Pharmacokinetics of intraperitoneal cisplatin and doxorubicin

Effectiveness and mechanism of cisplatin combined with PDT on human lung adenocarcinoma A549 cells transplanted tumor in nude mice

This study aims to investigate the effect and mechanism of photodynamic therapy (PDT) combined with cisplatin on human lung adenocarcinoma A549 cells transplanted tumors in nude mice, and to provide a theoretical basis for clinical PDT. Construction of a nude mouse lung cancer transplantation tumor model using the human lung adenocarcinoma A549 cell line, and the mice were randomly divided into four groups: the control group, the cisplatin alone group, the PDT alone group, and the cisplatin combined PDT group. The apoptosis of tumor cells in the four groups was observed and compared by the TUNEL method, and the mRNA expression levels of apoptosis-related genes Bax, caspase-3 and Survivin, as well as the expression levels of the corresponding proteins, were detected by the real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) and the protein immunoblotting technique (Western blot) respectively. The results showed that photodynamic force combined with cisplatin was effective in inhibiting tumor growth, and its effect was superior to that of cisplatin or PDT alone. This may be related to the promotion of apoptosis, specifically through the up-regulation of Bax and caspase-3, and the down-regulation of Survivin gene expression, thus inhibiting cell proliferation.

The Emerging Role of Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in Pancreatic Cancer

Peritoneal spread is a frequent cause of metastasis in both the synchronous and metachronous settings for patients with pancreatic cancer. Recent improvements in systemic chemotherapy for pancreatic cancer may now allow for the careful selection of patients with oligometastatic disease isolated to the peritoneum who may benefit from consolidative cytoreduction and HIPEC.

Development of rice bran-derived nanoparticles with excellent anti-cancer activity and their application for peritoneal dissemination

BACKGROUND

Rice bran a by-product of the rice milling process is currently underutilized. Recent studies have shown that plant-derived nanoparticles (pdNPs) can be mass-produced at a low cost and exhibit biological and therapeutic activities. Rice bran contains various anti-cancer compounds, including γ-oryzanol and γ-tocotrienol, and rice bran-derived nanoparticles (rbNPs) can be employed as novel therapeutic agents for cancer treatment.

RESULTS

Koshihikari rice bran was suspended in water, and the suspension was centrifuged and filtered through a 0.45-µm-pore size syringe filter. The filtrate was ultracentrifuged, and the precipitates were suspended to obtain rbNPs. The rbNPs were negatively charged exosome-like nanoparticles with an average diameter of approximately 130 nm. The rbNPs exhibited cytotoxic activities against cancer cells but not against normal cells. The cytotoxic activity of rbNPs to murine colon adenocarcinoma colon26 cells was significantly greater than DOXIL® or other pdNPs. The rbNPs induced cell cycle arrest and apoptosis, and reduced the expression of proliferative proteins, including β-catenin and cyclin D1. Intraperitoneal injections of rbNPs into mice bearing peritoneal dissemination of colon26 cells significantly suppressed tumor growth with no significant adverse effects.

CONCLUSION

These results indicated that rbNPs are promising nanoparticles, hold significant potential for anti-cancer applications, and are expected to play a vital role in cancer treatment.

HIPEC in Peritoneal Metastasis of Gastric Origin: A Systematic Review of Regimens and Techniques

(1) Background: Peritoneal metastasis in gastric cancer is associated with a poor prognosis. Complete cytoreductive surgery including gastrectomy and complete removal of all peritoneal lesions followed by hyperthermic intraperitoneal chemotherapy (HIPEC) achieves promising results. There exists an immersive variety of approaches for HIPEC that makes it difficult to weigh different results obtained in the literature. In order to enable standardization and development of HIPEC, we here present a systematic review of different drug regimens and technical approaches. (2) Methods: PubMed, Embase, and the Cochrane Library were systematically searched on 26 May 2021 using the mesh terms “intraperitoneal chemotherapy AND gastric cancer”. Under consideration of systematic review guidelines, articles reporting on HIPEC in combination with CRS were selected. Data on duration, drugs, dosage, and other application parameters as well as morbidity and long term survival data were extracted for subsequent statistical analysis, tabulation, and descriptive synthesis. We assessed the risk of bias due to inhomogeneity of the patient cohort and incompleteness of report of HIPEC parameters. (3) Results: Out of 1421 screened publications, 42 publications presenting data from 1325 patients met the criteria. Most of the publications were single institutional retrospective cohort studies. The most common HIPEC regimen is performed after gastrointestinal anastomosis and consists of 50–200 mg/m² cisplatinum and 30–40 mg/m² mytomycin C at 42–43 °C for 60–90 min in a closed abdomen HIPEC system with three tubes. Almost every study reported incompletely on HIPEC parameters. Lower rates of anastomotic leakage were reported in studies that performed HIPEC after gastrointestinal anastomosis. Studies that performed open HIPEC and integrated a two-drug regimen indicated better overall survival rates. (4) Discussion: This is an exhaustive overview of the use of drug regimens and techniques for HIPEC after CRS for gastric cancer peritoneal metastasis. Other indications and application modes of intraperitoneal chemotherapy such as prophylactic or palliative HIPEC apart from CRS were not addressed. (5) Conclusion: Complete report of HIPEC parameters should be included in every publication. A consensus for dose expression either per BSA or as flat dose is desirable for comparison of the drug regimens. Despite numerous variations, we identified the most common regimens and techniques and their advantages and disadvantages according to the data in the literature. More phase I/II studies are needed to identify the best approach for HIPEC. (6) Other: This review was not supported by third parties.

PIPAC for the Treatment of Gynecologic and Gastrointestinal Peritoneal Metastases: Technical and Logistic Considerations of a Phase 1 Trial

BACKGROUND

Peritoneal metastases (PM) from ovarian, gastric, appendiceal, or colorectal origin can be treated via cytoreductive surgery with or without the addition of hyperthermic intraperitoneal chemotherapy (HIPEC) for selected patients. Unfortunately, not all patients are candidates for aggressive surgical debulking. For these patients, pressurized intraperitoneal aerosolized chemotherapy (PIPAC) has emerged as an alternative method for intraperitoneal (IP) chemotherapy administration. This report presents the design and implementation of the first phase 1 trial to evaluate the safety and efficacy of PIPAC in the United States.

METHODS

This is an ongoing prospective phase 1 clinical trial of PIPAC for patients who have histologically confirmed ovarian, uterine, gastric, appendiceal, or colorectal cancer with PM and have progressed to at least one evidence-based chemotherapeutic regimen. The trial has two clinical arms. The patients in arm 1 have gynecologic and gastric malignancies treated with IP cisplatin and doxorubicin, and the arm 2 patients have colorectal and appendiceal malignancies treated with intravenous fluorouracil and leucovorin followed by IP oxaliplatin. All the patients are monitored for dose-limiting toxicities and adverse events.

