T1 colon cancer in the era of screening: risk factors and treatment.

BACKGROUND: The aim of this study was to identify risk factors for lymph node positivity in T1 colon cancer and to carry out a surgical quality assurance audit. METHODS: The sample consisted of consecutive patients treated for early-stage colon lesions in 15 colorectal referral centres between 2011 and 2014. The study investigated 38 factors grouped into four categories: demographic information, preoperative data, indications for surgery and post-operative data. A univariate and multivariate logistic regression analysis was performed to analyze the significance of each factor both in terms of lymph node (LN) harvesting and LN metastases. RESULTS: Out of 507 patients enrolled, 394 patients were considered for analysis. Thirty-five (8.91%) patients had positive LN. Statistically significant differences related to total LN harvesting were found in relation to central vessel ligation and segmental resections. Cumulative distribution demonstrated that the rate of positive LN increased starting at 12 LN harvested and reached a plateau at 25 LN. CONCLUSIONS: Some factors associated with an increase in detection of positive LN were identified. However, further studies are needed to identify more sensitive markers and avoid surgical overtreatment. There is a need to raise the minimum LN count and to use the LN count as an indicator of surgical quality.

Under-reporting of subjective symptoms and its prognostic value: a pooled analysis of 12 cancer clinical trials.

BACKGROUND: Oncologists tend to under-report subjective symptoms during cancer treatment. This study describes the under-reporting rate of selected symptoms and explores its association with overall survival (OS). A secondary aim is to test the association of patient-reported symptoms with OS. PATIENTS AND METHODS: This is a post hoc analysis on data pooled from 12 randomized trials, promoted by the National Cancer Institute of Naples (Italy), enrolling patients between 2002 and 2019, with published primary analyses. Occurrence and grade of six side-effects (anorexia, nausea, vomiting, constipation, diarrhea and fatigue) reported by physicians were compared with corresponding symptoms reported by patients in quality-of-life (QoL) questionnaires. Under-reporting was defined as the rate of cases reported grade 0 by the physician while grade ≥1 by the patient. Prognostic value was tested in a multivariable model stratified by trial, including age, sex and performance status as confounders. A landmark threshold was defined for OS analyses. RESULTS: 3792 patients with advanced lung, ovarian, pancreatic, breast or colorectal cancer were pooled; 2603 (68.6%) were eligible having at least one toxicity assessment and one QoL questionnaire, before the first planned disease restaging. Concordance between physicians' and patients' reporting was low with Cohen's k coefficients ranging from 0.03 (fatigue) to 0.33 (vomiting). Under-reporting ranged from 52.7% (nausea) to 80.5% (anorexia), and was not associated with OS. Patient-reported anorexia, vomiting and fatigue ('a little' or more) were significantly associated with shorter OS. CONCLUSIONS: Under-reporting of treatment side-effects is frequent, but it does not affect OS. Patients' reported symptoms should be used for prognostic evaluation.

Cetuximab as third-line rechallenge plus either irinotecan or avelumab is an effective treatment in metastatic colorectal cancer patients with baseline plasma RAS/BRAF wild-type circulating tumor DNA: Individual patient data pooled analysis of CRICKET and CAVE trials.

The rechallenge strategy is based on the concept that a subset of patients with RAS wild-type (WT) metastatic colorectal cancer (mCRC) could still benefit of epidermal growth factor receptor (EGFR) inhibition, after progression to an anti-EGFR based-therapy. We performed a pooled analysis of two-phase II prospective trials to determine the role of rechallenge in third-line mCRC patients with RAS/BRAF WT baseline circulating tumor DNA (ctDNA). Individual data of 33 and 13 patients from CAVE and CRICKET trials that received as third-line therapy cetuximab rechallenge were collected. Overall survival (OS), Progression-free survival (PFS), Overall response rate (ORR), Stable disease (SD) >6 months were calculated. Adverse events were reported. For the whole 46 patient population, median PFS (mPFS) was 3.9 months (95% Confidence Interval, CI 3.0-4.9) with median OS (mOS) of 16.9 months (95% CI 11.7-22.1). For CRICKET patients, mPFS was 3.9 months (95% CI 1.7-6.2); mOS was 13.1 months (95% CI 7.3-18.9) with OS rates at 12, 18, and 24 months of 62%, 23%, and 0%, respectively. For CAVE patients, mPFS was 4.1 months (95% CI 3.0-5.2); mOS was 18.6 months (95% CI 11.7-25.4) with OS rates at 12, 18, 24 months of 61%, 52%, 21%, respectively. Skin rash was more frequently reported in CAVE trial (87.9% vs. 30.8%; p = 0.001), whereas a increased incidence of hematological toxicities was observed in CRICKET trial (53.8%% vs. 12.1%; p = 0.003). Third-line cetuximab rechallenge in combination with either irinotecan or avelumab in RAS/BRAF WT ctDNA mCRC patients represents a promising therapy.

