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Background: The COVID-19 pandemic has had a major impact on access to health care resources. Our objective was to estimate the impact of the COVID-19 pandemic on the incidence of childhood cancer in Canada. We also aimed to compare the proportion of patients who enrolled in clinical trials at diagnosis, presented with metastatic disease or had an early death during the first 9 months of the COVID-19 pandemic compared with previous years.Methods: We conducted an observational study that included children younger than 15 years with a new diagnosis of cancer between March 2016 and November 2020 at 1 of 17 Canadian pediatric oncology centres. Our primary outcome was the monthly age-standardized incidence rates (ASIRs) of cancers. We evaluated level and trend changes using interventional autoregressive integrated moving average models. Secondary outcomes were the proportion of patients who were enrolled in a clinical trial, who had metastatic or advanced disease and who died within 30 days. We compared the baseline and pandemic periods using rate ratios (RRs) and 95% confidence intervals (CIs).Results: Age-standardized incidence rates during COVID-19 quarters were 157.7, 164.6, and 148.0 per million, respectively, whereas quarterly baseline ASIRs ranged between 150.3 and 175.1 per million (incidence RR 0.93 [95% CI 0.78 to 1.12] to incidence RR 1.04 [95% CI 0.87 to 1.24]). We found no statistically significant level or slope changes between the projected and observed ASIRs for all new cancers (parameter estimate [β], level 4.98, 95% CI -15.1 to 25.04, p = 0.25), or when stratified by cancer type or by geographic area. Clinical trial enrolment rate was stable or increased during the pandemic compared with baseline (RR 1.22 [95% CI 0.70 to 2.13] to RR 1.71 [95% CI 1.01 to 2.89]). There was no difference in the proportion of patients with metastatic disease (RR 0.84 [95% CI 0.55 to 1.29] to RR 1.22 [0.84 to 1.79]), or who died within 30 days (RR 0.16 [95% CI 0.01 to 3.04] to RR 1.73 [95% CI 0.38 to 15.2]).Interpretation: We did not observe a statistically significant change in the incidence of childhood cancer, or in the proportion of children enrolling in a clinical trial, presenting with metastatic disease or who died early during the first 9 months of the COVID-19 pandemic, which suggests that access to health care in pediatric oncology was not reduced substantially in Canada. [ABSTRACT FROM AUTHOR]

In this paper, we revisit the possibility, first raised using a data set collected in the 1970s, that there is a link between average radon concentrations and the incidence of childhood leukaemia and lymphoma in Canada. Following the launch of the National Radon Program in 2007, Health Canada completed a long-term radon survey in 33 census metropolitan areas (CMAs), which covers about 70% of the Canadian population. We used this data, together with leukaemia and lymphoma incidence rates among children (0–14 years of age) in the past decade (2006–15), and tried to link the city-level average radon concentrations to the leukaemia and lymphoma incidence rates in 33 major Canadian cities. Analyses were conducted for six subtypes (ALL, AML, CMD, HL, NHL and BL) of leukaemia and lymphoma. Estimated doses to red bone marrow from domestic radon exposure were low and we did not find any association between radon exposure at home and the increased risk for developing leukaemia among children under 15 years of age living in the CMAs. The results indicate a slight positive association for AML among 1–4 year males in CMAs of Peer Group C and NHL among 5–9 year females in CMAs of Peer Group A; however, these should be interpreted with caution owing to the crude exposure assessment and possibilities of other confounding factors. [ABSTRACT FROM AUTHOR]

Background: While impressive gains in childhood cancer survival have been reported both in Canada and internationally, it has been almost 15 years since the last comprehensive evaluation of Canadian data., Data and Methods: Data are from the population-based Canadian Cancer Registry, record-linked to the Canadian Vital Statistics Death database. Children aged 0 to 14 diagnosed with new primary malignant cancers from 1992 to 2017 in Canada except Quebec were included. Overall survival was measured using observed survival proportions (OSPs). Estimates for the 2013-to-2017 period were predicted using the period method; otherwise, the cohort method was used., Results: For the 2013-to-2017 period, five-year OSPs were at least 90% for 10 of 24 individual cancer groups or subgroups reported. Survival was highest for thyroid carcinomas (100%) and Hodgkin lymphomas (99%) and lowest for other gliomas (42%). A significant increase in the five-year OSP from the 1992-to-1996 period (77%) to the 2013-to-2017 period (84%) was observed for all childhood cancers combined, but not since the 2003-to-2007 period. The greatest increase was for chronic myeloproliferative diseases (35.4 percentage points); for lymphoid leukemias, survival increased from 85% to 93%. Survival was relatively poor at baseline for hepatic tumours, malignant bone tumours, and soft tissue and other extraosseous sarcomas, and it remained virtually unchanged. Once children survived five years, the probability of surviving another five years exceeded 95% across most diagnoses., Discussion: Significant improvements in both short- and long-term paediatric cancer survival have been made in Canada since the early to mid-1990s. These findings are clinically meaningful and are likely to be reassuring to families.

