Prognostic value of specific KRAS mutations in patients with colorectal peritoneal metastases.

BACKGROUND: There is little evidence on KRAS mutational profiles in colorectal cancer (CRC) peritoneal metastases (PM). This study aims to determine the prevalence of specific KRAS mutations and their prognostic value in a homogeneous cohort of patients with isolated CRC PM treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. MATERIALS AND METHODS: Data were collected from 13 Italian centers, gathered in a collaborative group of the Italian Society of Surgical Oncology. KRAS mutation subtypes have been correlated with clinical and pathological characteristics and survival [overall survival (OS), local (peritoneal) disease-free survival (LDFS) and disease-free survival (DFS)]. RESULTS: KRAS mutations occurred in 172 patients (47.5%) out of the 362 analyzed. Two different prognostic groups of KRAS mutation subtypes were identified: KRASMUT1 (G12R, G13A, G13C, G13V, Q61H, K117N, A146V), median OS > 120 months and KRASMUT2 (G12A, G12C, G12D, G12S, G12V, G13D, A59E, A59V, A146T), OS: 31.2 months. KRASMUT2 mutations mainly occurred in the P-loop region (P < 0.001) with decreased guanosine triphosphate (GTP) hydrolysis activity (P < 0.001) and were more frequently related to size (P < 0.001) and polarity change (P < 0.001) of the substituted amino acid (AA). When KRASMUT1 and KRASMUT2 were combined with other known prognostic factors (peritoneal cancer index, completeness of cytoreduction score, grading, signet ring cell, N status) in multivariate analysis, KRASMUT1 showed a similar survival rate to KRASWT patients, whereas KRASMUT2 was independently associated with poorer prognosis (hazard ratios: OS 2.1, P < 0.001; DFS 1.9, P < 0.001; LDFS 2.5, P < 0.0001). CONCLUSIONS: In patients with CRC PM, different KRAS mutation subgroups can be determined according to specific codon substitution, with some mutations (KRASMUT1) that could have a similar prognosis to wild-type patients. These findings should be further investigated in larger series.

Multicentre randomized clinical trial of colonic J pouch or straight stapled colorectal reconstruction after low anterior resection for rectal cancer.

BACKGROUND: Colonic J pouch reconstruction has been found to be associated with a lower incidence of anastomotic leakage than straight anastomosis. However, studies on this topic are underpowered and retrospective. This randomized trial evaluated whether the incidence of anastomotic leakage was reduced after colonic J pouch reconstruction compared with straight colorectal anastomosis following anterior resection for rectal cancer. METHODS: This multicentre RCT included patients with rectal carcinoma who underwent low anterior resection followed by colorectal anastomosis. Patients were assigned randomly to receive a colonic J pouch or straight colorectal anastomosis. The main outcome measure was the occurrence of major anastomotic leakage. The incidence of global (major plus minor) anastomotic leakage and general complications were secondary outcomes. Risk factors for anastomotic leakage were identified by regression analysis. RESULTS: Of 457 patients enrolled, 379 were evaluable (colonic J pouch arm 190, straight colorectal arm 189). The incidence of major and global anastomotic leakage, and general complications was 14·2, 19·5 and 34·2 per cent respectively in the colonic J pouch group, and 12·2, 19·0 and 27·0 per cent in the straight colorectal anastomosis group. No statistically significant differences were observed between the two arms. In multivariable logistic regression analysis, male sex (odds ratio 1·79, 95 per cent c.i. 1·02 to 3·15; P = 0·042) and high ASA fitness grade (odds ratio 2·06, 1·15 to 3·71; P = 0·015) were independently associated with the occurrence of anastomotic leakage. CONCLUSION: Colonic J pouch reconstruction does not reduce the incidence of anastomotic leakage and postoperative complications compared with conventional straight colorectal anastomosis. Registration number NCT01110798 (http://www.clinicaltrials.gov).

Malignant pleural mesothelioma immune microenvironment and checkpoint expression: correlation with clinical-pathological features and intratumor heterogeneity over time.