Regorafenib monotherapy as second-line treatment of patients with RAS-mutant advanced colorectal cancer (STREAM): an academic, multicenter, single-arm, two-stage, phase II study.

BACKGROUND: Maintaining angiogenesis inhibition and switching the chemotherapy backbone represent the current second-line therapy in patients with RAS-mutant metastatic colorectal cancer (mCRC). Regorafenib, an oral multikinase inhibitor, prolonged overall survival (OS) in the chemorefractory setting. MATERIALS AND METHODS: STREAM was an academic, multicenter, single-arm phase II trial, evaluating the activity of regorafenib in RAS-mutant mCRC, in terms of the rate of patients who were progression-free after 6 months from study entry (6mo-PF). Patients were pretreated with fluoropyrimidine, oxaliplatin, and bevacizumab. According to Simon's two-stage design, ≥18 patients 6mo-PF were needed in the overall population (N = 46). Secondary endpoints were safety, objective response rate (ORR), progression-free survival (PFS), and OS. Early metabolic response by [18F]2-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography ([18F]-FDG PET/CT) scan was an exploratory endpoint. EudraCT Number: 2015-001105-13. RESULTS: The number of patients 6mo-PF was 8/22 at the first stage and 14/46 in the overall population. The ORR was 10.9%, disease control rate was 54.6%, median (m)PFS was 3.6 months [95% confidence interval (CI) 1.9-6.7 months], mOS was 18.9 months (95% CI 10.3-35.3 months), and mPFS2 (from study entry to subsequent-line progression) was 13.3 months (95% CI 8.4-19.7 months). Long benefiter patients (>6mo-PF) significantly more often had a single metastatic site and lung-limited disease. No unexpected toxicity was reported. Grade ≥3 events occurred in 39.1% of patients, with hand-foot syndrome (13%), fatigue, and hyperbilirubinemia (6.5%) occurring mostly. Baseline metabolic assessment was associated with OS in the multivariate analysis, while early metabolic response was not associated with clinical outcomes. CONCLUSIONS: The study did not meet its primary endpoint. However, regorafenib was well tolerated and did not preclude subsequent treatments. Patients with good prognostic features (single metastatic site and lung-limited disease) reported clinical benefit with regorafenib. The exploratory metabolic analysis suggests that baseline [18F]-FDG PET/CT might be useful to select patients with a favorable outcome. A chemotherapy-free interval with regorafenib was associated with durable disease control in a selected group of patients with favorable clinical characteristics.

Establishment of patient-derived tumor organoids to functionally inform treatment decisions in metastatic colorectal cancer.

