Antitumor effectiveness of electrochemotherapy: a systematic review and meta-analysis.

BACKGROUND: This systematic review has two purposes: to consolidate the current knowledge about clinical effectiveness of electrochemotherapy, a highly effective local therapy for cutaneous and subcutaneous tumors; and to investigate the differences in effectiveness of electrochemotherapy with respect to tumor type, chemotherapeutic drug, and route of drug administration. METHODS: All necessary steps for a systematic review were applied: formulation of research question, systematic search of literature, study selection and data extraction using independent screening process, assessment of risk of bias, and statistical data analysis using two-sided common statistical methods and meta-analysis. Studies were eligible for the review if they provided data about effectiveness of single-session electrochemotherapy of cutaneous or subcutaneous tumors in various treatment conditions. RESULTS: In total, 44 studies involving 1894 tumors were included in the review. Data analysis confirmed that electrochemotherapy had significantly (p < .001) higher effectiveness (by more than 50%) than bleomycin or cisplatin alone. The effectiveness was significantly higher for intratumoral than for intravenous administration of bleomycin (p < .001 for CR%, p = .028 for OR%). Bleomycin and cisplatin administered intratumorally resulted in equal effectiveness of electrochemotherapy. Electrochemotherapy was more effective in sarcoma than in melanoma or carcinoma tumors. CONCLUSIONS: The results of this review shed new light on effectiveness of electrochemotherapy and can be used for prediction of tumor response to electrochemotherapy with respect to various treatment conditions and should be taken into account for further refinement of electrochemotherapy protocols.

Electrochemotherapy: a new technological approach in treatment of metastases in the liver.

Electrochemotherapy is now in development for treatment of deep-seated tumors, like in bones and internal organs, such as liver. The technology is available with a newly developed electric pulse generator and long needle electrodes; however the procedures for the treatment are not standardized yet. In order to describe the treatment procedure, including treatment planning, within the ongoing clinical study, a case of successful treatment of a solitary metastasis in the liver of colorectal cancer is presented. The procedure was performed intraoperatively by inserting long needle electrodes, two in the center of the tumor and four around the tumor into the normal tissue. The insertion of electrodes proved to be feasible and was done according to the treatment plan, prepared by numerical modeling. After intravenous bolus injection of bleomycin the tumor was exposed to electric pulses. The delivery of the electric pulses did not interfere with functioning of the heart, since the pulses were synchronized with electrocardiogram in order to be delivered outside the vulnerable period of the ventricles. Also the post treatment period was uneventful without side effects. Re-operation of the treated metastasis demonstrated feasibility of the reoperation, without secondary effects of electrochemotherapy on normal tissue. Good antitumor effectiveness with complete tumor destruction was confirmed with histological analysis. The patient is disease-free 16 months after the procedure. In conclusion, treatment procedure for electrochemotherapy proved to be a feasible technological approach for treatment of liver metastasis. Due to the absence of the side effects and the first complete destruction of the treated tumor, treatment procedure for electrochemotherapy seems to be a safe method for treatment of liver metastases with good treatment effectiveness even in difficult-to-reach locations.

Electrochemotherapy of solid tumors--preclinical and clinical experience.

Electrochemotherapy consists of administration of the chemotherapeutic drug followed by application of electric pulses to the tumor, in order to facilitate the drug uptake into the cells. Only two chemotherapeutics are currently used in electrochemotherapy, bleomycin and cisplatin, which both have hampered transport through the plasma membrane without electroporation of tumors. Based on extensive preclinical studies, elaborating on parameters for effective tumor treatment and elucidating the mechanisms of this therapy, electrochemotherapy is now in clinical use. It is in standard treatment of melanoma cutaneous metastases in Europe. However it is effective also for cutaneous metastases of other tumor types. Currently the technology is being developed also for treatment of bigger, deep seated tumors. With long needle electrodes and new electric pulse generators, clinical trials are on-going for treatment of liver metastases, bone metastases and soft tissue sarcomas.

Electrochemotherapy in treatment of tumours.