RESULTS

Practical and technical considerations for the phase 1 PIPAC trial are presented. These considerations include patient selection, operating room setup, and technical details for successful aerosolized chemotherapy delivery. The phase 1 study results will be reported separately at completion of the trial.

CONCLUSIONS

The PIPAC treatment is a feasible, minimally invasive approach that permits IP delivery of chemotherapy. Once completed, the ongoing phase 1 trial will help to provide safety and initial efficacy data.

Sodium Thiosulfate Reduces Acute Kidney Injury in Patients Undergoing Cytoreductive Surgery Plus Hyperthermic Intraperitoneal Chemotherapy with Cisplatin: A Single-Center Observational Study

Background

Cytoreductive surgery (CRS) in combination with hyperthermic intraperitoneal chemotherapy (HIPEC) represents a multimodal treatment concept for patients with peritoneal surface malignancies. The use of intraperitoneal cisplatin (CDDP) is associated with a risk of acute kidney injury (AKI). The aim of this study is to evaluate the protective effect of perioperative sodium thiosulfate (STS) administration on kidney function in patients undergoing CRS and CDDP-based HIPEC.

Patients and Methods

We retrospectively analyzed clinical data of all patients who underwent CRS and CDDP-based HIPEC at our hospital between March 2017 and August 2020. Patients were stratified according to the use of sodium thiosulfate (STS vs. no STS). We compared kidney function and clinical outcome parameters between both groups and determined risk factors for postoperative AKI on univariate and multivariate analysis. AKI was classified according to acute kidney injury network (AKIN) criteria.

Results

Of 238 patients who underwent CRS and CDDP-based HIPEC, 46 patients received STS and 192 patients did not. There were no significant differences in baseline characteristics. In patients who received STS, a lower incidence (6.5% vs. 30.7%; p = 0.001) and severity of AKI (p = 0.009) were observed. On multivariate analysis, the use of STS (OR 0.089, p = 0.001) remained an independent kidney-protective factor, while arterial hypertension (OR 5.283, p < 0.001) and elevated preoperative urea serum level (OR 5.278, p = 0.032) were predictors for postoperative AKI.

Conclusions

The present data suggest that STS protects patients from AKI caused by CRS and CDDP-based HIPEC. Further prospective studies are needed to validate the benefit of STS among kidney-protective strategies.

Supplementary Information

The online version contains supplementary material available at 10.1245/s10434-021-10508-x.

Study Protocol: Phase I Dose Escalation Study of Oxaliplatin, Cisplatin and Doxorubicin Applied as PIPAC in Patients with Peritoneal Metastases

Pressurized Intra-Peritoneal Aerosol Chemotherapy (PIPAC) is a novel laparoscopic intraperitoneal chemotherapy approach offered in selected patients affected by non-resectable peritoneal carcinomatosis. Drugs doses currently established for nebulization are very low: oxaliplatin (OXA) 120 mg/sm, cisplatin (CDDP) 10.5 mg/sm and doxorubicin (DXR) 2.1 mg/sm. A model-based approach for dose-escalation design in a single PIPAC procedure and subsequent dose escalation steps is planned. The starting dose of oxaliplatin is 100 mg/sm with a maximum estimated dose of 300 mg/sm; an escalation with overdose and under-dose control (for probability of toxicity less than 16% in case of under-dosing and probability of toxicity greater than 33% in case of overdosing) will be further applied. Cisplatin is used in association with doxorubicin: A two-dimensional dose-finding design is applied on the basis of the estimated dose limiting toxicity (DLT) at all combinations. The starting doses are 15 mg/sm for cisplatin and 3 mg/sm for doxorubicin. Safety is assessed according to Common Terminology Criteria for Adverse Events (CTCAE version 4.03). Secondary endpoints include radiological response according to Response Evaluation Criteria in Solid Tumor (version 1.1) and pharmacokinetic analyses. This phase I study can provide the scientific basis to maximize the optimal dose of cisplatin, doxorubicin and oxaliplatin applied as PIPAC.

Case Report: Cytoreductive Surgery and HIPEC Associated With Liver Electrochemotherapy in a Cholangiocarcinoma Patient With Peritoneal Carcinomatosis and Liver Metastasis Case Report

Introduction: Cholangiocarcinoma (CCA) is the second most common primary tumor of the liver, and the recurrence after hepatic resection (HR), the only curative therapy, is linked with a worse prognosis. Systemic chemotherapy (SC) and liver loco-regional treatments, like trans-arterial chemoembolization (TACE) or radio embolization (TARE), have been employed for the treatment of unresectable intrahepatic metastasis (IM) with benefit on overall survival (OS), but SC has a limited effect on peritoneal metastasis (PM). In the last years, novel treatments like electrochemotherapy (ECT) with bleomycine (BLM) for IM and cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS and HIPEC) for PM have been applied in small series but with encouraging results. We hereby describe the first synchronous application of ECT and CRS and HIPEC for the treatment of a patient with IM and PM from CCA. Case Description: A 47-year-old male patient with CCA underwent HR followed by adjuvant SC. After 14 months, for the occurrence of IM, the patient underwent a second HR and SC. Nonetheless, a new recurrence occurred and a third attempt of HR was proposed. Due to the intraoperative finding of unresectable IM with PM, no resective procedure was performed and the patient was referred to our center. CRS and HIPEC with cisplatin and mitomycin for PM and ECT with BLM on a bulky metastasis of the hepatic hilum were performed after 38 months from the first HR. The length of hospital stay was 19 days. At the computed tomography (CT) performed 11 days after treatment complete necrosis of the treated IM was detected. Results: CT scan after 3 and 6 months and magnetic resonance after 9 months were performed. Necrosis of the treated IM nor PM but progression of the residual liver lesions was observed. After 3 months, the patient received SC and underwent TACE after 8 months and TARE after 9 months for the residual liver metastases. At 14 months from CRS and HIPEC, the patient is alive, in good condition, and with stability of the disease. Conclusions: The association of ECT and CRS and HIPEC could be safe and effective for the treatment of unresectable recurrent intrahepatic CCA with PM.

