Ontario Cancer Registry Research Articles

Symptom Evolution in Patients with Esophageal and Gastric Cancer Receiving Palliative Chemotherapy: A Population-Based Study.

Palliative chemotherapy (PC) is associated with a modest survival benefit in patients with incurable esophageal and gastric cancer; however, changes in symptom profile during treatment are not well described. Understanding the trajectory of symptoms during treatment may lead to improved care and facilitate shared decision making. In this study, we address this knowledge gap among all patients receiving PC in the Canadian province of Ontario. Patients diagnosed with incurable esophageal and gastric cancer who received PC from 2012 to 2017 were identified from the Ontario Cancer Registry. Patients with one or more recorded Edmonton Symptom Assessment System (ESAS) scores in the 12months following cancer diagnosis were included. The ESAS includes scores from 0 to 10 in nine domains (anxiety, depression, drowsiness, lack of appetite, nausea, pain, shortness of breath, tiredness, and lack of well-being). Symptom severity is categorized as none-mild (≤ 3), moderate (4-6), or severe (7-10). We focused on potentially modifiable symptoms, i.e. nausea, pain, and anxiety/depression. Logistic regression was used to identify factors associated with moderate-severe ESAS scores in these domains. Among those patients with serial ESAS scores (at 8 ± 2 and 12 ± 2weeks) receiving chemotherapy, we describe changes during treatment (decrease by ≥ 1 = improved; - 1 > 0 > 1 = unchanged; increase by ≥ 1 = deteriorated). The cohort included 1900 patients who received PC, of whom 79% (1497/1900) had one or more recorded ESAS scores. In multivariate analysis, younger patients were more likely to have moderate-severe scores in nausea (odds ratio [OR] 1.89, 95% confidence interval [CI] 1.23-2.90 [p < 0.01] in patients aged 41-50years compared with patients aged ≥ 71years) and pain (OR 1.88, 95% CI 1.36-2.60 [p < 0.01] in patients aged 51-60years compared with patients aged ≥ 71years). Compared with males, females were more likely to report moderate-severe scores in anxiety/depression (OR 1.58, 95% CI 1.21-2.08 [p < 0.01]). At 8 ± 2weeks from PC initiation, symptom scores were unchanged in 19-42% of patients, improved in 30-51% of patients, and deteriorated in 17-35% of patients. The greatest change in symptom burden was observed for appetite (51% improvement) and anxiety/depression (35% deterioration). Similar trends were observed at 12 ± 2weeks. In this large, population-based study, we observed that younger patients were more likely to report moderate-severe symptoms in pain and nausea, and females were more likely to report moderate-severe symptoms in anxiety/depression. Anxiety/depression symptoms become increasingly problematic for a substantial proportion of patients receiving PC. Supportive care efforts to mitigate these symptoms in routine practice are needed.

Canada follows the US in the rise of bilateral mastectomies for unilateral breast cancer: a 23-year population cohort study.

The use of contralateral prophylactic mastectomy (CPM) continues to grow despite the absence of evidence supporting a survival benefit. This study's objectives were to (1) describe the trends in the rates of unilateral and bilateral mastectomy (BM) in women diagnosed with unilateral breast cancer (UBC) in Ontario, Canada from 1991 to 2013, and (2) identify factors associated with BM to treat UBC. This retrospective cohort analysis included all women aged 18 and older diagnosed with UBC between January 1991 and December 2013. Health administrative data from the Institute for Clinical Evaluative Sciences, the Ontario Cancer Registry, and the Discharge Abstract Database were used to identify all breast cancer and mastectomy cases. Age-adjusted mastectomy rates were plotted over time. Univariable and multivariable analyses included clinically significant covariates. From 1991 to 2013 there were 172,165 cases of UBC and 64,886 mastectomies (37.7%) performed in Ontario. 13.6% of the mastectomies were bilateral. BM rates increased over sixfold (from 4 to 25%) across all age groups under age 70 over a 23-year period. On multivariable analysis, younger age, higher income, rural community, earlier breast cancer stage, lobular histology, availability of reconstruction and teaching hospitals were associated with increased odds of BM. This is the largest population study of breast cancer patients in Canada and shows an increasing rate of BM for UBC. The results are similar to those already described in the US and highlight the importance of continued efforts to promote efficient communication and evidence-based decision-making prior to breast surgery.

Medical Immunosuppression and Outcomes in Cutaneous Melanoma: A Population-Based Cohort Study.

