Preoperative downstaging chemoradiation with concurrent irinotecan and capecitabine in MRI-defined locally advanced rectal cancer: a phase I trial (NWCOG-2).

BACKGROUND: The aim of this study was to investigate the safety of neoadjuvant chemoradiation using radiotherapy (RT) combined with concurrent capecitabine and irinotecan for locally advanced rectal cancer before surgery. METHODS: Forty-six patients were recruited and treated on the basis that MRI scanning had shown poor-risk tumours with threatening (< or =1 mm) or involvement of the mesorectal fascia. Conformal RT was given using 3 or 4 fields at daily fractions of 1.8 Gy on 5 days per week to a total dose of 45 Gy. Concurrently oral capecitabine was given twice daily throughout radiotherapy continuously from days 1 to 35 and intravenous irinotecan was given once per week during weeks 1 to 4 of RT. Dose levels were gradually escalated as follows. Dose level 1: capecitabine 650 mg m(-2) b.i.d. and irinotecan 50 mg m(-2); Dose level 2: capecitabine 650 mg m(-2) b.i.d. and irinotecan 60 mg m(-2); Dose level 3: capecitabine 825 mg m(-2) b.i.d. and irinotecan 60 mg m(2); Dose level 4: capecitabine 825 mg m(-2) b.i.d. and irinotecan 70 mg m(-2). RESULTS: Diarrhoea (grade 3, no grade 4) was the main serious acute toxicity with lesser degrees of fatigue, neutropenia, anorexia and palmar-plantar erythrodysesthesia. The recommended dose for future study was dose level 2 at which 3 of 14 patients (21%) developed grade 3 diarrhoea. Postoperative complications included seven pelvic or wound infections and two anastomotic and two perineal wound dehiscences. There were no deaths in the first 30 days postoperatively. Of 41 resected specimens, 11 (27%) showed a pathological complete response (pCR) and five (12%) showed an involved circumferential resection margin (defined as < or =1 mm). The 3-year disease-free survival (intent-to-treat) was 53.2%. CONCLUSION: In patients with poor-risk MRI-defined locally advanced rectal cancer threatening or involving the mesorectal fascia, preoperative chemoradiation based on RT at 45 Gy in 25 daily fractions over 5 weeks with continuous daily oral capecitabine at 650 mg m(-2) b.i.d. days 1-35 and weekly IV irinotecan at 60 mg m(-2) weeks 1-4, provides acceptable acute toxicity and postoperative morbidity with encouraging response and curative resection rates.

Weekly fluorouracil at 425 mg/m(2) plus low-dose folinic acid for 24 weeks as adjuvant treatment for colorectal cancer: assessment of toxicity and delivery.

AIMS: To assess the toxicity and dose delivery of weekly bolus 5-fluorouracil (5-FU) at 425 mg/m(2) plus low-dose folinic acid (FA) for 24 weeks as adjuvant treatment for colorectal cancer. MATERIALS AND METHODS: Data were collected on toxicity and dose reductions, stoppages, delays and intensity from 100 consecutive patients receiving this adjuvant regimen after curative surgery. RESULTS: There were 53 men and 47 women (median age: 64 and 65 years, respectively); 77 patients with colon cancer and 23 with cancer of the rectum; 34 patients with Dukes' stage B and 66 with Dukes' stage C. Thirty-seven patients experienced at least one grade 3 or 4 toxicity, mainly diarrhoea (20 patients) or fatigue (14 patients). Only one grade 4 toxicity was noted (diarrhoea). In multivariate analysis, increased grade 3 and 4 toxicity was significantly associated with female gender (P = 0.001) and age >65 years (P = 0.046). Forty patients completed the 24 cycles without dose reduction or delay. Forty-one patients required at least one dose reduction. The median 'conventional' dose intensity (DI), calculated from the first cycle to the last, was 408 mg/m(2)/week (96%). The median DI over 24 weeks was 387 mg/m(2)/week (91%). A higher median 24-week DI was delivered to men (407 mg/m(2)/week, 96%) than women (361 mg/m(2)/ week, 85%; P = 0.009). Women older than 65 years showed a significantly reduced median DI over 24 weeks (347 mg/ m(2)/week, 82%) compared with men aged 65 years or younger (407 mg/m(2)/week, 96%; P = 0.049) and men older than 65 years (425 mg/m(2)/week, 100%; P = 0.001), although the difference against women aged 65 years or younger (377 mg/ m(2)/week, 89%) was not statistically significant (P = 0.09). CONCLUSION: This regimen has shown what might be considered high rates of grade 3 and 4 toxicity for an adjuvant treatment, although the delivered DI was acceptable. Caution is urged in the treatment of elderly female patients who have statistically higher rates of grade 3 and 4 toxicity and lower DI.