Heterogeneity in tumor chromatin-doxorubicin binding revealed by in vivo fluorescence lifetime imaging confocal endomicroscopy

We present an approach to quantify drug-target engagement using in vivo fluorescence endomicroscopy, validated with in vitro measurements. Doxorubicin binding to chromatin changes the fluorescence lifetime of histone-GFP fusions that we measure in vivo at single-cell resolution using a confocal laparo/endomicroscope. We measure both intra- and inter-tumor heterogeneity in doxorubicin chromatin engagement in a model of peritoneal metastasis of ovarian cancer, revealing striking variation in the efficacy of doxorubicin-chromatin binding depending on intra-peritoneal or intravenous delivery. Further, we observe significant variations in doxorubicin-chromatin binding between different metastases in the same mouse and between different regions of the same metastasis. The quantitative nature of fluorescence lifetime imaging enables direct comparison of drug-target engagement for different drug delivery routes and between in vitro and in vivo experiments. This uncovers different rates of cell killing for the same level of doxorubicin binding in vitro and in vivo.

Cirrhosis is not a contraindication to cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in highly selected patients

BACKGROUND

Patient selection for cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is critically important to optimizing outcomes. There is currently no literature regarding the safety of CRS/HIPEC in patients with cirrhosis. The aim of this case series is to report the outcomes of three patients with well-compensated cirrhosis who underwent CRS/HIPEC.

METHODS

Patients were identified from a prospectively maintained peritoneal surface malignancy database. Patient, tumor, and operative-related details were recorded as short-term postoperative outcomes. Results were analyzed using descriptive statistics.

RESULTS

All patients had well-compensated (Child-Pugh Class A) cirrhosis and Eastern Cooperative Oncology Group (ECOG) performance status of 0. One patient had preoperative evidence of portal hypertension. All safely underwent CRS/HIPEC with completeness of cytoreduction (CC) scores of 0. The postoperative morbidity profile was unique, but all complications were manageable and resulted in full recovery to preoperative baseline status.

CONCLUSIONS

Patient selection for CRS/HIPEC is critical for optimization of short- and long-term outcomes. This small series suggests that well-compensated cirrhosis should not be an absolute contraindication to CRS/HIPEC.

Effect of Irradiation on Tissue Penetration Depth of Doxorubicin after Pressurized Intra-Peritoneal Aerosol Chemotherapy (PIPAC) in a Novel Ex-Vivo Model

Background: This study was performed to assess the impact of irradiation on the tissue penetration depth of doxorubicin delivered during Pressurized Intra-Peritoneal Aerosol Chemotherapy (PIPAC).

Methods: Fresh post mortem swine peritoneum was cut into 10 proportional sections. Except for 2 control samples, all received irradiation with 1, 2, 7 and 14 Gy, respectively. Four samples received PIPAC 15 minutes after irradiation and 4 other after 24 hours. Doxorubicin was aerosolized in an ex-vivo PIPAC model at 12 mmHg/36°C. In-tissue doxorubicin penetration was measured using fluorescence microscopy on frozen thin sections.

Results: Doxorubicin penetration after PIPAC (15 minutes after irradiation) was 476 ± 74 µm for the control sample, 450 ± 45µm after 1 Gy (p > 0.05), 438 ± 29 µm after 2 Gy (p > 0.05), 396 ± 32 µm after 7 Gy (p = 0.005) and 284 ± 57 after 14 Gy irradiation (p < 0.001). The doxorubicin penetration after PIPAC (24 hours after irradiation) was 428 ± 77 µm for the control sample, 393 ± 41 µm after 1 Gy (p > 0.05), 379 ± 56 µm after 2 Gy (p > 0.05), 352 ± 53 µm after 7 Gy (p = 0.008) and 345 ± 53 after 14 Gy irradiation (p = 0.001).

Conclusions: Higher (fractional) radiation dose might reduce the tissue penetration depth of doxorubicin in our ex-vivo model. However, irradiation with lower (fractional) radiation dose does not affect the tissue penetration negatively. Further studies are warranted to investigate if irradiation can be used safely as chemopotenting agent for patients with peritoneal metastases treated with PIPAC.

Prognostic factors of intraperitoneal chemotherapy for peritoneal carcinomatosis of gastric cancer: A retrospective study from a single center

Peritoneal carcinomatosis (PC) of gastric origin is currently recognized as a terminal disease with a poor prognosis. Advancements in novel therapeutic approaches, including intraperitoneal chemotherapy (IPC), have recently been made and it is believed that this may have contributed to the improved survival observed in patients with PC. The present study aimed to investigate overall survival (OS) and the associated prognostic factors in patients with PC of gastric origin who underwent IPC. A total of 57 patients were studied, with a median age of 51 years. The median follow-up time was 12.4 months. PC was diagnosed in all patients with gastric cancer. The median survival time of all patients was 10.1 months, whilst the OS rate at 1, 2 and 3 years was observed to be 46, 19 and 12%, respectively. Symptomatic ascites and a signet ring cell (SRC) histopathological type were demonstrated to signify a poor prognosis. Complete resection of all gross disease (CCR-0) and an increased number of cycles of systemic chemotherapy were independent factors that were observed to correlate with increased OS. The most common morbidities of grade 3/4 adverse effects were bone marrow suppression, nausea or vomiting, and diarrhea. In conclusion, IPC is an important treatment option for patients with PC that has originated from gastric cancer. Symptomatic ascites and SRC adenocarcinoma serve as negative clinicopathological prognostic factors, whilst CCR-0 and increased systemic chemotherapy cycles (≥4 cycles) may prove to be an important therapeutic option for PC patients.

Quality of life of patients with end-stage peritoneal metastasis treated with Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC)

BACKGROUND

Quality of Life (QoL) plays an important role in patients with peritoneal metastasis and is deteriorating continuously until death. Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) is an innovative palliative treatment of peritoneal metastasis. We present the first QoL results under PIPAC therapy.

METHODS

Retrospective analysis of QLQ30 questionnaire results during repeated courses of PIPAC applications in palliative patients with pretreated peritoneal metastasis.

RESULTS

91 patients (M:F = 40:51, median age 64 (34-77) years) with 158 PIPAC applications were analyzed. 86% patients had previously received systemic chemotherapy. Peritoneal metastasis was advanced (Peritoneal Carcinomatosis Index I = 16 ± 10). At admission, only moderate impairment of functioning (62-83%) and symptom scores (17-47%) was observed. 48 patients received at least 2 PIPAC every 6 weeks. After PIPAC # 1, the global physical score deteriorated slightly (from 82% to 75%), but improved after PIPAC # 2 (up to 89%). Gastrointestinal symptoms (nausea/vomiting, constipation, diarrhoea, anorexia) remained stable under PIPAC therapy.

CONCLUSIONS

Quality of life was relatively high in this group of patients with advanced, pretreated peritoneal metastasis, explaining their wish for further therapy. Functioning scores and disease-related symptoms were not altered for at least 3 months in the patients able to receive repeated PIPAC. Except for a transient moderate increase of pain scores, PIPAC did not cause therapy-related QoL deterioration, especially no gastrointestinal symptoms.

