Droplet-embedded Culture Drug Sensitivity Test Research Articles

Effect of oxaliplatin-based chemotherapy on chemosensitivity in patients with peritoneal metastasis from colorectal cancer treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: proof-of-concept study

BackgroundChemosensitivity testing, including collagen gel droplet‐embedded culture drug sensitivity test, has proven to be a useful tool in therapeutic decision‐making. This retrospective analysis investigated chemosensitivity testing of peritoneal metastases collected during cytoreductive surgery (CRS), and its impact on survival in patients with colorectal cancer.MethodsAll patients with peritoneal metastasis from colorectal cancer who underwent CRS with or without hyperthermic intraperitoneal chemotherapy (HIPEC) between November 2008 and October 2014 were included. The growth inhibition rate was expressed as the ratio between the image density after treatment (T) and that before treatment (control, C). Tumours with a reduction in T/C ratio of less than 20 per cent were defined as resistant and those with a reduction of 20 per cent or more as sensitive. Groups were compared for overall (OS) and disease‐free (DFS) survival.ResultsOf 84 eligible patients, 81 received neoadjuvant chemotherapy (NACT), including 56 patients with an oxaliplatin‐based regimen. Mean(s.d.) follow‐up was 23·4(22·9) months. The median overall survival of all patients was 19·0 (i.q.r. 5·7–36·1) months, with a progression‐free survival time of 10·1 (4·5–17·0) months. Patients who received oxaliplatin‐based NACT had significantly altered chemosensitivity to oxaliplatin; only 20 of 51 such patients showed chemosensitivity to oxaliplatin compared with 16 of 24 who did not undergo oxaliplatin‐based NACT (P = 0·046). However, patients who showed chemoresistance to oxaliplatin had similar OS to those with chemosensitivity (18·8 versus 18·1 months; P = 0·835). The choice of HIPEC agents in patients who received oxaliplatin‐based NACT did not significantly influence survival (oxaliplatin versus mitomycin C: median OS 20·6 (10·9–24·8) versus 19·0 (10·5–34·6) months, P = 0·811; DFS 6·6 (2·8–25·7) versus 9·3 (4·1–13·9) months, P = 0·191).ConclusionPatients who had oxaliplatin‐based NACT showed a higher rate of chemoresistance to oxaliplatin at the time of CRS and HIPEC. The impact of chemosensitivity testing on OS remains unclear and needs further investigation.

Optimal Contact Concentration of Paclitaxel in the Collagen Gel Droplet-Embedded Culture Drug Sensitivity Test for Human Oral Squamous Cell Carcinoma and Evaluation of Combination with Cetuximab

Objective: A combination of the taxane anticancer drug paclitaxel (PTX) and molecular target drug cetuximab (cMab) is effective for the treatment of head and neck squamous cell carcinoma (HNSCC). However, its use is associated with serious side effects, such as neuropathy and myelosuppression. In addition, it is administered regardless of patient sensitivity because biomarkers indicating its efficacy are unavailable. Therefore, we investigated the usefulness of setting the indicated contact concentration of PTX and predicted the antitumor effect of combined contact with cMab using the collagen gel droplet-embedded culture drug sensitivity test (CD-DST). Method: Twelve human oral squamous cell carcinoma (OSCC) cell lines (i.e., SAS, HSC-2, HSC-3, HSC-4, OSC-19, OSC-20, KON, HO-1-N-1, HO-1-u-1, SAT, SCC-4, and Nialym) were used. Using the CD-DST, we calculated the optimal contact concentration of the cells with PTX based on the clinical response rate of HNSCC and evaluated the combined contact with cMab. Furthermore, nude mice were treated with standalone PTX and PTX + cMab, and the results were compared with those of the CD-DST. Results: Based on the CD-DST, 0.1 μg/mL was the optimal contact concentration of PTX, to which the cells showed dose-dependent sensitivity. Moreover, the CD-DST method was used to evaluate the antitumor effects on OSCC even when PTX was used in combination with cMab. The antitumor effects in the CD-DST and nude mice were correlated (p < 0.05). Conclusion: The CD-DST results suggested that it was possible to predict the clinical effects of single-contact PTX and the enhancing effect of cMab + PTX.