Melanoma and the immune system are intimately related. However, the association of immunosuppressive medications (ISMs) with survival in melanoma is not well understood. The study evaluated this at a population level. A cohort of patients with a diagnosis of invasive cutaneous melanoma (2007-2015) was identified from the Ontario Cancer Registry and linked to identify demographics, stage at diagnosis, prescription of immunosuppressive medications (both before and after diagnosis), and outcomes. The demographics of patients with and without prescriptions for ISM were compared. Patients eligible for Ontario's Drug Benefit Plan were included to ensure accurate prescription data. The primary outcome was overall survival. Cox Proportional Hazards Regression models identified factors associated with mortality, including use of ISM as a time-varying covariate. Of the 4954 patients with a diagnosis of cutaneous melanoma, 1601 had a prescription for ISM. The median age of the patients was 74years. Overall, 58.4% of the patients were men (60.5% of those without ISM and 54% of those using ISM; p < 0.001). The use of oral immunosuppression was associated with an increased hazard of death (hazard ratio, 5.84; 95% confidence interval, 5.11-6.67; p < 0.0001) when control was used for age, disease stage at diagnosis, anatomic site, comorbidity, and treatment. Other factors associated with death were increasing age, male sex, increased disease stage, truncal location of primary melanoma, and inadequate treatment. In sensitivity analysiswith steroid-onlyISM use excluded, survival did not differ significantly (p = 0.355). The use of immunosuppressive steroids for melanoma is associated with worse overall survival. Use of steroids should be limited when possible.

Decreased Colorectal Cancer Incidence and Incidence-Based Mortality in the Screening-Age Population of Ontario.

Background and AimsWe aimed to evaluate trends in Ontario, Canada, 2002 to 2016, in uptake of colorectal evaluative procedures, colorectal cancer (CRC) incidence and incidence-based mortality in the colorectal screening-age population.MethodsWe defined the screening age-eligible population as persons 51 to 74 years of age with ≥1 year eligibility for the Ontario Health Insurance Plan, excluding those with a diagnosis of CRC in the Ontario Cancer Registry (OCR) prior to age 50 or January 1, 2002. We computed annual up-to-date status with colorectal evaluative procedures from billing claims, and CRC incidence from the OCR. In order to compute incidence-based CRC mortality, we included persons with a first diagnosis of CRC between the ages of 51 and 74, diagnosed between January 1, 1992 and December 31, 2001, still alive and <75 years of age on January 1, 2002, based on cause of death from the OCR. Overall, age-stratified and sex-stratified trends were evaluated by Cochran–Armitage trend tests.ResultsPersons up to date with colorectal evaluative procedures increased from 628,214/2,782,061 (22.6%) in 2002 to 2,584,570/4,179,789 (62.2%) in 2016. CRC incidence fell from 129.3/100,000 in 2002 to 94.54/100,000 in 2016, and incidence-based CRC mortality fell from 40.8/100,000 to 24.1/100,000. Decreasing trends in overall and stratified incidence and mortality were all significant, except among persons 51 to 54 years old.ConclusionsThere was continued increase in persons up-to-date with colorectal evaluative procedures, and significant decrease in CRC incidence and incidence-based CRC mortality from 2002 through 2016.

Assessment of Secondary Sarcomas Among Patients With Cancer of the Abdomen or Pelvis Who Received Combinations of Surgery, Radiation, and Chemotherapy vs Surgery Alone