Background: Tumor immune microenvironment (TME) plays a key role in malignant pleural mesothelioma (MPM) pathogenesis and treatment outcome, supporting a role of immune checkpoint inhibitors as anticancer approach. This study retrospectively investigated TME and programmed death ligand 1 (PD-L1) expression in naïve MPM cases and their change under chemotherapy. Patients and methods: Diagnostic biopsies of MPM patients were collected from four Italian and one Slovenian cancer centers. Pathological assessment of necrosis, inflammation, grading, and mitosis was carried out. Ki-67, PD-L1 expression, and tumor infiltrating lymphocytes were detected by immunohistochemistry. When available, the same paired sample after chemotherapy was analyzed. Pathological features and clinical characteristics were correlated to overall survival. Results: TME and PD-L1 expression were assessed in 93 and 65 chemonaive MPM samples, respectively. Twenty-eight samples have not sufficient tumor tissue for PD-L1 expression. Sarcomatoid/biphasic samples were characterized by higher CD8+ T lymphocytes and PD-L1 expression on tumor cells, while epithelioid showed higher peritumoral CD4+ T and CD20+ B lymphocytes. Higher CD8+ T lymphocytes, CD68+ macrophages, and PD-L1 expression were associated with pathological features of aggressiveness (necrosis, grading, Ki-67). MPM cases characterized by higher CD8+ T-infiltrate showed lower response to chemotherapy and worse survival at univariate analysis. Patients stratification according to a combined score including CD8+ T lymphocytes, necrosis, mitosis, and proliferation index showed median overall survival of 11.3 months compared with 16.4 months in cases with high versus low combined score (P < 0.003). Subgroup exploratory analysis of 15 paired samples before and after chemotherapy showed a significant increase in cytotoxic T lymphocytes in MPM samples and PD-L1 expression in immune cells. Conclusions: TME enriched with cytotoxic T lymphocytes is associated with higher levels of macrophages and PD-L1 expression on tumor cells and with aggressive histopathological features, lower response to chemotherapy and shorter survival. The role of chemotherapy as a tumor immunogenicity inducer should be confirmed in a larger validation set.

Rectal sparing approach after preoperative radio- and/or chemotherapy (RESARCH) in patients with rectal cancer: a multicentre observational study.

BACKGROUND: Rectum-sparing approaches appear to be appropriate in rectal cancer patients with a major (mCR) or complete clinical response (cCR) after neoadjuvant therapy. The aim of the present study is to evaluate the effectiveness of rectum-sparing approaches at 2 years after the completion of neoadjuvant treatment. STUDY DESIGN: Patients with rectal adenocarcinoma eligible to receive neoadjuvant therapy will be prospectively enrolled. Patients will be restaged 7-8 weeks after the completion of neoadjuvant therapy and those with mCR (defined as absence of mass, small mucosal irregularity no more than 2 cm in diameter at endoscopy and no metastatic nodes at MRI) or cCR will be enrolled in the trial. Patients with mCR will undergo local excision, while patients with cCR will either undergo local excision or watch and wait policy. The main end point of the study is to determine the percentage of rectum preservation at 2 years in the enrolled patients. CONCLUSION: This protocol is the first prospective trial that investigates the role of both local excision and watch and wait approaches in patients treated with neoadjuvant therapy for rectal cancer. The trial is registered at clinicaltrials.gov (NCT02710812).

Bowel function and quality of life after local excision or total mesorectal excision following chemoradiotherapy for rectal cancer.