Examination of Factors Influencing the Success Rates of an In Vitro Chemosensitivity Test for Lung Cancer Using Collagen Gel Droplet-Embedded Cultures

Objective: We evaluated the success rates and factors influencing the success rates of the Collagen Gel Droplet-Embedded Culture Drug Sensitivity Test (CD-DST) for pleural effusate in lung cancer patients with carcinomatous pleurisy.Materials and methods: Thirty-two patients with lung cancer having carcinomatous pleurisy were enrolled in this study between January 2014 and May 2017. Their pleural effusions were analysed by CD-DST, and the subjects were classified into two groups: successful cases and unsuccessful cases, based on whether the test was able to successfully determine drug sensitivity. We investigated whether the properties of the pleural effusate might influence the success rate of CD-DST. We observed that the CD-DST tended to have good success rates in patients with higher pH, higher percentage of lymphocytes, higher cell counts, and lower percentage of neutrophils in their pleural effusate. The red blood cell count was higher in the effusate of unsuccessful than successful cases.Conclusion: Our results suggest that the diagnostic success rates of CD-DST for pleural effusion from patients with lung cancer might improve by appropriate sample selection.

Anterior Gradient 3 Promotes Breast Cancer Development and Chemotherapy Response.

PurposeAnterior gradient 3 (AGR3) belongs to human anterior gradient (AGR) family. The function of AGR3 on cancer remains unknown. This research aimed to investigate if AGR3 had prognostic values in invasive ductal carcinoma (IDC) of breast cancer and could promote tumor progression.Materials and MethodsAGR3 expression was detected in breast benign lesions, ductal carcinoma in situ and IDC by immunohistochemistry analysis. AGR3’s correlations with clinicopathological features and prognosis of IDC patients were analyzed. By cell function experiments, collagen gel droplet-embedded culture drug sensitivity test and cytotoxic analysis, AGR3’s impacts on proliferation, invasion ability, and chemotherapeutic drug sensitivity of breast cancer cells were also detected.ResultsAGR3 was up-regulated in luminal subtype of histological grade I-II of IDC patients and positively correlated with high risks of recurrence and distant metastasis. AGR3 high expression could lead to bone or liver metastasis and predict poor prognosis of luminal B. In cell lines, AGR3 could promote proliferation and invasion ability of breast cancer cells which were consistent with clinical analysis. Besides, AGR3 could indicate poor prognosis of breast cancer patients treated with taxane but a favorable prognosis with 5-fluoropyrimidines. And breast cancer cells with AGR3 high expression were resistant to taxane but sensitive to 5-fluoropyrimidines.ConclusionAGR3 might be a potential prognostic indicator in luminal B subtype of IDC patients of histological grade I-II. And patients with AGR3 high expression should be treated with chemotherapy regimens consisting of 5-fluoropyrimidines but no taxane.

Optimal Cetuximab Contact Concentration Using a Collagen Gel Droplet- Embedded Culture Drug Chemosensitivity Test in Human Oral Squamous Carcinoma Cell Lines

