British Columbia Cancer Registry Research Articles

Obstructive sleep apnea severity, circulating biomarkers, and cancer risk.

To determine whether obstructive sleep apnea (OSA) severity and/or biomarkers of inflammation/angiogenesis are associated with incident cancer in this clinical cohort. Consenting adult patients at the University of British Columbia Hospital between 2003 and 2014 completed a questionnaire about their medical history and sleep habits prior to undergoing a polysomnogram. Blood samples were collected the morning after polysomnography and processed for biomarkers of inflammation and angiogenesis. The clinical, polysomnography, and biomarker data were linked to the British Columbia Cancer Registry to ascertain incident cancer diagnoses. Cox proportional hazard regression was used to assess the association between OSA severity and biomarker concentrations with cancer risk. A total of 1,990 patients were included in the analysis with a mean follow-up time of 12.8 years; 181 of them (9.1%) developed cancer after polysomnography. OSA severity was significantly associated with cancer risk after controlling for relevant covariates (hazard ratio = 1.08 per 10 events/h apnea-hypopnea index increase, confidence interval = 1.02-1.15, P = .015). In an exploratory analysis, 2 biomarkers were significantly associated with an increased cancer risk after controlling for relevant covariates (hazard ratio per interquartile range pg/mL increase of endostatin = 1.45, confidence interval = 1.12-1.87, P = .01 and hazard ratio for interquartile range pg/mL increase of vascular cell adhesion molecule-1 = 1.48, confidence interval = 1.04-2.11, P = .03, respectively). OSA severity was an independent risk factor for cancer. Furthermore, 2 circulating markers were significantly associated with cancer risk. If these preliminary findings can be reproduced in other cohorts, biomarkers could potentially be used to prognosticate patients with OSA with respect to cancer risk. Hirsch Allen AJ, Kendzerska T, Bhatti P, etal. Obstructive sleep apnea severity, circulating biomarkers, and cancer risk. J Clin Sleep Med. 2024;20(9):1415-1422.

Age-Specific Trends of Invasive Cervical Cancer Incidence in British Columbia, Canada, 1971-2017.

This study examined invasive cervical cancer (ICC) incidence trends in British Columbia (BC) by age and stage-at-diagnosis relative to World Health Organization ICC elimination targets (4 per 100,000 persons). Incident ICC cases (1971-2017) were obtained from the BC Cancer Registry. Annual age-standardized incidence rates (ASIRs) per 100,000 persons were generated using the direct method. ASIRs were examined among all ages 15+ years and eight age groups using Joinpoint Regression with the Canadian 2011 standard population. Standardized rate ratios (SRRs) compared stage II-IV (late) versus stage I (early) ASIRs by age (2010-2017). ICC ASIRs did not reach the elimination target. ASIRs declined from 18.88 to 7.08 per 100,000 persons (1971-2017). Stronger declines were observed among ages 45+ years, with the largest decline among ages 70-79 years (AAPC = -3.2%, 95% CI = -3.9% to -2.6%). Among ages 25-69 years, varying levels of attenuation in declining trends and stabilization were observed since the 1980s. SRRs indicated higher rates of late-stage ICC among ages 55+ years (SRR-55-69 years = 1.34, 95% CI = 1.08-1.71). Overall, ICC incidence declined in BC since 1971 but did not reach the elimination target. The pace of decline varied across age groups and increased with age. Continued efforts are needed to progress cervical cancer elimination among all age groups.

Small area disease mapping of cancer incidence in British Columbia using Bayesian spatial models and the smallareamapp R Package.

There is an increasing interest in small area analyses in cancer surveillance; however, technical capacity is limited and accessible analytical approaches remain to be determined. This study demonstrates an accessible approach for small area cancer risk estimation using Bayesian hierarchical models and data visualization through the smallareamapp R package. Incident lung (N = 26,448), female breast (N = 28,466), cervical (N = 1,478), and colorectal (N = 25,457) cancers diagnosed among British Columbia (BC) residents between 2011 and 2018 were obtained from the BC Cancer Registry. Indirect age-standardization was used to derive age-adjusted expected counts and standardized incidence ratios (SIRs) relative to provincial rates. Moran's I was used to assess the strength and direction of spatial autocorrelation. A modified Besag, York and Mollie model (BYM2) was used for model incidence counts to calculate posterior median relative risks (RR) by Community Health Service Areas (CHSA; N = 218), adjusting for spatial dependencies. Integrated Nested Laplace Approximation (INLA) was used for Bayesian model implementation. Areas with exceedance probabilities (above a threshold RR = 1.1) greater or equal to 80% were considered to have an elevated risk. The posterior median and 95% credible intervals (CrI) for the spatially structured effect were reported. Predictive posterior checks were conducted through predictive integral transformation values and observed versus fitted values. The proportion of variance in the RR explained by a spatial effect ranged from 4.4% (male colorectal) to 19.2% (female breast). Lung cancer showed the greatest number of CHSAs with elevated risk (Nwomen = 50/218, Nmen = 44/218), representing 2357 total excess cases. The largest lung cancer RRs were 1.67 (95% CrI = 1.06-2.50; exceedance probability = 96%; cases = 13) among women and 2.49 (95% CrI = 2.14-2.88; exceedance probability = 100%; cases = 174) among men. Areas with small population sizes and extreme SIRs were generally smoothed towards the null (RR = 1.0). We present a ready-to-use approach for small area cancer risk estimation and disease mapping using BYM2 and exceedance probabilities. We developed the smallareamapp R package, which provides a user-friendly interface through an R-Shiny application, for epidemiologists and surveillance experts to examine geographic variation in risk. These methods and tools can be used to estimate risk, generate hypotheses, and examine ecologic associations while adjusting for spatial dependency.

