Tuning the hysteresis of a metal-insulator transition via lattice compatibility

Structural phase transitions serve as the basis for many functional applications including shape memory alloys (SMAs), switches based on metal-insulator transitions (MITs), etc. In such materials, lattice incompatibility between transformed and parent phases often results in a thermal hysteresis, which is intimately tied to degradation of reversibility of the transformation. The non-linear theory of martensite suggests that the hysteresis of a martensitic phase transformation is solely determined by the lattice constants, and the conditions proposed for geometrical compatibility have been successfully applied to minimizing the hysteresis in SMAs. Here, we apply the non-linear theory to a correlated oxide system (V_1−xW_xO₂), and show that the hysteresis of the MIT in the system can be directly tuned by adjusting the lattice constants of the phases. The results underscore the profound influence structural compatibility has on intrinsic electronic properties, and indicate that the theory provides a universal guidance for optimizing phase transforming materials.

The effect of the lattice degrees of freedom on the metal-insulator transition of VO₂ remains a topic of debate. Here the authors show that the lattice compatibility of the high temperature tetragonal phase and the low-temperature monoclinic phase strongly influences the electronic transition, as manifested in the tunability of its hysteresis via chemical substitution.

Good Health and Wellness: Measuring Impact Through an Indigenous Lens

In 2014, the Centers for Disease Control and Prevention (CDC) commissioned the Urban Indian Health Institute (UIHI) to coordinate a multifaceted national evaluation plan for Good Health and Wellness in Indian Country (GHWIC), CDC's largest investment in chronic disease prevention for American Indians and Alaska Natives (AI/ANs). GHWIC is a collaborative agreement among UIHI, CDC, tribal organizations, and individual tribes. In collaboration, UIHI and CDC drew upon an indigenous framework, prioritizing strength-based approaches for documenting program activities, to develop a 3-tiered evaluation model. The model incorporated locally tailored metrics, adherence to tribal protocols, and cultural priorities. Ultimately, federal requirements and data collection processes were aligned with tribal strengths and bidirectional learning was promoted. We describe how UIHI worked with tribal recipients, tribal health organizations, Tribal Epidemiology Centers, and CDC to develop and implement the model on the basis of an indigenous framework of mutual trust and respect.

Responsible Research With Urban American Indians and Alaska Natives

American Indian and Alaska Native (AI/AN) communities harbor understandable mistrust of research. Outside researchers have historically controlled processes, promulgating conclusions and recommended policies with virtually no input from the communities studied. Reservation-based communities can apply sovereignty rights conferred by the federal government to change this research trajectory. Many tribes now require review and approval before allowing research activities to occur, in part through the development of regulatory codes and oversight measures. Tribal oversight ensures that research is directed toward questions of importance to the community and that results are returned in ways that optimize problem solving. Unfortunately, tribal governance protections do not always extend to AI/ANs residing in urban environments. Although they represent the majority of AI/ANs, urban Indians face an ongoing struggle for visibility and access to health care. It is against this backdrop that urban Indians suffer disproportionate health problems. Improved efforts to ensure responsible research with urban Indian populations requires attention to community engagement, research oversight, and capacity building. We consider strategies to offset these limitations and develop a foundation for responsible research with urban Indians.

Community dissemination and genetic research: moving beyond results reporting

The community-based participatory research (CBPR) literature notes that researchers should share study results with communities. In the case of human genetic research, results may be scientifically interesting but lack clinical relevance. The goals of this study were to learn what kinds of information community members want to receive about genetic research and how such information should be conveyed. We conducted eight focus group discussions with Yup'ik Alaska Native people in southwest Alaska (N = 60) and 6 (N = 61) with members of a large health maintenance organization in Seattle, Washington. Participants wanted to receive genetic information they "could do something about" and wanted clinically actionable information to be shared with their healthcare providers; they also wanted researchers to share knowledge about other topics of importance to the community. Although Alaska Native participants were generally less familiar with western scientific terms and less interested in web-based information sources, the main findings were the same in Alaska and Seattle: participants wished for ongoing dialogue, including opportunities for informal, small-group conversations, and receiving information that had local relevance. Effective community dissemination is more than a matter of presenting study results in lay language. Community members should be involved in both defining culturally appropriate communication strategies and in determining which information should be shared. Reframing dissemination as a two-way dialogue, rather than a one-way broadcast, supports the twin aims of advancing scientific knowledge and achieving community benefit.

Factors that influence mammography use among older American Indian and Alaska Native women

INTRODUCTION

American Indian and Alaska Native (AIAN) women have relatively high breast cancer mortality rates despite the availability of free or low-cost screening.

PURPOSE

This qualitative study explored issues that influence the participation of older AIAN women in mammography screening through tribally directed National Breast and Cervical Cancer Early Detection Programs (NBCCEDPs).

METHODS

We interviewed staff (n = 12) representing five tribal NBCCEDPs and conducted four focus groups with AIAN women ages 50 to 80 years (n = 33).

RESULTS

Our analysis identified four main areas of factors that predispose, enable, or reinforce decisions around mammography: financial issues and personal investments, program characteristics including direct services and education, access issues such as transportation, and comfort zone topics that include cultural or community-wide norms regarding cancer prevention.

CONCLUSION

This study has implications for nurse education and training on delivering effective mammography services and preventive cancer outreach and education programs in AIAN communities.

Launching native health leaders: reducing mistrust of research through student peer mentorship

OBJECTIVES

We assessed the impact of Launching Native Health Leaders (LNHL), a peer-mentoring and networking program that introduced American Indian/Alaska Native (AI/AN) undergraduates to health and research careers and concepts of community-based participatory research (CBPR).

METHODS

We conducted 15 interviews and 1 focus group with students who had attended 1 or more LNHL meetings, which took place during 9 professional health research conferences in 2006 to 2009. We completed data collection in 2010, within 1 to 4 years of LNHL participant engagement in program activities.

RESULTS

Participants described identity and cultural challenges they encountered in academic institutions and how their views shifted from perceiving research as an enterprise conducted by community outsiders who were not to be trusted toward an understanding of CBPR as contributing to AI/AN health.

CONCLUSIONS

LNHL provided a safe environment for AI/AN students to openly explore their place in the health and research arenas. Programs such as LNHL support AI/AN student development as leaders in building trust for academic-tribal partnerships.

Building partnerships in community-based participatory research: budgetary and other cost considerations

Community-based participatory research (CBPR) is an important framework for partnering with communities to reduce health disparities. Working in partnership with community incurs additional costs, some that can be represented in a budget summary page and others that are tied to the competing demands placed on community and academic partners. These cost considerations can inform development of community-academic partnerships. We calculated costs from a case study based on an ongoing CBPR project involving a Community Planning Group (CPG) of community co-researchers in rural Alaska and a bicultural liaison group who help bridge communication between CPG and academic co-researchers. Budget considerations specific to CBPR include travel and other communication-related costs, compensation for community partners, and food served at meetings. We also identified sources of competing demands for community and academic partners. Our findings can inform budget discussions in community-academic partnerships. Discussions of competing demands on community partners' time can help plan timelines for CBPR projects. Our findings may also inform discussions about tenure and promotion policies that may represent barriers to participation in CBPR for academic researchers.