Objective: There is no established therapy for recurrent/metastatic head and neck squamous cell carcinoma (HNSCC), making decisions regarding anticancer agent use and other treatments difficult. Cetuximab, an anticancer drug used as molecular targeted therapy, is administered irrespective of patient sensitivity due to unavailability of biomarkers predicting its efficacy. We investigated the utility of antitumor effect prediction of cetuximab using collagen gel droplet-embedded culture drug sensitivity test (CD-DST).Methods: We evaluated 13 human oral squamous carcinoma cell lines (Ca9-22, SAS, SAT, HSC-2, HSC-3, HSC-4, OSC-19, OSC-20, HO-1-N-1, HO-1-u-1, KON, SCC-4, and Nialym). The expression of cetuximab-related genes was confirmed in each cancer cell line using RT-PCR, and CD-DST was used to measure cell line sensitivity to cetuximab and to calculate an optimal contact concentration based on the HNSCC clinical response rate and efficacy rate. Furthermore, CD-DST was performed at this calculated optimal contact concentration using the treatment regimens cetuximab+cisplatin and cetuximab+cisplatin+5-fluorouracil. In vivo assessment was performed in nude mice that were administered cetuximab (250 μg/ml) and cisplatin alone and in combination, and the results were compared with the CD-DST results. Results: Results of RT-PCR showed no specificity. With CD-DST, the optimal contact concentration of cetuximab was 250 µg/ml. An enhanced antitumor effect was observed in some of the cell lines with low susceptibility to CDDP and CF. Antitumor effects for CD-DST and nude mouse experiments were almost equal.Conclusions: CD-DST can indicate the clinical efficacy of cetuximab. Regarding anticancer drug groups, low-sensitivity cell lines exhibited high sensitivity for regimen including cetuximab, suggesting cetuximab may enhance the antitumor effects of existing cytotoxic anticancer drugs.

Clinical study on collagen gel droplet-embedded culture drug sensitivity test for multidrug combination chemotherapy and super selective intra-arterial infusion chemoradiotherapy in oral squamous cell carcinoma.

Using trace three-dimensional culture, the collagen gel droplet-embedded culture drug sensitivity test (CD-DST) can be tested even in cases with a small number of cells, including oral squamous cell carcinoma (OSCC), and evaluation of the antitumor effect with a drug concentration close to the in vivo level is possible. The present report aimed to evaluate the utility of the CD-DST in the assessment of the in vitro efficacy of single-agent and multidrug combination chemotherapy for OSCC in comparison with the clinical response rates and to examine the possible clinical application of CD-DST for such cases. A total of 33 OSCC patients from whom 33 samples were obtained from January 2010 to September 2015 were included. CD-DST was performed, individually and in combination, on the three drugs [i.e., cisplatin (CDDP), 5-fluorouracil (5-FU), and docetaxel (DOC)] and on super selective intra-arterial infusion chemoradiotherapy (IACRT). The overall evaluable rate of the CD-DST in OSCC was 81.8% (27 of 33 cases) and the sensitivity to each anticancer drug was evaluated. The in vitro efficacy rates of IACRT, cisplatin + 5-fluorouracil, and docetaxel + cisplatin + 5-fluorouracil (TPF) confirmed the estimated clinical response rates. In 14 of 33 patients, the results of CD-DST were compared with clinical efficacy, which was judged based on measurable lesions on imaging. For TPF therapy, the sensitivity test of the IACRT had a positive predictive value of 90.9% (10 of 11 cases) and a negative predictive value of 100% (3 of 3 cases); the accuracy of the susceptibility test for the anticancer agents was 92.8% (13 of 14 cases). The CD-DST may be useful in selecting multidrug combination chemotherapy and IACRT for OSCC, however, accumulation of further clinical data is required in the future.

Impact of the individualization of the first-line chemotherapy for advanced colorectal cancer based on collagen gel droplet-embedded drug sensitivity test.

Leucovorin (FOL) and fluorouracil (5-FU) plus oxaliplatin (l-OHP; FOLFOX) or FOL and 5-FU plus irinotecan (SN-38; FOLFIRI) are widely used as first-line chemotherapy regimens in the treatment of advanced colorectal cancer (CRC). However, second-line chemotherapy must be abandoned in certain cases due to disease progression, adverse effects or high medical cost. Therefore, the most effective regimen should be selected as first-line chemotherapy. We reported that individualization of first-line treatment (FOLFOX/FOLFIRI/Dual/Poor responder) was possible using the collagen gel droplet-embedded culture drug sensitivity test (CD-DST) and that individualized first-line chemotherapy with CD-DST may improve the prognosis of patients with unresectable CRC. The aim of the present prospective cohort study was to evaluate the individualization of first-line chemotherapy using CD-DST, with a focus on prognosis. Between March 2008 and December 2015, tumor specimens were obtained from 120 patients with CRC who had not received preoperative chemotherapy. CD-DST was performed and the growth inhibition rate (IR) was determined by exposure for 24 h with 5-FU and l-OHP (6.0 and 3.0 µg/ml, respectively) and 5-FU and SN-38 (6.0 and 0.2 µg/ml, respectively). The cumulative distribution of IR values under each condition was evaluated on the basis that the clinical response to FOLFOX and FOLFIRI is equivalent (~50%). The prognosis of dual responder was improved compared with that of poor responders, however this difference was identified to be significant. There was no different prognosis between patients treated with an appropriate first-line regimen and patients treated with an inappropriate first-line regimen in dual responders. However, in poor responders, there were significant differences of prognosis between patients treated with an appropriate first-line regimen and patients treated with an inappropriate first-line regimen (P=0.036). In conclusion, the results from the present study suggest that administration of the recommended first-line regimen using CD-DST for patients with unresectable CRC is important for the improvement of prognosis, particularly in poor responders.