The association of radiation and chemotherapy with the development of secondary sarcoma is known, but the contemporary risk has not been well characterized for patients with cancers of the abdomen and pelvis. To compare the risk of secondary sarcoma among patients treated with combinations of surgery, radiation, or chemotherapy with patients treated with surgery alone and the general population. This population-based cohort study included 173 580 patients in Ontario, Canada, with nonmetastatic cancer of the prostate, bladder, colon, rectum or anus, cervix, uterus, or testis. Patients were enrolled from January 1, 2002, to January 31, 2017. Data analysis was conducted from March 1, 2019, to January 31, 2020. Treatment combinations of radiation, chemotherapy, and surgery. Diagnosis of sarcoma based on histologic codes from the Ontario Cancer Registry. Time to sarcoma was compared using a cause-specific proportional hazard model. Of 173 580 patients, most were men (125 080 [72.1%]), and the largest group was aged between 60 and 69 years (58 346 [33.6%]). Most patients had genitourinary cancer (86 235 [51.4%]) or colorectal cancer (69 241 [39.9%]). Overall, 64 301 (37.1%) received surgery alone, 51 220 (29.5%) received radiation alone, 15 624 (9.0%) were treated with radiation and chemotherapy, 15 252 (8.8%) received radiation with surgery, and 11 822 (6.8%) received all 3 treatments. A total of 332 patients (0.2%) had sarcomas develop during a median (interquartile range) follow-up of 5.7 (2.2-8.9) years. The incidence of sarcoma was 0.3% among those who underwent radiation alone (138 of 51 220) and radiation with chemotherapy (40 of 15 624), 0.2% among those who received radiation and surgery (36 of 15 252) and all 3 modalities (25 of 11 822), and 0.1% among those who received surgery with chemotherapy (13 of 14 861) and surgery alone (80 of 64 801). Compared with a reference group of patients who had surgery alone, the greatest risk of sarcoma was found among patients who underwent a combination of radiation and chemotherapy (cause-specific relative hazard [csRH], 4.07; 95% CI, 2.75-6.01; P < .001), followed by patients who had radiation alone (csRH, 2.35; 95% CI, 1.77-3.12; P < .001), radiation with surgery (csRH, 2.33; 95% CI, 1.57-3.46; P < .001), and all 3 modalities (csRH, 2.27; 95% CI, 1.44-3.58; P < .001). In the general population, 7987 events occurred during 46 554 803 person-years (17.2 events per 100 000 person-years). The standardized incidence ratio for sarcoma among patients treated with radiation compared with the general population was 2.41 (95% CI, 1.57-3.69; 41.3 events per 100 000 person-years). The annual number of cases of sarcoma increased from 2009 (15 per 100 000 persons) to 2016 (32 per 100 000 persons), but the annual rate did not change during the study period. In this cohort study, patients treated with radiation or chemotherapy for abdominopelvic cancers had an increased rate of sarcoma. Although the absolute rate is low, patients and physicians should be aware of this increased risk of developing sarcoma.

Primary sarcomas of the spine: population-based demographic and survival data in 107 spinal sarcomas over a 23-year period in Ontario, Canada

Background contextSpinal sarcomas are a rare, heterogeneous group of mesenchymal tumors. Current literature reporting demographic variables and survival information is limited to small case series, and a single registry with variable treatment modalities and time periods. PurposeWe report on population-level data regarding all spinal sarcomas diagnosed over a 23-year period in Ontario, Canada, for the purposes of calculating incidence and prevalence of these tumors. Secondarily, survival is assessed by tumor type as well as adjuvant therapies during this time period. Study designRetrospective Cohort Study Patient samplePopulation-based data from the Institute for Clinical Evaluative Sciences (ICES) between 1993 and 2015. Outcome measuresOutcome measures include incidence and prevalence of spinal osteosarcoma, Ewing's sarcoma, and chondrosarcoma of the spine, as well as 2-, 5-, 10- and 15-year survival and prevalence of adjuvant therapies. MethodsUtilizing population-based data from the Institute for Clinical Evaluative Sciences (ICES) between 1993 and 2015, ICD codes were searched and available data extracted for the purposes of reporting basic demographic information and calculation of Kaplan Meyer survival curves. Databases include the Ontario Cancer Registry, Discharge Abstract Database, Ontario Health Insurance Plan, National Ambulatory Care Reporting System, Registered Persons DataBase (death) were analyzed. ResultsOne hundred and seven spinal sarcomas were identified, with a mean incidence was 0.38 sarcomas per million population per year, that was stable over time. The mean prevalence was 8.1 sarcomas per million population. The most common diagnosis was Ewing's sarcoma (48 [44.9%] patients), followed by chondrosarcoma (33 [30.8%] patients), and osteosarcoma (26 [24.3%] patients). Chondrosarcoma had the highest survival rates with 77.2% and 64.2% 5- and 10-year survival rates, respectively, followed by Ewing's sarcoma with 48.1% and 44.9% 5 and 10-year survival and osteosarcoma with 36.0% and 30.9% 5- and 10-year survival. ConclusionsSpinal sarcoma is a rare disease with variable survival depending on the histologic diagnosis. This population-level study involves a heterogeneous group of patients with variable stages of disease at presentation and variable treatments. Our data fit with the published literature for survival for those treated conservatively and surgically. Our data show considerable improvement in 5- and 10-year mortality when compared with previous population level studies on earlier patient cohorts, likely reflecting improvements in systemic and surgical treatments.