BACKGROUND: Metastatic colorectal cancer (mCRC) patients tend to have modest benefits from molecularly driven therapeutics. Patient-derived tumor organoids (PDTOs) represent an unmatched model to elucidate tumor resistance to therapy, due to their high capacity to resemble tumor characteristics. MATERIALS AND METHODS: We used viable tumor tissue from two cohorts of patients with mCRC, naïve or refractory to treatment, respectively, for generating PDTOs. The derived models were subjected to a 6-day drug screening assay (DSA) with a comprehensive pipeline of chemotherapy and targeted drugs against almost all the actionable mCRC molecular drivers. For the second cohort DSA data were matched with those from PDTO genotyping. RESULTS: A total of 40 PDTOs included in the two cohorts were derived from mCRC primary tumors or metastases. The first cohort included 31 PDTOs derived from patients treated in front line. For this cohort, DSA results were matched with patient responses. Moreover, RAS/BRAF mutational status was matched with DSA cetuximab response. Ten out of 12 (83.3%) RAS wild-type PDTOs responded to cetuximab, while all the mutant PDTOs, 8 out of 8 (100%), were resistant. For the second cohort (chemorefractory patients), we used part of tumor tissue for genotyping. Four out of nine DSA/genotyping data resulted applicable in the clinic. Two RAS-mutant mCRC patients have been treated with FOLFOX-bevacizumab and mitomycin-capecitabine in third line, respectively, based on DSA results, obtaining disease control. One patient was treated with nivolumab-second mitochondrial-derived activator of caspases mimetic (phase I trial) due to high tumor mutational burden at genotyping, experiencing stable disease. In one case, the presence of BRCA2 mutation correlated with DSA sensitivity to olaparib; however, the patient could not receive the therapy. CONCLUSIONS: Using CRC as a model, we have designed and validated a clinically applicable methodology to potentially inform clinical decisions with functional data. Undoubtedly, further larger analyses are needed to improve methodology success rates and propose suitable treatment strategies for mCRC patients.

Clinical efficacy of sequential treatments in KRASG12C-mutant metastatic colorectal cancer: findings from a real-life multicenter Italian study (CRC-KR GOIM).

BACKGROUND: The presence of KRASG12C mutation in metastatic colorectal cancer (mCRC) correlates with poor outcome. Although different selective inhibitors are under clinical development, the optimal treatment remains uncertain. Thus, we conducted a retrospective analysis in a large cohort of patients with KRASG12C mCRC treated in 12 Italian oncology units. PATIENTS AND METHODS: Patients with unresectable mCRC harboring KRASG12C mutation receiving a first-line chemotherapy doublet or triplet between 2011 and 2021 were included in the study. Evaluation of overall response rate (ORR), progression-free survival (PFS) and overall survival (OS) analysis was carried out. RESULTS: A total of 256/6952 (3.7%) patients with mCRC displayed KRASG12C mutation; of these, 111 met the inclusion criteria. The ORR of first-line therapy was 38.7% (43/111). Median PFS (mPFS) was 9 months [95% confidence interval (CI) 7.5-10.5 months]. After progression, only 62% and 36% of the patients are fit to receive second or third lines of treatment, with limited clinical benefit. Median OS (mOS) was 21 months (95% CI 17.4-24.6 months). In patients receiving first-line triplet chemotherapy, ORR was 56.3% (9/16), mPFS was 13 months (95% CI 10.3-15.7 months) and mOS was 32 months (95% CI 7.7-56.3 months). For irinotecan-based doublets, ORR was 34.5 (10/29), mPFS was 9 months (95% CI 6.4-11.6 months) and mOS was 22 months (95% CI 16.0-28.0 months). With oxaliplatin-based doublets ORR was 36.4% (24/62), mPFS was 7 months (95% CI 4.6-9.4 months) and mOS was 18 months (95% CI, 13.6-22.4 months). CONCLUSION: Patients with KRASG12C-mutant mCRC had a disappointing response to standard treatments. Within the limitations of a retrospective study, these results suggest that first-line chemotherapy intensification with FOLFOXIRI is a valid option in fit patients.

Germinal BRCA1-2 pathogenic variants (gBRCA1-2pv) and pancreatic cancer: epidemiology of an Italian patient cohort.