Collagen gel droplet-embedded culture drug sensitivity testing in hard palate cancer-predicted antitumor efficacy of cetuximab: A case report.

In vitro anticancer drug sensitivity assessments have been performed for various types of cancer, and an association with clinical response has been observed. The collagen gel droplet-embedded culture drug sensitivity test (CD-DST) is an in vitro anticancer drug sensitivity test that has recently reported to be useful in oral squamous cell carcinoma (OSCC). CD-DST allows for the analysis of a smaller number of cells compared with other anticancer drug sensitivity tests. The present study reported a successful analysis of anticancer drug sensitivity using CD-DST on cervical lymph node tissue dissected following neoadjuvant chemotherapy from a 55-year-old man with advanced hard palate cancer. Tumor resection and bilateral neck dissection were performed following neoadjuvant chemotherapy (docetaxel + cisplatin + 5-fluorouracil; TPF) for hard palate cancer T2N2cM0. Local recurrence and cervical multiple skin metastasis occurred ~8 months after surgery, and the patient received six doses of cetuximab (C-mab) + cisplatin + 5-fluorouracil (C-mab + PF) administration, which is a type of molecular-targeted therapy. Following the use of the CD-DST method, the clinical response was noted as stable disease following execution of TPF and partial response following execution of C-mab + PF. In addition, low sensitivity by TPF and high sensitivity by C-mab + PF were reported. The CD-DST method reflected the clinical response for the patient, and the results of the current study indicate that CD-DST is a useful tool for selecting chemotherapeutic drugs for patients with OSCC.

The Collagen Gel Droplet-embedded Culture Drug Sensitivity Test in Relapsed Hepatoblastoma.

There are few treatment options for patients with unresectable or refractory hepatoblastoma which has failed to respond to the standard treatment. The rarity of the disease and lack of experimental materials have hampered the development of new treatments. In this study, the collagen gel droplet-embedded culture drug sensitivity test was used to evaluate the effectiveness of the multikinase inhibitors sorafenib and sunitinib, and other drugs, in relapsed hepatoblastoma tumor tissues. Tumor samples from 6 patients with relapsed hepatoblastoma were tested for drug sensitivity by the collagen gel droplet-embedded culture drug sensitivity test; evaluable results were obtained from 5 of them. All samples were judged to be sensitive to sorafenib with a 50% growth inhibitory concentration (IC50) of 0.5 to 3.1 μg/mL. Sunitinib did not achieve IC50 in 2 of 3 samples within the tested concentration range based on clinically observed serum concentrations. In the drug combination assay using a hepatoblastoma cell line, sorafenib showed synergistic effects with SN-38, an active metabolite of irinotecan. Our results provide the basic science background warranting future clinical trials of a combination of sorafenib and irinotecan for relapsed or refractory hepatoblastoma.

Protein and mRNA expression of folic acid-associated enzymes as biomarkers for the cytotoxicity of the thymidylate synthase-targeted drugs, pemetrexed and S-1, in non-small cell lung cancer.