Abstract A10: Using large linked databases to understand cancer care access in northwestern Ontario, Canada

Abstract Residents in Ontario, Canada have universal public health insurance, and the Ontario Health Insurance Plan (OHIP) and almost all medically necessary services are captured in large linked databases. We leveraged these databases through the Ontario Cancer Data Linkage Project (cdLINK), to help us better understand access to cancer care for patients who reside in Northwestern Ontario, Canada. Northwestern Ontario is an area that covers a large geographic landmass (&amp;gt;385,000 square kilometers) with low population density (0.4 people per square kilometer), and these factors often make the provision of health care challenging. This population-based retrospective study used the Ontario Cancer Registry (OCR) to define a cancer cohort of all residents of Northwestern Ontario who had a primary diagnosis of cancer, who were alive for at least 30 days, and who died from any cause between 2010 and 2016. Each index cancer case was linked with OHIP and Registered Persons Database (RPDB), and from these administrative sources we defined whether a consultation occurred, as well as selected sociodemographic factors associated with a consultation. We identified 2583 index cases (2010-2016). Of these, 78% (n=2007/2583) had receipt of a specialist consultation, defined as either a medical or radiation oncologist consultation. Factors associated with not receiving a specialist consultation included older age (p&amp;lt;0.0001, Odds Ratio (OR) 0.29; 95% Confidence Interval (CI) 0.19-0.44) and rural residence (p&amp;lt;0.0001, OR 0.48; 95% CI 0.48-0.72). Factors associated with receiving a specialist consultation included increased duration of disease (p&amp;lt;0.0001, OR 1.32; 95% CI 1.19-1.46), a diagnosis of breast cancer (p&amp;lt;0.0001, OR 2.51; 95% CI 1.43-4.42), and a diagnosis of lung cancer (p&amp;lt;0.0001, OR 1.77; 95% CI 1.38-2.26). Linkage of administrative health records offers an important opportunity to understand access to care and factors associated with access to care. Future planned research will explore health services utilization and outcomes from cancer care in residents of Northwestern Ontario. Citation Format: Michela Febbraro, Michael Conlon, Joseph Caswell, Nicole Laferierre. Using large linked databases to understand cancer care access in northwestern Ontario, Canada [abstract]. In: Proceedings of the AACR Special Conference on Modernizing Population Sciences in the Digital Age; 2019 Feb 19-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(9 Suppl):Abstract nr A10.

Cancer surveillance among workers in plastics and rubber manufacturing in Ontario, Canada

ObjectiveOccupational exposure to agents in plastics and rubber manufacturing has been associated with elevated risk of certain cancers. We sought to evaluate cancer risk among workers employed in occupations and...

Perioperative blood transfusion and resection of colorectal cancer liver metastases: outcomes in routine clinical practice

BackgroundPrior work has shown associations between blood transfusion (BT) and inferior outcomes during resection for colorectal cancer liver metastases (CRLM). Herein, we describe short and long-term outcomes relating to perioperative BT in routine clinical practice. MethodsAll CRLM resections in Ontario, Canada from 2002 to 2009 were identified using the Ontario Cancer Registry. Log-binomial regression and Cox regression were used to explore factors associated with receipt of BT and the association of BT with 5-year cancer specific (CSS) and overall survival (OS), respectively. ResultsThe study included 1310 patients; 31% (403/1310) had perioperative BT. Transfused patients had longer median length of stay (9 vs. 7 days, p < 0.001), higher 90-day mortality (9% vs. 1%, p < 0.001), greater 90-day readmission (28% vs. 16%, p < 0.001), and inferior 5-year CSS (41% vs. 48%, p = <0.001) and OS (38% vs. 47%, p < 0.001). Transfusion was independently associated with inferior CSS (HR = 1.35, 95% CI: 1.11–1.63) and OS (HR = 1.30, 95% CI: 1.10–1.53), however, excluding 90-day postoperative deaths showed these associations were no longer significant. ConclusionPerioperative BT is common in patients undergoing resection of CRLM. While transfusion is associated with greater morbidity, mortality, and inferior survival, after excluding early postoperative deaths, BT does not appear to be independently associated with CSS or OS.

Retrospective cohort study of unresectable stage III non-small-cell lung cancer in Canada.

The management of unresectable stage iii non-small-cell lung cancer (nsclc) is complex and best determined through multidisciplinary consultation. A longitudinal, population-level study was carried out to describe the management approach and outcomes of treatment in the real-world setting in Ontario. Individuals diagnosed with nsclc between 1 April 2010 and 31 March 2015 were identified in the Ontario Cancer Registry. Unresectable disease was defined as no surgery reported within 3 months of diagnosis. Initial treatments included radiotherapy (rt, curative or palliative), chemotherapy, targeted therapy, and chemoradiation [crt, concurrent (ccrt) or sequential (scrt)]. Survival was calculated from diagnosis with stage iii disease to death or last follow-up. Of the 24,729 individuals diagnosed with nsclc, 5243 (21.2%) had stage iii disease, with most of the latter group (4542, 86.6%) having unresectable disease. Median age was 70 years, and 54.2% were men. The frequency of first-line treatment was ccrt, 22.1%; palliative rt, 21.0%; curative rt, 19.6%; no treatment, 19.6%; chemotherapy alone, 11.6%; scrt, 5.4%; and targeted therapy, 0.7%. Median overall survival (mos) was 14.2 months [95% confidence interval (ci): 13.6 months to 14.7 months], with the longest survival observed in patients who received targeted therapy (mos: 34.7 months; 95% ci: 21.4 months to 51.2 months), and the poorest, in those receiving no cancer treatment (mos: 5.9 months; 95% ci: 5.0 months to 6.4 months). The mos in patients receiving ccrt was 23.6 months (95% ci: 21.4 months to 25.6 months). Guideline-recommended ccrt is undertaken in only a small proportion of patients with unresectable nsclc in Ontario. The reasons for low uptake of that recommendation are only partly understood.