Strategies and stakeholders: minority recruitment in cancer genetics research

The Cancer Genetics Network (CGN) is one of a growing number of large-scale registries designed to facilitate investigation of genetic and environmental contributions to health and disease. Despite compelling scientific and social justice arguments that recommend diverse participation in biomedical research, members of ethnic minority groups continue to be chronically underrepresented in such projects. The CGN studies reported in this issue used strategies well documented to increase minority participation in research activities, including use of community-targeted materials, addressing community trust concerns, and the adoption of personalized and flexible research protocols. Here, we review the outcome of these efforts to increase minority recruitment to the CGN, and ask what lessons the findings suggest for future minority recruitment initiatives.

Testing system for ferromagnetic shape memory microactuators

Ferromagnetic shape memory alloys are a class of smart materials that exhibit a unique combination of large strains and fast response when exposed to magnetic field. Accordingly, these materials have significant potential in motion generation applications such as microactuators and sensors. This article presents a novel experimental system that measures the dynamic magnetomechanical behavior of microscale ferromagnetic shape memory specimens. The system is comprised of an alternating magnetic field generator (AMFG) and a mechanical loading and sensing system. The AMFG generates a dynamic magnetic field that periodically alternates between two orthogonal directions to facilitate martensitic variant switching and to remotely achieve a full magnetic actuation cycle, without the need of mechanical resetting mechanisms. Moreover, the AMFG is designed to produce a magnetic field that inhibits 180 degrees magnetization domain switching, which causes energy loss without strain generation. The mechanical loading and sensing system maintains a constant mechanical load on the measured specimen by means of a cantilever beam, while the displacement is optically monitored with a resolution of approximately 0.1 microm. Preliminary measurements using Ni(2)MnGa single crystal specimens, with a cross section of 100x100 microm(2), verified their large actuation strains and established their potential to become a material of great importance in microactuation technology.

Preoperative radiotherapy for operable rectal cancer--is a lower dose to a reduced volume acceptable?

AIMS

A retrospective audit was carried out to determine the rate of local recurrence (recurrent tumour within the lesser pelvis or the perineal wound) in 88 rectal cancer patients treated with 20 Gy/four fractions of adjuvant preoperative radiotherapy and curative surgery.

MATERIALS AND METHODS

All patients were followed-up by clinical examination with rigid sigmoidoscopy at 6 monthly intervals if the rectum was intact, and computed tomography of the pelvis at 1, 2 and 5 years after surgery. In total, 171 patients with rectal cancer were identified under the care of one surgeon over a period of 11 years from May 1992 to April 2003. We excluded patients with rectal cancer from preoperative adjuvant radiotherapy if they had evidence at presentation of distant metastases, if they had fixed rectal tumours, were treated by local excision and had previous radiotherapy to the pelvis. On this basis, only 88 were considered for preoperative radiotherapy and curative resection with a median follow-up of 5.16 years.

RESULTS

The 5-year survival by stage was Dukes A 96%, Dukes B 65% and Dukes C 36%. Overall, four patients (of 88) developed a recurrence within the lesser pelvis or the perineal wound, giving a local recurrence of 4.2% at 3 years (from a Kaplan-Meier graph).

CONCLUSIONS

This single-centre audit suggests that a lower dose of radiotherapy to a smaller volume provides an acceptable local recurrence rate that compares very favourably with the well-publicised Swedish and Dutch trials of 25 Gy/five fractions. It was not the intention of this audit to suggest that this dose should be widely adopted. However, given the long-term gastrointestinal morbidity and risk of second malignancies, we advise caution when formulating even more intensive radiotherapy and chemoradiotherapy regimens for rectal cancer.

Limited field Radiotherapy for Early Stage, Infra-diaphragmatic Hodgkin's Lymphoma

AIMS

To analyse the treatment outcome for patients with stage I and II infra-diaphragmatic Hodgkin's lymphoma.

MATERIALS AND METHODS

A retrospective review of case notes for 33 consecutive patients treated between 1988 and 2000. Twenty-five out of 33 patients received radiotherapy alone, three out of 33 patients received minimal initial chemotherapy (MIT) (4 weeks VAPEC B) and five patients received six cycles of ChlVPP EVA hybrid chemotherapy before radiotherapy. Radiotherapy was given as a limited field in 32 out of 33 patients.

RESULTS

Twenty-seven out of 33 patients were men (82%), and the median age was 47 years. Fifteen of the 33 patients were stage IA, 15 were IIA, 1 was IB and 2 were IIB. The median follow-up was 71 months. Histological subtype was lymphocyte predominant (15/33), nodular sclerosis (11/33), mixed cellularity (4/33), lymphocyte-rich classical (1/33) and unclassifiable (2/33). The 5-year overall survival was 89% and 5-year relapse-free survival was 85%. The median time to relapse was 37 months (range 7-65 months). One out of five relapses was within the previous radiotherapy field. All five relapses had received radiotherapy alone and four were salvaged with chemotherapy. There have been four second malignancies and one patient transformed to high-grade non-Hodgkin's lymphoma. No patient has died of Hodgkin's lymphoma.

CONCLUSIONS

In our cohort of patients with infra-diaphragmatic stage I and II Hodgkin's lymphoma treated with limited-field radiotherapy, no patients died from uncontrolled disease. The use of MIT may reduce the risk of relapse and obviate the need for conventional salvage chemotherapy. Late relapses may occur, and second malignancies are a cause for concern underlining the need for long-term follow-up.

Randomized clinical trial of adjuvant radiotherapy and 5-fluorouracil infusion in colorectal cancer (AXIS)

Background

Postoperative portal vein infusion (PVI) of 5-fluorouracil (5-FU) is a well tolerated and widely applicable treatment for colorectal cancer that might have an enormous public health impact, even if it produced survival benefits of just a few per cent. Very large trials are required to detect such differences, and the Adjuvant X-ray and 5-FU Infusion Study (AXIS) is the largest such trial yet reported.

Methods

Consenting patients with presumed colorectal cancer were randomized to surgery with or without 7 days of PVI (1 g 5-FU plus 5000 units heparin in 1 litre 5 per cent dextrose infused over each 24-h period). In addition, patients with rectal cancer could be randomized to radiotherapy or no radiotherapy to be given either before or after surgery.