Background: Cosmetic breast implants may impair the ability to detect breast cancers. The aims of this study were to examine whether implants and implant characteristics are associated with more advanced breast tumors at diagnosis and poorer survival., Methods: Study population includes all invasive breast cancer cases diagnosed during follow-up of the large Canadian Breast Implant Cohort. A total of 409 women with cosmetic breast implants and 444 women with other cosmetic surgery were diagnosed with breast cancer. These women were compared for stage at diagnosis using multinomial logistic regression models. Cox proportional hazards regression models were used for breast cancer-specific mortality analyses. Comparisons were also conducted according to implant characteristics., Results: Compared with women with other cosmetic surgery, those with cosmetic breast implants had at later stage breast cancer diagnosis (OR of having stage III/IV vs. stage I at diagnosis: 3.04, 95% confidence interval (CI): 1.81-5.10; P < 0.001). A nonstatistically significant increase in breast cancer-specific mortality rate for women with breast implants relative to surgical controls was observed (HR = 1.32, 95% CI: 0.94-1.83, P = 0.11). No statistically significant differences in stage and breast cancer mortality were observed according to implant characteristics., Conclusions: At diagnosis, breast cancers tended to be at more advanced stages among women with cosmetic breast implants. Breast cancer-specific survival was lower in these women although the reduction did not reach statistical significance., Impact: Further investigations of the effect of breast implants on breast cancer prognosis are warranted., (2012 AACR)

Cosmetic breast implants are not associated with increased breast cancer incidence, but variations of risk according to implant characteristics are still poorly understood. As well, the assessment of cancer risk for sites other than breast needs to be clarified. The purpose of this study was to fill these research gaps. This study presents an extended analysis of 10 more years of follow-up of a large Canadian cohort of women who received either cosmetic breast implants (n = 24,558) or other cosmetic surgery (15,893). Over 70% of the implant cohort was followed for over 20 years. Cancer incidence among implant women was compared to those of controls using multivariate Poisson models and the general female population using the standardized incidence ratios (SIRs). Women with breast implants had reduced rates of breast and endometrial cancers compared to other surgery women. Subglandular implants were associated to a reduced rate of breast cancer compared to submuscular implants [incidence rate ratio (IRR) = 0.78, 95% confidence interval (CI) = 0.63-0.96] and this reduction persisted over time. We observed a sevenfold increased rate (IRR = 7.36, 95% CI = 1.86-29.12) of breast cancer in the first 5 years after the date of surgery for polyurethane-coated subglandular implant women but this IRR decreased progressively over time (p value for trend = 0.02). We also observed no increased risk of rarer forms of cancer among augmented women. A reduction in breast cancer incidence was observed for women with subglandular implants relative to women with submuscular implants. Possible increase of breast cancer incidence shortly after breast augmentation with polyurethane implants needs to be verified., (Copyright © 2012 UICC.)

Previous studies have shown conflicting results on the prognosis of colorectal mucinous adenocarcinoma. This study compared prognostic characteristics of patients diagnosed with mucinous and non-mucinous adenocarcinomas in a Canadian series. Analyses were based on 165 colorectal mucinous and 1215 non-mucinous adenocarcinoma patients who were registered at the Ottawa Regional Cancer Centre from 1994 to 1997, with follow-up extending to December 31, 2001. Differences in survival were examined using the relative survival analysis and the Cox proportional hazards model. For colon, rectum and both combined, the distribution for age at diagnosis, stage and treatment of patients with mucinous adenocarcinoma was similar to that of non-mucinous patients (all p > or = 0.12). Patients with mucinous histology had fewer well- or moderately-differentiated tumours than non-mucinous patients (all p < 0.01). Overall, no statistically significant differences were noted in 5-year relative survival between mucinous and non-mucinous carcinoma for colon, rectum and their combination (p > or = 0.35 for each). However, when the stages were considered separately, patients with stage III mucinous carcinoma had worse survival than patients with non-mucinous carcinoma for both sites. Multivariate analysis of combined data for colon and rectal cancers indicated that independent significant prognostic factors were stage for mucinous, with age and grade as well as stage for non-mucinous carcinoma. In conclusion, no significant differences in stage distribution and overall survival were found between mucinous and non-mucinous patients for colorectal cancer.

Aims: The FADS1/FADS2 gene cluster encodes Delta-5 and Delta-6 desaturase, rate-limiting enzymes in metabolism of linoleic (LA) to arachidonic (ARA) and alpha-linolenic to eicosapentaenoic and docosahexaenoic acid (DHA). Single nucleotide polymorphisms (SNPs) in FADS1/FADS2 contribute to variability in blood lipid fatty acids. Altered n-6 and n-3 fatty acids have been related to perinatal depression (PPD)., Methods: We genotyped rs174553, rs99780, rs174575, and rs174583 in FADS1/FADS2, analyzed blood lipid fatty acids and assessed PPD risk as an Edinburgh Postnatal Depression Scale (EPDS) score > or =10 for 69 pregnant women., Results: 21, 12 and 15% women had an EPDS score > or =10 at 36 weeks' gestation, 2 and 6 months postpartum, respectively. Quantitative trait analysis showed an association between rs174575 and PPD risk at 36 weeks' gestation and 6 months postpartum. With haplotype ACCC (major alleles) for rs174553, rs99780, rs174575, rs174583, respectively, as reference, GTCT was positively associated with PPD risk at 36 weeks' gestation, p = 0.028, and higher LA and lower ARA in plasma (p = 0.0001, p < 0.0001) and RBC ethanolamine phospholipids (p = 0.007, p = 0.005)., Conclusions: We show that SNPs in FADS1/FADS2 are associated with higher blood lipid LA and lower ARA and PPD risk., (Copyright 2010 S. Karger AG, Basel.)