Effectiveness of Trastuzumab in Routine Clinical Practice: A Population-based Study of Patients with HER-2-positive Oesophageal, Gastroesophageal and Gastric Cancer

AimsIn the pivotal Trastuzumab for Gastric Cancer (ToGA) trial, trastuzumab improved median survival in patients with advanced HER-2-positive gastric and gastroesophageal cancer from 11.1 to 13.8 months; however, its effectiveness in routine clinical practice has not been evaluated. Our objective was to evaluate the uptake and outcomes of trastuzumab in a population-based cohort of patients with oesophageal, gastroesophageal and gastric cancer in Ontario, Canada. Materials and methodsThe Ontario Cancer Registry and linked treatment records were used to identify all patients with oesophageal, gastroesophageal and gastric cancer treated with trastuzumab during 2012–2017. Outcomes were analysed from the time of first trastuzumab cycle and included a primary outcome (survival) and secondary outcomes (uptake, delivery, 30-day hospital admission and 30-day mortality). Trends over the study period and survival were evaluated. ResultsIn total, 476 patients with oesophageal, gastroesophageal and gastric cancer received trastuzumab during the study period. The mean age was 62 years, 78% (370/476) were male, and 65% (312/476) had gastric cancer. The annual number of patients receiving trastuzumab increased over the study period (53 in 2012 and 101 in 2017). The median number of cycles of trastuzumab delivered was six. Thirty-day hospital admission and mortality rates were 17% and 4%, respectively. The median overall survival was 282 days (9.3 months). ConclusionsThe median survival of patients treated with trastuzumab for advanced oesophageal, gastroesophageal and gastric cancer in routine practice is substantially less than that observed in the pivotal clinical trial. Studies of comparative effectiveness using real-world data offer insight into outcomes achieved in routine practice.

Population Trends in Lobular Carcinoma of the Breast: The Ontario Experience.

Invasive lobular carcinoma (ILC) is less common that invasive ductal carcinoma (IDC), and more challenging to diagnose by examination and screening mammography. This study evaluated current trends in ILC incidence, and described the 5-, 10-, and 15-year survival probabilities for women diagnosed with ILC in Ontario, Canada. This retrospective cohort analysis included all women aged 18years and older diagnosed with breast cancer between 1991 and 2015. Health administrative data from the Institute of Clinical Evaluative Sciences and the Ontario Cancer Registry were used to identify breast cancer cases. Age-adjusted incidence was plotted by year. Crude proportions were plotted by year of diagnosis for stage and hormone receptor status. Kaplan-Meier curves were generated to determine the 5-, 10-, and 15-year survival probabilities for ILC and IDC. From 1991 to 2015, there were 194,065 cases of breast cancer in Ontario, 14.7% of which were ILC. The age-adjusted incidence of breast cancer increased 1.04-fold, while ILC rates increased 1.53-fold. All bilateral breast cancers were of lobular origin. The proportion of stage 1 ILC decreased, while the proportion of stage 2-4 ILC increased. The 5-, 10-, and 15-year overall survival probabilities for women diagnosed with ILC were 82.7%, 65.3%, and 50.2%, respectively. This study contains the largest population dataset of ILC evaluated to date. While total breast cancer incidence rates in Ontario are largely unchanged, ILC incidence rates are steadily increasing and there is a trend towards diagnosis of ILC at a later stage. These trends highlight the ongoing diagnostic and treatment challenge ILC presents for patients and clinicians.

Discrepancy in pathology reports upon second review of radical orchiectomy specimens for testicular germ cell tumors.