The thymidylate synthase (TS)-targeted drugs, pemetrexed and S-1, exert an important role in advanced non-small cell lung cancer (NSCLC) treatment; folic acid-associated enzymes are expected to behave as biomarkers, although their role has yet to be fully elucidated. In the present study, a single-institutional prospective analysis, in which the mRNA and protein expression levels of five folic acid-associated enzymes were evaluated with surgical specimens of NSCLC, was performed. Drug sensitivity was evaluated using a collagen gel droplet-embedded culture drug sensitivity test (CD-DST) in vitro. A total of 50 patients with NSCLC were enrolled, and the mRNA and protein expression levels of five enzymes were assessed in 47 and 46 patients, respectively. A significant association was identified between mRNA and protein expression in TS (r=0.6266), but the correlation between mRNA and protein expression levels for the other four enzymes was poor. TS mRNA expression was significantly higher in poorly differentiated tumors compared with moderately differentiated tumors (P=0.0399). TS protein expression was significantly higher in patients with pleural invasion or lymphatic invasion compared with those lacking them (P=0.027 and 0.030, respectively). CD-DST revealed that none of the tumors that were sensitive to pemetrexed, but not to S-1, were well differentiated, whereas none of the tumors that were sensitive to S-1, but not to pemetrexed, were poorly differentiated. More prominent vascular invasion was observed in the tumors that were sensitive to S-1. The only factors that exhibited the potential to discriminate the cytotoxicity of pemetrexed from S-1 were tumor differentiation grade and vascular invasion.

Relationships of MMP-9, E-cadherin, and VEGF expression with clinicopathological features and response to chemosensitivity in gastric cancer.

The matrix metalloproteinase-9, E-cadherin, and vascular endothelial growth factor play an important role in behavior of tumor cell growth, invasion, and metastasis. In this study, we investigated the relationships of matrix metalloproteinase-9, E-cadherin, and vascular endothelial growth factor expression with clinicopathological features and results of chemosensitivity tested by collagen gel droplet-embedded culture-drug sensitivity test in gastric cancer. Fresh specimens were used for collagen gel droplet-embedded culture-drug sensitivity test and paired fixed specimens were used for immunohistochemistry. Positive expression of matrix metalloproteinase-9 was associated with poorly differentiated carcinoma (p = 0.032), lymph node metastasis (p = 0.022), and tumor stage (p = 0.023). Negative expression of E-cadherin was associated with poorly differentiated carcinoma (p = 0.007), lymph node metastasis (p = 0.012), and tumor stage (p = 0.007). Positive expression of vascular endothelial growth factor was associated with tumor size (p = 0.040) and stage (p = 0.007). Collagen gel droplet-embedded culture-drug sensitivity test was successfully evaluated in 56 patients. Among them, 29 (51.7%) patients were resistant to TS-1 and 31 (55.3%) patients were resistant to L-OHP. The L-OHP resistance rate in vascular endothelial growth factor positive patients was significantly higher than that in negative patients (p = 0.031). The L-OHP resistance rate in E-cadherin negative patients was significantly higher than that in positive patients (p = 0.014). In conclusion, matrix metalloproteinase-9, E-cadherin, and vascular endothelial growth factor were involved in tumor invasion and metastasis. Positive expression of matrix metalloproteinase-9 and vascular endothelial growth factor and negative expression of E-cadherin were malignant markers for gastric cancer. Positive expression of vascular endothelial growth factor and negative expression of E-cadherin were associated with L-OHP resistance.

P2.02-026 Individualized Adjuvant Chemotherapy for Resected Lung Cancer According to Collagen Gel Droplet-Embedded Culture Drug Sensitivity Test