Results

Between November 1989 and December 1997, 3583 patients were randomized with respect to PVI. The survival hazard ratios (95 per cent confidence interval (c.i.)) in all patients randomized and in the curatively resected subgroup (71·2 per cent of patients) were 1·00 (0·92 to 1·11) and 0·94 (0·83 to 1·06) respectively. Tests for heterogeneity suggested a greater treatment benefit for patients with colonic cancer than for patients with rectal cancer with respect to disease-free survival (hazard ratio 0·79 versus 1·03; P = 0·07), and there was a non-significant trend with respect to overall survival (hazard ratio 0·87 versus 1·03; P = 0·17). No survival benefit was seen in the 761 patients randomized with respect to radiotherapy; although not statistically significant, the impact on local recurrence rates was similar to that reported in the literature.

Conclusion

No overall benefit of PVI was established in AXIS when colonic and rectal cancers were considered together, but the evidence suggesting a differential treatment effect according to site of cancer in AXIS was strongly supported by a meta-analysis incorporating the previous trials. Combining the data gave hazard ratios of 0·82 and 1·00 for colonic and rectal tumours respectively (test for interaction, P = 0·024), equating to an absolute survival benefit for patients with colonic cancer of 5·8 (95 per cent c.i. 2·8 to 8·5) per cent, a level close to that seen for prolonged systemic therapy.

Differential association of SMC1alpha and SMC3 proteins with meiotic chromosomes in wild-type and SPO11-deficient male mice

SMC proteins are components of cohesin complexes that function in chromosome cohesion. We determined that SMC1alpha and SMC3 localized to wild-type mouse meiotic chromosomes, but with distinct differences in their patterns. Anti-SMC3 coincided with axial elements of the synaptonemal complex, while SMC1alpha was observed mainly in regions where homologues were synapsed. This pattern was especially visible in pachytene sex vesicles where SMC1alpha localized only weakly to the asynapsed regions. At diplotene, SMC3, but not SMC1alpha, remained bound along axial elements of desynapsed chromosomes. SMC1alpha and SMC3 were also found to localize along meiotic chromosome cores of Spo11 null spermatocytes, in which double-strand break formation required for DNA recombination and homologous pairing were disrupted. In Spo11 -/- cells, SMC1alpha localization differed from SMC3 again, confirming that SMC1alpha is mainly associated with homologous or non-homologous synapsed regions, whereas SMC3 localized throughout the chromosomes. Our results suggest that the two cohesin proteins may not always be associated in a dimer and may function as separate complexes in mammalian meiosis, with SMC1alpha playing a more specific role in synapsis. In addition, our results indicate that cohesin cores can form independently of double-strand break formation and homologous pairing.

Raltitrexed plus radiotherapy for the treatment of unresectable/recurrent rectal cancer: a phase I study

BACKGROUND

Current consensus is that a combination of radiotherapy and chemotherapy may provide the optimal treatment for patients with unresectable rectal cancer. Raltitrexed has proven efficacy in the treatment of advanced colorectal cancer and has an acceptable toxicity profile. The aim of this phase I study was to determine the recommended dose of raltitrexed in combination with radiotherapy in patients with unresectable/recurrent rectal cancer.

PATIENTS AND METHODS

Patients were treated with radiotherapy (25 fractions at 2.0 Gy per fraction) five times per week for 5 weeks. Raltitrexed was administered on days 1 and 22 at 2.0, 2.6 and 3.0 mg/m(2).

RESULTS

A total of 20 patients were entered into the study. Dose-limiting toxicities were recorded in three of 20 patients following the first dose of raltitrexed; one patient at 2.6 mg/m(2) (grade 3 diarrhoea, grade 3 neutropenia and grade 2 pyrexia) and two patients at 3.0 mg/m(2) (one grade 3 neutropenia and one grade 4 diarrhoea). The most common non-haematological and haematological treatment-related adverse events were diarrhoea (11 of 20, two grade 3, one grade 4) and leukopenia (eight of 20, one grade 3, one grade 4), respectively.

CONCLUSIONS

The recommended dose of raltitrexed in combination with radiotherapy for future studies is 2.6 mg/m(2).

Comparison of intermittent and continuous palliative chemotherapy for advanced colorectal cancer: a multicentre randomised trial

BACKGROUND

Policies of UK clinicians regarding the duration of chemotherapy for patients with advanced colorectal cancer are not consistent. We aimed to compare effectiveness of continuous and intermittent chemotherapy in such patients.

METHODS

Patients who responded or had stable disease after receiving 12 weeks of the regimens described by de Gramont and Lokich, or raltitrexed chemotherapy, were randomised to either intermittent (a break in chemotherapy, re-starting on the same drug on progression), or continuous chemotherapy until progression.

FINDINGS

354 patients (178 intermittent, 176 continuous) were enrolled from 42 UK centres. At randomisation, 41% of participants had part or complete response; 59% were stable. Only 66 (37%) patients allocated to intermittent treatment restarted as planned, after a median of 130 days. Median time on treatment after restarting was 84 days. Patients in the continuous group remained on treatment for a median of a further 92 days. Similar proportions of patients in both groups received second-line therapy. Patients on intermittent chemotherapy had significantly fewer toxic effects and serious adverse events than those in the continuous group. There was no clear evidence of a difference in overall survival (hazard ratio 0.87 favouring intermittent, 95% CI 0.69-1.09, p=0.23).

INTERPRETATION

Our findings provided no clear evidence of a benefit in continuing therapy indefinitely until disease progression. They showed that it is safe to stop chemotherapy after 12 weeks and re-start the same treatment on progression in patients with chemosensitive advanced colorectal cancer.

ChlVPP/EVA hybrid versus the weekly VAPEC-B regimen for previously untreated Hodgkin's disease

PURPOSE

To test the hypothesis that a chemotherapy regimen of relatively low toxicity and 11 weeks' duration (doxorubicin, cyclophosphamide, etoposide, vincristine, bleomycin, and prednisolone [VAPEC-B]) is at least as effective in terms of disease control as 6 months' treatment with chlorambucil, vinblastine, procarbazine, and prednisone/etoposide, vincristine, and doxorubicin (ChlVPP/EVA hybrid), which is associated with a high risk of permanent sterility.

PATIENTS AND METHODS

Two hundred eighty-two patients with previously untreated Hodgkin's disease, clinical stages I/II (plus mediastinal bulk and/or B symptoms) and clinical stages III/IV were randomized at three United Kingdom and one Italian center to receive either six monthly cycles of ChlVPP/EVA hybrid or 11 weekly cycles of VAPEC-B. After chemotherapy and a restaging evaluation, radiotherapy was administered to sites of previous bulk or residual radiographic abnormality before patients were observed off treatment.

