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O F Dent

Publications and source records attributed to O F Dent.

At least 19 recordsLinked to original sources
PubMed2007

Assessing the evidence for an association between circumferential tumour clearance and local recurrence after resection of rectal cancer.

OBJECTIVE: Circumferential resection margin involvement (CRMI) after resection of rectal cancer is regarded as a risk factor for local recurrence. We have been able to identify only nine peer-reviewed English-language publications which focus primarily on this association, and they report widely differing rates of local recurrence. The aims of this study were to review possible reasons for this variability and to assess the evidence for the micrometrically measured threshold defining CRMI. METHOD: Methodological and statistical evaluation of relevant literature. RESULTS: Several factors which could account for this variability are discussed including the nature of the patient series, surgical technique, curative vs palliative resections, pathology technique, the definition of CRMI, adjuvant therapy, tumour stage, definition and ascertainment of local recurrence, length of follow-up and method of analysis. The objective evidence for the conventional definition of CRMI as tumour 1 mm or less from a circumferential margin is considered along with the evidence supporting a recent proposal that the margin be extended to 2 mm or less. The evidence is numerically weak in both cases and we believe that neither definition should be set in concrete at this stage. CONCLUSION: Pending further research, we recommend that routine pathology reports should record frank tumour transection, if present, or otherwise report the histological width of the margin between the tumour and the nearest circumferential line of resection in millimetres. The definition of CRMI should be simply histological evidence of tumour in a line of resection, that is, a margin of 0 mm. The definition of CRMI as a margin of <or=1 mm should not be adopted as a basis for assessing the quality of surgery.

Humans↗
PubMed2006

Local recurrence after curative resection for rectal cancer is associated with anterior position of the tumour.

BACKGROUND: Mobilization of rectal cancer can be difficult if the tumour is located anteriorly and may result in a higher incidence of local recurrence. The aim of this study was to determine whether local recurrence and survival following curative resection of rectal cancer were associated with the position of the tumour. METHODS: Data were drawn from a comprehensive, prospective hospital registry of all resections for rectal cancer from January 1990 to December 1998, with follow-up to December 2003. RESULTS: The 5-year local recurrence rate was 15.9 (95 per cent confidence interval (c.i.) 11.0 to 22.8) per cent in 176 patients with tumours that had an anterior component compared with 5.8 (95 per cent c.i. 2.8 to 11.9) per cent in 132 patients with tumours without an anterior component (P = 0.009). This association persisted after adjustment for other factors linked to local recurrence (hazard ratio (HR) 2.4 (95 per cent c.i. 1.1 to 5.4)). Similarly, anterior position had a significant negative independent association with survival (HR 1.4 (95 per cent c.i. 1.0 to 2.00)). CONCLUSION: Anterior position is an independent negative prognostic factor for both local recurrence and survival after curative resection of rectal cancer.

Adult↗
PubMed2006

Risk factors for tumour present in a circumferential line of resection after excision of rectal cancer.

BACKGROUND: Transected tumour in a circumferential line of resection after excision of rectal cancer carries a high likelihood of local recurrence. The aim of this study was to identify independent risk factors for transected tumour and to examine their temporal variability. METHODS: Data were drawn from a comprehensive, prospective hospital registry of all resections for rectal cancer from January 1971 to July 2004. Transected tumour was defined as tumour present histologically in a line of resection and was assessed in all specimens. RESULTS: Transection occurred in 129 of 1613 patients (8.0 (95 per cent confidence interval 6.7 to 9.4) per cent). The following variables were independently associated with transected tumour: tumour perforation, a non-restorative operation, tumour adherence, non-standardized operative technique, preoperative radiotherapy, male sex, histological involvement of an adjacent organ or tissue, high-grade tumour and venous invasion. The mean number of risk factors per patient per year and the annual percentage of patients with transection varied distinctly over the history of the database. CONCLUSION: The varying prevalence of risk factors, both within and between hospitals and patient series, should be taken into account if the rate of transection is to be regarded as an index of the quality of surgery.

Aged↗
PubMed2005

Effect of supervised surgical training on outcomes after resection of colorectal cancer.