The efficacy of adjuvant chemotherapy for locally advanced lung cancer cannot be assessed during the treatment, since there is no measurable lesion after surgical resection. We conducted a prospective clinical trial according to the results of drug sensitivity test with an aim to individualize adjuvant chemotherapy. Patients with resectable c-Stage IB-IIIA non-small cell lung cancer were registered between 2005 and 2010. Collagen gel droplet-embedded culture drug sensitivity test (CD-DST) was performed on fresh surgical specimen. The clinical utility and prognostic outcome of adjuvant chemotherapy with carboplatin/paclitaxel in patients who showed chemo-sensitivity on CD-DST were evaluated. The primary endpoint was disease-free survival, and the secondary endpoints were overall survival and adverse effects during chemotherapy. Among 92 registered patients, 87 (p-Stage IB in 54, IIA in 4, IIB in 10, IIIA in 19) were eligible and were included in the analysis. All patients were followed up for more than 5 years. The median age was 66 years old. The success rate of CD-DST was 87% and chemo-sensitivity to carboplatin and/or paclitaxel was observed in 75% of patients. Adjuvant chemotherapy was completed in 70% and the 5-year disease-free and overall survival rates were 68% and 82%, respectively. The 5-year disease-free and overall survival rates in Stage II–IIIA patients were 58% and 75%, respectively. As for the adverse effects during adjuvant chemotherapy, grade 4 neutropenia was found in 13%. Chemo-sensitivity could be evaluated using CD-DST after lung cancer surgery. CD-DST might contribute to individualized adjuvant chemotherapy for locally advanced lung cancer.

Collagen gel droplet-embedded culture drug sensitivity testing in squamous cell carcinoma cell lines derived from human oral cancers: Optimal contact concentrations of cisplatin and fluorouracil.

The collagen gel droplet-embedded culture drug sensitivity test (CD-DST) is an anticancer drug sensitivity test that uses a method of three-dimensional culture of extremely small samples, and it is suited to primary cultures of human cancer cells. It is a useful method for oral squamous cell carcinoma (OSCC), in which the cancer tissues available for testing are limited. However, since the optimal contact concentrations of anticancer drugs have yet to be established in OSCC, CD-DST for detecting drug sensitivities of OSCC is currently performed by applying the optimal contact concentrations for stomach cancer. In the present study, squamous carcinoma cell lines from human oral cancer were used to investigate the optimal contact concentrations of cisplatin (CDDP) and fluorouracil (5-FU) during CD-DST for OSCC. CD-DST was performed in 7 squamous cell carcinoma cell lines derived from human oral cancers (Ca9-22, HSC-3, HSC-4, HO-1-N-1, KON, OSC-19 and SAS) using CDDP (0.15, 0.3, 1.25, 2.5, 5.0 and 10.0 µg/ml) and 5-FU (0.4, 0.9, 1.8, 3.8, 7.5, 15.0 and 30.0 µg/ml), and the optimal contact concentrations were calculated from the clinical response rate of OSCC to single-drug treatment and the in vitro efficacy rate curve. The optimal concentrations were 0.5 µg/ml for CDDP and 0.7 µg/ml for 5-FU. The antitumor efficacy of CDDP at this optimal contact concentration in CD-DST was compared to the antitumor efficacy in the nude mouse method. The T/C values, which were calculated as the ratio of the colony volume of the treatment group and the colony volume of the control group, at the optimal contact concentration of CDDP and of the nude mouse method were almost in agreement (P<0.05) and predicted clinical efficacy, indicating that the calculated optimal contact concentration is valid. Therefore, chemotherapy for OSCC based on anticancer drug sensitivity tests offers patients a greater freedom of choice and is likely to assume a greater importance in the selection of treatment from the perspectives of function preservation and quality of life, as well as representing a treatment option for unresectable, intractable or recurrent cases.

Personalized first-line chemotherapy for advanced colorectal cancer using the collagen gel droplet-embedded culture drug sensitivity test.

e14523 Background: The most effective regimen should be selected as first-line chemotherapy for colorectal cancer (CRC) patients since disease progression, adverse events, or even high medical cost...

Hyperthermic intraperitoneal chemotherapy with mitomycin C and 5-fluorouracil in patients at high risk of peritoneal metastasis from colorectal cancer: A preliminary clinical study.