RESULTS

Further accrual to the trial was halted at the planned third interim analysis in September 1996. After a median follow-up of 4.9 years, freedom from progression (FFP), event-free survival (EFS), and overall survival (OS) are all significantly better in the population treated with ChlVPP/EVA than VAPEC-B, where the comparative 5-year results are 82% and 62% (FFP), 78% and 58% (EFS), and 89% and 79% (OS), respectively. The superiority of ChlVPP/EVA was seen in both low-risk and intermediate/high-risk patients, although subset analysis suggested that ChlVPP/EVA and VAPEC-B produce equivalent results in the best-prognosis patients (Hasenclever score <or= 2, nonbulky disease).

CONCLUSION

Apart from possibly in the best-prognosis group, where results are equivalent, ChlVPP/EVA hybrid produces significantly better FFP, EFS, and OS than VAPEC-B in patients with previously untreated Hodgkin's disease.

Comparison of survival, palliation, and quality of life with three chemotherapy regimens in metastatic colorectal cancer: a multicentre randomised trial

BACKGROUND

This randomised trial compared three chemotherapy regimens in the first-line treatment of advanced colorectal cancer, in terms of their effect on overall and progression-free survival; other endpoints included toxicity, symptom palliation, and quality of life.

METHODS

905 patients were randomly assigned the de Gramont regimen (n=303; folinic acid 200 mg/m(2), fluorouracil bolus 400 mg/m(2), and infusion 600 mg/m(2) on days 1 and 2, repeated every 14 days), the Lokich regimen (n=301; protracted venous infusion of fluorouracil 300 mg/m(2) daily), or raltitrexed (n=301; 3 mg/m(2) intravenously every 21 days). Analyses were by intention to treat.

FINDINGS

Median follow-up of survivors was 67 weeks. For the de Gramont, Lokich, and raltitrexed groups, respectively, median survival was 294, 302, and 266 days. The hazard ratios for overall survival were 0.88 (95% CI 0.70-1.12, p=0.17) for de Gramont versus Lokich, and 0.99 (0.79-1.25, p=0.94) for de Gramont versus raltitrexed. An increase in treatment-related deaths was seen on raltitrexed (de Gramont one, Lokich two, raltitrexed 18) due to combined gastrointestinal and haematological toxicity. Patients' assessment of quality of life showed that raltitrexed was inferior to the fluorouracil-based regimens, especially in terms of palliation and functioning.

INTERPRETATION

The deGramont and Lokich regimens were similar in terms of survival, quality of life, and response rates. The Lokich regimen was associated with more central line complications and hand-foot syndrome. Raltitrexed showed similar response rates and overall survival to the de Gramont regimen and was easier to administer, but resulted in greater toxicity and inferior quality of life.

Integrating the oral fluoropyrimidines into the management of advanced colorectal cancer

In colorectal cancer, leucovorin-modulated 5-fluorouracil (5-FU) has been the mainstay of both adjuvant treatment and treatment of metastatic disease for many years. In advanced disease, response rates of 10-43% are reported; efforts to improve efficacy through schedule modification, including prolonged infusions, have led to limited success. New agents with improved efficacy, tolerability and ease of administration are required. Among the newer drugs, irinotecan and oxaliplatin are becoming established as first- and second-line treatment for advanced disease. Their novel mechanisms of action have proven to be of value in 5-FU-resistant patients. In tandem with these developments, thymidylate synthase inhibition has remained an important objective and oral fluoropyrimidines such as capecitabine and UFT (uracil plus tegafur)/leucovorin have been developed with this goal in mind. Two large, phase III studies of capecitabine in metastatic disease demonstrated objective response rates of 26.6 and 24.8%. UFT/leucovorin has also been evaluated in phase III trials, with an 11.7% response rate reported. Both agents are being evaluated in combination with oxaliplatin and irinotecan, and ultimately oral fluoropyrimidines as monotherapy or combination therapy may replace intravenous (i.v.) 5-FU as first-line treatment for metastatic colorectal cancer.

Irinotecan combined with fluorouracil compared with fluorouracil alone as first-line treatment for metastatic colorectal cancer: a multicentre randomised trial

BACKGROUND

Irinotecan is active against colorectal cancer in patients whose disease is refractory to fluorouracil. We investigated the efficacy of these two agents combined for first-line treatment of metastatic colorectal cancer.

METHODS

387 patients previously untreated with chemotherapy (other than adjuvant) for advanced colorectal cancer were randomly assigned open-label irinotecan plus fluorouracil and calcium folinate (irinotecan group, n=199) or fluorouracil and calcium folinate alone (no-irinotecan group, n=188). Infusion schedules were once weekly or every 2 weeks, and were chosen by each centre. We assessed response rates and time to progression, and also response duration, survival, and quality of life. Analyses were done on the intention-to-treat population and on evaluable patients.

FINDINGS

The response rate was significantly higher in patients in the irinotecan group than in those in the no-irinotecan group (49 vs 31%, p<0.001 for evaluable patients, 35 vs 22%, p<0.005 by intention to treat). Time to progression was significantly longer in the irinotecan group than in the no-irinotecan group (median 6.7 vs 4.4 months, p<0.001), and overall survival was higher (median 17.4 vs 14.1 months, p=0.031). Some grade 3 and 4 toxic effects were significantly more frequent in the irinotecan group than in the no-irinotecan group, but effects were predictible, reversible, non-cumulative, and manageable.

INTERPRETATION

Irinotecan combined with fluorouracil and calcium folinate was well-tolerated and increased response rate, time to progression, and survival, with a later deterioration in quality of life. This combination should be considered as a reference first-line treatment for metastatic colorectal cancer.

Randomised trial of irinotecan plus supportive care versus supportive care alone after fluorouracil failure for patients with metastatic colorectal cancer

BACKGROUND

In phase II studies, irinotecan is active in metastatic colorectal cancer, but the overall benefit has not been assessed in a randomised clinical trial.

METHODS

Patients with proven metastatic colorectal cancer, which had progressed within 6 months of treatment with fluorouracil, were randomly assigned either 300-350 mg/m2 irinotecan every 3 weeks with supportive care or supportive care alone, in a 2:1 ratio.

FINDINGS

189 patients were allocated irinotecan and supportive care and 90 supportive care alone. The mean age of the participants was 58.8 years; 181 (65%) were men and 98 (35%) were women. WHO performance status was 0 in 79 (42%) patients, 1 in 77 (41%) patients, and 2 in 32 (17%) patients. Tumour-related symptoms were present in 134 (71%) patients and weight loss of more than 5% was seen in 15 (8%) patients. With a median follow-up of 13 months, the overall survival was significantly better in the irinotecan group (p=0.0001), with 36.2% 1-year survival in the irinotecan group versus 13.8% in the supportive-care group. The survival benefit, adjusted for prognostic factors in a multivariate analysis, remained significant (p=0.001). Survival without performance-status deterioration (p=0.0001), without weight loss of more than 5% (p=0.018), and pain-free survival (p=0.003) were significantly better in the patients given irinotecan. In a quality-of-life analysis, all significant differences, except on diarrhoea score, were in favour of the irinotecan group.