The BC Generations Project as a tumor tissue resource for cancer research.

e22512 Background: Population-based cohort studies can be a resource for tumor specimens, annotated with demographic, lifestyle, and health history data, that support innovative studies of cancer. These data are increasingly important for clinical studies as they can be useful predictors of prognosis and treatment response (1,2) Our aim was to establish and test a process for accessing tumor samples, held at pathology laboratories around British Columbia (BC), for participants of the BC Generations Project (BCGP). Methods: Through the BC Cancer Registry, pathology reports linked with each BCGP solid cancer case were manually reviewed to extract information (e.g., location of pathology laboratory, sample type (i.e., biopsy or excision), and accession number) needed to request tumor samples. From among the successfully abstracted pathology reports, we randomly selected a total of 200 breast, lung, bladder, and pancreatic cancer cases for which to attempt retrieval of formalin-fixed, paraffin-embedded (FFPE) blocks from pathology laboratories across BC. We selected these cancer sites as they capture a representative range of cancer characteristics (e.g., tumor sizes) with which to evaluate the effectiveness of our access process. Results: We successfully identified pathology reports for 1,100 (93%) of the 1,180 incident solid cancer cases diagnosed in BCGP as of 2019 and we successfully retrieved 183 (92%) of the 200 FFPE that we requested from pathology laboratories. No important differences in retrieval rates by cancer site, sample location (Greater Vancouver vs. Outside Greater Vancouver), sample type (biopsy vs. excision) or year of diagnosis were identified. Conclusions: This linkage exercise demonstrates the tremendous potential for BCGP to serve as a population-based resource for highly annotated tumor tissue samples. A text mining solution recently implemented by the Registry will allow us to automate the process for data abstraction and should capture pathology reports for 100% of all newly diagnosed BCGP cancer cases moving forward. This will further enhance the utility of BCGP as a high-quality tumor tissue research resource.

The BC Generations Project as a Tumor Tissue Resource for Cancer Research.

Population-based cohort studies can be a resource for tumor specimens, annotated with demographic, lifestyle, and health history data, that support innovative studies of cancer. Our aim was to establish and test a process for accessing tumor samples, held at pathology laboratories around British Columbia (BC), for participants of the BC Generations Project (BCGP). Through the BC Cancer Registry, we identified pathology reports for 1100 (93%) of the 1180 incident solid cancer cases diagnosed in BCGP as of 2019. Using manually abstracted data from the reports, we successfully retrieved 183 (92%) of the 200 formalin-fixed, paraffin-embedded (FFPE) blocks (breast, lung, bladder, and pancreas cancer cases) that we requested from pathology laboratories. No important differences in retrieval rates by cancer site, sample location (Greater Vancouver vs. Outside Greater Vancouver), sample type (biopsy vs. excision) or year of diagnosis were identified. A text mining solution recently implemented by the Registry will allow us to automate the process for data abstraction and should capture pathology reports for 100% of all newly diagnosed BCGP cancer cases moving forward. This will further enhance the utility of BCGP as a high-quality tumor tissue research resource.