We sought to evaluate the discrepancies between primary pathology report and second pathology review of radical orchiectomy (RO) specimens. A retrospective review was performed of RO specimens from the Ontario Cancer Registry. All cases required both a primary pathology report and a second pathology review from another institution. Histopathological variables assessed included histological subtype and components of mixed germ cell tumor (GCT), pathological tumor (pT) stage, lymphovascular invasion (LVI), spermatic cord invasion, and surgical margin. Between 1994 and 2015, 5048 ROs were performed with 2719 (53.9%) seminoma and 2029 (40.2%) non-seminoma. Of these, 519 (10.3%) received a second pathology review. There was concordance between primary pathology report and second pathology review in 326 (62.8%) cases. The most common discrepancies involved a change in pT stage (n=148, 28.5%), with upstaging in 83 (16%) and downstaging in 65 (12.5%) cases relative to the original pT stage. The second most common discrepancy regarded the reporting of LVI (n=121, 23.3%), with 62 (11.9%) reporting presence of LVI when the primary pathology report did not. Other discrepancies included a change in the histological subtype in 28 (5.4%) cases and spermatic cord margin status in five (9.6%) cases. Only 10% of orchiectomy specimens underwent a second pathology review, with nearly 40% of reviews leading to a meaningful change in parameters. Such variation could lead to incorrect tumor staging, estimate of relapse risk, and inappropriate treatment decisions. Expert pathology review of RO specimens should be considered, as it has significant implications for decision-making.

Pulmonary and overall healthcare utilization after childhood and young adult thyroid cancer.

Differentiated thyroid carcinoma (DTC) in children, adolescents, and young adults is associated with excellent prognosis. However, little is known about the long-term utilization of healthcare resources among survivors. The objective of this study was to compare the utilization of healthcare resources among DTC survivors to the general population, with a focus on pulmonary-related resource utilization. Population-based linked data were used to retrospectively ascertain DTC patients from the Ontario Cancer Registry, age <30 years at diagnosis between 1992 and 2011. DTC cases were individually matched 1:10 to the general population on age, sex, diagnosis year, and rural status. Billing records for all-cause hospitalizations, emergency department visits, pulmonary subspecialist visits, and chest imaging were compared using incidence rate ratios (IRR). A total of 2456 individuals with DTC were identified, with women representing the majority (82.8%) of cases. Compared to controls, hospitalization and emergency department visit IRRs were 2.56 (95% CI, 2.49-2.63) and 2.22 (95% CI, 2.18-2.26), respectively. An excess of pulmonary diagnostic imaging was observed for chest radiography (IRR, 2.7; 95% CI, 2.6-2.8) and pulmonary CT's (IRR, 17.5; 95% CI, 15.8-19.3). Patients who underwent radioactive iodine therapy had a higher incidence of pulmonary-related healthcare utilization than those who did not. The highest healthcare utilization for all modalities was observed in the 30 to 90 days after DTC diagnosis with a steady decline further from diagnosis; however, elevated utilization was observed throughout the observation period. Health services utilization is high for primary DTC survivors, irrespective of the time since diagnosis. Radioactive iodine therapy is associated with higher rates of utilization. These findings have ramifications for treatment, surveillance and for policy formulation.

Retrospective cohort study of real-world treatment patterns and overall survival in patients with chronic lymphocytic leukemia (CLL) diagnosed between 2010 to 2017 in Ontario, Canada.

e20003 Background: With recent advances in treatment of CLL, it is important to understand emerging treatment patterns and associated outcomes. A population-based study was undertaken to describe the management and survival of CLL patients in Ontario, Canada. Methods: Patients diagnosed with CLL between January 1, 2010 and December 31, 2017 were identified in the Ontario Cancer Registry and linked to provincial administrative databases. Treatment patterns by line of therapy were characterized, including analyses of time to initiation and between therapies. Overall survival was calculated. Results: 2,887 CLL patients were identified (median age 68yr; 67% male). The mean time from diagnosis to first line (1L) treatment was 651 days with 35% of patients receiving fludarabine-cyclophosphamide-rituximab (FCR) based treatment. During the study period, 71% of patients did not yet receive second line (2L) therapy and did not have subsequent follow up, while 19% received 2L ibrutinib. Median time to 2L initiation from 1L treatment discontinuation was 636 days. The table summarizes 1L and 2L therapies. Of the 827 patients on 2L therapy, 65% received ibrutinib. After the introduction of publicly funded novel agents in 2015, a shift in treatment patterns away from FCR and chlorambucil based regimens was observed. Overall mean survival for the cohort from diagnosis was 6.8yrs, and mean 5 year probability of survival was 72.4%. Conclusions: A shift in treatment patterns for CLL can be seen with the introduction of newer therapies, such as ibrutinib. The results can support healthcare decision-makers by characterizing the size of this patient population, real world treatment patterns and survival outcomes for patients with CLL. [Table: see text]

Venous Thromboembolism During Chemotherapy for Testicular Cancer: A Population-Based Study