AIM: Electrochemotherapy is a local drug delivery approach aimed at treatment with palliative intent of cutaneous and subcutaneous tumour nodules of different histologies. Electrochemotherapy, via cell membrane permeabilising electric pulses, potentiates the cytotoxicity of non-permeant or poorly permeant anticancer drugs with high intrinsic cytotoxicity, such as bleomycin or cisplatin, at the site of electric pulse application. METHODS: An overview of preclinical and clinical studies is presented, and the treatment procedure is further critically evaluated. RESULTS: In clinical studies electrochemotherapy has proved to be a highly efficient and safe approach for treating cutaneous and subcutaneous tumour nodules. The treatment response for various tumours (predominantly melanoma) was approximately 75% complete and 10% partial response of the treated nodules. CONCLUSIONS: Electrochemotherapy is a new, clinically acknowledged method for the treatment of cutaneous and subcutaneous tumours. Its advantages are high effectiveness on tumours with different histologies, simple application, minimal side effects and the possibility of effective repetitive treatment.

Breast reconstruction following mastectomy for invasive breast cancer by free flaps from the abdomen is oncologically safe.

AIMS: To report the long-term results of oncological safety of breast reconstruction by autologous tissue following mastectomy for invasive breast cancer. METHODS: One-hundred-fifty-six consecutive patients with invasive breast cancer treated with mastectomy and reconstruction by autologous tissue were reviewed throughout (from 1987 to 2003 with median follow up time of 66 months). RESULTS: Median patient age was 45.9 years (range 26-68). The 157 observed tumors had mean diameter of 25+/-19 mm, 70 of them were poorly differentiated, and 137 were invasive ductal carcinoma. Multifocal disease was present in 44 patients. Breast reconstruction was carried out only by autologous tissue (free flaps were used in 95% and free TRAM flap transfer was the most common reconstructive procedure). There was only one local recurrence as first site of recurrence, thus yielding a local recurrence rate of 0.6%. CONCLUSIONS: Breast reconstruction by autologous tissue following mastectomy for invasive breast cancer is an oncologically safe procedure.

Prognostic significance of tyrosinase mRNA detected by nested RT-PCR in patients with malignant melanoma.

The aim of this study was to evaluate the role of tyrosinase mRNA appearance in blood of malignant melanoma (MM) patients, especially with advanced stages, for predicting the disease progression, and consequently the survival. The tyrosinase mRNA was measured by nested RT-PCR in peripheral venous blood samples obtained from 86 patients (53 male and 33 female) with mainly stage III and IV MM. The data were analyzed using standard methods for survival analysis and logistic regression. Tyrosinase was negative in the MM patients with the disease stage I or II, positive tyrosinase was in 11/50 patients with stage III and in 5/22 patients with stage IV. Systemic metastases developed in 14/16 patients with positive tyrosinase and in 41/70 with negative tyrosinase. The 3-year survival was 8% and 28% among the patients with positive and the patients with negative tyrosinase, respectively. The log rank test showed statistically significant better survival of tyrosinase negative patients when compared to tyrosinase positive patients (p=0.039). Multivariate analysis using logistic regression indicated tyrosinase to be a statistically significant prognostic factor for the survival of MM patients after controlling for Breslow and ulceration values (p=0.006). Positive tyrosinase in peripheral venous blood is statistically significant, and more importantly independent negative predictor of survival.

The significance of adrenal metastases from lung carcinoma.

AIM: The aim of our study was to correlate spread of the lung cancer into the adrenal glands with the progression of the primary disease. METHODS: We diagnosed and confirmed adrenal metastases in 50 patients with non-small cell lung cancer (NSCLC). We correlated the site of the primary lung carcinoma with the site of the adrenal metastasis, and the adrenal metastasis pattern, ipsi-, contra-, and bilateral adrenal metastases, with the operability and number of other sites of metastatic disease. RESULTS: Adrenal metastases were ipsilateral in 20 patients, contralateral in 15 patients and bilateral in 15 patients. An inverse incidence of contra- and bilateral metastasis was observed in 37% of operated patients, and in 71% of patients with inoperable carcinoma. The difference between both groups was statistically significant (P=0.034). CONCLUSIONS: We suggest that an isolated ipsilateral adrenal metastasis in a patient with resectable primary NSCLC could be considered (and treated) as a localized disease rather than a symptom of systemic spread.

Added value of blue dye in sentinel node biopsy for breast cancer.