Outcomes From Opportunistic Salpingectomy for Ovarian Cancer Prevention

Opportunistic salpingectomy (OS), which is the removal of fallopian tubes during hysterectomy or instead of tubal ligation without removal of ovaries, is recommended to prevent ovarian cancer, particularly serous ovarian cancer. However, the effectiveness of OS is still undetermined. To examine observed vs expected rates of ovarian cancer among individuals who have undergone OS. This is a population-based, retrospective cohort study of all individuals in British Columbia, Canada, who underwent OS or a control surgery (hysterectomy alone or tubal ligation) between 2008 and 2017, with follow-up until December 31, 2017. Those with any gynecological cancer diagnosed before or within 6 months of their procedure were excluded. Data analysis was performed from April to August 2021. Removal of both fallopian tubes at the time of hysterectomy or instead of tubal ligation while leaving ovaries intact. An ovarian cancer diagnosis listed in the British Columbia Cancer Registry. Age-specific rates of epithelial and serous ovarian cancer in the control group were combined with the specific follow-up time in the OS group to calculate expected numbers (and 95% CIs) of ovarian cancers in the OS group. These were compared with observed numbers. Age-adjusted expected and observed numbers of breast and colorectal cancers were also examined in the OS group. There were 25 889 individuals who underwent OS (mean [SD] age, 40.2 [7.1] years; median [IQR] follow-up, 3.2 [1.6-5.1] years) and 32 080 who underwent hysterectomy alone or tubal ligation (mean [SD] age, 38.2 [7.9] years; median [IQR] follow-up, 7.3 [4.6-8.7] years). There were no serous ovarian cancers in the OS group and 5 or fewer epithelial ovarian cancers. The age-adjusted expected number was 5.27 (95% CI, 1.78-19.29) serous cancers and 8.68 (95% CI, 3.36-26.58) epithelial ovarian cancers. Age-adjusted expected vs observed numbers of breast cancers (22.1 expected vs 23 observed) and colorectal cancers (9.35 expected vs 8 observed) were not significantly different. In this cohort study, the OS group had significantly fewer serous and epithelial ovarian cancers than were expected according to the rate at which they arose in the control group. These findings suggest that OS is associated with reduced ovarian cancer risk.

Prognostic value and cost benefit of HPV testing for oropharyngeal cancer patients.

High-risk human papillomavirus (HR-HPV) can cause oropharyngeal squamous cell carcinoma (OpSCC). The revised 8th edition of the AJCC Staging Manual now stages OpSCC by incorporating p16 immunohistochemistry (IHC), the surrogate marker for HPV status. This study assessed the prognostic values of p16 and HPV markers. We identified 244 OpSCC patients diagnosed between 2000 and 2008 from the British Columbia Cancer Registry with enough tissue to conduct experiments. Formalin-fixed, paraffin-embedded tissue sections were stained for p16 IHC, RNA in situ hybridization (ISH) HPV 16 and 18, and DNA ISH HR-HPV. Electronic charts were reviewed to collect clinical and outcome data. Combined positive RNA and/or DNA ISH was used to denote HPV status. Human papillomavirus was positive among 77.9% of samples. Using HPV as the benchmark, p16 IHC had high sensitivity (90.5%), but low specificity (68.5%). Distinct subgroups of patients were identified by sequential separation of p16 then HPV status. Among both p16-positive and p16-negative groups, HPV-positive patients were younger, more males, and had better clinical outcomes, especially 5-year overall survival. We further evaluated the technical costs associated with HPV testing. Human papillomavirus is more prognostic than p16 for OpSCC. Clinical laboratories can adopt HPV RNA ISH for routine analysis.

Oral Fludarabine and Intravenous Rituximab (FR) for Chronic Lymphocytic Leukemia (CLL): Long Term Outcomes and Secondary Malignancies in 673 Patients Treated in British Columbia (BC)

Oral Fludarabine and Intravenous Rituximab (FR) for Chronic Lymphocytic Leukemia (CLL): Long Term Outcomes and Secondary Malignancies in 673 Patients Treated in British Columbia (BC)

Performance of the Fecal Immunochemical Test in Patients With a Family History of Colorectal Cancer.

ObjectiveTo assess the performance of a fecal immunochemical test (FIT) among participants of a population-based colorectal cancer (CRC) screening program with one or more first-degree relatives (FDR) with CRC.MethodsAsymptomatic 50 to 74 years olds with a FDR diagnosed with CRC, enrolled in a colon screening program completed FIT (two samples, cut-off 20 µg Hemoglobin/gram feces) and underwent colonoscopy. FIT-interval CRCs were identified from the British Columbia cancer registry. Logistic regression analysis was used to identify variables associated with the detection of CRC and high-risk polyps (nonmalignant findings that required a 3-year surveillance colonoscopy) in those patients undergoing FIT and colonoscopy.ResultsOf the 1387 participants with a FDR with CRC, 1244 completed FIT with a positivity rate of 10.8%, 52 declined FIT but underwent colonoscopy and 90 declined screening. Seven CRCs were identified: six in patients with a positive FIT, one in a patient who only had colonoscopy. No CRCs were found in patients with a negative FIT. The positive and negative predictive values of FIT in the detection of CRC were 4.8% and 100%, respectively. On multivariate logistic regression, positive FIT, and not type of family history, was the only variable associated with detection of CRC or high-risk polyps. At 2-year follow-up, there was no FIT interval cancer detected in the study cohort.ConclusionFIT is more strongly associated with high-risk findings on colonoscopy than type of family history. FIT may be an alternative screening strategy to colonoscopy in individuals with a single FDR with CRC.

