 41.1% (30/73) for CDDP, 82.6% (57/69) for DOC, 82.8% (58/70) for PTX, and 49.2% (33/67) for CPT11. CDDP sensitivity and outcome were not correlated in patients who received CDDP. Sensitivities to CDDP, DOC, PTX, and CPT11 were not correlated with any patient characteristic. Patients with poorly differentiated adenocarcinoma tended to be sensitive to CDDP (P=0.051). CONCLUSIONS: No difference between CDDP sensitivity or outcome was observed in patients receiving CDDP. The CD-DST showed a high sensitivity to DOC and PTX in the present patients.

A PDX model combined with CD-DST assay to evaluate the antitumor properties of KRpep-2d and oxaliplatin in KRAS (G12D) mutant colorectal cancer.

Patient-derived xenograft (PDX) models are more faithful in maintaining the characteristics of human tumors than cell lines and are widely used in drug development, although they have some disadvantages, including their relative low success rate, long turn-around time, and high costs. The collagen gel droplet embedded culture drug sensitivity test (CD-DST) has been used as an in-vitro drug sensitivity test for patients with cancer because of its high success rate of primary cell culture, high sensitivity, and good clinical relevance, but it is based on an in-vitro cell culture and may not simulate the tumor microenvironment accurately. This study aims to combine a PDX model with CD-DST to evaluate the efficiency of antitumor agents. KRpep-2d, a small peptide targeting KRAS (G12D), and oxaliplatin were used to verify the feasibility of this approach. Whole-exome sequencing and Sanger sequencing were first applied to test and validate the KRAS mutation status of a panel of colorectal cancer PDX tissues. One PDX model was verified to carry KRAS (G12D) mutation and was used for in-vivo and the CD-DST drug tests. We then established the PDX mouse model from the patient with the KRAS (G12D) mutation and obtained viable cancer cells derived from the same PDX model. Next, the antitumor abilities of KRpep-2d and oxaliplatin were estimated in the PDX model and the CD-DST. We found that KRpep-2d showed no significant antitumor effect on the xenograft model or on cancer cells derived from the same PDX model. In contrast, oxaliplatin showed significant inhibitory effects in both tests. In conclusion, the PDX model in combination with the CD-DST assay is a comprehensive and feasible method of evaluating the antitumor properties of compounds and could be applied for new drug discovery.

PTEN Is Activated by the Addition of Cetuximab to Paclitaxel in Oral Squamous Cell Carcinoma.

BACKGROUND/AIM: The mechanisms through which cetuximab (cMab) coadministration with paclitaxel (PTX) enhances antitumor efficacy remain unclear. We examined the mechanism of the antitumor enhancing effect of cMab by determining changes in gene expression in the PI3K-AKT pathway. MATERIALS AND METHODS: Eight human oral squamous cell carcinoma (OSCC) cell lines were cultured three-dimensionally and exposed to PTX + cMab. The expression levels of PTEN mRNA in OSCC cell lines after anticancer drug treatment were assessed using real-time PCR. PTEN mRNA expression levels were also confirmed after administration of PTX + cMab in vivo. Western blot analysis was used to confirm the results at the protein level. RESULTS: PTEN mRNA and protein expression were significantly increased only in the cell lines with high sensitivity to PTX + cMab, and similar results were observed in vivo. CONCLUSION: PTEN activation may enhance the antitumor effect of PTX + cMab.

Evaluating the effectiveness of chemotherapy for thymic epithelial tumors using the CD-DST method.

BACKGROUND: Thymic epithelial tumors (TET) are frequently eligible for curative-intent surgical resection. For locally advanced TETs, chemotherapy has been used to both reduce the tumor burden and achieve prolonged disease control. However, effective therapy for this disease largely remains to be determined. Here, we report the chemosensitivity of 100 patients with TETs determined by the collagen gel droplet embedded culture-drug sensitivity test (CD-DST). METHODS: A total of 100 patients with TETs underwent surgical resection. The efficacy of antitumor agents on TET cells was tested by CD-DST. RESULTS: Thymic epithelial tumors were pathologically confirmed after surgery: two cases were type A thymoma, 17 were type AB, 12 were type B1, 44 were type B2, 12 were type B3, and there were 13 cases with thymic carcinoma. A total of 36% patients with TETs were sensitive to different types of chemotherapeutic agents. There was no significant differences in age, histological type, clinical staging, or association with autoimmune diseases between sensitive and nonsensitive cases. Type B1 and B2 thymoma were relatively more sensitive to chemotherapeutic agents (6/12 and 18/44, respectively), while sensitivity of type B3 cases to chemotherapeutic agents was much lower (only 2/12). Cases with type A thymoma were not sensitive to any antitumor drugs. Among 11 chemotherapeutic agents tested in our study, the sensitivity of TETs to EPI was the highest (16%). No patients with thymoma were sensitive to Alimta (Pemetrexed). CONCLUSIONS: Our work illuminates the effectiveness of chemotherapy for TETs and provides important clues for choosing antitumor drugs with relatively high drug sensitivity to TETs in advance.

In Vitro Chemosensitivity Test for Gastric Cancer Specimens Predicts Effectiveness of Oxaliplatin and 5-Fluorouracil.

