Biomedical subjects

W J Mackillop

Publications and source records attributed to W J Mackillop.

At least 19 recordsLinked to original sources

PubMed2006

Associations between socioeconomic status and cancer survival: choice of SES indicator may affect results.

PURPOSE: Two previous studies, by Gorey et al. and Boyd et al., compared associations between socioeconomic status (SES) and cancer survival in Canada and the United States. Both studies used SES information from population censuses linked to cancer registries. This study investigates why two similar studies led to apparently conflicting results. METHODS: We conducted analyses following analytic details provided by the previously published studies to describe cancer survival in Toronto, Canada, and Detroit, MI. We examined the effects of choice of census indicators and census levels on the observed SES-related gradients in cancer survival. RESULTS: Significant associations between SES and cancer survival were observed in Toronto for several major disease sites when median household income was used as an SES indicator. Associations were weaker when a poverty indicator was used. In Detroit, similar SES gradients were observed by using both income and poverty as SES indicators. When SES quintiles were represented by income ranks, SES-associated survival gradients were much steeper in Detroit than Toronto. When SES was described by the median income in each quintile, gradients were similar in the two cities. CONCLUSIONS: The apparent contradiction in results of two previous studies is related to the choice of SES indicators. Poverty may not be an indicator of choice for such an intercountry comparison.

Data Interpretation, Statistical↗

PubMed2006

Explaining socioeconomic status effects in laryngeal cancer.

INTRODUCTION: People with lower socioeconomic status (SES) experience shorter survival times after a cancer diagnosis for many disease sites. We determined whether area-level SES was associated with the outcomes: cause-specific survival and local-regional failure in laryngeal cancer in Ontario, Canada. When we found an association we sought explanations that might be related to access to care including age, sex, rural residence, tumor stage, lymph node status, use of diagnostic imaging, treatment type, percentage of prescribed radiotherapy delivered, number of radiotherapy interruption days, treatment waiting time, and treating cancer center. MATERIALS AND METHODS: The study population consisted of 661 glottic and 495 supraglottic stage-stratified randomly-sampled patients identified using the Ontario Cancer Registry. Area-level SES quintiles were assigned using adjusted median household income from the Canadian Census. Other data were collected from patient charts. Explanations for SES effects were determined by measuring whether the effect moved toward the null value by at least 10% when an access indicator was added to a the model. RESULTS: Socioeconomic status was not related to either outcome for those with supraglottic cancer, but an association was present in glottic cancer. With the highest socioeconomic status quintile as the referent group, the relative risks for patients in the lowest socioeconomic quintile were 2.75 (95% CI 1.48, 5.12) for cause-specific survival and 1.90 (95% CI 1.24, 2.93) for local-regional failure. Disease stage as measured by T-category explained between 3% and 23% of these socioeconomic effects. None of the other access indicators met our 10% change criterion. CONCLUSION: We question why people in lower socioeconomic quintiles were not diagnosed earlier in the disease progression. Having ruled out several variables that may be related to access to care, additional biologic and social variables should be examined to further understand socioeconomic status effects.

Adult↗

PubMed2006

Waiting times for cancer surgery in Ontario: 1984-2000.

AIMS: Despite persistent public interest and the perception among clinicians and patients that increased waiting time for cancer surgery is related to worse outcomes, little is known about waiting time for cancer surgery. Our aim is to describe changes in waiting times for cancer surgery in Ontario between 1984 and 2000, and associated factors. MATERIALS AND METHODS: The interval between date of diagnosis and admission for surgery for all patients receiving surgical treatment for cancers of the larynx, hypopharynx, stomach, colon, rectum, breast, cervix, uterus, prostate, bladder, lung and oesophagus was calculated for all patients in Ontario between 1984 and June 2000. This was accomplished by retrospective review of prospectively gathered electronic records. RESULTS: Median waiting times for cancer surgery increased for all cancer types, including substantial increases for oesophageal cancer (from 14 days between 1984 and 1987 to 33 days between 1998 and 2000), breast cancer (12-27 days), and laryngeal cancer (16-33 days). A similar increase in waiting times for patients awaiting radiation therapy was identified. The proportion of patients receiving diagnosis and definitive resection on the same admission for colon cancer decreased (from 79.4% between 1984 and 1987 to 47.9% between 1998 and 2000) for laryngeal cancer (35.5-9.4%), and for lung cancer (61.6-23.0%). Age, sex, cancer site, hospital type, household income and cancer centre location were all independently related to waiting times. CONCLUSIONS: Waiting times for cancer surgery increased substantially between 1984 and 2000. Waiting times were influenced by disease, patient and health-system-related factors.