OBJECTIVE: Germline BRCA1-2 pathogenic variants (gBRCApv) increase the risk of pancreatic cancer and predict for response to platinating agents and poly(ADP-ribose) polymerase inhibitors. Data on worldwide gBRCApv incidence among pancreatic ductal adenocarcinoma (PDAC) patients are sparse and describe a remarkable geographic heterogeneity. The aim of this study is to analyze the epidemiology of gBRCApv in Italian patients. MATERIALS AND METHODS: Patients of any age with pancreatic adenocarcinoma, screened within 3 months from diagnosis for gBRCApv in Italian oncologic centers systematically performing tests without any selection. For the purposes of our analysis, breast, ovarian, pancreas, and prostate cancer in a patient's family history was considered as potentially BRCA-associated. Patients or disease characteristics were examined using the χ2 test or Fisher's exact test for qualitative variables and the Student's t-test or Mann-Whitney test for continuous variables, as appropriate. RESULTS: Between June 2015 and May 2020, 939 patients were tested by 14 Italian centers; 492 (52%) males, median age 62 years (range 28-87), 569 (61%) metastatic, 273 (29%) with a family history of potentially BRCA-associated cancers. gBRCA1-2pv were found in 76 patients (8.1%; 9.1% in metastatic; 6.4% in non-metastatic). The gBRCA2/gBRCA1 ratio was 5.4 : 1. Patients with gBRCApv were younger compared with wild-type (59 versus 62 years, P = 0.01). The gBRCApv rate was 17.1% among patients <40 years old, 10.4% among patients 41-50 years old, 9.2% among patients 51-60 years old, 6.7% among patients aged 61-70 years, and 6.2% among patients >70 years old (none out of 94 patients >73 years old). gBRCApv frequency in 845 patients <74 years old was 9%. Patients with/without a family history of potentially BRCA-associated tumors had 14%/6% mutations. CONCLUSION: Based on our findings of a gBRCApv incidence higher than expected in a real-life series of Italian patients with incident PDAC, we recommend screening all PDAC patients <74 years old, regardless of family history and stage, due to the therapeutic implications and cancer risk prevention in patients' relatives.

Vorinostat synergises with capecitabine through upregulation of thymidine phosphorylase.

BACKGROUND: Potentiation of anticancer activity of capecitabine is required to improve its therapeutic index. In colorectal cancer (CRC) cells, we evaluated whether the histone deacetylase-inhibitor vorinostat may induce synergistic antitumour effects in combination with capecitabine by modulating the expression of thymidine phosphorylase (TP), a key enzyme in the conversion of capecitabine to 5-florouracil (5-FU), and thymidylate synthase (TS), the target of 5-FU. METHODS: Expression of TP and TS was measured by real-time PCR, western blotting and immunohistochemistry. Knockdown of TP was performed by specific small interfering RNA. Antitumour activity of vorinostat was assessed in vitro in combination with the capecitabine active metabolite deoxy-5-fluorouridine (5'-DFUR) according to the Chou and Talay method and by evaluating apoptosis as well as in xenografts-bearing nude mice in combination with capecitabine. RESULTS: Vorinostat induced both in vitro and in vivo upregulation of TP as well as downregulation of TS in cancer cells, but not in ex vivo treated peripheral blood lymphocytes. Combined treatment with vorinostat and 5'-DFUR resulted in a synergistic antiproliferative effect and increased apoptotic cell death in vitro. This latter effect was impaired in cells where TP was knocked. In vivo, vorinostat plus capecitabine potently inhibited tumour growth, increased apoptosis and prolonged survival compared with control or single-agent treatments. CONCLUSIONS: Overall, this study suggests that the combination of vorinostat and capecitabine is an innovative antitumour strategy and warrants further clinical evaluation for the treatment of CRC.

Current status on response to treatment in locally advanced rectal cancer: what the radiologist should know.

The assessment of tumor response, after neoadjuvant radiochemotherapy (nCRT), allows stratifying the patient in order to consider the proper therapeutical management. Histopathology analysis of the surgical specimen is considered the gold standard to assess tumour response and the definition of a complete cancer response is related to the clinical and endoscopic features, by direct evaluation of the rectal wall. However, imaging studies, especially Magnetic Resonance Imaging (MRI) have provided additional parameters, as the evaluation of nodal or mesorectal status. MRI provides a radiological tumour regression grade (mrTRG) that is correlated with the pathologic tumor regression grade (pTRG). Functional MRI parameters have additional impending in early prediction of the efficacy of therapy and can be valuable in drug development processes. Some of functional methodologies are already part of clinical practice: diffusion-weighted MRI (DW-MRI) and perfusion imaging (dynamic contrast enhanced MRI [DCE-MRI]). Other technologies, such as radiomics with MRI are still in the experimental phase. An adequate radiological report describing the restaging of rectal cancer after nCRT should be a "structured report" to improve communication in a multidisciplinary team.