BACKGROUND: Local excision for rectal cancer is expected to offer a better functional outcome than conventional surgery. The aim of the present study was to compare quality of life and bowel function in patients with rectal cancer who underwent either local excision or conventional surgery after chemoradiotherapy. METHODS: This was a retrospective multicentre study. Patients who underwent local excision were compared with those who had mesorectal excision. Quality of life and bowel function were investigated using validated questionnaires (European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30, EORTC QLQ-CR29 and Memorial Sloan-Kettering Cancer Center Bowel Function Instrument) at a median follow-up of 49 (range 13-95) months. Further analysis was undertaken of data from patients who underwent local excision alone compared with those requiring subsequent radical surgery. Statistical significance was set at P < 0·010. RESULTS: The mean constipation score was significantly better in the local excision group than in the mesorectal excision group (3·8 (95 per cent c.i. 0·3 to 7·2) versus 19·8 (12·1 to 27·4); P < 0·001). Compared with patients who underwent mesorectal excision, those who had local excision had less sensation of incomplete emptying (mean score 3·7 (3·4 to 4·0) versus 2·8 (2·5 to 3·1); P < 0·001) and second bowel movements within 15 min (mean score 3·6 (3·3 to 3·9) versus 3·0 (2·7 to 3·3); P = 0·006). Patients who underwent local excision alone scored better than those who had mesorectal excision, particularly for bowel function, who, in turn, scored better than patients requiring subsequent radical surgery following local excision. CONCLUSION: Patients who underwent local excision had a better quality of life and bowel function than those who underwent mesorectal excision.

Differences in telomere length between sporadic and familial cutaneous melanoma.

BACKGROUND: Several pieces of evidence indicate that a complex relationship exists between constitutional telomere length (TL) and the risk of cutaneous melanoma. Although the general perception is that longer telomeres increase melanoma risk, some studies do not support this association. We hypothesize that discordant data are due to the characteristics of the studied populations. OBJECTIVES: To evaluate the association of TL with familial and sporadic melanoma. MATERIALS AND METHODS: TL was measured by multiplex quantitative polymerase chain reaction in leukocytes from 310 patients with melanoma according to familial/sporadic and single/multiple cancers and 216 age-matched controls. RESULTS: Patients with sporadic melanoma were found to have shorter telomeres compared with those with familial melanoma. In addition, shorter telomeres, while tending to reduce the risk of familial melanoma regardless of single or multiple tumours, nearly trebled the risk of single sporadic melanoma. CONCLUSIONS: This is the first time that TL has been correlated to opposite effects on melanoma risk according to the presence or absence of familial predisposition. Individual susceptibility to melanoma should be taken into account when assessing the role of TL as a risk factor.

Circulating cell-free DNA: a promising marker of regional lymphonode metastasis in breast cancer patients.

PURPOSE: We undertook the current study with untreated breast cancer to (1) role the variations in the plasma levels of cfDNA and the size distribution in early stage, (2) determine the frequency in plasma of methylation of three candidate genes, RASSF1A, MAL, and SFRP1, and (3) to determine whether detection of cfDNA variations and methylation changes in plasma might have specific clinical utility. METHODS AND MATERIALS: Thirty-nine patients woman patients (median age 64 years; range, 36-90 years) who underwent surgery for primary BR and 49 healthy females' subjects (control group without any breast lesion) were evaluated. The cfDNA levels were analyzed using quantitative real-time polymerase chain reaction of ß-globin. Based on the ALU repeats, the cfDNA was considered as either total (fragments of 115 bp, ALU115) or tumoral (fragments of 247 bp, ALU247). The association between the levels of the ALU247, ALU115 repeat, and ALU 247/115and the pathologic tumor characteristics was analyzed. Used methylight qPCR method, cfDNA from plasma samples of healthy donors and patients with breast cancer were evaluated for the diagnotic value of the methylation status of three genes (RASSF1A, MAL, SFRP1) frequently methylated in breast cancer. RESULTS: The baseline levels of cfDNA were significantly higher in the patients with cancer, and the level of ALU247 was the most accurate circulating cfDNA marker in discriminating the cancer from non-cancer subjects. A high statistical significance was found by considering the T stage and patients with regional LN metastasis positive cancers showed significantly higher cfDNA level of ALU247. Moreover, patients with methylation of at least one of the gene under investigate showed a higher quantity of cfDNA ALU115 (p< 0.0001) and ALU247 level (p< 0.0001). CONCLUSIONS: We observed that necrosis could be a potential source of circulating tumour-specific cfDNA ALU247; and that cfDNA ALU247 and methylated cfDNA (RASSF1A, MAL and SFRP1) are both a phenotypic feature of tumour biology.