Aged↗

PubMed2006

Comparing the predictive value of neural network models to logistic regression models on the risk of death for small-cell lung cancer patients.

Cancer is one of the leading causes of mortality in the developed world, and prognostic assessment of cancer patients is indispensable in medical care. Medical researchers are accustomed to using regression models to predict patient outcomes. Neural networks have been proposed as an alternative with great potential. Nonetheless, empirical evidence remains lacking to support the application of this technique as the appropriate method to investigate cancer prognosis. Utilizing data on patients from two National Cancer Institute of Canada clinical trials, we compared predictive accuracy of neural network models and logistic regression models on risk of death of limited-stage small-cell lung cancer patients. Our results suggest that neural network and logistic regression models have similar predictive accuracy. The distributions of individual predicted probabilities are very similar. On occasion, however, the prediction pairs are quite different, suggesting that they do not always give the same interpretations of the same variables.

Adult↗

PubMed2003

A population-based study of malignant spinal cord compression in Ontario.

DESIGN: Population-based cohort study. BACKGROUND: Malignant spinal cord compression (MSCC) has long been recognized as an important complication of cancer, but its incidence is unknown. OBJECTIVES: To describe the incidence, the management, and the outcome of MSCC in the cancer population of the Canadian province of Ontario. METHODS: Episodes of MSCC, and treatments used for each episode, were identified by linking electronic hospital separation records and cancer centre records to Ontario's population-based cancer registry. The cumulative frequency of MSCC in the last 5 years of life was described in the 121435 patients who died of cancer in Ontario between 1990 and 1995. Survival after the first episode of MSCC, and duration of hospitalization with MSCC, was described. RESULTS: The cumulative probability of experiencing at least one episode of MSCC in the 5 years preceding death from cancer was 2.5% overall, and ranged from 0.2% in cancer of the pancreas to 7.9% in myeloma. Overall, 60.2% of first episodes of MSCC were treated with primary radiotherapy, and 16.1% with surgery +/- postoperative radiotherapy, while in the remaining 23.7%, there was no record of radiotherapy or surgery. Overall, the median survival following the first episode of MSCC was 2.9 months. The diagnosis of MSCC was associated with a doubling of the time spent in hospital in the last year of life. CONCLUSION: MSCC is a fairly common occurrence among patients dying of cancer. There is a 40-fold variation in the cumulative incidence of MSCC among different types of cancer.

Adolescent↗

PubMed2003

Evolution of treatment for Hodgkin's disease: a population-based study of radiation therapy use and outcome.

AIM: To examine changes in radiotherapy (RT) use, cause-specific survival (CSS), and overall survival (OS) in a population-based cohort of Hodgkin's disease (HD) patients diagnosed from 1982 to 1996. MATERIALS AND METHODS: Adult patients with HD diagnosed from 1 January 1982 to 31 December 1996 (n = 3957) were identified from the Ontario Cancer Registry. The cohort was divided into three consecutive 5-year periods: 1982-1986, 1987-1991, and 1992-1996. RT use, CSS and OS in each of these three periods were compared. For the entire cohort, the cumulative incidence of different causes of death was calculated. RESULTS: The proportion of patients receiving RT within 11 weeks of diagnosis declined over the three consecutive periods (25.1%, 15.6%, 11.7%, P < 0.001), as did the proportion receiving RT within 45 weeks (57.0%, 51.0%, 48.1%; P < 0.001). There was a significant increase in 5-year CSS over time (81%, 87%, 89%; P < 0.001), and OS (72%, 77%, 82%; P < 0.001), which remained significant in multivariable analyses. The cumulative incidence of death from causes other than HD was equal to the incidence of HD-related death within 12 years of diagnosis. CONCLUSIONS: There was a significant decline in the use of RT as the primary treatment modality and as part of the initial management of HD from 1982-1996 in Ontario. A greater proportion of patients received their RT after a delay consistent with the receipt of prior chemotherapy. There was also a significant increase in the CSS and OS over this period. These findings are in keeping with the adoption of effective chemotherapy in the treatment of HD.

Adult↗

PubMed2003

Radiotherapy patterns of practice: T1N0 glottic cancer in Ontario, Canada.