Sentinel node biopsy in breast cancer is a new rapidly advancing minimal invasive procedure which enables nodal staging of clinically node negative breast cancer patients without performing complete axillary dissection. There are still controversies over the added value of Blue Dye when lymphoscintigraphy and gamma probe are used. In our series, 91 consecutive patients with invasive breast carcinoma were operated by a single surgeon, using lymphoscintigraphy, gamma probe and Blue Dye. The sentinel nodes (SLN) were histologically examined by HE and immunohistochemistry. Lymphoscintigraphy was succesful in 81 patients (89%). After the injection of Blue Dye, SLN could be identified in all 91 patients. Metastases in the SLN were present in 35 patients. We retrieved 128 SLN, of these 93 were hot and blue, 19 only hot and 16 only blue. The distribution of metastatic and nonmetastatic SLN between these three labeling groups was not different (P = 0.9361). We could not show any difference in the metastatic involvement of SLN in patients in whom preoperative lymphoscintigraphy could visualise the SLN preoperatively compared to those in whom it could not (P = 0.7315). False negativity calculated in our initial series of 36 patients was 0%. Our study showed added value of Blue Dye in detection of metastatic and nonmetastatic SLN.

Immunohistochemical localization of group II phospholipase A2 in the tumours and mucosa of the colon and rectum.

BACKGROUND: Group II phospholipase A(2)(PLA(2)) is an enzyme important in malignant transformation and in the invasion process of malignant cells. The aim of the present study was to investigate the expression of group II PLA(2)in the cancers of the colorectum, peritumoural mucosa and in the mucosa distant from the tumour. METHODS: Resection specimens from 57 patients with colorectal carcinoma (caecum 10, ascending 10, transverse 10, sigmoid colon nine, and rectum 18) were analysed immunohistochemically. Histological slides from paraffin blocks were stained by the human monoclonal group II PLA(2)antibody ('Upstate Biotechnology', Lake Placid, NY 12946, USA. Antibody Class: IgG1k. Immunogen: HPC purifed human sperm phospholipase A(2)- 14 kDa enzyme) using the standard DAKO peroxidase-labelled streptavidin-biotin method by TechMate 500 stainer. Group II PLA(2)expression was evaluated semi-quantitatively according to the extensivity and intensivity of the positive cells. For statistical evaluation the Kruskal-Wallis one way analysis of variance on ranks and the Mann-Whitney rank sum tests were used. RESULTS: The highest expression of group II PLA(2)was found in the peritumoural mucosa (median 4.00), much lower in the mucosa distal from the tumour (median 0.70) and almost no activity in the tumour itself (median 0.00), all differences were statistically significant (all pairwise multiple comparison procedures - Dunn's Method P<0.05). The expression of group II PLA(2)was higher in the left colon and rectum than in the right colon (Mann-Whitney rank sum test P<0.05). CONCLUSIONS: Our results suggest that there is variation of the group II PLA(2)expression throughout the mucosa and tumours of the colorectum, which might reflect the progression of neoplastic process.

Detection of tyrosinase mRNA by an optimised nested RT-PCR in the peripheral blood of patients with advanced malignant melanoma.

Malignant melanoma (MM) has a high metastatic potential even in small primary lesions, and an early distinction between localized and regionally/distally advanced disease is of major importance for the patients' treatment and, consequently, for their survival. Exploiting the fact that tyrosinase is a tissue specific enzyme which is only expressed in normal skin melanocytes and MM cells that invade the blood during metastasizing, the objective of our study was to optimise the nested RT-PCR assay for the detection of tyrosinase mRNA and, hence, to detect circulating melanoma cells (CMC) in whole venous blood of MM patients. Eighteen MM patients (stage III and IV, according to AJCC) and 8 healthy subjects were included in our study. Following optimisation of the procedure, the lowest detection limit of 10 MM cells per 1 ml of the blood was achieved. Tyrosinase mRNA was detected in 27.8% (5/18) of blood samples from MM patients and in none of the healthy volunteers. Preliminary results of this study suggest that the method is sensitive and specific to the CMC detection in the peripheral blood and may thus be helpful in determining the disease stage and, consequently, in planning treatment.

Metastatic intraperitoneal spread is initiated by phospholipase A2.

A new hypothesis is introduced, i.e. that intraperitoneal tumor spread is initiated by activation of phospholipase A2. This view may well have some new therapeutic implications.