Perioperative chemotherapy alone versus preoperative chemoradiotherapy for locally advanced distal esophageal and gastroesophageal junction cancer: A 10-year review of the British Columbia (BC) Cancer Registry.

4028 Background: The optimal treatment strategy for resectable cancer of the distal esophagus (ESOPH) and gastroesophageal junction (GEJ) remains controversial. This study evaluates patterns of practice in BC, rates of complete surgical resection, and survival outcomes of patients treated with perioperative chemotherapy alone (CA), per MAGIC or FLOT4 protocol, versus preoperative chemoradiotherapy (CRT), per CROSS protocol. Methods: We undertook a provincial analysis of initially resectable, locally advanced, cancer of the ESOPH and/or GEJ who underwent surgery in BC, from 2008 to 2018. Baseline patient, tumor, treatment, and clinical outcome data were collected from the BC Cancer Registry. Kaplan-Meier survival and multivariate regression analyses were conducted. Results: Among 575 patients, 468 underwent surgery and were included (Table). More surgeries were aborted intraoperatively in the CA cohort compared to CRT (12% vs 2%, p<0.001). There was no difference in age, sex, or ECOG performance status among the cohorts, and 83% were adenocarcinoma. While 82% of ESOPH involving GEJ (N = 251, 54%) is treated with CRT, only 53% of GEJ alone (N=217, 46%) is treated with CRT (p<0.001). CRT is associated with a higher rate of complete or partial pathologic response compared to CA (59% vs 39%, p=0.002). R0 resection rate was 90% and 94% in the CA and CRT cohort, respectively (p=0.383). There is no statistically significant difference in overall survival, with medians of 29.6 and 26.0 months for patients treated with CA and CRT, respectively (p=0.723). Cancer-specific survival is also not significantly different (p=0.565). In the CA cohort, 37% of patients complete all 8 cycles of FLOT and 52% of patients complete all 6 cycles of MAGIC (p=0.396). Conclusions: Patients treated with CRT have higher rates of complete resection and pathologic response, but their survival is not significantly different compared to those treated with CA. [Table: see text]

Older Adults with Acute Myeloid Leukemia in Rural Areas Are Less Likely to Receive Azacitidine with Worsened Overall Survival