AIMS: To describe the variation in the delivery of radiation therapy to patients with T1N0 glottic cancer who were diagnosed in Ontario, Canada, between 1982 and 1995. MATERIALS AND METHODS: The patient population consisted of a random sample of 461 patients treated with curative intent from the nine cancer centres that administer radiation therapy in the province. Abstracted variables included prescribed dose (Gy) and fractionation (f), beam energy and arrangement, set-up, field size, beam modifiers, positioning and treatment interruptions. RESULTS: Thirteen prescribed dose-fractionation schemes (> or = four cases each) were identified, including 50.0-53.0 Gy/20 f (54.5%), 55.0-61.0 Gy/25 f (30.3%), and 60.0-66.0 Gy/30-33 f (7.7%). All regimens used one fraction per day, 5 days per week. An isocentric set-up was used (94.3%), with megavoltage (MV) beam energies of Cobalt-60 (87.9%), 6 MV (6.1%) and 4 MV (6.1%). A lateral parallel-opposed pair of beams was the predominant technique (76.4%) versus an anterior oblique pair (17.2%) or angle-down pair (caudally directed fields to achieve shoulder clearance, 5.7%). Wedging (96.3%) and bolus (11.8%) were used as beam-modifying devices. Predominant field-width dimensions were 5.0-6.0 cm (43.4%) and 6.5-7.0 cm (43.1%), and field length dimensions were 5.0-6.0 cm (49.5%) and 6.5-7.0 cm (35.0%). Head, neck or chin immobilisation was used in 86.9% of the cases, with 94.6% of these being custom-made. We found that radiotherapy practice was stable over time, except for a trend of increasing field size and increasing use of immobilisation. In contrast, we found practice variations among the province's cancer centres. On the basis of our findings, we defined a predominant technical practice consisting of Cobalt-60 (reflecting machine availability during the period of the study), an isocentric set-up, a lateral parallel-opposed pair technique with wedging, and supine-head neutral positioning with custom immobilisation. Forty-two per cent of the cases had one or more components of treatment that differed from this definition. CONCLUSIONS: Description of practice variation can provoke discussion about unrecognised differences in practice policies, perhaps identifying the need for better evidence, treatment guidelines, or both.

Canada↗

PubMed2003

The appropriate rate of breast conserving surgery: an evidence-based estimate.

PURPOSE: The objective of the present study was to estimate the proportion of incident cases of breast cancer that should receive breast conserving surgery (BCS), using an evidence-based approach. METHODS: An extensive search of the literature was undertaken to identify eligibility criteria for BCS. The eligibility criteria for BCS were combined with the information about case mix and patient preference to estimate the need for BCS. An epidemiological approach was then used to estimate the incidence of each eligibility criterion for BCS in a typical North American population of breast cancer patients. The effect of sampling error on the estimated appropriate rate of BCS was calculated, and the effect of systematic error using alternative sources of information, was estimated by sensitivity analysis. RESULTS: The analysis showed that 69.6% of breast cancer cases are eligible for BCS, and that 48.0 +/- 6.0% of breast cancer patients are both eligible for BCS and prefer it to mastectomy. Based on sensitivity analysis, the plausible range of the appropriate rate was 42.1% to 49.43%. The proportion of breast cancer cases in which BCS was appropriate was stage dependent; 63.0 +/- 11.5% in ductal carcinoma in-situ; 57.0 +/- 9.9% in stage I; 52.2 +/- 9.4% in stage II, and 27.2 +/- 5.2% in stage III. CONCLUSIONS: This model suggests that BCS is appropriate in 48% of all breast cancer patients. This information may be useful in auditing surgical practice, and may serve as a basis for planning of ancillary services, including radiotherapy.

Breast Neoplasms↗

PubMed2002

Time spent in hospital in the last six months of life in patients who died of cancer in Ontario.