Microvascular free tissue transfer in the management of squamous cell carcinoma of the tongue during pregnancy.

We describe a 36-year-old patient with a stage III carcinoma (pT2N1M0) of the tongue that presented in the second trimester of pregnancy. It was treated by primary excision and reconstruction with a free flap. To our knowledge this is the first reported case of successful microvascular free tissue transfer for oral cancer during pregnancy.

Massive haemoptysis death and other morbidity associated with high dose rate intraluminal radiotherapy for carcinoma of the bronchus.

Four hundred and six patients with primary non-small cell carcinoma of the bronchus causing symptoms due to endobronchial disease, were treated with intraluminal radiotherapy (ILT) using the microSelectron-HDR machine at the Christie Hospital, Manchester, between April 1988 and the end of 1992. An assessment of morbidity for this treatment is presented, particularly with regard to the risk factors and causes of massive haemoptysis death. The most common early side-effect was a mild transient exacerbation of cough which usually resolved within 2-3 weeks. At various times following ILT treatment 83 bronchoscopies were carried out randomly in 55 patients. In bronchoscopies carried out within the first 3 months following ILT, no tumour was visible in 80% of cases. A mucosal radiation reaction score (RRS) was used to grade bronchoscopic appearance after ILT treatment. Overall, 55% of bronchoscopic examinations showed some degree of mucosal radiation reaction. The majority of radiation reactions from 6 months onwards after ILT demonstrated a degree of fibrosis. A radiation reaction was seen more frequently after treatment with 2000 cGy as opposed to 1500 cGy at 1 cm from the central axis of the radiation source. Thirty-two patients were identified who had died from massive haemoptysis (MH) as a terminal event. A Cox multivariate regression analysis showed that the treatment-related factors of increased dose at first ILT (P = 0.004), prior laser treatment at the site of ILT (P = 0.020) and second ILT treatment in the same location as the first ILT treatment (P = 0.047), all significantly increased the relative risk of MH death compared with their effect on the relative risk of death from other causes (OC). (In addition a fourth treatment-related factor, namely the concurrent use of ILT and external beam radiotherapy (EB) had a P value of 0.08). Twenty out of 25 assessable MH-death patients (80%) had evidence of recurrent or residual tumour before death but 5 patients (20%) did not. For surviving patients the instantancious risk of death at any one time (the cause-specific death rate expressed as deaths per 100 cases per month), showed a sharp peak for MH deaths between 9 and 12 months post ILT in contradistinction to OC death where the peak was between 3 and 6 months post ILT. These findings may imply a role for late radiation reaction in the treatment-related risk factors identified as increasing the relative risk of MH death and possible mechanisms are discussed. The results have implications for treatment regimes that use a dose of 2000 cGy at 1 cm in a single fraction technique, that have a high frequency of previous laser treatment, that use multiple, repeated ILT treatments in the same location and that use ILT concurrently with EB.

Long-term survival and symptom palliation in small primary bronchial carcinomas following treatment with intraluminal radiotherapy alone.

Between April 1988 and December 1992, 37 patients with small, previously unirradiated, primary non-small cell carcinomas of the bronchus causing symptoms due to endobronchial disease were treated at the Christie Hospital, Manchester, with a single fraction of high dose rate intraluminal radiotherapy (ILT) using the microSelectron-HDR machine. Small primary (SP) lesions were defined as being less than 2 cm in diameter in a direction perpendicular to the central axis of the iridium-192 treatment source. Fifteen patients (41%) were treated to a dose of 15 Gy and 22 patients (59%) to 20 Gy at a distance of 1 cm from the central axis of the source. At 6 weeks following ILT, improvement in symptoms was seen in the following percentages of patients: haemoptysis 96%, pulmonary collapse 69%, cough 55% and dyspnoea 52%. The magnitude of improvement in these symptoms was largely maintained in patients surviving to 4 months and then 12 months post-ILT. Median actuarial survival was 709 days, 2-year survival 49.4% and 5-year survival 14.1%. Overall, there was no significant difference in survival after treatment with 20 Gy compared with 15 Gy at 1 cm. At the close of study, there were four patients still alive without disease recurrence with survivals of 38, 48, 49 and 63 months. All had had biopsy-proven squamous cell carcinomas and all had been treated with 20 Gy at 1 cm. Five patients died from massive haemoptysis as a terminal event at 4, 9, 9, 10 and 11 months post-ILT, well below the median survival for this group of patients. Again, all had been treated with 20 Gy as opposed to 15 Gy at 1 cm. Over the same time period, 287 patients with non-small cell carcinomas of more than 2 cm in diameter (large primary lesions, LP), were treated with a single fraction of ILT only, as their initial treatment. A consistently greater percentage of patients with SP lesions showed an improvement in the symptoms of haemoptysis and pulmonary collapse when compared with patients with LP lesions. Patients with LP lesions demonstrated a decreased actuarial survival when compared with SP lesions, with median survival being 156 days, 2-year survival 3.1% and no survivors beyond 39 months. This study demonstrates that, in patients with small endobronchial carcinomas a single fraction of ILT can give efficient palliation of symptoms and lead to long term disease-free survival, but that a dose of 20 Gy may be at the limit of bronchial radiation tolerance for a single dose technique employing a high dose rate source.