Hyperthermic intraperitoneal chemotherapy with cisplatin and paclitaxel in advanced ovarian cancer: a multicenter prospective observational study

OBJECTIVE

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been recently reported with favorable oncological outcomes as treatment of advanced epithelial ovarian cancer (EOC). The aim of this study was to demonstrate the feasibility of CRS+HIPEC with cisplatin and paclitaxel for the treatment of advanced EOC.

METHODS

This is a prospective observational study of 54 patients, from April 2007 to October 2013, with primary or recurrent peritoneal carcinomatosis due to EOC. The mean age was 54.51±9.34. Thirty patients (59%) had primary EOC, and 24 patients (41%) had recurrent disease.

RESULTS

Mean peritoneal cancer index was 10.11 (range, 0 to 28), complete cytoreduction (CC0) was achieved for 47 patients (87%), CC1 for seven patients (13%). Patients with suboptimal cytoreduction (CC2 and CC3) were not included in the study. The mean stay in intensive care unit was 4.73±5.51 days and the mean hospitalization time was 24.0±10.03 days. We did not observe any intraoperative death. Seven patients (13%) required additional operations. Three patients (5.6%) died within 30 days from the procedure. Severe complications were seen in 19 patients (35.2%). During the follow-up period, disease recurred in 33 patients (61.1%); the median disease-free survival time was 12.46 months and the median overall survival time was 32.91 months.

CONCLUSION

CRS+HIPEC with cisplatin and paclitaxel for advanced EOC is feasible with acceptable morbidity and mortality. Additional follow-up and further studies are needed to determine the effects of HIPEC on long term survival.

Rose-bengal-conjugated gold nanorods for in vivo photodynamic and photothermal oral cancer therapies

Gold nanorods (GNRs) conjugated with rose bengal (RB) molecules exhibit efficient singlet oxygen generation when illuminated by 532 nm green light and high photothermal efficiency under 810 nm near-infrared (NIR) irradiation. In vitro experiments show that reactive oxygen species generated by green light and hyperthermia produced by NIR light constitute two different mechanisms for cancer cell death. The RB-GNRs also exhibit improved photodynamic efficacy by enhancing the uptake of RB by cancer cells. In vivo experiments are conducted on hamster cheek pouches to resemble the human oral cancer conditions more accurately to assess the therapeutic effectiveness. Compared to the single photodynamic therapy (PDT) or photothermal therapy (PTT), the RB-GNRs with combined PDT-PTT capabilities provide better therapeutic effects against oral cancer and have large potential in cancer treatment.

The use of cardiac output monitoring to guide the administration of intravenous fluid during hyperthermic intraperitoneal chemotherapy

AIM

The optimal strategy for intravenous (IV) fluid management during administration of hyperthermic intraperitoneal chemotherapy (HIPEC) is unclear. In this prospective study we describe the use of a LiDCOrapid™ (LiDCO, Cambridge, UK) cardiac output monitor to guide IV fluid management during cytoreductive surgery (CRS) with HIPEC. The aim of this study was to determine whether cardiac output monitoring will allow close maintenance of physiological parameters during the HIPEC phase.

METHOD

Twenty-five patients who underwent CRS combined with HIPEC were included in the study. Intra-operative IV fluid boluses were titrated using parameters measured by the LiDCOrapid™ monitor. Stroke volume variation was maintained below 10% with fluid boluses and mean arterial pressure was maintained within 20% of the baseline figure with vasopressors.

RESULTS

There was no significant change in heart rate and cardiac output. The systemic vascular resistance dropped from an average of 966 dyn.s/cm-5 to 797 dyn s/cm(5) at 60 min during the HIPEC phase (P = 0.62) despite an increase in the dose of phenylepherine. The average total volume of fluid given was 748 ml in the first 30 min and 630 ml in the second 30 min with an average urine output of 307 and 445 ml, respectively. The change in lactate levels was not statistically or clinically significant.

CONCLUSION

LiDCOrapid™ is an effective noninvasive tool for guiding fluid management in this population. It allows the anaesthesiologist to maintain tight control of essential physiological parameters during a phase of the procedure in which there is a risk of renal injury.

The benefit of intraperitoneal chemotherapy for the treatment of colorectal carcinomatosis

The clinical practice of hyperthermic intraperitoneal chemoperfusion (HIPEC) for carcinomatosis has lacked preclinical justification. A standardized mouse model was created to evaluate the independent effects of intraperitoneal chemotherapy. Diffuse colorectal carcinomatosis was generated in mice prior to intraperitoneal lavage with mitomycin C (MMC) at clinically comparable dosing for variable lengths of time. Tumor volumes, MMC tissue concentrations and survival were measured in comparison to saline lavage and intravenous MMC. Magnetic resonance imaging revealed a direct correlation between tumor volume, MMC dose and exposure time and survival. Intravenous MMC demonstrated a rapid clearance from the blood, lower peritoneal tissue concentrations, less tumor growth inhibition and decreased survival compared to intraperitoneal administration. Intraperitoneal chemotherapy inhibited tumor growth independent of cytoreduction or hyperthermia, demonstrated improved peritoneal tissue concentration and was associated with increased survival. These data support the clinical utility of the intraperitoneal chemotherapy component of HIPEC.

Renal and hepatic toxicities after pressurized intraperitoneal aerosol chemotherapy (PIPAC)

Background

Both in animal models and in human patients, pressurized intraperitoneal aerosol chemotherapy (PIPAC) has been shown to improve local bioavailability of chemotherapy in peritoneal nodules, as compared with conventional peritoneal lavage. Pharmacokinetic studies show a low drug concentration in peripheral venous blood. However, hepatic and renal toxicities induced by delivering chemotherapeutic drugs into the abdomen as a pressurized aerosol have not yet been investigated.

Methods

Liver and renal function as well as toxicity parameters were monitored after eight PIPAC applications with doxorubicin (1.5 mg/m² body surface) and cisplatin (7.5 mg/m² body surface) in three end-stage patients suffering therapy-resistant peritoneal carcinomatosis. PIPAC was repeated at 4-week intervals (three times in two patients, twice in one patient). Peripheral venous blood was collected preoperatively and then daily until the 5th postoperative day, and sent to the hospital’s clinical chemistry laboratory. Statistical analysis was performed by analysis of variance (ANOVA).

Results

Gamma-glutamyltransferase was significantly elevated (p < 0.05) in the early postoperative phase. Glutamic oxaloacetic transaminase [aspartate aminotransferase], glutamic pyruvic transaminase [alanine aminotransferase], and bilirubin levels were not influenced by the procedure. Quick-test remained normal. Serum creatinine levels were not altered.