BACKGROUND: The process of training surgeons in technique for resection of colorectal cancer should not compromise patient care or outcomes. The aim of this study was to compare morbidity, mortality and survival rates after resection performed by trainees with those for a consultant surgeon. METHODS: Outcomes for 150 patients operated on by a single colorectal surgeon at a private hospital were compared with those of 344 patients admitted under the same surgeon and operated on by closely supervised trainee surgeons in a public teaching hospital between 1995 and 2002. RESULTS: Co-morbidity was significantly more common in patients operated on by trainees; their American Society of Anesthesiologists grades were higher and tumours were more advanced. Of 16 postoperative complications evaluated, only respiratory and cardiac problems were significantly more common in patients operated on by trainees. There was no difference in operative mortality, local recurrence or 2-year survival rate after adjustment for age and tumour stage. CONCLUSION: Outcomes after resection for colorectal cancer did not differ between the consultant and trainees in the context of a closely supervised training programme.

Aged↗
PubMed2005

What factors influence survival in patients with unresected synchronous liver metastases after resection of colorectal cancer?

OBJECTIVE: The aim of this study was to determine whether the survival of patients with untreated synchronous liver metastases after resection of a colorectal cancer was associated with any features of the primary tumour. METHODS: Information for 398 consecutive patients with unresected liver metastases in the period 1971-2001 was examined by multivariate survival analysis. RESULTS: Of 19 clinical and pathological variables considered, survival was independently associated only with residual tumour in a line of resection (hazard ratio (HR) 1.95), venous invasion (HR 1.87), right colonic tumour (HR 1.68), lymph node metastasis (HR 1.54), and extra-hepatic metastasis (HR 1.16); 8.3% of patients had none of these adverse features. Their 2-year overall survival rate was 39.2%, compared with only 16.5% (P < 0.001) in those with one or more adverse features. CONCLUSIONS: These findings may assist in selecting patients most likely to benefit from treatment of hepatic metastases and in counselling patients and their relatives.

Aged↗
PubMed2005

Low level microsatellite instability may be associated with reduced cancer specific survival in sporadic stage C colorectal carcinoma.

BACKGROUND: Colorectal cancers (CRCs) may be categorised according to the degree of microsatellite instability (MSI) exhibited, as MSI-high (MSI-H), MSI-low (MSI-L), or microsatellite stable (MSS). MSI-H status confers a survival advantage to patients with sporadic CRC. AIMS: To determine if low levels of MSI are related to the clinicopathological features and prognosis of sporadic stage C CRC. PATIENTS: A total of 255 patients who underwent resection for sporadic stage C CRC were studied. No patient received chemotherapy. Minimum follow up was five years. METHODS: DNA extracted from archival malignant and non-malignant tissue was amplified by polymerase chain reaction using a panel of 11 microsatellites. MSI-H was defined as instability at > or =40% of markers, MSS as no instability, and MSI-L as instability at >0% but <40% of markers. Patients with MSI-H CRC were excluded from analysis as they have previously been shown to have better survival. RESULTS: Thirty three MSI-L and 176 MSS CRCs were identified. There was no difference in biological characteristics or overall survival of MSI-L compared with MSS CRC but MSI-L was associated with poorer cancer specific survival (hazard ratio 2.0 (95% confidence interval 1.1-3.6)). CONCLUSIONS: Sporadic MSI-L and MSS CRCs have comparable clinicopathological features. Further studies are required to assess the impact of MSI-L on prognosis.

Adult↗
PubMed2004

Adverse histopathological findings as a guide to patient management after curative resection of node-positive colonic cancer.

BACKGROUND: The aim of this study was to identify patient and tumour characteristics that might assist in developing an improved approach to patient selection for chemotherapy after resection of clinicopathological stage C colonic cancer. METHODS: Clinical, pathological and follow-up data have been collected prospectively for all patients undergoing resection for colorectal cancer at Concord Hospital since 1971. From an initial 2980 patients, after exclusions 378 remained who had a potentially curative operation for colonic cancer with nodal metastases and did not receive adjuvant chemotherapy. Associations between several pathological features and survival were examined by proportional hazards regression. RESULTS: In a multivariate model, both overall and colonic cancer-specific survival rates were negatively associated with serosal surface involvement, apical node metastasis, high histological grade and venous invasion. The survival of patients with stage C disease who had none of these adverse features was not significantly different from that of patients with stage B lesions. However, survival diminished significantly when one or more of the adverse features were present. CONCLUSION: Patients with a stage C tumour but with none of the identified adverse features experience relatively good survival and are unlikely to benefit from adjuvant chemotherapy. In this series such patients accounted for 40.5 per cent of patients with stage C disease.