INTERPRETATION

Our study shows that despite the side-effects of treatment, patients who have metastatic colorectal cancer, and for whom fluorouracil has failed, have a longer survival, fewer tumour-related symptoms, and a better quality of life when treated with irinotecan than with supportive care alone.

A comparative study of facial profiles in extraction and nonextraction treatment

Evaluation of facial profiles and facial balance is a constant, continuous study and learning process for orthodontists. Tooth movement and proper positioning of the teeth to ensure favorable facial changes and to avoid unfavorable changes should be in the orthodontist's "diagnostic" mind from the very first examination. The continuous controversy concerning extraction of premolar teeth and its supposed effects on the facial profile led to the development of this study, which compares the pretreatment and posttreatment facial profiles of patients who underwent premolar extraction with those of patients who did not undergo extraction. The study comprised 170 consecutively treated patients. One hundred-eight of the patients were treated with premolar extraction, and 62 were treated without premolar extraction. The diagnostic extraction and treatment decisions were based on a total space analysis with differential extraction protocols. The Z-angle (an angular measurement) and the E-value (a linear measurement) were used to quantify and compare the pretreatment and posttreatment profiles of the two groups. Both groups completed treatment within the normal ranges of the profile measurement values with the lip profile position slightly more retrusive in the nonextraction group. The nonextraction group's posttreatment Z-angle was 5.27 degrees greater and the posttreatment E-value was 1.47 mm more negative than that of the extraction group. The extraction group began treatment with greater facial imbalance and had the greatest improvement in facial esthetics.

The in vitro radiosensitivity of human head and neck cancers

A study was made of the intrinsic radiosensitivity of 140 biopsy and surgical specimens of malignant head and neck tumours of different histologies. Using a soft-agar clonogenic assay, the material was assessed for the ability to grow in culture (colony-forming efficiency; CFE) and inherent tumour radiosensitivity (surviving fraction at 2 Gy, SF2). The success rate for obtaining growth was 74% (104/140) with a mean CFE of 0.093% (median 0.031) and a range of 0.002-1.3%. SF2 was obtained for 88 of 140 specimens, representing a success rate of 63% with a mean SF2 of 0.48 (median 0.43) and a range of 0.10-1.00. There were no significant differences in radiosensitivity between different sites of the head and neck region. There were no significant relationships between SF2 and disease stage, nodal status, tumour grade, patient age, primary tumour growth pattern and CFE. The results were compared with those for other tumour types previously analysed with the same assay. The distribution of the SF2 values for the head and neck tumours was similar to that for 145 cervix carcinomas and there was no significant difference in mean radiosensitivity between the two tumour types. Also, there was no significant difference in radiosensitivity between head and neck tumours and either breast or colorectal cancers. However, a group of eight lymphomas was significantly more radiosensitive. These results confirm the feasibility of carrying out radiosensitivity measurements using a soft-agar clonogenic assay on head and neck tumours. In addition, the work has shown that radiosensitivity is independent of many clinical parameters and that the mean value is similar to that reported for cervix carcinomas.

Early protrusion reduction--two phase malocclusion correction: a case report

What is early treatment? Does early treatment imply early correction? There is confusion as to what these terms mean in clinical orthodontics today. This case report of two phase malocclusion correction addresses the issue of early treatment verses early correction. It attempts to add some perspective to the two terms and give the clinical orthodontist some sound guidelines as to whether to initiate two "phases" of treatment.

Transforming growth factor beta 1 expression in human colorectal tumours: an independent prognostic marker in a subgroup of poor prognosis patients

Members of the transforming growth factor beta (TGF-beta family, in particular TGF-beta 1, are some of the most potent inhibitory growth factors in a variety of cell types. Resistance to TGF-beta 1-induced growth inhibition is frequently observed in colorectal carcinomas and is associated with tumour progression. Perturbations of TGF-beta 1 expression and function, therefore, may contribute to the loss of some constraints on tumour cell growth. In this study we have examined the expression of TGF-beta 1 and its precursor latency-associated peptide (LAP)-TGF-beta in human colorectal tumours using immunohistochemical techniques. In 86% of the tumours the LAP-TGF-beta complex was present in both the stromal and epithelial cells, whereas the mature TGF-beta 1 peptide was expressed in the glandular epithelium of 58.3% of these tumours. Intense staining for TGF-beta 1 was positively associated with advanced Dukes' stage. Furthermore, there was a significant correlation between the presence of TGF-beta 1 in the tumours and a shorter post-operative survival. This was most significant in a subgroup of patients who had received only a palliative operation. These results suggest that TGF-beta 1 expression may be useful as an independent prognostic indicator for a subgroup of patients who have a particularly poor prognosis.

Randomized trial assessing the addition of interferon alpha-2a to fluorouracil and leucovorin in advanced colorectal cancer. Colorectal Cancer Working Party of the United Kingdom Medical Research Council

PURPOSE

To determine the effects of interferon alpha-2a (IFN alpha) on the efficacy and toxicity of fluorouracil (FUra) and leucovorin (LV) in patients with advanced colorectal cancer.

PATIENTS AND METHODS

Two hundred sixty chemotherapy-naive patients were randomized to FUra/LV alone or FUra/LV plus IFN alpha. All patients received: LV 200 mg/m2 intravenous (IV) infusion over 2 hours, then FUra 400 mg/m2 i.v. bolus plus 400 mg/m2 i.v. infusion over 22 hours, all repeated on day 2. Treatment was every 2 weeks for up to 12 cycles. Patients randomized to IFN alpha received 6 x 10(6) IU subcutaneously every 48 hours throughout. Objective response (OR) and toxicity were assessed conventionally; in addition, palliative benefit and adverse effects were assessed using quality-of-life (QoL) questionnaires.

RESULTS

There were no differences in OR rate, progression-free survival, or overall survival. OR rates in assessable patients were as follows: FUra/LV alone (n = 104), complete or partial response (OR) = 27%, no change (NC) = 34%; FUra/LV/IFN alpha (n = 101), OR = 28%, NC = 30%. Median survival was 10 months in both arms. Dose-limiting FUra toxicities were not significantly increased by co-administration of IFN alpha, and the delivered FUra dose-intensity was not significantly reduced. However, QoL was adversely affected: patients on IFN alpha were less likely to report improvement in pretreatment physical and psychologic symptoms, and more likely to report new or worsening symptoms.

CONCLUSION

IFN alpha, at a dose that impaired QoL, did not improve the efficacy of FUra/LV. The power of this trial is sufficient to exclude with 95% confidence a benefit of 15% in OR or 10 weeks in median survival. Accordingly, we cannot recommend the use of IFN alpha as a clinical modulator of FUra/LV in the treatment of advanced colorectal cancer.