High dose rate intraluminal radiotherapy for carcinoma of the bronchus: outcome of treatment of 406 patients.

In April 1988 the Christie Hospital started using the microSelectron-HDR machine to deliver intraluminal radiotherapy (ILT) to inoperable bronchial carcinomas causing symptoms due to endobronchial disease. Results of treatment in the first 406 patients with primary non-small-cell carcinoma are presented. Three main categories of patient were defined. Category 1 consisted of 324 patients (79.8%) who were previously unirradiated and received a single fraction of ILT as their primary treatment, mostly to a dose of 1500 cGy (76%) or 2000 cGy (23%) at 1 cm from the centre of the iridium-192 treatment source. The percentage of these patients whose symptoms or signs were improved at 6 weeks following ILT were as follows: stridor 92%, haemoptysis 88%, cough 62%, dyspnoea, 60%, pain, 50% and pulmonary collapse, 46%. Approximately two-thirds of these patients (67.3%) derived long lasting palliation and required no further treatment during their lifetime. The other third of patients needed subsequent treatment at some stage because of recurrence of their symptoms and in this situation external beam radiotherapy (EB) or a repeat ILT treatment was effectively utilised. Category 2 consisted of 65 patients (16%) who had previously received EB but required ILT when their tumour recurred. At 6 weeks post-ILT levels of symptom palliation were broadly similar to those obtained if ILT was used in previously unirradiated individuals, although the improvement was not so well sustained with time and only 7% showed improvement in pulmonary collapse at 6 weeks. Category 3 consisted of 17 patients (4.2%) in whom ILT was used concurrently with EB as a combined initial treatment. Similar levels of palliation were seen when compared with patients who received a single ILT treatment only. Overall, ILT was well tolerated in terms of early and late morbidity. In conclusion, the efficiency of a single ILT treatment in palliating symptoms due to endobronchial tumour in previously unirradiated individuals is comparable with that reported in series where treatment for advanced lung cancer combines a prolonged course of EB concurrently with several ILT treatments.

The effect of pH on the early interaction of West Nile virus with P388D1 cells.

The interaction between the flavivirus West Nile virus (WNV) and cells of the mouse macrophage-like cell line, P388D1, was assayed by transmission electron microscopy, by following the association of [35S]methionine-labelled virus with cells, and by using a radiobinding assay with an 125I-labelled F(ab')2 fragment of a monoclonal antibody directed against the major viral envelope surface glycoprotein. Using electron microscopy, both fusion and endocytosis were observed at pH 6.4, but at pH 8.0 only endocytosis was observed. When 35S-labelled WNV was bound to the P388D1 cell surface at 0 degrees C, less virus eluted on warming to 37 degrees C at mildly acidic than at alkaline or neutral pH values. The monoclonal antibody fragment had an increased affinity for cell surface viral E glycoprotein after prebound WNV was warmed at mildly acidic pH values. It is proposed that the warming of cell-virus mixtures at low pH results in fusion with a consequent reduction in elution of virus and an increase in the recognition of cell surface-expressed viral envelope glycoprotein by labelled antibody.

The uncoating and infectivity of the flavivirus West Nile on interaction with cells: effects of pH and ammonium chloride.

Infectivity of the West Nile virus (WNV; Flaviviridae) was inactivated on exposure for brief periods (90 s) to pH 6.6 and below. This inactivation was not due to decreased interaction between cells and acid-treated virus. The RNA of [3H]uridine-labelled virus particles prebound to the cell surface before acidic pH treatment underwent rapid uncoating within 1 min at 37 degrees C at the same pH values that inactivated virus particles. The uncoating of [3H]uridine-labelled virus particles was also studied over longer time periods after synchronized internalization by P388D1 cells. At pH 7.6 uncoating occurred rapidly after a reproducible time lag of 1 min on warming to 37 degrees C and was essentially complete by 15 to 30 min after the start of internalization, leaving uncoated RNA in an infectious form. In contrast, at pH 6.2 viral uncoating occurred rapidly without any time lag and the uncoated RNA appeared to be far less infectious than that uncoated at pH 7.6. Ammonium chloride could almost totally inhibit both the infectivity and uncoating of virus particles on synchronized internalization into P388D1 cells, with a pH optimum of 8.0. These results suggest that the uncoating of virus particles is dependent on an acidic pH, although the location of uncoating (prelysosomal endosome or plasma membrane) decides whether the uncoated RNA will be infectious or not. Essentially the same results were obtained when infections were carried out in the presence of enhancing antibody.