AimsVenous thromboembolism (VTE) is a potential complication among germ cell tumour patients. We evaluated the incidence rate, timing and factors associated with VTE among patients with germ cell cancer in routine practice. Materials and methodsThe Ontario Cancer Registry was linked to electronic records of treatment to identify all cases of testicular cancer treated in Ontario during 2000–2010. Administrative databases were used to identify VTE in the 3 months before and 5 years after orchiectomy. We explored patient-, disease- and treatment-related factors associated with VTE among all patients as well as those with detailed chemotherapy records available. ResultsDuring 2000–2010, 2650 patients underwent orchiectomy for testicular cancer; among this cohort, 920 (33%) received chemotherapy. The VTE rate was 8% (69/920) among patients treated with chemotherapy and 0.6% (11/1730) among those without chemotherapy. Among the patients treated with chemotherapy who had VTE, 13% (9/69) occurred in the month before starting chemotherapy, 62% (42/69) in the first 3 months after starting and 25% thereafter. For patients who received three and four cycles, VTE rates were 8% (21/258) and 16% (19/121), respectively. In adjusted analyses, the only factor independently associated with VTE was increasing number of cycles (odds ratio 3.91 for four cycles, odds ratio 1.63 for three cycles (P = 0.022) compared with one to two cycles). ConclusionThis population-based study confirms findings from institutional case series regarding the high rate of VTE among patients with germ cell tumours treated with chemotherapy. Future studies should evaluate the extent to which VTE prophylactic strategies might mitigate this risk.

A population-based analysis of breast cancer incidence and survival by subtype in Ontario women.

Breast cancer (bca) is the type of cancer most frequently diagnosed among women in Canada. Breast cancer is categorized into various molecular subtypes by the expression of estrogen receptor (er), progesterone receptor (pgr), and her2 (human epidermal growth factor receptor 2). Currently, Canada has no national cancer registry with epidemiology data by subtype. Thus, we conducted a study to determine incidence, survival, and clinicopathologic characteristics by bca subtype [triple negative breast cancer (tnbc); her2+; and hormone receptor-positive (hr+), her2-] in Canadian women newly diagnosed with bca. Female patients diagnosed between 1 April 2012 and 31 March 2016 (fiscal 2012-2015) were identified in the Ontario Cancer Registry, and individual patient data were linked to data in provincial health administrative databases. Descriptive statistics and Kaplan-Meier curves were generated. In this cohort, 3277 women (9.5%) had tnbc, 4902 (14.3%) had her2+ bca, and 22,247 (64.8%) had hr+, her2-breast cancer. The annual incidence was 15 per 100,000 for the tnbc group, 21-23 per 100,000 for the her2+ group, and 97-105 per 100,000 for the hr+, her2- group. The lowest median overall survival (mos) of 8.9 months was observed in women with clinical stage iv tnbc. In comparison, the mos was 37.3 months in those with her2+ disease and 35.2 months in those with and hr+, her2- metastatic bca. In the present study, the most recent and largest administrative database analysis of a Canadian population to date, we observed a subtype distribution consistent with previously reported data, together with comparable annual incidence and overall survival patterns.

PCN350 USING REAL WORLD DATA TO DETERMINE HEALTH SYSTEM COSTS OF CANADIANS DIAGNOSED WITH CHRONIC LYMPHOCYTIC LEUKEMIA

With the recent advances of novel treatments for patients with chronic lymphocytic leukemia (CLL), and fiscal constraints of the publicly funded healthcare system in Canada, understanding the real world economic impact of CLL is critical. The objective of this study was to determine the health system costs of CLL patients treated in Ontario, Canada. Patients diagnosed and treated between January 1, 2010 and December 31, 2017 were identified in the Ontario Cancer Registry and linked to provincial administrative databases, capturing hospitalizations, cancer clinic visits, physician services and novel treatments (radiation and inexpensive chemotherapies were excluded). Total cohort, annual and mean per patient/control costs (CAD 2017) were determined using a costing methodology available at the Institute for Clinical Evaluative Sciences called GETCOST. Short-term episodes (e.g., hospitalizations) attributed costs by multiplying the encounter’s resource intensity weight by an annual cost per weighted case; long-term episodes (e.g., complex care) attributed costs by weighted days, and costs of visit-based encounters were determined by utilization. 2,572 CLL patients/cases were identified and matched with 7,611 controls (median age 68 years; 66% male). The overall total cost for cases was $254.7M (mean cost per patient was $99,900); oral medications based on list price ($56.5M), inpatient hospitalizations ($49.1M), and cancer clinic visits ($46.2M) were the top three cost contributors. The mean cost per control was $46,382 with inpatient hospitalizations, physician services and oral medications the top three cost contributors. For CLL patients, year 1 after diagnosis had the highest mean cost ($31,928) followed by year 2 ($17,665). By calendar year, 2016 and 2017 had the highest mean costs. Real world costs for CLL patients may have been increasing over time. Exploring whether investment in new novel agents resulted in improved survival would be key.