PURPOSE: To describe hospital bed utilization in the final 6 months of life in patients dying of cancer in Ontario, Canada. PATIENTS AND METHODS: Hospital separation records were linked to a population-based cancer registry to identify factors associated with hospitalization in the 203,713 patients who died of cancer in Ontario between 1986 and 1998. RESULTS: Between 1986 and 1998, 5.3% of all acute care beds in Ontario were devoted to the care of cancer patients in the last 6 months of life. The mean time spent in hospital in the last 6 months of life decreased from 34.3 days in 1986 to 22.7 days in 1998. Hospitalization rates increased exponentially during the last month of life. Patients younger than 50 years of age, women, and residents of poorer communities spent significantly longer in hospital than others. Hospitalization rates differed very little among the common solid tumors, but patients with CNS malignancies, the lymphomas, and the leukemias spent significantly longer in hospital than the other groups. There was significant interregional variations in hospitalization that were not explained by differences in case mix. There was a statistically significant inverse correlation between the rate of use of palliative radiotherapy and the hospital bed use in the county in which the patient resided. CONCLUSION: The total time spent in hospital in the last 6 months of life has decreased over the last decade, but acute care hospitals continue to play a large role in the care of patients who are dying of cancer.

Adult↗

PubMed2001

Risk of thyroid carcinoma in a female population after radiotherapy for breast carcinoma.

BACKGROUND: There is increasing concern regarding the risk of developing a second primary tumor in adjacent organs as a result of scattered radiation among patients who have undergone radiotherapy (RT) for breast carcinoma. Previous studies have focused mainly on the possible increase in the incidence of contralateral breast carcinoma. To the authors' knowledge, the risk of thyroid carcinoma among these women has not been explored to date. METHODS: In this population-based, retrospective cohort study, the authors identified 194,798 women who were diagnosed with invasive breast carcinoma (exclusive of those with distant metastasis) between 1973 and 1993, and ascertained subsequent cases of thyroid carcinoma utilizing data from the Surveillance, Epidemiology, and End Results (SEER) program of the U.S. National Cancer Institute. Poisson regression was used to calculate the age-standardized incidence ratio (SIR) of thyroid carcinoma and to model the influence of RT on the relative risk (RR) between the RT cohort (48,495 women) and the non-RT cohort (146,303 women). RESULTS: A total of 28 women in the RT cohort and 112 women in the non-RT cohort subsequently developed thyroid carcinoma. The distribution of thyroid carcinoma histologies in both the RT cohort and the non-RT cohort was similar to that in the female general population. Overall, there was no significant increase in the risk of thyroid carcinoma in either the RT cohort or the non-RT cohort compared with the general population; the SIR was 1.1 (95% confidence interval [95% CI], 0.8-1.6) for the RT cohort and 1.2 (95% CI, 1.0-1.4) for the non-RT cohort. When the RT cohort was compared with the non-RT cohort, the RR of thyroid carcinoma was 1.0 (95%CI, 0.7-1.5). CONCLUSIONS: The risk of radiation-associated thyroid carcinoma after initial RT for breast carcinoma was so low as to be undetectable in the current large population-based study. Continued monitoring of these women will be required to document that these findings are maintained with even longer follow-up periods. However, with 10,895 women having been followed for > 10 years at the time of last follow-up in the current study, these findings should be reassuring to women considering RT for their breast carcinoma. Therefore, women who have received RT for breast carcinoma require no special surveillance for their thyroid gland. Furthermore, previous breast radiation need not be a factor in determining the optimal management of thyroid nodules arising in women who received RT for breast carcinoma.

Adenocarcinoma, Follicular↗

PubMed2001

A comparison of published head and neck stage groupings in carcinomas of the tonsillar region.

BACKGROUND: The combination of T, N, and M classifications into stage groupings was designed to facilitate a number of activities including: the estimation of prognosis and the comparison of therapeutic interventions among similar groups of cases. The authors tested the UICC/AJCC 5th edition stage grouping and seven other TNM-based groupings proposed for head and neck cancer to determine their ability to meet these expectations in a specific site: carcinoma of the tonsillar region. METHODS: The authors defined four criteria to assess each stage grouping scheme: 1) The subgroups defined by T and N comprising a given group within a grouping scheme have similar survival rates (hazard consistency); 2) The survival rates differ across the groups (hazard discrimination); 3) The prediction of cure is high (outcome prediction); and 4) The distribution of patients among the groups is balanced. The authors identified or derived a measure for each criterion and the findings were summarized using a scoring system. The range of scores was from 0 (best) to 7 (worst). Data were from a retrospective chart review on 642 cases of carcinoma of the tonsillar region treated with radiotherapy for cure at the Princess Margaret Hospital from 1970-1991. None of the patients had distant metastases. RESULTS: The scheme proposed by Synderman and Wagner, which was published in Otolaryngology Head and Neck Surgery in 1995 (vol.112, pages 691-4), scored best at 1.2. The UICC/AJCC scheme scored worst at 6.1. The hazard consistency ranged from a 3.1% average survival difference to 6.7% across the 8 schemes. The hazard discrimination measure varied by 28% from the best to worst scheme. Prediction varied by up to almost twofold across the schemes assessed. The distribution of patients varied from expected by between 0.13% and 0.57%. CONCLUSION: UICC/AJCC stage groupings were defined without empirical investigation. When tested, this scheme did not perform as well as any of seven empirically-derived schemes the authors evaluated. The results of the current study suggest that the usefulness of the TNM system can be enhanced by optimizing the design of stage groupings through empirical investigation.

