National Trends and Dynamic Responses in the Canadian Radiation Oncology Workforce From 1990 to 2018.

PURPOSE: To report radiation oncology (RO) workforce and cancer incidence trends in Canada and explore the relationship between the two. METHODS AND MATERIALS: Canadian radiation oncologist, trainee, and cancer incidence data from 1990 to 2018 were collected from the following publicly accessible administrative and health information databases: Canadian Post-MD Education Registry (1990-2018), Canadian Medical Association Physician Data Centre (1994-2018), Canadian Institute for Health Information/Scott's Medical Database (1990-2017), Canadian Cancer Registry (1990-2017), and Statistics Canada (1990-2017). Descriptive statistics were used to summarize the data. RESULTS: The Canadian RO workforce grew from 240 radiation oncologists in 1990 to 567 in 2018, with the largest growth period from 2005 to 2015 adding 207 radiation oncologists. Regional analyses revealed steady or stepwise growth in all Canadian regions, except in Québec, where the number of radiation oncologists decreased from 86 in 1990 to 57 in 2003 before rising to 139 by 2018. Trainee totals were between 54 and 173 per year with 2 periods of growth (1990-1996 and 2001-2008) and regression (1996-2001 and 2008-2018), signifying trainee supply variability. Female proportions of the workforce and trainees, respectively, rose steadily from 18% to 38% and 28% to 50%, while the workforce proportion with non-Canadian medical degrees decreased from 40% to 26%. Radiation oncologists younger than 40 years increased from 70 to 171, whereas those age 60 years and older decreased from 85 in 1990 to 31 in 2002 and then increased to 108 in 2017. Annual cancer incidence rose steadily from 103,780 to 206,290 cases/year. The annual cancer incidence-to-provider ratio fluctuated (364-475:1) and trended lower with time, and proportional cancer incidence-to-provider ratios varied between 0.7:1 and 1.6:1 in Canada's regions before approaching 1:1. CONCLUSIONS: Our study demonstrates the challenges and successes of managing the Canadian radiation oncologist workforce. These data will inform policy makers and other stakeholders to ensure that the profession meets the current and future needs of Canadian cancer patients.

Phase II study of hypofractionated image-guided radiotherapy for localized prostate cancer: outcomes of 55 Gy in 16 fractions at 3.4 Gy per fraction.

PURPOSE: To estimate the late morbidity of a novel, hypofractionated external beam radiotherapy schedule of 55 Gy in 16 fractions (4 fractions/week, 3.4 Gy per fraction) for localized prostate cancer. METHODS AND MATERIALS: A multi-center phase 2 study enrolled seventy-three patients between September 2004 and June 2006. After insertion of fiducial gold markers, they were treated with image-guidance (IGRT) using conformal techniques with intensity-modulation, if necessary, and then followed every 6 months for toxicity rating and PSA. Patient reported outcomes were collected yearly. Median follow up was 4.6 years. RESULTS: At 4 years post-radiotherapy, the cumulative incidence of combined urinary and bowel grade 3 toxicity was 7% (95% CI 3-16%) and grade 2+ was 33% (95% CI 24-46%). All except two patients recovered from their grade 3 events. Patient-reported reduction of function was most pronounced at year two for urinary function (mean -7, SD 16), and at year one for bowel function (mean -7, SD 21). The cumulative incidence of biochemical (PSA nadir+2) or biopsy-proven relapse at 4 years was 9% (95% CI 4-18%). CONCLUSIONS: Hypofractionated radiotherapy is clinically feasible and more convenient than conventional schedules for patients with localized prostate cancer. Phase 3 multicenter studies are on-going (NCT00126165).

ABVD alone versus radiation-based therapy in limited-stage Hodgkin's lymphoma.

BACKGROUND: Chemotherapy plus radiation treatment is effective in controlling stage IA or IIA nonbulky Hodgkin's lymphoma in 90% of patients but is associated with late treatment-related deaths. Chemotherapy alone may improve survival because it is associated with fewer late deaths. METHODS: We randomly assigned 405 patients with previously untreated stage IA or IIA nonbulky Hodgkin's lymphoma to treatment with doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) alone or to treatment with subtotal nodal radiation therapy, with or without ABVD therapy. Patients in the ABVD-only group, both those with a favorable risk profile and those with an unfavorable risk profile, received four to six cycles of ABVD. Among those assigned to subtotal nodal radiation therapy, patients who had a favorable risk profile received subtotal nodal radiation therapy alone and patients with an unfavorable risk profile received two cycles of ABVD plus subtotal nodal radiation therapy. The primary end point was 12-year overall survival. RESULTS: The median length of follow-up was 11.3 years. At 12 years, the rate of overall survival was 94% among those receiving ABVD alone, as compared with 87% among those receiving subtotal nodal radiation therapy (hazard ratio for death with ABVD alone, 0.50; 95% confidence interval [CI], 0.25 to 0.99; P=0.04); the rates of freedom from disease progression were 87% and 92% in the two groups, respectively (hazard ratio for disease progression, 1.91; 95% CI, 0.99 to 3.69; P=0.05); and the rates of event-free survival were 85% and 80%, respectively (hazard ratio for event, 0.88; 95% CI, 0.54 to 1.43; P=0.60). Among the patients randomly assigned to ABVD alone, 6 patients died from Hodgkin's lymphoma or an early treatment complication and 6 died from another cause; among those receiving radiation therapy, 4 deaths were related to Hodgkin's lymphoma or early toxic effects from the treatment and 20 were related to another cause. CONCLUSIONS: Among patients with Hodgkin's lymphoma, ABVD therapy alone, as compared with treatment that included subtotal nodal radiation therapy, was associated with a higher rate of overall survival owing to a lower rate of death from other causes. (Funded by the Canadian Cancer Society and the National Cancer Institute; HD.6 ClinicalTrials.gov number, NCT00002561.).