AIM: Cisplatin plus 5-fluorouracil (5-FU) or S-1 is a standard therapy for gastric cancer (GC). However, cisplatin is emetic and potentially nephrotoxic. Oxaliplatin may be less toxic, but few basic data are available for this setting. Here, we evaluated oxaliplatin for GC, by testing surgical specimens. MATERIALS AND METHODS: We evaluated effects of oxaliplatin and 5-FU, alone and in combination, on surgical specimens from 11 patients with GC, using collagen gel droplet embedded culture drug tests. RESULTS: Oxaliplatin was less efficacious than 5-FU, and its synergistic effect was less in tumors highly sensitive to 5-FU than in those with low sensitivity. Tumor differentiation and drug sensitivity were not correlated. CONCLUSION: Although oxaliplatin monotherapy had little effect on GC, we saw a limited synergistic effect of oxaliplatin with 5-FU in 5-FU-sensitive patients. Collagen gel droplet embedded culture drug tests may predict this synergistic effect, and help select candidates for this or other regimens.

Differences in chemosensitivity between primary and paired metastatic lung cancer tissues: In vitro analysis based on the collagen gel droplet embedded culture drug test (CD-DST).

BACKGROUND: To elucidate the differences in chemosensitivity to anticancer drugs between primary and metastatic lesions in non-small cell lung cancer (NSCLC) patients, we examined the in vitro chemosensitivities of surgically resected NSCLC tissues. METHODS: A total of 32 specimens were enrolled: 26 specimens of primary lesions paired with metastases in the lymph node, 3 specimens of primary lesions paired with metastases in the adrenal gland, and 3 specimens of primary lesions paired with metastases in the lung. The collagen gel droplet embedded culture drug test (CD-DST) was applied to examine the sensitivity of the tissues to anticancer drugs, including cisplatin, gemcitabine, vinorelbine, docetaxel and 5-fluorouracil. RESULTS: The degree of in vitro sensitivity to each anticancer drug varied between the primary and metastatic lesions. The sensitivity of the paired metastatic lesions was significantly lower than that of the primary lesions only for gemcitabine (P=0.029), vinorelbine (P=0.012), and docetaxel (P=0.009). The incidence of cases diagnosed as CD-DST-sensitive among the paired metastatic lesions was significantly lower than that for the primary lesions for vinorelbine (P=0.035) or docetaxel (P=0.022). The difference in the sensitivity to gemcitabine between the primary and paired non-lymphatic metastases was clearer than that between the primary lesion and paired lymph node metastases. CONCLUSIONS: The sensitivities of the paired metastatic lesions to some anticancer drugs were significantly lower than those of the primary lesions. When performing chemotherapy based on CD-DST data using primary tumors from patients with postoperative recurrence, an appropriate regimen can be selected by carefully considering these differences.

Collagen Gel Droplet-Embedded Culture Drug Sensitivity Test (CD-DST) for a Leiomyosarcoma Originating in the Inferior Vena Cava / 日本心臓血管外科学会雑誌

The collagen gel droplet-embedded culture drug sensitivity test (CD-DST) identifies effective anticancer drug using resected tumor specimen, enabling tailor-made chemotherapy for a rare tumor. We report a case of the patient with leiomyosarcoma originating in the inferior vena cava, to which CD-DST was applied. This application has not been previously reported to the best of our knowledge. A 61-year-old woman consulted a nearby hospital because of abdominal pain. Computed tomography revealed an inferior vena cava tumor. The tumor was resected with the inferior vena cava, which was reconstructed with a 16 mm ePTFE graft. The tumor was diagnosed as leiomyosarcoma histopathologically. CDDP, VP-16, ADR, and VDS were CD-DST showed the tumor to be sensitive. Her postoperative course has been good without recurrence of tumor for 6 months, and the results of CD-DST may be helpful for chemotherapy strategy in case of recurrence.

Collagen gel droplet-embedded culture drug-sensitivity test and potential for personalizing cancer treatment.

Sensitivity testing for general anticancer agents involves culturing cancer cells, exposure to an anticancer agent, and assessing the degree of growth inhibition. One such method is the collagen gel droplet-embedded culture drug-sensitivity test (CD-DST). Clinical results confirm a close correlation of a better than 75% accuracy between CD-DST results and responses to anticancer agents administered in the clinical setting. Although there have been few randomized, controlled studies of the CD-DST method, the general observation is that cancer patients survive longer if their disease responds to an anticancer agent than if it is ineffective. Therefore, it can be extrapolated that the high diagnostic accuracy of CD-DST is indirect evidence that this method can be used to select the group for whom chemotherapy will be effective, with a resultant prolongation of their survival time, and the group for whom chemotherapy will be ineffective, with no increased survival time.

Application of CD-DST in Treatment of Carcinoma of Large Intestine / 浙江中医药大学学报

It makes review on the application of CD-DST on clinical treatment and sci-research of the carcinoma of large intestine from its technological principle and characteristics.It views that as an advanced test technology of medical allergy in vitro, there’s successful report in clinical treatment and concerned scientific study of tumor, however, it’s mainly used in lung cancer and gynecological tumor, the application in the carcinoma of large intestine waits for promotion.