Liver radiologic findings of chemotherapy-induced toxicity in liver colorectal metastases patients.

There are a number of chemotherapy-effects that should be assessed with liver imaging since they have an influence on surgical morbidity. Chemotherapy-related complications, steatosis, chemotherapy-associated steatohepatitis (CASH), and SOS might impair the hepatic parenchyma, thus reducing the functionality and influencing the outcome following resection. The main role of a radiologist is to provide an accurate diagnosis of the lesion. With constant advances in medicine, a radiologist's role should extend beyond just reporting the data of tumor, providing additional information that may greatly improve patient care. Radiologists should assess both chemotherapy effects on the hepatic metastasis itself, as well as chemo-induced focal and diffuse modifications of non-tumor hepatic parenchyma, since it is important to avoid impaired hepatic function after hepatic resection.

Phase I and pharmacokinetic study of tomudex combined with 5-fluorouracil plus levofolinic acid in advanced head and neck cancer and colorectal cancer.

In vitro studies have shown a schedule-dependent synergism between Tomudex and 5-fluorouracil (5-FU). Incubation of different types of head and neck and colorectal cancer cells with levofolinic acid (LFA) plus 5-FU for 4 or 24 h, after 24-h incubation with Tomudex, produces a clear synergism. The purpose of this study was to evaluate the tolerability and activity of a combination of Tomudex, LFA, and 5-FU in advanced head and neck and colorectal cancer. Furthermore, the potential for 5-FU pharmacomodulation by Tomudex was also evaluated through an intrapatient assessment of dihydropyrimidine dehydrogenase (DPD) activity and 5-FU AUC with and without pretreatment with Tomudex. Eligible patients were treated with Tomudex at the starting dose of 1.5 mg/m2 on day 1, LFA at a fixed dose of 250 mg/m2 on day 2, immediately followed by bolus 5-FU at the starting dose of 600 mg/m2. Tomudex and 5-FU doses were alternately escalated. Courses were repeated every 2 weeks. In the second course, LFA and 5-FU were administered on day 1 and Tomudex on day 2; further treatment was given according to the sequence used in the first course. Plasma 5-FU concentrations were analyzed on courses 1 and 2 using a high-performance liquid chromatography assay with UV detection. DPD activity was measured in peripheral blood mononuclear cells on courses 1 and 2 using incubation of cytosol with [14C]FU and quantitation of metabolite formation. Fifty-eight patients were enrolled in the study. Dose escalation was stopped at step 8, because of the occurrence of dose-limiting toxicity in two of three patients. The dose level immediately before (3 mg/m2 Tomudex, 1050 mg/m2 5-FU) was selected for further evaluation. Tomudex and 5-FU mean dose intensities actually delivered at the seventh step were 1.32 and 462 mg/m2/week, respectively. Six of 40 patients with metastatic colorectal cancer obtained an objective response (15%; 95% confidence interval, 6-30%). In particular, three complete responses and three partial responses were observed. Six of 17 patients with locally advanced or metastatic head and neck cancer obtained an objective response (1 complete response + 5 partial responses; 35%; 95% confidence interval, 14-62%). Median duration of response in colorectal cancer patients was 12 months. 5-FU AUC was not significantly different between the two courses (median intrapatient difference, 9.3%; P = 0.28). DPD activity in course 1 was significantly higher than course 2 (P = 0.041) in the 16 patients in which values were evaluable. The combination of Tomudex, LFA, and 5-FU is well tolerated and active in colorectal and head and neck cancer. The Tomudex mean dose intensity actually delivered is higher than usually achieved in monotherapy. The absence of a clear pharmacokinetic interaction suggests that the synergism of Tomudex and 5-FU might occur at the cellular level.

Dopamine and somatostatin inhibition of prolactin secretion from MMQ pituitary cells: role of adenosine triphosphate-sensitive potassium channels.