Aged↗
PubMed2003

Anastomotic leakage after curative anterior resection results in a higher prevalence of local recurrence.

BACKGROUND: The aim of this study was to determine whether leakage from a colorectal anastomosis following potentially curative anterior resection for rectal cancer is an independent risk factor for local recurrence. METHODS: The study included all patients who had a potentially curative anterior resection with anastomosis for adenocarcinoma of the rectum between 1971 and 1991 at Concord Hospital. The data were collected prospectively, with complete follow-up for at least 5 years. The Kaplan-Meier method was used to compare time to recurrence between strata of categorical variables. Proportional hazards regression was used in multivariate modelling. RESULTS: There were 403 patients in the study. After adjustment for lymph node metastases, the distal resection margin of resection, non-total anatomical dissection of the rectum and the level of anastomosis, multivariate analysis identified a significant association between anastomotic leakage and local recurrence (hazard ratio 3.8, 95 per cent confidence interval 1.8 to 7.9). CONCLUSION: Leakage following a colorectal anastomosis after potentially curative resection for adenocarcinoma of the rectum is an independent predictor of local recurrence.

Adenocarcinoma↗
PubMed2003

Surgical technique and survival in patients having a curative resection for colon cancer.

PURPOSE: This study was performed to determine whether the adoption of a standardized technique for resection of colon cancer, based on mobilization along anatomic planes, resulted in improved survival after adjustment for other known prognostic factors. METHODS: Patients undergoing a potentially curative, elective colonic resection at Concord Hospital from 1971 to 1995 were included. None received adjuvant therapy. Data were recorded prospectively. Overall survival and colon-cancer-specific survival were examined by the Kaplan-Meier method and proportional-hazards regression in relation to patient and tumor characteristics and the introduction of a standardized surgical technique in 1980. RESULTS: Overall five-year survival rose from 48.1 percent before 1980 to 63.7 percent after 1980 (P < 0.0001); cancer-specific survival rose from 66.4 percent to 76.6 percent (P = 0.002). Factors that did not change significantly before and after 1980 were patient age and gender, tumor site, stage, grade, serosal surface involvement, and apical node metastases. The proportion of tumors > or =5 cm in diameter decreased after 1980 (61.9 to 49.2 percent, P = 0.001) but survival was unrelated to size. Venous invasion rose after 1980 (9 to 15.8 percent, P = 0.014). Multiple regression with adjustment for age, stage, grade, venous invasion, serosal surface involvement, and apical node metastases showed significantly shorter overall survival before the introduction of the standardized technique (hazard ratio, 1.5; 95 percent confidence interval, 1.2-1.8) and significantly shorter colon-cancer-specific survival (hazard ratio, 1.7; 95 percent confidence interval, 1.3-2.2). The proportion of patients having a noncurative operation because of residual tumor in a line of resection (excluded from the survival analyses) fell from 10.6 percent (confidence interval, 7-15.3 percent) before 1980 to 3.2 percent (confidence interval, 2-4.9 percent) after 1980. CONCLUSION: As in rectal cancer surgery, mobilization of the colon along anatomic planes is an important principle that influences outcome and needs to be emphasized.

Aged↗
PubMed2002

Combined endoscopic laser and radiotherapy palliation of advanced rectal cancer.

BACKGROUND: In the palliative treatment of patients with advanced, inoperable rectal cancer, combined endoscopic laser and radiotherapy have been claimed to be more effective than laser therapy alone. The number of laser treatments, laser energy used, relapse rate, treatment of relapse, morbidity and survival in consecutive patients who were treated either by laser therapy alone or laser plus radiotherapy was compared. METHODS: Prospective data were analysed with regard to number of treatments, laser energy used, relapse rate, morbidity and survival for 56 consecutive patients. RESULTS: The crude relapse rate was significantly higher in the laser only group than in the laser plus radiotherapy group (58 and 15%, respectively; P = 0.002). There was no difference between the groups in the median total number of laser treatments or the mean total laser energy used. In patients experiencing a relapse, there was no difference in the median number of relapses, the number of laser treatments post-relapse or the total energy used post-relapse. Survival did not differ between the groups and there were no treatment-related deaths. CONCLUSIONS: These findings demonstrate a clear reduction in relapse after using combined laser and radiotherapy to palliate patients with advanced rectal cancer with no appreciable additional morbidity and have encouraged continuing use of this treatment.