Cardiac perforation associated with continuous infusional chemotherapy

The case history is reported of a 51-year-old man with metastatic colonic carcinoma who was receiving a continuous 5-fluorouracil infusion via a central venous catheter and who developed cardiac perforation and pericardial effusion. This complication has not previously been reported in association with continuous chemotherapy infusion.

Recombinant human erythropoietin and platinum-based chemotherapy in advanced ovarian cancer

PURPOSE

Patients with ovarian cancer often experience dose-limiting myelotoxicity, nephrotoxicity and anemia following treatment with platinum-based chemotherapy.

PATIENTS AND METHODS

To investigate the ability of recombinant human erythropoietin (epoetin alfa) to prevent the development of anemia, 30 patients with advanced ovarian carcinoma receiving cisplatin or carboplatin were randomly assigned to treatment with subcutaneous epoetin alfa 300 IU/kg three times a week in addition to conventional supportive treatment, or conventional supportive treatment alone, for up to six chemotherapy cycles. The dose of epoetin alfa was reduced if hemoglobin concentration exceeded 15 g/dL.

RESULTS

A highly significant difference in mean hemoglobin concentrations was observed between the two groups during the first cycle of chemotherapy due to a significant decrease in mean hemoglobin concentration in the control group. A maximal difference of 3.4 g/dL was achieved during cycle three. Fewer patients required blood or platelet transfusions in the epoetin alfa-treated group, although the difference was not significant compared to the control group. Epoetin alfa was well tolerated.

CONCLUSION

Epoetin alfa appears to be effective and well tolerated in preventing hemoglobin decline in patients undergoing aggressive cyclic platinum-based chemotherapy for advanced ovarian carcinoma.

Results of a randomized trial comparing MVPP chemotherapy with a hybrid regimen, ChlVPP/EVA, in the initial treatment of Hodgkin's disease

PURPOSE AND METHODS

Between December 1984 and August 1992, 423 patients with newly diagnosed Hodgkin's disease (HD) were entered onto a randomized clinical trial that compared the regimen of mechlorethamine, vinblastine, procarbazine, and prednisone (MVPP) with a doxorubicin-containing hybrid regimen (chlorambucil, vinblastine, procarbazine, and prednisone/etoposide, vincristine, and doxorubicin [ChlVPP/EVA]). Median age for the group was 29.5 years (range, 15.2 to 68.8), and 52% had bulk disease.

RESULTS

After chemotherapy, patients in the hybrid arm of the trial had a higher complete remission (CR) rate (68.1% v 55.3%) and a lower failure rate (2.4% v 12.5%) than those in the MVPP arm. There were also fewer deaths during treatment in the hybrid arm of the trial (five v 13). With a median follow-up period for survivors of 4.5 years (range, 0 to 9), actuarial 5-year progression-free survival (PFS) for all cases is 80% in the hybrid arm and 66% in the MVPP arm (P = .005). A nonsignificant trend toward a better overall survival in the hybrid arm of the trial has also been identified.

CONCLUSION

These results suggest that ChlVPP/EVA hybrid is superior to MVPP in the treatment of HD. It has therefore been adopted as standard first-line therapy at the two centers.

Definition of local recurrence after surgery for rectal carcinoma

Local recurrence rates of rectal carcinoma have been analysed among 284 patients in a prospective randomized multicentre trial of adjuvant preoperative radiotherapy for locally advanced rectal carcinoma. Wide variations in local recurrence rates are demonstrated depending on the definition of local recurrence employed and the subgroup studied. Thus after surgical operation alone, rates as high as 43.3 per cent or as low as 12.7 per cent can be calculated. After both adjuvant preoperative radiotherapy and operation the overall local recurrence rate is 12.8 per cent, although the local recurrence rate inside the radiotherapy field (true recurrence) may be as low as 2.3 per cent. It is recommended that local recurrence after operation for rectal carcinoma be defined as any detectable local disease at follow-up, occurring either alone or in conjunction with generalized recurrence, in patients who have undergone resection. A rate should be given both for all patients and for those operated on for cure, but not for the latter group alone as this could introduce bias.

Adjuvant preoperative radiotherapy for locally advanced rectal carcinoma. Results of a prospective, randomized trial

PURPOSE

A prospective, randomized clinical trial was conducted by the Northwest Rectal Cancer Group to study the effects of preoperative radiotherapy given one week before surgery in locally advanced (tethered or fixed) rectal carcinoma.

METHODS

A total of 284 patients were entered into the trial between 1982 and 1986; 141 were allocated to receive surgical treatment alone, and 143 were allocated to receive preoperative radiotherapy. A 10 x 10 x 10 cm volume in the posterior pelvis, centered on the tumor, was irradiated at a dose of 20 Gy, divided into four daily fractions of 5 Gy each.

RESULTS

No differences were observed in any of the clinicopathologic variables in the two arms of the trial; there were no striking down-staging effects in the irradiated tumors. After a minimum follow-up period of 96 months, the overall and cancer-related mortality rates were similar in both arms of the study (P = 0.21 and P = 0.09, respectively). There was a highly significant reduction in local recurrences in the irradiated group (12.8 percent x-ray therapy vs. 36.5 percent surgery; P = 0.0001). The majority of local recurrences after preoperative radiotherapy occurred inside the radiotherapy field (10 cases; 7 percent), with only six cases (5 percent) outside the field. No significant difference was observed in the rates of distant metastasis between the two treatment groups (P = 0.73).

CONCLUSIONS

Although there is no statistically significant survival benefit in the whole series, there is a survival benefit for the subset of patients considered by the surgeon to have undergone a curative operation. We recommend that this form of adjuvant therapy should be offered to all patients with locally advanced rectal cancer who are to undergo radical surgery.

An evaluation of five different methods for estimating proliferation in human colorectal adenocarcinomas

Five different methods of determining cell proliferation have been compared in samples taken from a group of 125 human colorectal tumours labelled in vivo with iododeoxy-uridine (IUdR). The labelling index (LI) was obtained immunocytochemically using monoclonal antibodies against proliferating cell nuclear antigen (PCNA), the Ki67 antigen and IUdR (IUdRimm). Incorporation of IUdR was also determined flow cytometrically (IUdRfcm) and PCNA expression was measured in both formalin- and methanol-fixed tissue (PCNAf and PCNAm respectively). There was significant variation in the results obtained both within and between the different assays. Paired analysis of the data showed that the correlation between the different methods of determining the LI was poor. However, the IUdRfcm LI was significantly correlated with both IUdRimm (r = 0.39; n = 78; P < 0.001 by Spearman's test) and Ki67 LIs (r = 0.32; n = 87; P < 0.001). The IUdRimm LI was also significantly related to the Ki67 LI (r = 0.44; n = 60; P < 0.001). The median IUdRfcm and IUdRimm LIs were significantly higher in the aneuploid vs. the diploid tumours (17.4% vs. 6.2% for IUdRfcm; 23.2% vs. 18.9 for the IUdRimm; P < 0.001 and P = 0.014 respectively by Mann-Whitney U-test) but none of the other proliferative indices showed this relationship. Finally, none of the LIs showed a significant association with the clinical characteristics of the tumours such as stage, grade, age, sex or fixity. The findings of this investigation highlight the need for carefully controlled studies when assessing the value of proliferation markers in solid human tumours.