Carcinoma, Squamous Cell↗

PubMed2001

Increased risk of soft tissue sarcoma after radiotherapy in women with breast carcinoma.

BACKGROUND: Numerous studies to date have suggested an association between radiation exposure and the development of soft tissue sarcoma. The current study was performed to quantify the risk of soft tissue sarcoma in the vicinity of previously irradiated anatomic regions in women with breast carcinoma. METHODS: In this population-based, retrospective cohort study, 194,798 women who were diagnosed with invasive breast carcinoma (exclusive of those with distant metastasis) between 1973--1995 were identified, and subsequent soft tissue sarcoma cases utilizing the data from the Surveillance, Epidemiology, and End Results Program (SEER) were ascertained. Poisson regression analysis was used to calculate age standardized incidence ratios (SIR) and to model the influence of radiotherapy (RT) on the relative risk (RR) between the RT and non-RT cohorts. RESULTS: A total of 54 women in the RT cohort and 81 women in the non-RT cohort subsequently developed soft tissue sarcoma. In the RT cohort, the SIR was 26.2 (95% confidence interval [95% CI], 16.5--41.4) for angiosarcoma and was 2.5 (95% CI, 1.8--3.5) for other sarcomas; in the non-RT cohort, the SIRs were 2.1 (95% CI, 1.0--4.4) and 1.3 (95% CI, 1.0--1.7), respectively. The RT cohort demonstrated a higher risk of developing both angiosarcoma (RR: 15.9; 95% CI, 6.6--38.1) and other sarcomas (RR: 2.2; 95% CI, 1.4--3.3) compared with the non-RT cohort, and the largest increase was observed in the chest wall/breast. The elevated RR was significant even within 5 years of RT, but it reached a maximum between 5--10 years. CONCLUSIONS: The risk of soft tissue sarcoma, especially angiosarcoma, was elevated after RT in women with breast carcinoma.

Adult↗

PubMed2001

Estimating the need for radiotherapy for lung cancer: an evidence-based, epidemiologic approach.

BACKGROUND AND OBJECTIVES: Current estimates of the proportion of cancer patients who will require radiotherapy (RT) are based almost entirely on expert opinion. The objective of this study was to use an evidence-based approach to estimate the proportion of incident cases of lung cancer that will require RT at any point in the evolution of the illness. METHODS: A systematic review of the literature was undertaken to identify indications for RT for lung cancer, and to ascertain the level of evidence that supported each indication. An epidemiologic approach was then used to estimate the incidence of each indication for RT in a typical North American population of lung cancer patients. The effect of sampling error on the estimated appropriate rate of RT was calculated mathematically, and the effect of systematic error, was estimated by sensitivity analysis. RESULTS: It was shown that 53.6% +/- 3.3% of small-cell lung cancer (SCLC) cases develop one or more indications for RT at some point in the course of the illness, 45.4% +/- 4.3% in their initial treatment, and 8.2% +/- 1.5% later for recurrence of progression. Overall, 64.3% +/- 4.7% of non-small-cell lung cancer (NSCLC) cases require RT, 45.9% +/- 4.3% in their initial treatment, and 18.3% +/- 1.8% later in the course of the illness. The proportion of NSCLC cases that ever require RT is stage dependent; 41.0% +/- 5.5% in Stage I; 54.5% +/- 6.5% in Stage II; 83.5% +/- 10.6% in Stage III; and 65.7% +/- 7.6% in Stage IV. In total, 61.0% +/- 3.9% of all patients with lung cancer will develop one or more indications for RT at some point in the illness, 44.6% +/- 3.6% in their initial treatment, and 16.5% +/- 1.5% later for recurrence or progression. CONCLUSION: This method provides a rational starting point for the long-term planning of radiation services, and for the audit of access to RT at the population level. We now plan to extend this study to the other major cancer sites to enable us to estimate the appropriate RT treatment rate for the cancer population as a whole.