Factors Associated With Chemoradiation Therapy Interruption and Noncompletion Among Patients With Squamous Cell Anal Carcinoma

Definitive chemoradiation for anal cancer is effective but may be associated with toxic effects, and some patients may not be able to complete the planned treatment. Identifying factors associated with treatment interruption and noncompletion is important to target quality improvement efforts. To identify rates of chemoradiation treatment interruption or noncompletion and factors associated with this among patients with anal cancer treated in routine clinical practice. In this population-based, retrospective cohort study, the Ontario Cancer Registry was used to identify all incident cases of squamous cell anal cancer treated with curative-intent radiation from 2007 to 2015 in Ontario, Canada. Final analysis of data was performed on August 9, 2019. Curative-intent radiation therapy. Treatment interruption was defined as more than 7 days between fractions of radiation. Radiation completion was defined as receipt of 45 Gy or more and 25 fractions of radiation. Chemoradiation completion was defined as radiation completion and 2 doses of combination chemotherapy. Associations between patient factors and treatment interruption and noncompletion were estimated with log-binomial models. Cox proportional hazard models were used to estimate the association of treatment interruption or noncompletion with all-cause death, cancer-specific death, and the combined outcome of colostomy or death. Overall, 1125 patients with stage I-III anal cancer were treated with curative-intent radiation. Treatment interruptions occurred in 262 (23%). Radiation and chemoradiation noncompletion occurred in 199 (18%) and 280 (25%), respectively. No associations were found to correlate with an increased risk of treatment interruption. Patients older than 70 years were less likely to complete chemoradiation (risk ratio [RR], 0.60; 95% CI, 0.52-0.70), compared with those younger than 50 years. Patients with a higher number of comorbidities were also less likely to complete chemoradiation (RR, 0.70; 95% CI, 0.51-0.95). Patients who did not complete chemoradiation had a higher risk of requiring salvage abdominoperineal resection (RR, 1.54; 95% CI, 1.03, 2.31), overall death (hazard ratio [HR], 1.54; 95% CI, 1.23-1.92), cancer-specific death (HR, 1.59; 95% CI, 1.14-2.22), and colostomy or death (HR, 1.80; 95% CI: 1.10-2.93). Treatment interruptions longer than 7 days were not associated with death. Many patients undergoing curative-intent chemoradiation for anal cancer experienced treatment interruption or noncompletion. Quality improvement initiatives to optimize treatment continuity and completion are needed.

Real-world comparative effectiveness of second-line ipilimumab for metastatic melanoma: a population-based cohort study in Ontario, Canada

BackgroundFor novel cancer treatments, effectiveness in clinical practice is not always aligned with clinical efficacy results. As such it is important to understand a treatment’s real-world effectiveness. We examined real-world population-based comparative effectiveness of second-line ipilimumab versus non-ipilimumab treatments (chemotherapy or targeted treatments).MethodsWe used a cohort of melanoma patients receiving systemic treatment for advanced disease since April 2005 from Ontario, Canada. Patients were identified from provincial drug databases and the Ontario Cancer Registry who received second-line ipilimumab from 2012 to 2015 (treated) or second-line non-ipilimumab treatment prior to 2012 (historical controls). Historical controls were chosen, to permit the most direct comparison to pivotal trial findings. The cohort was linked to administrative databases to identify baseline characteristics and outcomes. Kaplan-Meier curves and multivariable Cox regression models were used to assess overall survival (OS). Observed potential confounders were adjusted for using inverse probability of treatment weighting (IPTW).ResultsWe identified 329 patients with metastatic melanoma (MM) who had received second-line treatments (189 treated; 140 controls). Patients receiving second-line ipilimumab were older (61.7 years vs 55.2 years) compared to historical controls. Median OS were 6.9 (95% CI: 5.4–8.3) and 4.95 (4.3–6.0) months for ipilimumab and controls, respectively. The crude 1-year, 2-year, and 3-year OS probabilities were 34.3% (27–41%), 20.6% (15–27%), and 15.2% (9.6–21%) for ipilimumab and 17.1% (11–23%), 7.1% (2.9–11%), and 4.7% (1.2–8.2%) for controls. Ipilimumab was associated with improved OS (IPTW HR = 0.62; 95% CI: 0.49–0.78; p < 0.0001).ConclusionsThis real-world analysis suggests second-line ipilimumab is associated with an improvement in OS for MM patients in routine practice.