The sulfonylurea glibenclamide, which is known to block ATP-sensitive potassium channels, increases, in a dose-dependent manner, the release of PRL from MMQ pituitary cells. Glibenclamide does not reduce the dopaminergic inhibition of forskolin-stimulated PRL secretion; conversely it almost completely abolishes the inhibitory effect of somatostatin (SRIF) on this parameter. The sulfonylurea dose dependently increases basal [Ca++]i, without affecting the increase in [Ca++]i induced by high concentrations of extracellular potassium. Glibenclamide does not modify dopamine-induced [Ca++]i reduction, whereas it abolishes the inhibitory effect of SRIF on basal [Ca++]i. In the presence of diazoxide, an opener of ATP-sensitive potassium channels, which lowers basal [Ca++]i, dopamine still reduces [Ca++]i whereas SRIF does not induce a further decrease. Glibenclamide induces the depolarization of the cell membrane and prevents the SRIF-evoked hyperpolarization. The hyperpolarization of the cell membrane induced by dopamine is not modified by glibenclamide. Diazoxide induces a cell membrane hyperpolarization that is enhanced by dopamine but not by SRIF. Finally, glibenclamide does not affect basal and stimulated adenylate cyclase activity. In conclusion, our findings show that, in MMQ cells, glibenclamide stimulates PRL release, suggesting an involvement of ATP-sensitive potassium channels in the regulation of PRL secretion. The reversal by glibenclamide of the effects of SRIF on calcium homeostasis, membrane potential, and PRL release suggests that this type of potassium channel participates to the somatostatinergic inhibition of PRL secretion. Conversely, we found that glibenclamide does not modify the dopaminergic inhibition of PRL secretion and second messenger systems, suggesting that ATP-sensitive potassium channels may not be involved in the inhibitory effect of dopamine on PRL release.

Alpha 1A- and alpha 1B-adrenergic receptors mediate the effect of norepinephrine on cytosolic calcium levels in rat PC C13 thyroid cells: thyrotropin modulation of alpha 1B-linked response via a adenosine 3',5'-monophosphate-protein kinase-A-dependent pathway.

The aim of the present study was to characterize the adrenergic receptors mediating the effects of norepinephrine on PC C13 rat thyroid cells and identify the molecular mechanisms by which TSH regulates the noradrenergic response. We studied TSH regulation of norepinephrine-induced cytosolic calcium increase by means of the fluorescent probe fura-2. In PC C13 cells grown and maintained in a medium containing TSH (PC C13 6H), norepinephrine caused a higher increase in cytosolic calcium than in PC C13 starved from TSH 5 days before the experiments (PC C13 5H). In both group of cells the calcium response to norepinephrine was concentration dependent and reduced by the removal of extracellular calcium ions. Reintroduction of TSH in the culture medium of the PC C13 5H cells induced the recovery of the norepinephrine-stimulated intracellular calcium rise similarly to that in the native PC C13 6H. This effect was complete after a 48-h incubation period and was abolished by the simultaneous treatment of the cells with the protein synthesis inhibitor cycloheximide, suggesting that TSH may stimulate the synthesis of alpha 1-adrenergic receptors in PC C13 cells. Because in these cells we found that TSH increased cAMP levels as well as inositol phosphate production, we tested whether the activation of a protein kinase-A and/or protein kinase-C was involved in TSH regulation of the adrenergic response. We found that the treatment of PC C13 5H cells with forskolin restored the effect of norepinephrine on the calcium level, and that KT5720, an inhibitor of the protein kinase-A, was able to prevent the recovery of the noradrenergic response induced by the readdition of TSH to the culture medium of PC C13 5H. Conversely, treatment of PC C13 5H cells with the protein kinase-C activator phorbol 12-myristate 13-acetate was ineffective. Norepinephrine also stimulated inositol phosphate production in PC C13 6H and, to a lesser extent, in PC C13 5H, but it did not affect the cAMP levels in the two groups of cells. To characterize alpha 1-adrenergic receptor subtypes mediating the effects of norepinephrine in PC C13 cells, we used antagonists of alpha 1A and alpha 1B receptors (WB4101 and chlorethylclonidine respectively).(ABSTRACT TRUNCATED AT 400 WORDS)

Direct effect of adenosine on prolactin secretion at the level of the single rat lactotroph: involvement of pertussis toxin-sensitive and -insensitive transducing mechanisms.