Validity and reliability of the MSKCC Bowel Function instrument in a sample of Italian rectal cancer patients.

AIMS: The purpose of this study was to translate the Memorial Sloan Kettering Cancer Centre (MSKCC) Bowel Function Instrument into Italian and to test its psychometric validity and reliability in a sample of Italian rectal cancer patients. METHODS: The MSKCC questionnaire was translated into Italian using a standard procedure of double-back translation. Construct validity was tested using a factor analysis and internal reliability was estimated using the Cronbach's alpha coefficient. Concurrent validity was determined by correlations with European Organisation for Research and Treatment of Cancer QLQ-C30 and QLQ-CR38 quality of life scales. A non-parametric analysis of variance was used to establish the discriminant validity of the questionnaire. Test-retest reliability was assessed using the intra-class correlation coefficient. RESULTS: 124 rectal cancer patients participated in the validation study. The number of missing items was 2.2%. The factorial structure was found to be quite similar to the original one and the internal reliability was 0.7 for urgency, 0.6 for frequency, and 0.7 for dietary subscale. The test-retest reliability was acceptable with one exception: the dietary subscale showed a low reproducibility (ICC = 0.4). All three subscales showed a significant correlation with the QLQ-C30 and QLQ-CR38 domains and were able to discriminate several groups of clinical relevance. CONCLUSIONS: The Italian version of the MSKCC Bowel Function Instrument shows acceptable psychometric properties and can be considered a valuable and specific instrument to assess bowel functions in rectal cancer patients, both for research purposes and in clinical practise.

Central nervous system failure in melanoma patients: results of a randomised, multicentre phase 3 study of temozolomide- and dacarbazine- based regimens.

BACKGROUND: This study compared the central nervous system (CNS) metastasis incidence between a temozolomide- and a dacarbazine-based regimen in untreated stage IV melanoma patients. METHODS: A total of 150 patients were randomly assigned to receive either oral temozolomide (200 mg m(-2) per day; days 1-5) or intravenous dacarbazine (800 mg m(-2); day 1), in combination with intravenous cisplatin (75 mg m(-2); day 1) and subcutaneous interleukin-2 (3 MU twice daily; days 9-18), every 28 days (CTI and CDI). RESULTS: A total of 149 patients were eligible for an intention-to-treat analysis (CTI: n=74, CDI: n=75). The 1-year cumulative CNS incidence failure was 20.6% for CTI and 31.1% for CDI (P=0.22). In all 24 patients in CTI (32%) and 34 (45%) in CDI developed CNS metastases; 31 patients died of early systemic progression, before CNS evaluation. Median survival time was 8.4 months in the CTI and 8.7 in the CDI arm; in patients with CNS metastases the median survival time was 13.5 months in the CTI and 11.5 in the CDI arm. No difference in toxicity was observed between the two arms. CONCLUSION: The incidence of CNS failures in metastatic melanoma was not significantly reduced and the clinical course was not modified substituting a dacarbazine-based regimen with a temozolomide-based regimen. Patients who developed CNS metastases did not have a worse prognosis than patients progressing in other sites and should not be excluded from new investigational studies.

Relationship between telomere shortening, genetic instability, and site of tumour origin in colorectal cancers.