Weekly VAPEC-B chemotherapy for high grade non-Hodgkin's lymphoma: results of treatment in 184 patients

BACKGROUND AND PATIENTS: A weekly schedule of chemotherapy (VAPEC-B) has been used to treat 184 consecutive patients with high grade non-Hodgkin's lymphoma (NHL). Median age for the group was 57 years (range 17-84) and 56% had stage IV disease.

RESULTS

Following chemotherapy, 114 (62%) patients achieved CR or CR(u), 32 (17%) PR and 15 (8%) had not responded or progressed. Response to VAPEC-B was highly stage dependent with 70% or more of patients with stages I-III achieving CR or CR(u) but only 50% of those with stage IV. Twenty-four (15%) patients died during treatment with VAPEC-B and in 13 cases death was due to sepsis. This complication occurred mainly in patients with stage IV disease aged 60 years or older. After a median follow up period of 4.1 years, the actuarial 4 year survival for 184 patients is 45%, an overall result heavily influenced by the poor outcome for 103 patients with stage IV disease (4 year survival of 28%). Patients with earlier stage disease fared correspondingly better (44% for stage III, 68% for stage II and 80% for stage I).

CONCLUSIONS

VAPEC-B gives similar results to other chemotherapy regimens currently used in the treatment of high grade NHL and has the advantage of brevity. Caution is advised in patients over the age of 60 especially in the presence of stage IV disease and dose reduction or haemopoietic growth factor support should be considered in these circumstances.

Intra-tumoral heterogeneity of tumour potential doubling times (Tpot) in colorectal cancer

Intra-tumoural heterogeneity of proliferation has been assessed by taking multiple biopsies from 30 colorectal cancers. Following in vivo IUDR labelling, dual parameter flow cytometry was used to measure tumour DNA index (DI) and labelling index (LI) and to derive DNA synthesis time (Ts) and potential doubling time (Tpot). Heterogeneity was seen for all parameters under investigation. Overall coefficients of variation (CV) and logarithmic transformation of Ts and Tpot (due to their non-gaussian distributions) indicate that LI (CV 25%) was the most variable parameter. Intra-tumoral heterogeneity in Tpot (lnTpot CV = 22%) was less than inter-individual variation (CV = 63%), suggesting that this variation should not be a limitation to the possible usefulness of this technique as an independent prognostic indicator. Correlations of Tpot values were examined between the shortest, the median and the value for a pooled homogenate sample from a single tumour. Using an homogenate, it was possible to accurately predict classification of tumour Tpot values as being below the median ('fast tumours') in 15 of 19 cases (79%). The data suggest that assaying an homogenate may allow a more rapid analysis of a multiply sampled tumour.

An assessment of the reliability and reproducibility of measurement of potential doubling times (Tpot) in human colorectal cancers

An assessment has been made of the reproducibility of measuring tumour proliferation using in vivo iododeoxyuridine (IUdR) labelling and flow cytometry. The variation that occurs between different institutions (Paterson Institute for Cancer Research, Manchester and the Gray Laboratory, Northwood), different observers and different runs on the same flow cytometer have been measured on 139 samples from 53 patients with colorectal cancer. The results demonstrate that the IUdR technique for measuring tumour proliferation is reproducible. Correlations were seen between measurements of Tpot obtained by different individuals and on separate machines. However, direct comparisons of the measured parameters showed that there were highly significant differences in the values obtained between institutes and observers (P < 0.001). Despite these variations, there were still significant detectable differences in Tpot measurements between individual tumours (P < 0.001). Analysis of the results obtained by running the same samples on two separate occasions on the same machine showed that the technique was highly reproducible and that the staining procedure was stable. Eighty per cent of the samples were similarly assigned to either above or below the median Tpot value, regardless which observer/laboratory combination was utilised. These data suggest that large clinical trials using Tpot should employ a single centre and a single individual to prepare, run and analyse samples.

ABC of colorectal diseases. Anal cancer

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Recombinant human erythropoietin in patients with ovarian carcinoma and anaemia secondary to cisplatin and carboplatin chemotherapy: preliminary results

Preliminary results from the first 21 patients of a group of 30 with International Federation of Gynaecology and Obstetrics (FIGO) stage II-IV epithelial ovarian carcinoma and anaemia are reported. Patients entered this open-label, comparative-group, out-patient study and were randomized to receive conventional support alone (control patients) or recombinant human erythropoietin (r-HuEPO) in addition to conventional support for 6 months. The aim of the study was to determine the effects of r-HuEPO on the anaemia induced by platinum-based chemotherapy. Patients randomized to r-HuEPO therapy received 300 U/kg subcutaneously 3 times weekly in addition to conventional chemotherapy. All patients underwent regular haematological monitoring. One patient developed a deep venous thrombosis after 17 doses of r-HuEPO; it was thought that this event may have been related to therapy and the patient was withdrawn from the study. Three other withdrawals occurred after 11, 15 and 40 doses of r-HuEPO because of progressive anaemia, metoclopramide-induced skin rash and change of chemotherapy, respectively. In the 21 patients analysed to date, there was a notable reduction in blood transfusion requirements during the 6 months of chemotherapy and an improvement in mean serial haemoglobin concentrations in patients on r-HuEPO compared with the control group. In conclusion, r-HuEPO has the potential for reducing haematological toxicity in patients with ovarian carcinoma receiving platinum-based chemotherapy. Also, r-HuEPO may allow modest dosage increments in chemotherapy or the addition of abdominopelvic radiotherapy.

Prognostic factors in colorectal carcinoma treated by preoperative radiotherapy and immediate surgery

The clinicopathologic staging of colorectal cancer is the subject of recent debate. We studied morphologic variables in a series of tumors resected from 284 patients. Half had been prospectively, randomly allocated to receive a 4-day schedule of preoperative pelvic radiotherapy followed by immediate surgery. There was a significant (P less than 0.01) difference in the distribution of tumors of various histopathologic grades between irradiated (XS) and unirradiated (S) patients and borderline differences in the predictive values of venous spread, tumor grading, and local spread. However, these differences were less marked in 180 tumors examined by one review pathologist. They were thought to be due to misinterpretation of changes induced by radiotherapy. No differences were detected in the distribution of tumors of various sizes and Dukes' stage in the XS and S groups. The review pathologist recorded a borderline (P = 0.049) difference in the distribution of tumors of various CEA staining patterns between the XS and S groups. In a Cox regression model. Dukes' staging remained the most important predictive variable for survival and pelvic recurrence in the XS and S groups. Dukes' staging was apparently unchanged by this schedule of preoperative radiotherapy, but Broders' grading may be unreliable. Any new clinicopathologic staging system for colorectal cancer should record when preoperative radiotherapy is delivered. More studies of radiotherapy effects are required.