A new mechanism for the neutralization of enveloped viruses by antiviral antibody.

Despite the considerable research that has been carried out into viral neutralization by antiviral antibody, its mechanisms remain poorly understood. Cases have been reported in which antiviral antibody can inhibit viral replication without inhibiting the binding and uptake of virus by susceptible cells. It has been shown that many enveloped viruses enter their target cells by endocytosis and are subsequently located in cellular compartments of increasing acidity. With several enveloped viruses this acidic pH can catalyse a fusion reaction between the membrane of the virus particle and that of a prelysosomal endosome, thus enabling the viral core to enter the cytosol and replication to commence. We have recently demonstrated that such an endosomal fusion event at mild acidic pH is involved in the entry pathway of the enveloped flavivirus, West Nile virus (WNV), into macrophages. We now show that antiviral antibody can neutralize WNV by inhibiting this intraendosomal acid-catalysed fusion step and we speculate on possible implications for the future design of antiviral vaccines.

pH-dependent fusion between the flavivirus West Nile and liposomal model membranes.

Fusion between purified [3H]uridine-labelled West Nile virus (WNV) particles and liposomes containing RNase, was assayed by degradation of the viral RNA to trichloroacetic acid-soluble material. Fusion of virus with liposomes containing phosphatidylcholine, phosphatidylethanolamine, sphingomyelin and cholesterol (at a molar ratio of 1:1:1:1.5) was found to be dependent on pH with maximum fusion occurring at pH 6.7 and below. At pH 6.6 fusion was rapid and was essentially complete within 2 min at 37 degrees C. At this time, approximately 50% of the viral RNA had been degraded and increasing the concentration of liposomes or time allowed for fusion increased this percentage only slightly. Fusion was dependent on temperature, was almost totally non-leaky and was not dependent on the presence of divalent cations. The lipid composition of liposomes was found to influence both the pH optimum for fusion and the maximum degree of fusion observed. Electron microscopy was used to visualize the fusion reaction between liposomes and virus particles.

Flavivirus infection enhancement in macrophages: an electron microscopic study of viral cellular entry.

The mode of entry of West Nile virus (WNV) into the macrophage-like cell line P388D1 was investigated at the electron microscopical level using synchronized infections. The presence of the antiviral monoclonal antibody F6/16A at a concentration that enhanced viral attachment to P388D1 cells ninefold made no difference to the entry pathway of WNV. In both the absence and presence of F6/16A the initial uptake of single viral particles was mediated by coated pits, and started within 30 s of warming the cells to 37 degrees C. Viral particles later appeared in fully or partially coated vesicles and later in uncoated prelysosomal endocytic vacuoles before degradation in lysosomes. However, aggregates of viral particles (five or more virus particles in cross-section), appeared to be phagocytosed whole by cells in a process which involved aggregates being engulfed by extensions of the plasma membrane. This process exhibited a slower time course than the uptake of single viral particles, becoming prominent 15 to 30 min after warming the cells to 37 degrees C. The involvement of a prelysosomal vacuolar compartment in the entry process was shown by a failure to stain for acid phosphatase. This compartment could be specifically loaded with viral particles when viral internalization occurred at 20 degrees C in the presence of 50 mM-ammonium chloride.

Flavivirus infection enhancement in macrophages: radioactive and biological studies on the effect of antibody on viral fate.

35S-labelled West Nile virus was used in radioactive binding, internalization and degradation studies in the macrophage cell line P388D1 in the absence or presence of various concentrations of antiviral antibody. Proteases were used to help distinguish between intracellular and extracellular (bound) virus. It was found that the enhancement in viral infectivity that occurs in the presence of subneutralizing concentrations of antiviral antibody was caused by (i) increased binding of virus to the cell surface and (ii) a higher specific infectivity of antibody-opsonized virus particles, apparently due to a more efficient internalization process. In contrast, little difference was found in the rate of internalization and intracellular degradation for virus particles that did enter the cells. Lysosomotropic amines were capable of markedly inhibiting viral replication in P388D1 cells at an early stage of infection both in the absence and presence of subneutralizing concentrations of antibody, although antibody-mediated enhancement of viral replication remained.