IntroductionAcute myeloid leukemia (AML) in older adults is a challenging clinical problem with a poor prognosis. Hypomethylating agents, such as azacitidine, improve survival in this population. (Oran B, Haematologica 2012) These treatments can be challenging to deliver, particularly in patients far from tertiary care centres. We examined whether residence outside of a major metropolitan area impacted referral patterns, treatments, and outcomes in a population-based cohort of AML patients over age 60 in British Columbia (BC), Canada.MethodsPatients with ICD-10 diagnoses of AML were identified from the population based BC Cancer registry and BC Cancer pharmacy database. Diagnoses between 2010 and 2016 were included. Exclusion criteria included diagnosis age less than 60 years, any treatment outside BC, or APL. The diagnosis of AML was verified by chart review. Azacitidine was available at our institution in 2010, and is used primarily for patients with bone marrow blast counts below 30%.Patients were defined as having a hematologist/oncologist assessment if a provider with these credentials was listed in notes or pathology reports. Patients were defined as having received a treatment if it was dispensed at least once, with a date after AML diagnosis. Patients were defined as urban if they had a mailing address in a center of >/= 100,000 people, per the Statistics Canada definition, and rural if they had a mailing address elsewhere. Urban residences included greater Vancouver, Victoria and Kelowna, which comprise 71.5% of the population. (Statistics Canada, 2016 census) Between group differences were assessed by 2-tailed t-test or chi-square tests. Overall survival (OS) was assessed by Kaplan-Meier, with a log-rank test, and Cox regression. A p < 0.05 was significant.ResultsA total of 879 patients over age 60 with AML, excluding APL, were identified. Of these, 525 (60%) resided in urban areas vs 354 (40%) residing in rural areas. These groups were similar for median age at diagnosis (urban 75.9 years, rural 74.3 years, p = 0.067), adverse cytogenetic profile (urban 56%, rural 44%, p = 0.356), NPM1 positivity (urban 69%, rural 31%, p = 0.101) and FLT3 positivity (urban 76%, rural 24%, p = 0.052). Rural residents were less likely to have a documented hematologist/oncologist assessment (urban 84%, rural 65%, p < 0.001).Few patients overall received induction chemotherapy (151, 17%), with no difference between rural and urban residency (p = 0.524). Similarly, few patients underwent hematopoietic stem cell transplantation (38, 4%), with no difference with place of residence (p = 1.000). Median OS for patients treated with induction chemotherapy was 11.0 months (95% CI 9.0 - 13.1 mo). Median OS for patients treated with subcutaneous (SC) azacitidine was 7.1 months (95% CI 4.8 - 9.5 mo) vs 4.7 months (95% CI 3.3 - 6.1 mo) with SC cytarabine. With best supportive care, the median OS was 1.7 months (95% CI 1.5 - 1.9 mo). Median follow-up was 43.7 months (95% CI 39.2 - 48.2 mo), with 706 (97%) of patients deceased at last follow-up.Amongst the 728 patients who did not receive induction chemotherapy, 82 (11%) received SC cytarabine and 127 (17%) received SC azacitidine. Place of residence did not impact whether patients received SC cytarabine (urban 10%, rural 13%, p = 0.285). Rural residents were, however, less likely to receive SC azacitidine (urban 21%, rural 12%, p = 0.002). In patients not undergoing induction, rural residents had a worse OS by Kaplan-Meier analysis (p = 0.021), with a hazard ratio of 1.2 (95% CI 1.026 - 1.387, p = 0.022) on univariate Cox regression.ConclusionsOlder adults with a diagnosis of AML who reside in rural areas of BC are less likely to have a documented hematologist/oncologist assessment, and are less likely to receive SC azacitidine. This group also has a worsened OS, though the effect size is modest. There was no difference in rates of treatment with potentially curative regimens, although this approach applied to a minority of patients.We hypothesize that this difference may be partially due to the travel burdens placed on rural patients who receive SC azacitidine, which must be administered in a healthcare facility, unlike SC cytarabine. Less access to supportive care in rural areas is also likely a contributing factor. Policymakers should direct additional resources for rural oncologic healthcare delivery, and the importance of low burden drug formulations is AML should be emphasized. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Adjuvant Chemoradiation Therapy for Clear Cell Carcinoma of the Ovary: A Population Based Study of Pelvic Versus Whole Abdominal Radiation Therapy

A previous population based study from our institute reported a large Progression Free Survival (PFS) benefit for a subset of patients with Clear Cell Carcinomas of the Ovary (CCCO), with the use of adjuvant chemotherapy (CT) and Radiation Therapy (RT) as compared to CT alone. As there are concerns of significant toxicities with the use of whole abdominal (WA) RT, in the recent years our group has used only pelvic RT (PRT). This presents a unique opportunity to evaluate the adjuvant use of these two RT modalities. Consecutive patients with Stage I or II CCCO diagnosed in British Columbia (BC) between 1984 and 2014 (n = 401) were identified from the BC Cancer Registry and the Cheryl Brown Ovarian Cancer Database. A total of 338 patients who received radical intent adjuvant treatment in BC, were included for chart review. Our current treatment protocol does not call for adjuvant RT in Stage IA/B disease or stage IC due to capsular rupture (ICr), and these patients were excluded for the final analysis of adjuvant RT. About 57.5% (n = 88) of the remaining patients received CT+RT, while 42.5% (n = 65) received CT alone. Thirty-six patients, in the more recent years, received PRT while a total of 52 had WART. After a median follow-up of 178 months, 127 patients had died, and the 10 year Overall Survival (OS) for the whole group was 70.3% (IA/B = 75.5%, IC rupture only (ICr) = 74.7%, IC other (ICo) = 56.9%, and II = 51.3%). For patients with Stage ICo and II disease the 5-yr PFS for adjuvant CT+RT vs. CT alone was 61.9% vs. 45.3% (P = 0.023). For patients treated with CT+RT, the 5yr-PFs was 68.0% for WART vs. 51.5% for PRT (P = 0.040). This difference retained statistical significance on multivariate analysis (HR = 2.35, 95% CI: 1.15-4.83, P = 0.020). There was no statistically significant OS difference for either comparison. For a subset of patients with CCCO (ICo and Stage II), our updated provincial data continues to document a significant PFS benefit with the use of CT+RT as compared to CT alone. We report inferior PFS rates with the use of PRT, and this cannot be assumed to be equivalent to WART.