Algorithms↗

PubMed2001

Phase I study of a decision aid for patients with locally advanced non-small-cell lung cancer.

PURPOSE: Many patients with locally advanced non-small-cell lung cancer (LA-NSCLC) are eligible for combined-modality therapy (CMT; chemotherapy and radiotherapy). Although CMT offers slightly higher chances of survival than radiotherapy alone (RT), it also carries a higher probability of toxicity, raising the possibility that some patients may prefer to decline CMT. We report a pilot study of a decision aid designed for patients in this setting. PATIENTS AND METHODS: The aid included a structured description of the treatment options and trade-off exercises designed to help clarify the patient's values for the relevant outcomes by determining the patient's survival advantage threshold (SAT; the increase in survival conferred by CMT over RT that the patient deemed necessary for choosing CMT). Additional outcome measures included each patient's strength of treatment preference, decisional conflict, objective understanding of survival information, and decisional role preference. RESULTS: Twenty-seven patients met the eligibility criteria for the study. Of these, seven declined the decision aid because they had a clear treatment preference. The remaining 20 participants completed the decision aid; 18 chose CMT, and two chose RT. All 20 patients wished to participate in the decision to some extent. All patients reported that using the decision support was useful to them and recommended its use for others. No patient or physician reported that the aid interfered with the physician-patient relationship. Patients' 3-year SATs and median SATs were each strongly correlated with their strengths of treatment preference (rho = 0.83, P <.001 and rho = 0.67, P =.02, respectively). For all but one patient, either their 3-year or median survival threshold was consistent with their final treatment choice. Ten patients reported a stronger treatment preference after using the decision aid. CONCLUSION: We conclude that implementing the decision-aid for patients with LA-NSCLC is feasible, that it demonstrates convergent validity, and that it is favorably evaluated by patients and their physicians. The aid seems to help patients understand the benefits and risks of treatment and to choose the treatment that is most consistent with their values. Further evaluation of the aid is warranted.

Aged↗

PubMed2001

The role of computed tomography in the T classification of laryngeal carcinoma.

BACKGROUND: The objectives of this study were 1) to describe patterns of use of computed tomography (CT) in laryngeal carcinoma, and 2) to characterize the contribution of CT to the T classification of laryngeal carcinoma. METHODS: The study population comprised 1195 patients with laryngeal carcinoma diagnosed from 1982 through 1995 chosen randomly from the Ontario provincial cancer registry. A chart review was conducted to obtain data on each case. Patient-related, tumor-related, and health-system-related factors were analyzed to identify factors associated with the use of CT. Descriptions of clinical exams and CT reports were reviewed to see how CT information modified T classification. Actuarial local control and cause specific survival curves were plotted by clinical T classification without and with CT to evaluate stage migration. The percentage of the variance in outcome explained by T classification in a Cox analysis was used to evaluate whether the prognostic accuracy of T classification was improved with the use of information from CT. RESULTS: Patients with glottic (20.1%) and supraglottic (41.7%) carcinoma underwent CT. The use of CT increased over time in glottic and supraglottic carcinoma combined from 17.2% in 1982-5 to 33.9% in 1991-5. Computed tomography was used less often in older patients with a 16% (95% confidence interval, 5-27%) decrease in the odds of having CT with each 10-year age increment. Computed tomography use varied considerably across the cancer center regions in Ontario. Computed tomography altered the T classification in 20.2% of those patients who had CT, with most being "upstages." Stage migration due to CT was demonstrated. Using information from CT in the assignment of T classification for 27.8% of this study population did not make a significant contribution to the ability of T classification to predict outcome over the entire group. CONCLUSIONS: There is large variation in the use of CT among different age groups and regions. The ability to compare outcomes by stage across geographic areas is compromised when the use of CT varies.

Analysis of Variance↗

PubMed2001

Factors affecting the use of palliative radiotherapy in Ontario.