Lack of a relationship between colony-forming efficiency and surviving fraction at 2 Gy

The relationship between in vitro radiation sensitivity and colony-forming efficiency has been examined for primary human tumors of the cervix, colorectum, and lymph gland. Tumors were cultured using the Courtenay-Mills soft agar clonogenic assay and radiosensitivity was assessed as surviving fraction at 2 Gy. There was no correlation between colony-forming efficiency and surviving fraction at 2 Gy, giving confidence to the use of surviving fraction at 2 Gy as a predictor of clinical outcome.

Predicting local recurrence of carcinoma of the rectum after preoperative radiotherapy and surgery

A prospective study of prognostic factors has been carried out in a group of 186 patients with tethered rectal carcinomas. Of these, 97 were randomized to surgery alone and 89 to receive preoperative radiotherapy (20 Gy in four fractions). DNA ploidy was determined by flow cytometry. DNA aneuploidy was detected in 60 patients (62 per cent) in the surgery only group, but in only 33 patients (37 per cent) after radiotherapy (P less than 0.01). There was a significant reduction in local recurrence in irradiated patients (P less than 0.0001). DNA diploid tumours were less likely to recur locally. This was more marked in the radiotherapy group (P = 0.01) than in the surgery only group (P = 0.06). After radiotherapy, only the surgeons' assessments of a 'curative' resection and DNA ploidy were independent predictors of local recurrence in multivariate regression analysis, whilst Dukes' classification was not. In conclusion, DNA ploidy may indicate response to radiotherapy and is an important predictor of subsequent local tumour progression.

The value of radiotherapy for rectal cancer

Discrepancies in morbidity and local recurrence rates in published clinical trials of pelvic XRT for colorectal cancer are caused by a variety of complex factors. It is, however, clear that XRT is able to cure early rectal carcinomas and is particularly useful in alleviating the symptoms of advanced or recurrent disease. The selection of appropriate cases for combinations of XRT and surgery can be made on the basis of digital examination under anaesthetic. One aim of these combinations is to reduce the number of patients with mobile tumours of the lower two-thirds of the rectum who require a permanent colostomy. In the absence of effective chemotherapy for metastatic disease, liver XRT may have a place in controlling the growth rate of occult liver metastases in selected patients.

Timing of prophylactic antibiotics in abdominal surgery: trial of a pre-operative versus an intra-operative first dose

When prophylactic antibiotics are used in abdominal surgery it is customary to give the first dose before the operation. Whilst intra-operative antibiotics may be effective in elective surgery, there may be an advantage to starting pre-operatively when there is already an infective focus such as appendicitis. Antibiotics started pre-operatively (group P) have been compared with antibiotics started after initial abdominal exploration (group T). Three intravenous doses of 500 mg metronidazole plus 1 g cephazolin were given in a randomized, double-blind study of 700 emergency and elective high-risk abdominal operations. Antibiotic plasma concentrations at the end of the operation were significantly lower in group P but lay well within the therapeutic range. Wound infection rates, which included minor and delayed infections, were similar in both groups (group P, 57 of 342, 16.7 per cent; group T, 55 of 358, 15.4 per cent; 95 per cent confidence intervals for the difference being -4.1 to +6.7 per cent. In appendicitis, wound infection rates were 12.1 and 13.9 per cent for groups P and T respectively. However, non-fatal deep sepsis was more common in group P (nine cases) than in group T (two cases) (chi 2 = 4.9, P less than 0.05). Postoperative infection was twice as common in obese patients whose body mass index (BMI) was greater than or equal to 26 (39 of 132, 30 per cent) than in thin patients whose BMI was less than 24 (41 of 288, 14 per cent; chi 2 = 13.8, P less than 0.001). This study failed to show any advantage to starting antibiotics pre-operatively, even in appendicitis.

Quantitative magnetic resonance imaging in rectal carcinoma

T1 and T2 relaxation times have been calculated in 30 patients with rectal carcinoma and seven patients with a fibrotic pelvic mass. The relaxation times were calculated using a multipoint iterative method with data from seven total saturation recovery and six spin-echo sequences. The results show that the calculated T1 relaxation value is a useful discriminant between carcinoma and pelvic fibrosis and should improve the detection of early tumour recurrence.

Three months' treatment with cyclophosphamide, VP-16-213 followed by methotrexate and thoracic radiotherapy for small cell lung cancer

One hundred eleven patients with inoperable but limited-stage small cell lung cancer were treated with three courses of cyclophosphamide (1.5, 2.5, and 3.5 g/m2, respectively) and VP-16-213 followed by methotrexate and thoracic radiotherapy. The total duration of treatment was 3 months. Patients were included who had pleural effusions, contralateral neck nodes, and bone marrow infiltration. The complete response (CR) rate was 56%, the majority confirmed by repeat bronchoscopy, with an 81% overall response rate. The minimum follow-up was 14 months. Median survival for all 111 patients was 11 months and 14 months (1-34+) for complete responders; the median survival was also 11 months for the 91 patients with conventional limited-stage disease, although 15 of the 19 patients alive at 14 months or more were from this subpopulation. There was no significant difference in the survival of those CR patients whose response was confirmed bronchoscopically and patients whose CR was assessed only radiologically and clinically. Forty-four patients with leukopenia (less than 1000 cells/microliter) received intravenous antibiotics for malaise and suspected infection. Close monitoring between treatments and direct access of patients to the hospital was encouraged. The majority of patients improved symptomatically as assessed by Karnofsky and Respiratory scores. These results support the view that short but intensive treatment without long-term or maintenance chemotherapy is beneficial.

Local radiotherapy in the management of squamous carcinoma of the anus

This paper describes the results of treating 74 patients with squamous cell carcinoma of the anal canal and perianal skin using interstitial radiotherapy as primary treatment. This technique does not involve irradiation of regional lymph nodes. The local control rate for patients with tumours smaller than 5 cm and with negative inguinal nodes was significantly better than for the remaining patients (64 versus 23 per cent). Only 3 of 41 patients with tumours less than 5 cm diameter had clinically significant nodes at presentation, while in 33 patients with tumours larger than 5 cm there were 6 with involved nodes at presentation. Local treatment using interstitial radiotherapy is suggested as useful primary treatment for small, node-negative carcinomas, with surgery held in reserve for failures.