Prognostic significance of peritoneal cytology in low-intermediate risk endometrial cancer

ObjectivesThere is uncertainty surrounding the prognostic value and clinical utility of peritoneal cytology in endometrial cancer. Our primary objective was to determine if positive cytology is associated with disease-free and overall survival in women treated surgically for endometrial cancer, specifically those with low or intermediate risk disease. MethodsThis was a retrospective population-based cohort study of British Columbia Cancer Registry patients who underwent surgery with peritoneal washings for endometrioid-type endometrial cancer from 2003 to 2009. Low risk was defined as Stage IA grade 1 or 2, and intermediate risk defined as Stage IA grade 3, or Stage IB grade 1 or 2 tumours. Five-year overall and disease free-survival were assessed using Kaplan-Meier estimation. Potential covariates including peritoneal cytology, grade, depth of myometrial invasion, LVSI, age, and adjuvant therapy were evaluated in a multivariable Cox proportional hazards model. ResultsThere were 849 patients, of whom 370 (43.6%) and 298 (35.1%) had low- and intermediate-risk disease, respectively. Overall, forty-nine (5.8%) patients had positive cytology, including 6 and 9 with low- and intermediate-risk respectively (2.2% within low and intermediate risk combined). Positive peritoneal cytology was not significantly associated with disease-free (HR 3.17, 95% CI 0.91–11.03) or overall survival (HR 1.33, 95% CI 0.47–3.76) in low and intermediate risk patients. Only age and extensive LVSI were associated with lower overall survival (HR 1.10, 95% CI 1.08–1.13, and HR 2.39, 95% CI 1.02–5.61, respectively). ConclusionsPositive peritoneal cytology was not associated with disease-free and overall survival in women with low and intermediate risk endometrial cancer.

Impact of modern treatment strategies on second cancer incidence for patients with early stage seminoma: A population-based study in British Columbia.

423 Background: The purpose of this study is to examine the incidence of Second Cancers (SC) in patients with Stage I or II Seminoma treated in British Columbia (BC), and compare rates between patients managed with Radiation Therapy, Chemotherapy, or Active Surveillance. Methods: Consecutive patients with Stage I or II Seminoma (n = 1549, 21167 person years) diagnosed in British Columbia between 1984 and 2013 were identified from the BC Cancer Registry and included in this study. Patients were managed with Radiation Therapy (RT; n = 663), Chemotherapy (CT; n = 259) or Active Surveillance (AS; n = 624). Data was extracted from the registry and verified by individual patient chart review. Cumulative incidence rates were computed using competing risk analysis. Age and Sex Standardized Incidence Ratios (ASIR) were calculated (compared to the Canadian population). Results: After a median follow-up of 14 years (RT group: 21.5yrs, CT group: 10yrs, AS group: 8yrs), the 15 year Overall Survival was 91.4%. Only 15 patients died from progressive Seminoma, while 46 died from second cancers. A total of 115 patients developed SCs, and the cumulative incidence (CI) of SC, at 15 years, was: 5.9% for patients who received RT, 8.6% for those who had CT, and 4.9% for patients managed with AS. The higher CI for patients treated with CT, versus RT, was not statistically significant (p = 0.08). The ASIR for RT, CT and AS groups were 1.31 (95% Confidence Intervals: 0.92- 1.86), 2.57 (1.07- 6.15; p = 0.03), and 1.38 (0.75- 2.54), respectively. Patients who underwent treatment at ages 30-44yr and 45-59yr had a significantly higher ASIRs of 4.33 (2.1- 8.9; p &lt; 0.001) and 1.8 (1.16- 2.8; p = 0.008). ASIR was not significantly different when stratified by radiation dose, field types, or year of diagnosis. Conclusions: We found no statistically significant difference in the Cumulative Incidence of Second Cancers for patients treated with Radiation Therapy versus Chemotherapy in our patient population. Longer follow-up for the CT group is required to confirm trends evident in our analysis.

Total and cancer-attributable phase-based costs for childhood cancer care: A population-based study in British Columbia, Canada.

11 Background: Childhood cancer presents unique issues regarding treatment, late effects, and long-term survival, but few studies have reported costs. Childhood cancer-specific costs are useful for economic evaluation and planning care. This study estimates total and cancer-attributable (net) medical costs for a population-based childhood cancer cohort in British Columbia, Canada, by phase of care. Methods: Patients diagnosed with cancer at ages 91 days to 14 years between 1995-2009 were identified from the British Columbia Cancer Registry, and followed to December 31, 2010. Data were linked with clinical and provincial administrative healthcare databases covering all medically-necessary costs. Total resource-specific costs (Canadian $ 2012) were estimated overall and for patients with leukemia, lymphoma, central nervous system (CNS), and “other” cancers. Net costs were calculated by subtracting healthcare costs for propensity-score-matched provincial samples of children without cancer from cancer patient costs. Results: Of the 1,440 cases, 33% had leukemia, with 23% CNS tumours, 10% lymphoma, 34% other cancers; 93% survived &gt;=1 year. Overall pre-diagnosis mean costs per patient were $4,633, of which $4,555 was attributable to the cancer. Overall initial (first-year) mean costs were $97,780 ($97,254). Overall continuing phase mean costs were $12,441 ($12,006). Overall final year of life mean costs were $284,201 ($283,652). Cancer types with highest costs were CNS (pre-diagnosis), leukemia (first-year), “other” cancers (continuing), and lymphoma (end-of-life). Virtually all inpatient hospitalizations were cancer-related, representing ~41% of pre-diagnosis, ~71% of first-year, ~57% of continuing, and ~73% of end-of-life costs. Conclusions: Management of childhood cancer is costly, and is higher than for adolescent cancer in all phases of care, reflecting greater morbidity and treatment complexity. Hospitalizations were the largest driver of costs in all post-diagnosis phases of care. Costs in the continuing phase, including surveillance and care for late effects, were 13% of first-year phase costs.