PURPOSE: To describe the use of palliative radiotherapy (PRT) and to identify factors associated with the use of PRT. MATERIALS AND METHODS: The Ontario Cancer Registry was used to identify 193,253 adult patients who died of cancer between 1986 and 1995. Radiotherapy records from all Ontario cancer centers and the data on socioeconomic status (SES) from the Canadian Census were linked to the Ontario Cancer Registry data. The proportion of cases who received at least one course of PRT at any time within 2 years of death (PRT(2Y)) was used as a primary measure of the use rate of PRT. RESULTS: Overall, 26.4% of cases underwent at least one course of PRT. PRT(2Y) remained relatively constant over the study period. PRT(2Y) was disease-specific and ranged from 4% for pancreatic cancer to 41% for prostate cancer. Age was negatively associated with PRT(2Y) (adjusted odds ratio [OR], 4.5 for the youngest group), and SES was positively associated with PRT(2Y) (adjusted OR, 1.2 for patients from wealthy communities). Patients who were initially diagnosed in a hospital affiliated with a cancer center (adjusted OR, 1.4) or who lived in a county in which a cancer center is located (adjusted OR, 1.2), or who resided in certain regions (adjusted OR, 1.20 for Hamilton and 1.17 for Kingston), were more likely to be treated with PRT. CONCLUSION: The use of PRT varied across the dispersed population in Ontario and was influenced by factors unrelated to the patient's needs. An effort should be made to reduce barriers to access for disadvantaged groups.

Adult↗

PubMed2001

A comparison of published head and neck stage groupings in carcinomas of the oral cavity.

BACKGROUND: The combination of T, N, and M classifications into stage groupings is meant to facilitate a number of activities, including the estimation of prognosis and the comparison of therapeutic interventions among similar groups of cases. We tested the UICC/AJCC 5th edition stage grouping and seven other TNM-based groupings proposed for head and neck cancer for their ability to meet these expectations in a specific site: carcinomas of the oral cavity. METHODS: We defined four criteria to assess each grouping scheme: (1) the subgroups defined by T, N, and M that make up a given group within a grouping scheme have similar survival rates (hazard consistency); (2) the survival rates differ among the groups (hazard discrimination); (3) the prediction of cure is high (outcome prediction); and (4) the distribution of patients among the groups is balanced. We identified or derived a measure for each criterion, and the findings were summarized by use of a scoring system. The range of scores was from 0 (best) to 7 (worst). The data are population based from a prospectively gathered series in Southern Norway, with 556 patients diagnosed from 1983 through 1995. Clinical stage assignment was used, and the outcome of interest was cause-specific survival. RESULTS: Summary scores across the eight schemes ranged from 1.66 for TANIS-3 to 6.50 for UICC/AJCC-5. The TANIS-7 staging scheme performed best on the hazard consistency criterion. The Kiricuta scheme performed best on the hazard discrimination criterion. Synderman predicted outcome best overall and Berg produced the most balanced distribution of cases among its groups. CONCLUSIONS: UICC/AJCC stage groupings were defined without empirical investigation. When tested, this scheme did not perform as well as any of seven empirically derived schemes we evaluated. Our results suggest that the usefulness of the TNM system could be enhanced by optimizing the design of stage groupings through empirical investigation.

Carcinoma, Squamous Cell↗

PubMed2001

Cancer patients' attitudes toward treatment options for advanced non-small cell lung cancer: implications for patient education and decision support.

The purpose of this study was to determine how people weigh both median survival time and 1-year survival probability when considering a choice between palliative Cisplatin-based chemotherapy with best supportive care (C+BSC) versus best supportive care alone (BSC) as treatment for advanced non-small cell lung cancer (NSCLC). Sixty people, previously treated for cancer, were interviewed as surrogate patients making a treatment decision. The interview included a structured description of the treatment options, and trade-off exercises used to clarify the participants' attitudes pertaining to the survival probabilities associated with each treatment.Participants' attitudes ranged from choosing the more toxic treatment if it offered no survival advantage to declining C+BSC no matter how large its advantage. Fifty-seven percent of participants would choose chemotherapy if the 1-year survival were 10% higher with C+BSC than with BSC alone. For 44 participants (76%), both their median survival and 1-year survival thresholds for accepting C+BSC were consistent, and for two (3%), neither threshold was consistent with their stated treatment preference. For the remaining 12 (21%), one threshold was discordant, but in all cases, this threshold was less relevant to his/her decision. Participants' thresholds could not be predicted reliably on the basis of patient age, sex, education, preferred role in treatment decision making, or previous treatment with chemotherapy. All but one participant recommended the interview as a decision-support strategy for actual patients. The findings suggest that patients with advanced NSCLC should be offered more than one treatment option, and that a systematic process for educating patients and for eliciting their preferences is desirable. The process described herein has potential for use in this clinical setting.

Aged↗