Exogenous phospholipid reduces postoperative peritoneal adhesions in rats.

OBJECTIVE: To find out if the previously described ability of phosphatidylcholine to reduce peritoneal adhesions is specific to it, or if other phospholipids such as phosphatidylinositol (PI) or DL-phosphatidylcholine dilauryl (DL-PC) have similar effects. DESIGN: Laboratory experiment. SETTING: University hospital, Sweden. MATERIALS: 160 rats which had had intraperitoneal adhesions induced at laparotomy by peritoneal defects repaired in one of two models. INTERVENTIONS: PI was given intraperitoneally either once in a dose of 20 or 40 mg/rat at the end of the operation, or at the end of the operation and repeated on the second and third postoperative days. DL-PC was given once at the end of the operation in a dose of either 20 or 40 mg/rat. MAIN OUTCOME MEASURES: Adhesions were assessed a week after operation by an observer who was unaware of the treatment given. RESULTS: PI given on three consecutive days significantly reduced adhesions formed postoperatively in both models (p < 0.05). Neither PI nor DL-PC given in a single dose of 20 mg/rat had any effect, whereas both PI and DL-PC given in single doses of 40 mg/rat significantly reduced adhesions (p < 0.05). CONCLUSION: Both PI and DL-PC are effective in the prevention and limiting of postoperative adhesions in rats.

Intra-abdominal adhesion formation is initiated by phospholipase A2.

The etiology of intra-abdominal adhesions is explained by hydrolysis of the peritoneal phospholipid layer caused by phospholipase A2 activity. This view could unify the pre-existing hypotheses that intra-abdominal adhesions are due to ischemia or increased plasminogen activator activity. New therapeutic approaches are suggested.

Phospholipase-resistant phosphatidylcholine reduces intra-abdominal adhesions induced by bacterial peritonitis.

The majority of intra-abdominal adhesions develop postoperatively or following peritonitis. We have previously shown that L-phosphatidylcholine reduces postoperative peritoneal adhesions in rats. In the present study, we examined whether adhesion formation after bacterial peritonitis is also reduced by L-phosphatidylcholine or by DL-alpha-phosphatidylcholine, which is degraded only 50% by phospholipase A2. Peritonitis was induced in the rat by caecal ligation and double puncture; cecotomy was performed 12, 15, or 18 h later. Adhesions were assessed blindly by a scoring system 7 days after cecotomy. When cecotomy was scheduled for 18 h after caecal ligation and puncture, the 7-day mortality was 90% (n = 20). When cecotomy was performed at 12 h, no mortality was seen; however, the adhesion score was low (2.3 +/- 0.7). When cecotomy was performed 15 h after caecal ligation and puncture, the mortality was 25% and the adhesion score was 4.3 +/- 0.9. This figure was reduced significantly by intraperitoneal instillation of L-phosphatidylcholine or DL-alpha-phosphatidylcholine for 3 subsequent days. However, the mortality increased by L-phosphatidylcholine (P < 0.01), whereas mortality after DL-alpha-phosphatidylcholine remained at 30%. We conclude that administration of both L-phosphatidylcholine and DL-alpha-phosphatidylcholine decrease adhesion formation after bacterial peritonitis.

Effect of phosphatidylcholine on postoperative adhesions after small bowel anastomosis in the rat.

The possibility of preventing postoperative adhesions using phosphatidylcholine (PC) was studied in rats. A small bowel anastomosis was created using continuous or interrupted 5/0 silk sutures. Adhesions were measured by recording the maximal length of adhesions around the anastomosis and the number of organs involved in the adhesions. PC was administered intraperitoneally either as a single dose or as three separate doses. Postoperative adhesions developed in all animals; the degree of adhesion was independent of the suture technique used. PC given once at a dose of 20 mg significantly decreased adhesion formation (P less than 0.01). The mechanism underlying this effect may be that the exogenous PC provides a lubricant layer replacing endogenous hydrolysed phospholipid. The result with repeated PC administration was not different from that after a single dose. Increasing the single dose of PC to 40 or 60 mg resulted in anastomotic dehiscence and subsequent peritonitis. It is concluded that PC in a single dose of 20 mg reduces adhesion formation after small bowel anastomosis in the rat.