BACKGROUND: Telomeres, located at chromosome ends, are progressively shortened during each cell cycle by replication-dependent loss of DNA termini. Although maintenance of telomere length is critical for cell-replicative potential and tumourigenesis, the erosion of telomeres can lead to genetic instability, a pivotal mechanism in the neoplastic process. PATIENTS AND METHODS: A total of 118 colorectal cancer (CRC) samples (53 right-colon, 30 left-colon, and 35 rectal tumours) and corresponding adjacent non-cancerous tissues were evaluated for telomere length, p53 mutation, and microsatellite instability (MSI). Telomere length was estimated by real-time PCR. RESULTS: Telomeres were significantly shorter in CRCs than in adjacent tissues, regardless of tumour stage and grade, site, or genetic alterations (P<0.0001). Moreover, in normal tissues, but not in tumours, telomere length inversely correlated with age (r=-0.24, P=0.017). Telomere length in CRCs did not differ with tumour progression or p53 status; however, in CRCs carrying the wild-type p53, telomeres were significantly shorter in tumours with MSI than in those with stable microsatellites (P=0.027). Furthermore, telomere length differed according to tumour location, being longer in rectal cancers (P=0.03). CONCLUSIONS: These findings suggest that telomere shortening is a key initial event in colorectal carcinogenesis. The extent of telomere erosion is related to tumour origin site and may be influenced by the mismatch repair pathway.

Morbidity comparison of sentinel lymph node biopsy versus conventional axillary lymph node dissection for breast cancer patients: results of the sentinella-GIVOM Italian randomised clinical trial.

AIMS: To compare physical morbidity and health-related quality of life (HRQOL) in breast cancer patients who received standard axillary dissection (ALND) or sentinel lymph node biopsy (SLNB), followed by axillary dissection only in the case of sentinel-node positivity, within a randomised clinical trial. PATIENTS AND METHODS: Patients with early breast cancer < or =3cm and clinically negative axilla were randomly allocated to ALND or SLNB. All patients underwent physical examination every 6 months in order to assess any arm-related symptoms. A subset of patients completed the SF-36 quality of life questionnaire and the Psychological General Well Being Index (PGWBI) before randomisation, at 6 and 12 months after surgery and yearly thereafter. Results of the first 24 months are reported. RESULTS: Six-hundred and seventy-seven patients were available for analysis: 341 patients randomised to the ALND group and 336 to the SLNB group. Six months after surgery, the SLNB group had significantly less lymph-oedema, movement restrictions, pain and numbness with respect to the ALND group. Lymph-oedema was also significantly reduced at 12 months and numbness remained significantly less frequent in the SLNB arm at all time points. Three-hundred and ten patients participated in the HRQOL assessment. The mean scores of the PGWB questionnaire general index and anxiety domain were significantly better in the SLNB group than in the ALND group but the difference ceased to be significant at 24 months. CONCLUSIONS: The SLNB is associated with reduced arm morbidity without evidence of a negative impact on psychological well being. While waiting for long-term results of ongoing randomised clinical trials, the SLNB may be proposed for early stage breast cancer patients after adequate information on the expected advantages and the possible risks.

Clinical impact of false-negative sentinel lymph nodes in breast cancer.

AIMS: To evaluate the incidence of false-negative (FN) sentinel lymph node (SLN) cases, their correlation with a series of clinico-pathologic parameters and their impact on adjuvant treatment indications and on clinical axillary relapse in the setting of a multicentric clinical trial comparing SLN biopsy with axillary lymph node dissection (ALND). METHODS: A series of 697 patients with primary breast cancer < or = 3 cm were randomized to SLN biopsy associated with ALND (ALND arm) or to SLN biopsy followed by ALND only if the SLN was metastatic (SLN arm). The FN SLN rate was assessed in the ALND arm. A series of 11 clinico-pathological parameters were tested for a possible association with FN results. The indications for adjuvant treatments were evaluated by considering both the FN nodal stages, as indicated by the SLN, and the true positive axillary status, as indicated by completion ALND. The occurrence of clinically evident axillary recurrences was evaluated in the two arms. RESULTS: The FN rate was 16.7%. Of the clinico-pathologic parameters tested, only a tumour size < or = 2 cm and the presence of a single metastatic axillary node was significantly associated with a risk of FN (p = 0.033 and p = 0.018, respectively). The FN SLN would have led to different adjuvant therapy indications in 12/18 cases. At 56 months, no clinically evident axillary nodal recurrences were present in the ALND arm patients, whereas one case of axillary recurrence was detected in the SLN arm patients. CONCLUSIONS: FN SLN biopsy is not uncommon, especially in the presence of a small primary tumour with a single nodal metastasis. An FN finding can lead to less than optimal adjuvant treatment. However, the clinical impact of FN in terms of axillary recurrence at 56 months was minimal.