Although hyperthermic intraperitoneal chemotherapy (HIPEC) has been extensively used to treat patients with peritoneal metastases (PM) from colorectal cancer (CRC), a standard protocol has not yet been established. The aim of this preliminary clinical study was to confirm in vitro the efficacy of mitomycin C combined with 5-fluorouracil (MMC-5FU) under hyperthermic conditions in CRC and investigate the pharmacokinetics and feasibility of HIPEC with MMC-5FU for patients at high risk of PM from CRC. To simulate HIPEC in vitro, we used the collagen gel droplet-embedded culture drug sensitivity test with the HCT166 colorectal cell line to assess the antitumor efficacy of MMC and 5FU as single-agent and combination treatments following incubation with HCT116 cells for 30 min at either 37 or 42°C. In addition, five patients at high risk of PM from CRC underwent surgical tumor resection followed by HIPEC with MMC-5FU. Our results demonstrated that the combined administration of MMC-5FU suppressed tumor cell proliferation more efficiently compared to either agent used alone. In addition, hyperthermia at 42°C significantly enhanced drug sensitivity. During the clinical application of HIPEC with MMC-5FU, no grade 4 hematological toxicities or surgical adverse events were recorded. In addition, there was no evidence of peritoneal recurrence during a median observational period of 38 months. Of note, two patients with positive intraoperative peritoneal cytology at the first surgery developed no peritoneal recurrence and exhibited negative peritoneal cytology at the second surgery. In conclusion, HIPEC using MMC-5FU was shown to be a feasible therapeutic option, with an acceptable toxicity profile, for patients at high risk of PM from CRC. Therefore, HIPEC with MMC-5FU may be a promising novel therapeutic option for such patients, which merits further verification of its safety and efficacy in large-scale clinical trials.

Protein-bound polysaccharide-K augments the anticancer effect of fluoropyrimidine derivatives possibly by lowering dihydropyrimidine dehydrogenase expression in gastrointestinal cancers

Protein-bound polysaccharide-K (PSK) enhances the antitumor effect of anticancer drug when used clinically in combination with such drugs. PSK is known to act by immune-mediated mechanisms; however, the relationship between PSK and metabolic enzymes of anticancer drugs is unknown. We used the collagen gel droplet-embedded culture drug sensitivity test (CD-DST) clinically to evaluate the sensitivity of anticancer drugs. In the present study, we modified the CD-DST by adding peripheral blood mononuclear cells (PBMCs) (immuno-CD-DST) and examined the antitumor effect of PSK in combination with anticancer drugs. First, HCT116 human colon cancer cells were cultured with PSK and 5-fluorouracil (5-FU) or 5'-deoxy-5-fluorouridine (5'-DFUR) in the presence or absence of PBMCs, and the antiproliferative effects were compared. In the presence of PBMCs, PSK augmented the inhibitory effects of 5-FU and 5'-DFUR on HCT116 cell proliferation. Next, using human gastric cancer and colon cancer cell lines, the effects of PSK on mRNA expression of various metabolic enzymes of fluoropyrimidines: dihydropyrimidine dehydrogenase (DPD), thymidylate synthase, thymidine phosphorylase and orotate phosphoribosyl transferase, were examined by real-time PCR. PSK significantly enhanced DPD mRNA expression in all of the cancer cell lines tested, but not those of the other enzymes. Addition of IFN-α and TRAIL, cytokines known to inhibit DPD expression, to the cultures reduced DPD mRNA expression in the cancer cells. When PBMC samples collected from healthy volunteers were cultured with PSK, IFN-α mRNA expression increased in 3 of the 5 PBMC samples, while TRAIL mRNA expression was unchanged. The present results propose the possibility that PSK induces PBMCs to express IFN-α which inhibits DPD expression, and consequently augments the antitumor effect of 5-FU or 5'-DFUR. Immuno-CD-DST is useful for evaluating drugs with immunological mechanisms of action.

Differences in Chemosensitivity between Primary and Metastatic Tumors in Colorectal Cancer

PurposeWe retrospectively evaluated the in vitro chemosensitivity of primary site and metastatic site tumors in colorectal cancer.MethodsVarious resected tumor samples (33 from lymph nodes, 42 from liver, six from lung, and 68 primary tumors) were assessed via a collagen gel droplet-embedded culture drug sensitivity test to determine chemosensitivity to a single agent or a combination of agents.ResultsSensitivity to combination chemotherapy was significantly higher than that of monotherapy in the primary site group, lymph node group, and liver group. There was significant difference between chemosensitivity of primary site and that of liver metastasis in each agent (5-FU, p<0.001; SN38, p = 0.045; 5-FU/SN38, p<0.001; OHP, p = 0.037; 5-FU/OHP, p = 0.045).ConclusionsTumors showed greater in vitro chemosensitivity to combination therapy when compared with monotherapy. Further, tumors that had metastasized to the liver were more resistant to chemotherapy when compared with matched primary tumors.