The management of inoperable Stage I endometrial cancer using intracavitary brachytherapy alone: a 20-year institutional review.

OBJECTIVE: To review our institution's results with primary low dose rate (LDR) intracavitary brachytherapy using Heyman's capsules for medically inoperable cancer of the endometrium. METHODS: The study was a retrospective review of inoperable early-stage endometrial cancer patients at the Cross Cancer Institute in Edmonton, Canada, treated with primary radiotherapy from January 10, 1986 to July 17, 2006. Forty-four patients with International Federation of Gynaecology and Obstetrics (FIGO) clinical Stage I disease were included in the study. Kaplan-Meier survival analysis was performed to obtain estimates of overall survival (OS), disease-free survival, and disease-specific survival (DSS). Tumor grade was assessed as a potential predictor of OS by comparing survival curves using a log-rank test. RESULTS: The median OS time was 75.5 months (95% confidence interval 55.6-95.3 months). For the entire group, the 5- and 10-year OS was 60.5% and 24.0%, respectively. The 5- and 10-year DSS was 87.7% and 79.7%, respectively. For a subset treated as planned, the 5- and 10-year OS was 54.5% and 34.5%, respectively. The 5- and 10-year DSS was 83.0% and 76.4%, respectively. When stratified by grade, trends in survival analysis are inversely related to grade. Both the trend analysis and the log-rank test were statistically significant at a p<0.05 level. CONCLUSIONS: Our experience with LDR brachytherapy for the treatment of Stage I endometrial cancer is comparable to surgical treatment and to results reported in the literature for high dose rate brachytherapy. Further study that would help define the indications for a primary radiotherapeutic approach in early-stage endometrial cancer may lower current thresholds for recommending primary radiotherapy versus surgery.

Correlates of exercise motivation and behavior in a population-based sample of endometrial cancer survivors: an application of the Theory of Planned Behavior.

BACKGROUND: Despite evidence of the benefits of exercise in cancer survivors, exercise participation rates tend to decline after treatments. Few studies have examined the determinants of exercise in less common cancer sites. In this study, we examined medical, demographic, and social cognitive correlates of exercise in endometrial cancer survivors using the Theory of Planned Behavior (TPB). METHODS: A mailed survey was completed by 354 endometrial cancer survivors (1 to 10 years postdiagnosis) residing in Alberta, Canada. The study was cross-sectional. Exercise behavior was assessed using the Godin Leisure Time Exercise Questionnaire and the TPB constructs were assessed with standard self-report scales. Multiple regression analyses were used to determine the independent associations of the TPB constructs with intention and behavior. RESULTS: Chi-square analyses indicated that marital status (p = .003), income level (p = .013), and body mass index (BMI) (p = .020) were associated with exercise. The TPB explained 34.1% of the variance in exercise behavior with intention (beta = .38, p < .001) and self-efficacy (beta = .18, p = .029) being independent correlates. For intention, 38.3% of the variance was explained by the TPB with self-efficacy (beta = .34, p < .001) and affective attitude (beta = .30, p < .001) being the independent correlates. The TPB mediated the associations of marital status and BMI with exercise but not income level. Age and BMI moderated the associations of the TPB with intention and behavior. CONCLUSION: The TPB may be a useful framework for understanding exercise in endometrial cancer survivors. Exercise behavior change interventions based on the TPB should be tested in this growing population.

Exercise preferences of endometrial cancer survivors: a population-based study.