Aged↗
PubMed2001

Local recurrence after curative resection of cancer of the rectum without total mesorectal excision.

PURPOSE: The aim of this article was to examine local recurrence after curative resection for carcinoma of the rectum in which the surgical technique of total mesorectal excision was not performed. METHODS: A single surgeon managed the patients and the data collected prospectively. Total excision of the distal mesorectum was not performed in the upper third or mid rectum. RESULTS: From 1969 to 1993 curative resections were performed in 549 patients, of which 17 died postoperatively, leaving 532 for analysis. Sphincter-saving resection was performed in 468 patients (88 percent) and abdominoperineal excision in 58 (10.9 percent). The pathology stages (Dukes) were A, 158 (29.7 percent); B, 184 (34.7 percent); and C, 190 (35.7 percent). Five hundred seventeen patients (97.2 percent) were followed up for a minimum of five years. The median period of follow-up was 82 months. Local recurrence confined to the pelvis occurred in 17 patients, and local recurrence associated with distant metastases occurred in 24 patients. The total five-year local recurrence rate was 7.6 percent. Local recurrence was increased in Stage C tumors (P = <0.0001). Diathermy dissection in the pelvis was associated with a decreased local recurrence rate (P = 0.023). The five-year survival rate in curative resections was 72.5 percent. CONCLUSIONS: It is essential that articles presenting local recurrence rates should include both local recurrence in isolation and that which occurs with distant metastases. Although total mesorectal excision for rectal cancer was not performed in this study, the local recurrence rate is not materially different from that in several articles where total mesorectal excision has been used. Whether the distal mesorectum needs to be pursued in mid-rectal cancer is not yet proven.

Adult↗
PubMed2001

Methodology and reporting in studies of local recurrence after curative excision of the rectum for cancer.

BACKGROUND: Widely varying rates have been reported in the extensive literature published in the English language on local recurrence after curative excision of rectal carcinoma. These variations may be attributable to differences in the case mix of pathological factors influencing recurrence, differences in surgical technique or expertise, differences in the administration of adjuvant therapy and various combinations of these. They may also arise from methodological differences among studies. METHODS: This paper reviews the adequacy of methodology and reporting in 21 recent studies of local recurrence after curative resection of rectal cancer. RESULTS: Many flaws in reporting and apparent inadequacies in methodology were identified. On an index of 26 criteria examined, eight studies scored no more than 8 and only three studies scored more than 11. CONCLUSION: To date, the value of reports of local recurrence rates following curative excision of rectal cancer has been limited by inadequacies in documentation and methodology. Suggestions are made for preferred procedures to be followed in the reporting of future studies.

Clinical Trials as Topic↗
PubMed2000

Prognostic significance of extensive microsatellite instability in sporadic clinicopathological stage C colorectal cancer.

BACKGROUND: Colorectal cancers exhibiting microsatellite instability (MSI) appear to have unique biological behaviour. This study analyses the association between extensive MSI (MSI-H), clinicopathological features and survival in an unselected group of patients with sporadic Australian Clinico-Pathological Stage (ACPS) C (tumour node metastasis stage III) colorectal cancer. METHODS: Some 255 patients who underwent resection for sporadic ACPS C colorectal cancer between 1986 and 1992 were studied. No patient had received chemotherapy. Minimum follow-up for all patients was 5 years. Archival normal and tumour DNA was extracted and amplified by polymerase chain reaction using a radioactive labelling technique. MSI-H was defined as instability in 40 per cent or more of seven markers. RESULTS: Twenty-one patients showed MSI-H. No association was found between MSI and age or sex. Tumours exhibiting MSI-H were more commonly right sided (P<0.00001), larger (P = 0.002) and more likely to be high grade (P = 0.049). After adjustment for age, sex and other pathological variables, patients whose cancers exhibited MSI-H had improved survival (P = 0.015). CONCLUSION: Recognition of MSI-H in sporadic ACPS C tumours identifies a subset of cancers with improved prognosis. Such stratification should be considered in trials of adjuvant therapy and may be relevant to therapeutic decision making.