Clinical potential of the anticancer drug sensitivity test for patients with synchronous stage IV colorectal cancer

We retrospectively evaluated the clinical efficacy and feasibility of a collagen gel droplet-embedded culture drug sensitivity test (CD-DST) to guide therapy for patients with stage IV colorectal cancer (CRC). We investigated 38 patients with stage IV CRC. All patients were younger than 85 years and had untreated evaluable metastatic lesions. The primary tumors were surgically resected, and the tissue samples were investigated by CD-DST. Patients treated with in vitro sensitive drugs were defined as Group A (n = 14), while those treated with in vitro non-sensitive drugs were defined as Group B (n = 24). We evaluated response rate (RR), progression-free survival (PFS), and overall survival (OS). RR was 85.71 % in Group A and 41.67 % in Group B (p = 0.0079). The median PFS was 696.5 days in Group A and 297.5 days in Group B (p = 0.0326). The median OS was 1,023.4 days in Group A and 518.5 days in Group B (p = 0.0061). The CD-DST can define chemoresistant and chemosensitive tumors. The use of CD-DST might be one of the tools to supplement informed consent prior to initiation of therapy.

Clinical predictive value of in vitro anticancer drug sensitivity test for the therapeutic effect of adjuvant chemotherapy in patients with stage II–III colorectal cancer

Clinically useful predictors of the efficacy of adjuvant chemotherapy following curative colorectal surgery remain to be determined. In the present study, we investigated the clinical utility of the collagen gel droplet-embedded culture drug sensitivity test (CD-DST) as a predictor of the therapeutic response to 5-fluorouracil (5-FU)-based adjuvant chemo-therapy in patients with stage II–III colorectal cancer. CD-DST was conducted using tumor samples surgically obtained from 189 patients. The therapeutic effect of 5-FU-based regimens between high (high-group) and low (low-group) sensitivity groups and a group that did not receive chemotherapy [CTx(-) group] was compared. CD-DST was successfully performed in 151 out of the 189 patients (79.9%), 87 of whom received 5-FU-based adjuvant chemotherapy after surgery. Twenty-seven of these 87 patients (31.0%) were classified as the high-group and the remaining 60 (69.0%) as the low-group. The 5-year recurrence-free survival (RFS) in the high-group was significantly higher compared to that in the low- and the CTx(-) groups. No differences in the 5-year RFS were observed between the low- and CTx(-) groups. In conclusion, CD-DST appears to be useful for predicting the therapeutic response to 5-FU-based adjuvant chemotherapy in patients with stage II-III colorectal cancer.

A rare case of primary choriocarcinoma in the sigmoid colon

Primary colorectal choriocarcinoma is an extremely rare neoplasm and is usually associated with a poor prognosis. Only 13 cases of colorectal choriocarcinoma have previously been reported. There is no standard chemotherapeutic regimen for this tumor type. A 68-year-old man presented with melena and was diagnosed with sigmoid colonic adenocarcinoma with multiple liver metastases. He underwent a laparoscopic sigmoidectomy. Pathology revealed choriocarcinoma with a focal component of moderately differentiated adenocarcinoma of colon origin. Based on the collagen gel droplet-embedded culture drug sensitivity test (CD-DST) results, mFOLFOX6 and bevacizumab were administered, which suppressed aggressive tumor growth for 4 mo. The patient died 9 mo after the initial diagnosis. Our study results suggest that the standard chemotherapy regimen for colorectal cancer might have suppressive effects against primary colorectal choriocarcinoma. Moreover, CD-DST may provide, at least in part, therapeutic insight for the selection of appropriate antitumor agents for such patients.