Total and cancer-attributable phase-based costs for adolescent cancer care: A population–based study in British Columbia, Canada.

12 Background: Cancer among adolescents presents unique issues regarding diagnosis, treatment, late effects, and survival; but little is known about their healthcare costs, which are useful for economic evaluations and planning care. This study estimates total and cancer-attributable (net) medical costs for a population-based adolescent cancer cohort in British Columbia, Canada, by phase of care. Methods: Patients diagnosed with cancer aged 15 to 19 years from 1995 to 2009 were identified from the British Columbia Cancer Registry, and followed to December 31st2010. Data were linked with clinical and provincial administrative healthcare databases covering all medically-necessary costs. Total resource-specific costs (Canadian $ 2012) by phase of care were estimated for all patients and specific common cancers. Net costs were calculated by subtracting healthcare costs for propensity-score-matched provincial samples of adolescents without cancer from cancer patient costs. Results: Of the 750 cases, approximately 26% had lymphoma, 17% germ cell, 14% bone and soft tissue sarcomas, 12% central nervous system (CNS), and 11% leukemia; 94% survived &gt; = 1 year. Total mean pre-diagnosis costs per patient were $3657, of which $3554 was attributable to the cancer. First-year mean costs were $60,531 ($59,826). Continuing phase mean costs were $8,413 ($7,708). Final year of life mean costs were $224,243 ($221,018). Cancer types with highest costs were CNS (pre-diagnosis), leukemia (first-year); bone and soft tissue (continuing), and leukemia (end-of-life). Virtually all inpatient hospitalizations were cancer-related, representing ~40% of pre-diagnosis, ~62% of first-year, ~56%of continuing, and ~72%of end-of-life costs respectively. Conclusions: Management of adolescent cancer is costly, but is lower than for childhood cancer in all phases of care. Total costs, cancer-attributable costs, and inpatient activity were highest in the end-of-life period. Hospitalizations were the largest driver of costs in all post-diagnosis phases of care. Costs in the continuing phase, including surveillance and care for late effects, were 14% of first-year phase costs.

Cervical cancer incidence in British Columbia: Predicting effects of changes from Pap to human papillomavirus screening and of changes in screening participation.

Objectives To estimate the impact of increased participation in screening, and of the proposed change from Pap to human papillomavirus screening on the incidence of cervical cancer in British Columbia. Methods For invasive cervical cancer cases diagnosed in British Columbia between 2002 and 2011, data were extracted on age and cancer morphology from the British Columbia Cancer Registry, and Pap screening history was obtained from the British Columbia Cervical Cancer Screening Program database. Only screening performed two to seven years prior to diagnosis was assumed to reduce subsequent risk of cancer. Results from randomized trials of human papillomavirus versus cytology screening and population based estimates of cytology screening were used to estimate the effect of a change in screening test and increases in participation. Results Between 2002 and 2011, there were 1663 cases of cervical cancer reported; 660 (367 squamous and 293 non-squamous) were eligible and screened two to seven years prior to diagnosis. The predicted reduction by changing to human papillomavirus screening was 363 (95% confidence interval = 124-496) representing 22% of all cases. If 50% of subjects not screened two to seven years prior had undergone Pap screening, it is projected that a further 268 cases (16%) could have been prevented; if they had undergone human papillomavirus screening, a further 365 cases (22%) could have been prevented. Conclusions For many women who develop cervical cancer, primary human papillomavirus testing could have substantially reduced their cancer risk. Human papillomavirus rather than Pap testing would further increase the gains from any increases in population screening participation.