Conclusions

Under the above conditions, PIPAC did not induce clinically relevant liver cytotoxicity. Liver metabolism and function were not altered. Renal function remained within the normal range. No cumulative toxicity was observed after repeated PIPAC. PIPAC appears to be associated with very limited hepatic and renal toxicity, which might be a significant advantage over other administration routes.

Toxicity of hyperthermic intraperitoneal chemotherapy (HIPEC) in pediatric patients with sarcomatosis/carcinomatosis: early experience and phase 1 results

BACKGROUND

Intra-abdominal metastasis is a rare form of tumor dissemination in children. Complete surgical resection is usually deemed impossible. Children are frequently offered palliative care only. We adopted an aggressive approach for these cases which includes removal of dozens to hundreds of tumor nodules followed by perfusion of the abdominal cavity with hyperthermic chemotherapy (HIPEC) with a curative intent.

METHODS

We evaluated toxicity in 23 children and young adults undergoing 27 HIPEC procedures using cisplatin. Disease diagnoses included rhabdomyosarcoma (RMS), non-RMS soft tissue sarcoma, (NRSTS), desmoplastic small round cell tumor, (DSRCT), mesothelioma, Wilms tumor, melanomatosis, and adenocarcinoma. Patients underwent cytoreductive surgery followed by cisplatin at 40.5-41 °C, for 90 minutes. A subset of these patients was enrolled on our phase 1 study and as part of dose escalation cohort received 150 mg/m(2) of cisplatin. All toxicities were recorded.

RESULTS

Maximum tolerated dose was 100 mg/m(2). Dose limiting toxicity was grade 3 renal failure. In five of 27, 18% had grade 3 or higher renal failure. One patient developed a subclinical decrease in hearing and there were 2 grade 3 hematologic toxicities, 2 grade 3 hepatic toxicities, and one grade 3 ileus. One patient suffered grade3 cardiotoxicity. There were no operative/perioperative mortalities. Surgical complications occurred in 5/27 (18%) of patients. With a follow-up of 6-60 months, seven patients (26%) had no recurrence.

CONCLUSIONS

HIPEC is reasonably tolerated in pediatric patients with extensive abdominal metastasis. More study is needed to determine for which histologies HIPEC is most efficacious.

Biodistribution and antitumoral effect of long-circulating and pH-sensitive liposomal cisplatin administered in Ehrlich tumor-bearing mice

Cisplatin (CDDP) is one of the most active cytotoxic agents and has been widely used in the treatment of peritoneal carcinomatosis by the intraperitoneal (i.p.) route. However, CDDP, a low-molecular-weight compound, is rapidly absorbed by the capillaries in the i.p. serosa and transferred to the bloodstream, inducing the appearance of systemic side-effects, such as nephrotoxicity. Furthermore, the i.p. CDDP chemotherapy is limited to patients whose residual tumor nodules are less than 0.5 cm in diameter after surgical debulking. The failure of i.p. therapy is attributed to the poor penetration of CDDP into larger tumors. One strategy to improve drug delivery in the peritoneal region and reduce toxicity is the use of drug delivery systems. The objective of the present work was to evaluate the biodistribution and antitumoral effect of long-circulating and pH-sensitive liposomes containing CDDP (SpHL-CDDP), as compared with free CDDP, after their i.p. administration in Ehrlich ascitic tumor-bearing mice. After administering a 6 mg/kg single i.p. bolus injection of either free CDDP or SpHL-CDDP, ascitic fluid (AF), blood and organs (kidneys, liver, spleen and lungs) were collected and analyzed for CDDP content. The area under the CDDP concentration–time curve (AUC) obtained for AF and blood after SpHL-CDDP administration was 3.3-fold larger and 1.3-fold lower, respectively, when compared with free CDDP treatment, thus indicating its high retention within the peritoneal cavity. The determination of the ratio between AUC in each tissue and that in blood (Kp) showed a lower accumulation of CDDP in kidneys after SpHL-CDDP treatment. The SpHL-CDDP treatment demonstrated a significant uptake by the liver and spleen. SpHL-CDDP treatment led to a higher survival rate of mice with initial or disseminated peritoneal carcinomatosis than CDDP treatment. These results indicate that SpHL-CDDP may be useful for i.p. chemotherapy due to their greater concentration in the peritoneal cavity.

Intraperitoneal administration of novel doxorubicin loaded polymeric delivery systems against peritoneal carcinomatosis: experimental study in a murine model of ovarian cancer

OBJECTIVE

Peritoneal spread is an adverse outcome in ovarian cancer. Despite clinical efficiency, intraperitoneal (i.p.) chemotherapy after cytoreductive surgery is associated with high systemic and local toxicity. Two polymer-drug delivery systems (P-HYD1-DOX and P-HYD2-DOX) were developed for i.p. administration by conjugating doxorubicin (DOX) to a poly(l-Lysine citramide) polymer carrier with a hydrazone-based degradable spacer. The aim of this study was to assess the antitumoral efficacy of these two conjugates in a xenograft model of human ovarian carcinomatosis.

METHODS

Peritoneal carcinomatosis was generated in athymic mice by i.p. injection of SKOV3-Luc cells. Free DOX, P-HYD1-DOX and P-HYD2-DOX solutions were administered i.p. at the same dose of 10 mg/kg (DOX eq.). For each treatment, tumor load and therapeutic efficacy were compared to untreated mice and assessed by bioluminescence imaging and survival rates. Toxicity profiles in each group and biodistribution of P-HYD2-DOX after i.p. administration were also determined.

RESULTS

P-HYD-1-DOX and P-HYD-2-DOX demonstrated significant antitumoral efficacy against peritoneal carcinomatosis. Compared to untreated group, P-HYD1-DOX improved median survival times from 58 to 105 days. For P-HYD2-DOX, median survival was not reached after a follow-up of 120 days. Bioluminescence showed high efficacy of P-HYD-2-DOX compared to free DOX but the difference was not significant. Biodistribution study confirmed that free and active DOX were successively released from P-HYD2-DOX in vivo. P-HYD-DOX conjugates were well tolerated by mice after i.p. injection.

CONCLUSION

P-HYD-DOX conjugates demonstrated significant activity against peritoneal carcinomatosis in a xenograft model of ovarian carcinomatosis and their ability to release active DOX in i.p. deposits and tumor. These features are of clinical interest for i.p. administration in the treatment of ovarian peritoneal carcinomatosis after cytoreductive surgery.