We studied the effect of adenosine on prolactin secretion by the anterior pituitary, and the transduction mechanisms whereby the purine exerts its action. Adenosine inhibited prolactin release in basal and in vasoactive intestinal peptide (VIP)- or TRH-stimulated conditions. Pertussis toxin pretreatment reduced the inhibition of VIP-stimulated prolactin secretion which was induced by adenosine, while it completely abolished the effect of the purine on TRH-evoked prolactin release. In membrane preparations of anterior pituitary cells, adenosine reduced the adenylate cyclase activity stimulated by VIP. Such an inhibition was not blocked by pertussis toxin pretreatment. Furthermore, the purine reduced TRH-stimulated inositol phosphate production in cultured anterior pituitary cells, an effect that was reversed by pretreatment with pertussis toxin. In addition, the nucleoside did not significantly affect the TRH-induced rise in intracellular calcium. In conclusion, our data show that adenosine inhibits prolactin secretion, acting on purinergic receptors coupled to the adenylate cyclase enzyme and phospholipase C. The effect of the nucleoside on adenylate cyclase seems to be achieved either by the involvement of an adenosine receptor coupled to the catalytic subunit of the enzyme via a pertussis toxin-sensitive G protein, or by the activation of a site directly coupled to the catalytic subunit of the adenylate cyclase (the P site). Its effect on phospholipase C seems to be mediated by a purinergic receptor coupled to the intracellular effector via a pertussis toxin-sensitive G protein.

Rapid detection of experimental E. coli endophthalmitis by the Limulus lysate test.

Experimental E. coli endophthalmitis was produced in rabbits. The Limulus lysate test was applied to aqueous and vitreous samples at various intervals after the intravitreal injection of E. coli organisms. Results indicated that this test is feasible using vitreous and aqueous samples. The Limulus test was positive for E. coli endotoxin within hours after infection, requiring only 1 hr to determine the presence of endotoxin after sampling. This test may have some value in the rapid diagnosis of gram-negative endophthalmitis.

Phase I study of mitoxantrone, raltitrexed, levofolinic acid and 5-fluorouracil in advanced solid tumours.

PURPOSE: We have recently evaluated the combination of raltitrexed, levofolinic acid (LFA) and 5-fluorouracil (5-FU) in advanced head and neck and colorectal cancer, and we have shown that this combination is well tolerated and has clinical activity. Clinical combination studies have shown that raltitrexed and anthracyclines can be combined at full doses without unexpected toxicities. Based on these observations, we started a phase I study of mitoxantrone plus raltitrexed administered on day 1, followed by LFA and 5-FU on day 2 in patients with advanced solid tumors. PATIENTS AND METHODS: Mitoxantrone was given at a starting dose of 6 mg/m2, raltitrexed at a fixed dose of 3 mg/m2, LFA at a fixed dose of 250 mg/m2, and 5-FU at a starting dose of 750 mg/m2. Mitoxantrone and 5-FU doses were subsequently escalated alternately up to dose-limiting toxicity. Treatment was repeated every 14 days. RESULTS: Four dose levels were tested in 18 patients. All three patients treated at the fourth dose level had grade 4 neutropenia after the first cycle. Therefore, this level was defined as the maximum tolerated dose and the dose level immediately below (mitoxantrone 7 mg/m2 and 5-FU 900 mg/m2) was selected for further evaluation. Neutropenia was the main toxic effect. Nonhaematologic side effects were mild. One complete response and five partial responses (all but one in patients with head and neck cancer) were observed, for an overall response rate of 33% (95% confidence interval, 13% to 59%). CONCLUSIONS: Mitoxantrone, raltitrexed and 5-FU can be combined at doses which are close to those used in monotherapy. The observed activity is encouraging, especially in the subset of patients with head and neck cancer.

Effect of acetyl-L-carnitine treatment on brain adenylate cyclase activity in young and aged rats.