Organochlorine levels in plasma and risk of multiple myeloma

Introduction: Multiple myeloma (MM) is a relatively rare cancer and little is known about its causes. Plasma levels of polychlorinated biphenyls (PCB) and organochlorine pesticides have been associated with increased risks of non-Hodgkin lymphoma and cutaneous malignant melanoma. There is very limited information regarding the association between these chemicals and the risk of MM, however, there is some evidence of an increased risk of MM in farmers related to exposure to organochlorine insecticides. The aim of this study is to investigate the association between plasma organochlorine levels and the risk of MM. Methods: A population-based case-control study was conducted in British Columbia (BC), Canada between 2009 and 2013. Cases were identified and recruited through the BC Cancer Registry, while age-group and sex-matched controls were randomly selected from the Consolidation File of the British Columbia Ministry of Health which contains identifying information on all participants in the population-based health insurance plan. 334 cases and 331 controls completed a computer-assisted telephone interview about environmental, lifestyle and medical factors, and provided a blood sample from which lipid adjusted levels of 14 congeners of PCB and 11 pesticides or pesticide metabolites were measured at the Centre de Toxicologie du Quebec. Initial analysis compared median analyte levels between cases and controls. Significance was assessed by the Mann-Whitney test. Results: MM cases had significantly higher levels of six PCB congeners and six pesticide analytes compared to controls. Conclusions: These initial suggest the possibility of an increased risk of MM with increased exposure to organochlorines. In order to confirm the associations, logistic regression models will be used to estimate the association between and the risk of MM adjusted for potential confounding factors including age, sex, education, BMI and weight loss.

Socio-economic deprivation: a significant determinant affecting stage of oral cancer diagnosis and survival.

BackgroundMany factors contribute to socioeconomic status (SES), yet in most survival studies only income is used as a measure for determining SES. We used a complex, composite, census-based metric for socioeconomic deprivation to better distinguish individuals with lower SES and assess its impact on survival and staging trends of oral cancers.MethodsOropharyngeal (OPC) and oral cavity cancer (OCC) cases were identified from the British Columbia cancer registry between 1981–2009 and placed into affluent and deprived neighborhoods using postal codes linked to VANDIX (a composite SES index based on 7 census variables encompassing income, housing, family structure, education, and employment). Stage and cancer-specific survival rates were examined by sex, SES, and time period.ResultsApproximately 50 % of OPC and OCC cases of both sexes resided in SES deprived neighborhoods. Numbers of cases have increased in recent years for all but OCC in men. The deprivation gap in survival between affluent and deprived neighborhoods widened in recent years for OPC and OCC in men, while decreasing for OPC and increasing slightly for OCC in women. Greater proportions of OCC cases were diagnosed at later stage disease for both sexes residing in deprived neighborhoods, a trend not seen for OPC.ConclusionSES remains a significant independent determinant of survival for both OPC and OCC when using a composite metric for SES. OPC survival rates among men have improved, albeit at slower rates in deprived communities. OCC screening programs need to be targeted towards SES-deprived neighborhoods where greater proportions of cases were diagnosed at a later stage and survival rates have significantly worsened in both sexes.

Late mortality, secondary malignancy and hospitalisation in teenage and young adult survivors of Hodgkin lymphoma: report of the Childhood/Adolescent/Young Adult Cancer Survivors Research Program and the BC Cancer Agency Centre for Lymphoid Cancer

Late complications affecting Hodgkin lymphoma (HL) survivors are well described in paediatric and adult-based publications. This study determined the late morbidity and mortality risk for 442 teenage and young adult (TYAs) 5-year HL survivors, diagnosed at 15-24 years of age between 1970 and 1999, identified from the British Columbia Cancer Registry. Treatment details were abstracted from charts. Survivors and a matched comparison cohort were linked to provincial administrative health datasets until December 2006 and regression analysis was performed, providing risk ratios regarding mortality, secondary malignancy and morbidity causing hospitalisation. Sixty (13·6%) survivors experienced late mortality with excess deaths from secondary cancer [standardised mortality ratio (SMR) 18·6; 95% confidence interval (CI) 11-29·4] and non-malignant disease (SMR 3·6; 95% CI 2·2-5·5). Excess secondary cancers (standardised incidence ratio 7·8; 95% CI 5·6-10·5) were associated with radiotherapy [Hazard ratio (HR) 2·7; 95% CI 1-7·7] and female gender (HR 1·8; 95% CI 1-3·4). Of 281 survivors treated between 1981 and 1999, 143 (51%) had morbidity resulting in hospitalisation (relative risk 1·45; 95% CI 1·22-1·73). Hospitalisation significantly increased with combined modality therapy, chemotherapy alone and recent treatment era. TYA HL survivors have excess risk of mortality and secondary malignancy continuing 30 years from diagnosis. Radiotherapy is associated with secondary malignancy and current response-adapted protocols attempt to minimise exposure, but late morbidity causing hospitalisation remains significant.