An Unusual Case of Peritoneal Carcinomatosis

The peritoneal surface remains an important failure site for patients with gastrointestinal and gynecologic malignancies. In the past, oncologists regarded peritoneal carcinomatosis as an incurable component of an intra-abdominal malignancy. During the last two decades, novel therapeutic approaches have emerged for peritoneal carcinomatosis patients. We report the first case of peritoneal carcinomatosis emerging from an extra-adrenal, intra-abdominal paraganglioma. This 49-year-old male was treated with cytoreductive surgery and hyperthermic intraperitoneal perioperative chemotherapy. Paragangliomas are rare tumors of neural crest-derived chromaffin cells and can originate either from the sympathetic or from the parasympathetic ganglia. It has been estimated that as many as 10% of the paragangliomas arise outside the adrenal glands. This case represents an unreported presentation of paraganglioma. Two possible origins of this malignancy, and the applied therapy, are discussed. We report the feasibility of cytoreductive surgery plus hyperthermic intraperitoneal perioperative chemotherapy in the treatment of this malignancy.

In vivo efficacy of paclitaxel-loaded injectable in situ-forming gel against subcutaneous tumor growth

Injectable in situ-forming gels have received considerable attention as localized drug delivery systems. Here, we examined a poly(ethylene glycol)-b-polycaprolactone (MPEG-PCL) diblock copolymer gel as an injectable drug depot for paclitaxel (Ptx). The copolymer solution remained liquid at room temperature and rapidly gelled in vivo at body temperature. In vitro experiments showed that Ptx was released from MPEG-PCL copolymer gels over the course of more than 14 days. Experiments employing intratumoral injection of saline (control), gel-only, Taxol, or Ptx-loaded gel into mice bearing B16F10 tumor xenografts showed that Ptx-loaded gel inhibited the growth of B16F10 tumors more effectively than did saline or gel alone. Further, intratumoral injection of Ptx-loaded gel was more efficacious in inhibiting the growth of B16F10 tumor over 10 days than was injection of Taxol. A histological analysis demonstrated an increase in necrotic tissue in tumors treated with Ptx-loaded gel. In conclusion, our data show that intratumoral injection of Ptx-loaded MPEG-PCL diblock copolymer yielded an in situ-forming gel that exhibited controlled Ptx release profile, and that was effective in treating localized solid tumors.

Large anti-HER2/neu liposomes for potential targeted intraperitoneal therapy of micrometastatic cancer

Effective targeting and killing of intraperitoneally disseminated micrometastases remains a challenge.

OBJECTIVE/METHODS

 In this work, we evaluated the potential of antibody-labeled PEGylated large liposomes as vehicles for direct intraperitoneal (i.p.) drug delivery with the aim to enhance the tumor-to-normal organ ratio and to improve the bioexposure of cancer cells to the delivered therapeutics while shifting the toxicities toward the spleen. These targeted liposomes are designed to combine: (1) specific targeting to and internalization by cancer cells mediated by liposome-conjugated tumor-specific antibodies, (2) slow clearance from the peritoneal cavity, and (3) shift of normal organ toxicities from the liver to the spleen due to their relatively large size.

RESULTS

 Conjugation of anti-HER2/neu antibodies to the surface of large (approximately 600 nm in diameter) PEGylated liposomes results in fast, specific binding of targeted liposomes to cancer cells in vitro, followed by considerable cellular internalization. In vivo, after i.p. administration, these liposomes exhibit fast, specific binding to i.p. cancerous tumors. Large liposomes are slowly cleared from the peritoneal cavity, and they exhibit increased uptake by the spleen relative to the liver, while targeted large liposomes demonstrate specific tumor uptake at early times. Although tissue and tumor uptake are greater for cationic liposomes, the tumor-to-liver and spleen-to-liver ratios are similar for both membrane compositions, suggesting a primary role for the liposome's size, compared to the liposome's surface charge.

CONCLUSIONS

 The findings of this study suggest that large targeted liposomes administered i.p. could be a potent drug-delivery strategy for locoregional therapy of i.p. micrometastatic tumors.

Intra-operative intra-peritoneal chemotherapy with cisplatin in patients with peritoneal carcinomatosis of ovarian cancer

Background

Intra-peritoneal (i.p.) chemotherapy is an encouraging treatment option for ovarian cancer with peritoneum involvement in addition with intravenous (i.v.) chemotherapy. Intra-operative i.p. chemotherapy is an interesting method of administration by enhancing the diffusion of chemotherapy. This study had assessed the feasibility of intra-operative i.p. chemotherapy in patients with peritoneal carcinoma of ovarian cancer.

Methods

From January 2003 to February 2006, 47 patients with stage III ovarian cancer were treated with standard paclitaxel carboplatin intravenous chemotherapy and debulking surgery with intra-operative i.p. chemotherapy. After optimal cytoreductive surgery, defined by no unresectable residual disease > 1 cm, i.p. chemotherapy was performed during surgery. The peritoneal cavity was filled by 3 litres of isotonic saline pre-heated at 37 degrees and 90 mg of cisplatin. The sequence was repeated twice during 2 hours based on previous published studies which optimized the cisplatin dosage and exposure duration. Optimal diffusion was obtained by stirring by hands during the 2 hours.

Results

Median age was 59.6 years. No severe haematological or non-haematological toxicity induced by intra operative i.p. chemotherapy was reported. No patient died due to the complications of surgery or the i.p. chemotherapy. No neurotoxicity occurred, and one patients had renal impairment.

Conclusion

This study demonstrates the feasibility of intra-operative i.p. chemotherapy with cisplatin after optimal resection of peritoneal tumor nodules. Further randomized trials are planned to investigate the clinical benefit of this therapeutic modality.

Toxicity and Outcomes Associated with Surgical Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) for Patients with Sarcomatosis

BACKGROUND

Treatment of peritoneal recurrence following surgical resection of intra-abdominal sarcomas presents a significant challenge to clinicians. Historically, treatment with systemic chemotherapy has been ineffective and surgical resection alone has not been durable. We prospectively evaluated the feasibility of cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy (HIPEC) with cisplatin (CDDP) alone or in combination with mitoxantrone (MITOX) for the treatment of sarcomatosis.

METHODS

Two phase I trials of HIPEC were conducted (1998-2003). Eligible patients with evidence of sarcomatosis underwent cytoreductive surgery followed by HIPEC. In the first trial, CDDP dosing was established as 90 mg/m2 with a perfusate time of 90 minutes and temperature of 41 degrees C. In the second trial, MITOX (20 mg/m2) was instilled following perfusion with CDDP. Toxicity, efficacy, and quality of life (QOL) were evaluated.

RESULTS

A total of 28 patients were enrolled in the two trials. We noted a higher overall toxicity score and complication rate with combination CDDP/MITOX versus CDDP alone and shorter overall survival duration (5.5 months vs 16.9 months, respectively). In addition, local recurrence rates were similar in both groups (CDDP 79% vs CDDP/MITOX 68%). As expected, QOL scores at 6-8 weeks following HIPEC were 15-25% lower than the baseline scores; however, they returned to baseline at 3-6 months.