The aim of the present study has been to evaluate the effect of acetyl-L-carnitine (ALCAR) on brain adenylate cyclase (AC) activity in adult and aged rats. In in vitro studies, ALCAR (1, 10 and 100 microM) did not exert any effect on frontal cortex basal AC activity. Acute and subchronic administrations of ALCAR were carried out in 4- and 25-month-old male Fisher rats and AC activity was determined in rat frontal cortex under both basal and stimulated conditions. The acute treatment of young rats with ALCAR (100 and 500 mg/kg s.c.) did not affect AC activity, whereas the subchronic administration of 250 mg/kg s.c. ALCAR enhanced the stimulation of AC by carbamylcholine (CCh), norepinephrine (NE) and dopamine (DA), without affecting the basal AC activity. Basal AC activity in old rats was lower than in young rats and was not modified by acute and subchronic ALCAR administration. Moreover, the response of the enzyme to CCh, NE and DA was potentiated by the subchronic administration of ALCAR. The concentration-response curve of CCh stimulation of AC activity in ALCAR-treated rats is shifted to the left in both young and aged rats. We conclude that ALCAR, subchronically administered, is able to enhance receptor-stimulated AC response in frontal cortex of both young and aged rats.

[Early evaluation using PET-FDG of the efficiency of neoadjuvant radiochemotherapy treatment in locally advanced neoplasia of the lower rectum]. / Valutazione precoce con PET-FDG della efficacia del trattamento radiochemioterapico neoadiuvante nelle neoplasie del retto inferiore localmente avanzate.

BACKGROUND AND PURPOSE: Preoperative chemoradiation allows downstaging of locally advanced rectal cancer and in selected patients also a sufficient downsizing to ensure sphincter preservation. Selection of patients warranting a preoperative approach is improved by magnetic resonance imaging (MRI) which is able to define the involvement of mesorectal circumferential margin. Similarly it would be crucial to define the response to chemoradiation during the treatment but traditional morphologic imaging techniques may fail in differentiating neoplastic tissue from scarring. PET-FDG has been successfully used in the detection of metastatic colorectal cancer allowing imaging of deposits as small as 0.5 cm and may have a role in evaluating early response to chemoradiation. METHODS: In the present study, in patients with T3-T4 rectal cancer undergoing preoperative chemoradiation PET-FDG and flow cytometry analysis on endoscopic biopsy specimen have been performed before, during and after preoperative chemoradiation. RESULTS: Chemoradiation treatment has been successful in terms of downsizing and downstaging of the tumor. PET-FDG was able to demonstrate local response at only ten-fifteen days after the beginning of neoadjuvant therapy, also identifying non responding patients. CONCLUSIONS: FDG-PET may have a role in defining the response to chemoradiation and modulate the treatments strategy in patients with advanced rectal cancer.

Biweekly oxaliplatin, raltitrexed, 5-fluorouracil and folinic acid combination chemotherapy during preoperative radiation therapy for locally advanced rectal cancer: a phase I-II study.

Oxaliplatin (OXA), raltitrexed (RTX), 5-fluorouracil (FU) and folinic acid (FA) have shown activity in metastatic colorectal cancer, radioenhancing effect and synergism when combined. We evaluated a chemotherapy (CT) combination of OXA, RTX and FU/FA during preoperative radiotherapy (RT) in locally advanced rectal cancer (LARC) patients. Fifty-one patients with LARC at high risk of recurrence (T4, N+ or T3N0 < or =5 cm from anal verge and/or circumferential resection margin < or =5 mm) received three biweekly courses of CT during pelvic RT (45 Gy). Surgery was planned 8 weeks after CT-RT. Recommended doses (RDs) determined during phase I were utilised in the subsequent phase II trial, where the rate of tumour regression grade (TRG) 1 or 2 was the main end point. No toxic deaths occurred, and severe toxicity was easily managed. In phase II, RDs delivered in 31 patients were OXA 100 mg m(-2) and RTX 2.5 mg m(-2) on day 1, and FU 900 mg m(-2) and LFA 250 mg m(-2) on day 2. Main severe toxicities by patients were grade 4 neutropenia (23%) and grade 3 diarrhoea (19%). In 71% (95% confidence limits, 52-86%) of patients, TRG1 (13) or TRG2 (9) was obtained. All patients are alive and recurrence-free after a median follow-up of 29 months. Combination of OXA, RTX and FU/FA with pelvic RT has an acceptable toxicity and a high clinical activity in LARC and should be studied further in patients at high risk of recurrence.