Phase II trial of docetaxel, cisplatin and fluorouracil followed by carboplatin and radiotherapy in locally advanced oesophageal cancer.

This study was performed to assess the efficacy and safety of docetaxel, cisplatin and fluorouracil combination in patients with unresectable locally advanced oesophageal squamous cell carcinoma. Treatment consisted of docetaxel 60 mg m(-2), cisplatin 75 mg m(-2) on day 1 and fluorouracil 750 mg m(-2) day(-1) on days 2-5, repeated every 3 weeks for three cycles, followed by carboplatin 100 mg m(-2) week(-1) for 5 weeks and concurrent radiotherapy (45 Gy in 25 fractions, 5 days week(-1)). After radiotherapy, eligible patients either underwent an oesophagectomy or received high dose rate endoluminal brachytherapy (HDR-EBT). Thirty-one out of 37 enrolled patients completed the planned chemotherapy and 30 completed chemoradiation. After completion of chemotherapy, 49% (95% CI: 32.2-66.2) had a clinical response. Twelve patients (32%) underwent a resection, which was radical in 60% (postoperative mortality: 0%). A pathological complete response was documented in four patients (11% of enrolled, 30% of resected). The median survival was 10.8 months (95% CI: 8.1-12.4), and the 1- and 2-year survival rates were 35.1 and 18.9%, respectively. Grade 3-4 toxicities were neutropoenia 32%, anaemia 11%, non-neutropoenic infections 18%, diarrhoea 6% and oesophagitis 5%. Nine patients (24%) developed a tracheo-oesophageal fistula during treatment. Even if the addition of docetaxel to cisplatin and 5-fluorouracil (5-FU) seems to be more active than the cisplatin and 5-FU combination, an incremental improvement in survival is not seen, and the toxicity observed in this study population is of concern. In order to improve the prognosis of these patients, new drugs, combinations and strategies with a better therapeutic index need to be identified.

A phase I-II study of weekly oxaliplatin, 5-fluorouracil continuous infusion and preoperative radiotherapy in locally advanced rectal cancer.

BACKGROUND: Oxaliplatin (OXA) significantly enhanced the antitumour activity of 5-fluorouracil (FUra) in patients with advanced colorectal cancer and displayed radiosensitising properties in preclinical studies. This study was thus performed to test the feasibility, identify the recommended doses (RDs) and explore preliminarily the clinical activity of weekly OXA and infused FUra combined with preoperative pelvic radiotherapy. PATIENTS AND METHODS: Forty-six patients with recurrent or locally advanced (cT3-4 and/or N+) adenocarcinomas of the mid-low rectum were treated with escalating doses of OXA (25, 35, 45, 60 mg/m2, weekly for 6 weeks) and FUra (200-225 mg/m2/day, 6-week infusion) concurrent to preoperative pelvic radiotherapy (50.4 Gy/28 fractions). The RDs for the phase II part of the study were immediately below the level resulting in dose-limiting toxicities in more than one third of the patients, or corresponded to the last planned dose level. RESULTS: In the escalation phase, dose-limiting toxicities only occurred in one patient at the fourth level and one of six patients treated at the last planned dose level (grade III diarrhoea). OXA 60 mg/m2 and FUra 225 mg/m2/day are therefore the RDs for the regimen. Among 25 patients globally treated at these doses (phase II part), the incidence of grade III diarrhoea was 16% with no grade IV toxicity. Neurotoxicity did not exceed grade II (12%). All patients completed radiotherapy and were operated on as scheduled. Twenty-one of 25 patients had the tumour down-staged after chemoradiation with seven (28%) pathological complete responses and 12 (48%) residual tumours limited to ypT1-2N0. CONCLUSIONS: Weekly OXA, at doses potentially active systemically, can be combined with full-dose, infused FUra and radiotherapy. Given the low toxicity and promising activity, this regimen is being compared to standard FUra-based pelvic chemoradiation in a randomised study.