Adult↗
PubMed2000

Trends in the specialist workforce in paediatrics in Australia, 1981-1997.

OBJECTIVE: The Royal Australasian College of Physicians has conducted periodic workforce censuses of Fellows practising paediatric medicine in Australia since 1981. The aim of this study was to document trends in the supply of paediatricians and to project these trends into the early 21st century. METHODOLOGY: Time series analysis using least squares regression. RESULTS: The paediatric consultant workforce in Australia increased in a linear manner from 374 in 1981 to 777 in 1997. If this trend persists, the number of paediatricians will grow by 62% to 1255 in 2016. The ratio of population aged 0-14 years per paediatrician fell from 9960:1 in 1981 to 5040:1 in 1997. The projected national decline in the child population will result in a ratio of 3050 children per paediatrician in the year 2016. The proportion of women in the paediatric workforce was 22.4% in 1997 and is projected to rise to at least 36% by 2016. The proportion aged 50 years and older rose from 22% in 1981 to 33.6% in 1997 and is projected to be 45% by the year 2016. The average total weekly working hours fell from 58.2 in 1984 to 53. 4 in 1997. The proportion practising in regional centres rose from 12 to 17.9%. CONCLUSIONS: The paediatric workforce in Australia has grown rapidly over the past 16 years. If this trend continues, the ratio of child population per paediatrician will continue to fall, acccentuated by the projected decline in the child population. The trends towards an ageing workforce with an increasing proportion of women, declining working hours and rising proportion practising in regional centres are expected to continue unless workforce intake or retirement change dramatically.

Adolescent↗
PubMed2000

Alcohol consumption in a community sample of older people.

OBJECTIVE: To examine the prevalence and pattern of alcohol use among community-living elderly Australians. METHODS: A survey was conducted of randomly selected non-institutionalised people aged 75 years and older living in the inner western suburbs of Sydney. Personal interviews by trained interviewers covered background demographic information and self-reported alcohol use. RESULTS: 72% of men and 54% of women drank alcohol. The median usual daily volume of ethanol consumed by drinkers was 10 grams for men and 1.3 grams for women. However 11% of male drinkers and 6% of female drinkers consumed at defined hazardous or harmful levels. CONCLUSIONS AND IMPLICATIONS: Although a sizeable majority of these older people were either non-drinkers or very light drinkers, a small but important proportion drank in the hazardous to harmful range. Despite increasing evidence of the health benefits of alcohol consumption it remains important to be alert for potentially harmful alcohol use among older people.

Aged↗
PubMed1999

Trends in the specialist workforce in internal medicine in Australia, 1981-1995.

OBJECTIVE: To describe trends over the period 1981 to 1995 in the supply of consultant physicians in adult medicine in Australia, and to project these trends into the early part of the 21st century. DESIGN: Analysis of workforce data collected by the Royal Australasian College of Physicians in censuses of Fellows in 1981, 1984, 1986, 1988, 1990, 1993 and 1995. MAIN OUTCOME: Number of physicians and ratio of population aged 50 years and older per physician. RESULTS: The workforce increased linearly from 1641 in 1981 to 2701 in 1995, while the population/physician ratio fell from 2180:1 to 1720:1, with a decreasing rate of decline. The ratio is projected to rise after 1996 to 1780:1 in 2016. Among the State and Territories, the higher the population/physician ratio in 1981 the greater the rate of subsequent decline. The proportion of women physicians rose linearly from 4.8% in 1981 to 10.6% in 1995. The age structure changed from a youthful triangular profile in 1981 towards a rectangular profile characteristic of an aged population. All specialty fields displayed a decreasing rate of decline in the population/physician ratio. The proportion of physicians practising in regional centres increased steadily from 9.3% in 1981 to 12.9% in 1995. CONCLUSIONS: Although the number of physicians has risen markedly since 1981 and the ratio of population aged 50 years and older per physician has fallen, trends suggest that the ratio will rise again early in the 21st century. Any deliberate attempt to limit the growth of the physician workforce might result in a deficit in the future when the demand for physicians is growing rapidly due to population ageing.

Adult↗