Exercise has gained recognition as an effective supportive care intervention for cancer survivors, yet participation rates are low. Knowledge of the specific exercise counseling and programming preferences of cancer survivors may be useful for designing effective interventions. In this study, we examined the exercise preferences of 386 endometrial cancer survivors. Participants completed a questionnaire that included measures of past exercise behavior, exercise preferences, and medical and demographic information. Some key findings were as follows: (a) 76.9% of participants said they were interested or might be interested in doing an exercise program and (b) 81.7% felt they were able or likely able to actually do an exercise program. Participants also indicated that walking was their preferred activity (68.6%) and moderate exercise was their preferred intensity (61.1%). Logistic regression analyses showed that meeting public health guidelines for exercise, being overweight or obese, receiving adjuvant treatment, months since diagnosis, income, marital status, and level of education all influenced exercise preferences. These results suggest that endometrial cancer survivors have unique exercise preferences that are moderated by a number of demographic and medical variables. These findings may have implications for the design and implementation of clinical and population-based exercise interventions for endometrial cancer survivors.

mtDNA mutations in invasive cervix tumors: a retrospective analysis.

We tested whether mtDNA mutations are associated with poor outcome in patients with invasive cervix cancer. Tumor samples were banked more than 10 years ago from women with diagnoses of invasive cervix cancer. Automated techniques were used to determine the sequence of the mtDNA-encoded Complex I subunits. Approximately one-third of all tumors had multiple mtDNA sequence alterations. Both univariate and multivariate analysis of the 10 years survival probability showed that the 10 years survival of patients whose tumors had eight or more nucleotide substitutions was significantly worse (P<0.0063 and P<0.012, respectively). The log-rank test also found a significant difference in overall survival (P<0.003). These results suggest that multiple mtDNA mutations are an independent marker of poor prognosis, and that prospective clinical trials that incorporate analysis of mitochondrial genetic alterations in cervix cancer are warranted.

Associations among exercise, body weight, and quality of life in a population-based sample of endometrial cancer survivors.

OBJECTIVES: Lack of exercise and excess body weight may exacerbate treatment-related declines in quality of life (QoL) in endometrial cancer survivors. The primary purpose of this study was to examine the associations among exercise, body weight, and QoL in a population-based sample of endometrial cancer survivors. METHODS: Participants were 386 endometrial cancer survivors residing in Alberta, Canada who completed a mailed survey that assessed self-reported exercise, height, and weight to calculate body mass index (BMI) and QoL using the Functional Assessment of Cancer Therapy-Anemia (FACT-An) scale. RESULTS: Descriptive data indicated that 70% of the sample were not meeting public health exercise guidelines and 72% were overweight or obese. Multivariate analyses of variance demonstrated that endometrial cancer survivors meeting public health guidelines for exercise and body weight reported significantly better QoL than survivors not meeting guidelines. The differences in QoL between the groups were clinically meaningful and were not altered when controlling for important demographic and medical variables. There were no interactions between exercise, BMI, age, or time since diagnosis. Lastly, multiple regression analysis identified that both exercise (beta = .21; P < .001) and BMI (beta = -.17; P < .001) were independently associated with QoL. CONCLUSIONS: These results suggest that exercise and body weight are important independent correlates of QoL in endometrial cancer survivors. Randomized controlled trials designed to test the causal effects of exercise and/or weight loss on QoL in endometrial cancer survivors are warranted.

Randomized comparison of ABVD chemotherapy with a strategy that includes radiation therapy in patients with limited-stage Hodgkin's lymphoma: National Cancer Institute of Canada Clinical Trials Group and the Eastern Cooperative Oncology Group.

PURPOSE: We report results of a randomized trial comparing ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) chemotherapy alone with treatment that includes radiation therapy in patients with limited-stage Hodgkin's lymphoma. PATIENTS AND METHODS: Patients with nonbulky clinical stage I to IIA Hodgkin's lymphoma were stratified into favorable and unfavorable risk cohorts. Patients allocated to radiation-containing therapy received subtotal nodal radiation if favorable risk or combined-modality therapy if unfavorable risk. Patients allocated to ABVD received four to six treatment cycles. RESULTS: We evaluated 399 patients. Median follow-up is 4.2 years. In comparison with ABVD alone, 5-year freedom from disease progression is superior in patients allocated to radiation therapy (P = .006; 93% v 87%); no differences in event-free survival (P = .06; 88% v 86%) or overall survival (P = .4; 94% v 96%) were detected. In a subset analyses comparing patients stratified into the unfavorable cohort, freedom from disease progression was superior in patients allocated to combined-modality treatment (P = .004; 95% v 88%); no difference in overall survival was detected (P = .3; 92% v 95%). Of 15 deaths observed, nine were attributed to causes other than Hodgkin's lymphoma or acute treatment-related toxicity. CONCLUSION: In patients with limited-stage Hodgkin's lymphoma, no difference in overall survival was detected between patients randomly assigned to receive treatment that includes radiation therapy or ABVD alone. Although 5-year freedom from disease progression was superior in patients receiving radiation therapy, this advantage is offset by deaths due to causes other than progressive Hodgkin's lymphoma or acute treatment-related toxicity.