Quality of life evaluation in a randomised trial of chemotherapy versus bio-chemotherapy in advanced melanoma patients.

This study analyses the health related quality of life (HRQOL) of advanced melanoma patients, in a randomised trial comparing bio-chemotherapy (bio-CT) versus chemotherapy (CT). The trial enrolled 178 patients and the median survival was not statistically different between the two arms. HRQOL was assessed at baseline and before each cycle of therapy, using the Rotterdam Symptom Checklist (RSCL) questionnaire completed with 140 patients. At baseline, overall quality of life and psychological distress scores were the most impaired, compared with the normal population. During treatment, the difference between the two arms in the changes from baseline was statistically significant (P=0.03) only in the overall quality of life score, with a decrease of 6.28 points in the bio-CT arm. The mean values decreased significantly in all domains in bio-CT arm, but only in activity level and physical symptom distress scores in the CT arm. Testing HRQOL variables and prognostic clinical factors in a Cox model, only the serum level of lactic dehydrogenase, baseline overall quality of life and the physical symptom distress scores remained significant independent prognostic factors for survival. A score of less than 75 points in the overall quality of life and in the physical symptom distress domains was associated with a Hazard Ratio (HR) of 2.31 (95% Confidence Interval (CI): 1.09-4.90) and 1.92 (95% CI: 1.10-3.36), respectively.

Effect of antiadhesive agents on peritoneal carcinomatosis in an experimental model.

BACKGROUND: Auto-crosslinked polysaccharide hyaluronan-based solution (Hyalobarrier-gel) prevents postoperative adhesions. However, its effect on tumour growth is still unknown. The aim of the present study was therefore to investigate the impact on survival of intra-abdominally administered Hyalobarrier-gel, native hyaluronan (HA) and hyaluronan/carboxymethylcellulose (HA/CMC), after intraperitoneal tumour implantation. METHODS: After receiving an intraperitoneal inoculum of the human HT29 colorectal cell line, 615 athymic nude mice were assigned randomly to five groups: groups 1 and 2 received Hyalobarrier-gel 20 mg/ml (n = 124) and 40 mg/ml (n = 126) respectively; groups 3 and 4 received HA (n = 120) and HA/CMC film (Seprafilm) (n = 123) respectively. The survival of each treated group was compared with that of group 5, the control, which had no treatment (n = 122). RESULTS: As 34 of the 615 mice were not eligible, 581 animals were considered for the analysis. At 120 days, 136 animals (23.4 per cent) were still alive. At autopsy there was macroscopic absence of tumour in 75 cases (12.9 per cent). No statistically significant differences were found between the treatment and the control groups with respect to postoperative death and absence of tumour implantation. There was no difference in survival rate between the control group and groups treated with Hyalobarrier-gel, HA or HA/CMC. CONCLUSION: Hyalobarrier-gel, HA and HA/CMC had no negative impact on the survival rate in mice that received an intraperitoneal implantation of HT29 colorectal human tumour cells.

Enkephalinase and angiotensin converting enzyme activities in human venous and arterial plasma.

Circulating opioids, particularly enkephalins, can act on specific receptors located on the neurovascular sympathetic junction. These peptides are quickly metabolized by enkephalinase and angiotensin converting enzyme (ACE). According to the parallel distribution of enkephalinase with opioid receptors in the rat brain, and its location in the vascular bed, putative differences of enkephalinase and ACE activity between arterial and venous plasma of the same subjects was researched. Venous enkephalinase activity was found to be greater than arterial activity. No arterovenous differences were present in ACE activity. The activities of both enzymes presented a positive correlation between venous and arterial plasma in the same subjects. The arterovenous difference in enkephalinase activity supports a release of the enzyme from microvessels.