CONCLUSIONS

Although the HIPEC technique is feasible for patients with sarcomatosis, it is associated with significant toxicity and limited clinical benefit. Combination CDDP/MITOX failed to demonstrate any benefit over CDDP alone; moreover, there was an increase in toxicity.

Biodistribution of doxorubicin-alkylated poly(l-lysine citramide imide) conjugates in an experimental model of peritoneal carcinomatosis after intraperitoneal administration

Peritoneal spread is a common manifestation in ovarian and gastrointestinal cancer. Intraperitoneal (i.p.) chemotherapy after cytoreductive surgery is associated with high systemic or local toxicity. A macromolecular drug delivery system was evaluated with the aim of improving the therapeutic index of i.p. chemotherapy. Peritoneal carcinomatosis was generated in BDIX rats (n=55) by i.p. injection of 2 million DHDK12 cells. Fourteen days later, doxorubicin (DOX) and two DOX-alkylated poly(L-lysine citramide imide) conjugates bearing 9.5% and 20.5% (w/w) chemically bound drug, respectively, were given i.p. to rats at a single 2 mg DOX/kg dose. Free and polymer-bound DOX were assessed in plasma, peritoneal fluid, abdominal tissues and heart, 15 min, 2, 6, 24, 48 and 168 h after injection. According to pharmacokinetic profiles, the peritoneal fluid areas under the concentration versus time curves (AUCs) were 2 and 2.6 times greater for the conjugates (P-DOX20 and P-DOX10, respectively) than for the free drug, respectively. Conjugates crossed the peritoneal barrier slower than the free drug. For the tumor, AUCs were, respectively, 3 and 7 times higher for the conjugates than for free DOX. The elimination half-lives of the conjugates were higher than that calculated for the free drug. Only very small concentrations were detected in peripheral organs and in the heart. In contrast, significant retention and accumulation of the conjugates were found in abdominal organs, particularly in the tumor. There was no sign of macroscopic chemical peritonitis after injection of the polymer-DOX conjugates. In conclusion, the conjugates have higher elimination half-lives than free DOX and were preferentially retained in abdominal organs and in the peritoneal carcinomatosis. This feature is of clinical interest to target tumor deposits.

Should intraperitoneal chemotherapy be considered as standard first-line treatment in advanced stage ovarian cancer?

Current standard therapy for patients with advanced stage epithelial ovarian cancer is cytoreductive surgery followed by combination chemotherapy with paclitaxel and carboplatin. Intraperitoneal (IP) chemotherapy has demonstrated improved outcome compared to standard intravenous treatment in three large randomized phase III trials and confirmed by Cochrane meta-analysis. Although compelling evidence suggests that IP therapy provides survival benefit in a selected group of ovarian cancer patients, it remains unclear which group of patients will really benefit from IP therapy, which is the optimal drug, dose and combination, and what is the real benefit of IP treatment alone. Other concerns about IP therapy are difficulties in completing the assigned treatment and management of its pattern of toxic side-effects. Today, IP chemotherapy has yet to gain a role as standard first-line treatment in advanced stage ovarian cancer. In the near future, efforts should aim at developing an effective IP regimen and research undertaken for a better understanding of the peritoneal environment.

Serum and intraperitoneal pharmacokinetics of cisplatin within intraoperative intraperitoneal chemotherapy: influence of protein binding

Intraperitoneal (i.p.) chemotherapy is a promising therapeutic method to improve the effectiveness of cisplatin in patients with ovarian cancer and peritoneum involvement. Intraperitoneal treatment can be intraoperatively performed just after a complete surgical resection of peritoneal tumor nodules. However, little is known regarding the pharmacokinetics of platinum during intraoperative i.p. chemotherapy (IIC). Serum and i.p. measurements of total and ultrafilterable platinum were performed to determined pharmacokinetic parameters in 11 consecutive patients who received a 2-h IIC with 50 mg/m cisplatin. Protein concentrations were determined in serum and peritoneal liquid at the same times. The cisplatin concentration required to kill OVCAR-3 human ovarian cancer cells and evaluation of cisplatin binding to proteins were determined in vitro. Platinum i.p. concentration decreased rapidly and quickly came under the cytotoxicity threshold (10 mg for 2 h). About 85% of i.p. and serum cisplatin was ultrafilterable during IIC. Platinum concentrations were closely related to protein concentrations. Due to the very low level of serum protein (almost 25 g/l), serum cisplatin binding during chemotherapy was very low (almost 25%), but increased with protein concentration recovery. These pharmacokinetic data show that a sufficient concentration to kill human ovarian cancer is not reached with a single i.p. bath containing 50 mg/m cisplatin for 2 h. A new protocol with a renewed bath and a higher cisplatin concentration is under investigation.

Oral Xeloda plus bi-platinu two-way combined chemotherapy in treatment of advanced gastrointestinal malignancies

AIM: To compare the effect, adverse events, cost-effectiveness and dose intensity (DI) of oral Xeloda vs calcium folinate (CF)/5-FU combination chemotherapy in patients with advanced gastrointestinal malignancies, both combined with bi-platinu two-way chemotherapy.

METHODS: A total of 131 patients were enrolled and randomly selected to receive either oral Xeloda (X group) or CF/5-FU (control group). Oral Xeloda 1 000 mg/m² was administered twice daily from d 1 to 14 in X group, while CF 200 mg/m² was taken as a 2-h intravenous infusion followed by 5-FU 600 mg/m² intravenously for 4-6 h on d 1-5 in control group. Cisplatin and oxaliplatin were administered in the same way to both the groups: cisplatin 60-80 mg/m² by hyperthermic intraperitoneal administration, and oxaliplatin 130 mg/m² intravenously for 2 h on d 1. All the drugs were recycled every 21 d, with at least two cycles. Pyridoxine 50 mg was given t.i.d. orally for prophylaxis of the hand-foot syndrome (HFS). Then the effect, adverse events, cost-effectiveness and DI of the two groups were evaluated.

RESULTS: Hundred and fourteen cases (87.0%) finished more than two chemotherapy cycles. The overall response rate of them was 52.5% (X group) and 42.4% (control group) respectively. Tumor progression time (TTP) was 7.35 mo vs 5.95 mo, and 1-year survival rate was 53.1% vs 44.5%. There was a remarkable statistical significance of TTP and 1-year survival between the two groups. The main Xeloda-related adverse events were myelosuppression, gastrointestinal toxicity, neurotoxicity and HFS, which were mild and well tolerable. Therefore, no patients withdrew from the study due to side effects before two chemotherapy cycles were finished. Both groups finished pre-arranged DI and the relative DI was nearly 1.0. The average cost for 1 patient in one cycle was ￥9 137.35 (X group) and ￥8 961.72 (control group), or US $1 100.89 in X group and $1 079.73 in control group. To add 1% to the response rate costs ￥161.44 vs￥210.37 respectively (US $19.45 vs $25.35). One-month prolongation of TTP costs ￥1 243.18 vs ￥1 506.17 (US $149.78 vs$181.47). Escalation of 1% of 1-year survival costs ￥172.74 vs ￥201.64 (US $20.75 vs $24.29).

CONCLUSION: Oral Xeloda combined with bi-platinu two-way combination chemotherapy is efficient and tolerable for patients with advanced gastrointestinal malignancies; meanwhile the expenditure is similar to that of CF/5-FU combined with bi-platinu chemotherapy, and will be cheaper if we are concerned about the increase of the response rate, TTP or 1-year-survival rate pharmacoeconomically.

In vivo anti-tumor effect of dual release of cisplatin and adriamycin from biodegradable gelatin hydrogel

The objective of this paper is to investigate the in vivo anti-tumor effect by dual release of cisplatin (CDDP) and adriamycin (ADM) from a biodegradable hydrogel. Hydrogels with different water contents were prepared through the chemical crosslinking of gelatin by various concentrations of glutaraldehyde. Aqueous solution of CDDP, ADM or their mixture (CDDP+ADM) was impregnated into the freeze-dried hydrogel, followed by air-drying to obtain the dried hydrogel incorporating the corresponding drug. Irrespective of the hydrogel water content, 8-20% of CDDP incorporated and 60-80% of ADM was released from the hydrogel in the phosphate-buffered saline solution (PBS) at 37 degrees C within the initial 6 h and thereafter little release was observed. When intratumorally applied into mice carrying a mass of Meth-AR-1 tumor cells, the hydrogel incorporating CDDP+ADM showed significant higher anti-tumor effect on the tumor growth suppression and on survival period than other drug applications. Combination effect assay revealed that the hydrogel incorporating CDDP+ADM showed a synergistic effect between the CDDP and ADM, while the solution form showed antagonistic. The concentration of CDDP and ADM in the tumor tissue maintained at higher levels over 14 days after application. The time course of in vivo CDDP retention was in a good accordance with that of hydrogel remaining, whereas ADM was released faster, followed by the sustained release for 14 days. No practically problematic change in the mouse body and blood biochemical parameters was observed by application of the hydrogel incorporating CDDP+ADM. We conclude that dual sustained release of CDDP and ADM attached to the tumor synergistically enhanced their in vivo anti-tumor effect through the trans-tissue delivery.

Basal, oxidative and alkylative DNA damage, DNA repair efficacy and mutagen sensitivity in breast cancer

Impaired DNA repair may fuel up malignant transformation of breast cells due to the accumulation of spontaneous mutations in target genes and increasing susceptibility to exogenous carcinogens. Moreover, the effectiveness of DNA repair may contribute to failure of chemotherapy and resistance of breast cancer cells to drugs and radiation. The breast cancer susceptibility genes BRCA1 and BRCA2 are involved in DNA repair. To evaluate further the role of DNA repair in breast cancer we determined: (1) the kinetics of removal of DNA damage induced by hydrogen peroxide and the anticancer drug doxorubicin, and (2) the level of basal, oxidative and alkylative DNA damage before and during/after chemotherapy in the peripheral blood lymphocytes of breast cancer patients and healthy individuals. The level of DNA damage and the kinetics of DNA repair were evaluated by alkaline single cell gel electrophoresis (comet assay). Oxidative and alkylative DNA damage were assayed with the use of DNA repair enzymes endonuclease III (Endo III) and formamidopyrimidine-DNA glycosylase (Fpg), recognizing oxidized DNA bases and 3-methyladenine-DNA glycosylase II (AlkA) recognizing alkylated bases. We observed slower kinetics of DNA repair after treatment with hydrogen peroxide and doxorubicin in lymphocytes of breast cancer patients compared to control individuals. The level of basal, oxidative and alkylative DNA damage was higher in breast cancer patients than in the control and the difference was more pronounced when patients after chemotherapy were engaged, but usually the level of DNA damage in these patients was too high to be measured with our system. Our results indicate that peripheral blood lymphocytes of breast cancer patients have more damaged DNA and display decreased DNA repair efficacy. Therefore, these features can be considered as risk markers for breast cancer, but the question whether they are the cause or a consequence of the illness remains open. Nevertheless, our results suggest that research on the mutagen sensitivity and efficacy of DNA repair could impact the development of new diagnostic and screening strategies as well as indicate new targets to prevent and cure cancer. Moreover, the comet assay may be applied to evaluate the suitability of a particular mode of chemotherapy to a particular cancer patient.

DNA damage and repair in type 2 diabetes mellitus

DNA damage may be associated with type 2 diabetes mellitus (T2DM) and its complications mainly through oxidative stress. Little is known about DNA repair disturbances potentially contributing to the overall extent of DNA damage in T2DM, which, in turn, may be linked with genomic instability resulting in cancer. To assess whether DNA repair may be perturbed in 2DM we determined: (1) the level of endogenous basal DNA damage, this means damage recognized in the alkaline comet assay (DNA strand breaks and alkali labile sites) as well as endogenous oxidative and alkylative DNA damage (2) the sensitivity to DNA-damaging agents hydrogen peroxide and doxorubicin and the efficacy of removing of DNA damage induced by these agents in peripheral blood lymphocytes of T2DM patients and healthy individuals. The level of DNA damage and the kinetics of DNA repair was evaluated by the alkaline single cell gel electrophoresis (comet assay). Oxidative and alkylative DNA damage were assayed with the use of DNA repair enzymes endonuclease III (Endo III) and formamidopyrimidine-DNA glycosylase (Fpg), recognizing oxidized DNA bases and 3-methyladenine-DNA glycosylase II (AlkA) recognizing alkylated bases. The levels of basal endogenous and oxidative DNA damage in diabetes patients were higher than in control subjects. There was no difference between the level of alkylative DNA in the patients and the controls. Diabetes patients displayed higher susceptibility to hydrogen peroxide and doxorubicin and decreased efficacy of repairing DNA damage induced by these agents than healthy controls. Our results suggest that type 2 diabetes mellitus may be associated not only with the elevated level of oxidative DNA damage but also with the increased susceptibility to mutagens and the decreased efficacy of DNA repair. These features may contribute to a link between diabetes and cancer and metrics of DNA damage and repair, measured by the comet assay, may be markers of risk of cancer in diabetes.