A genome-wide association study of contralateral breast cancer in the Women's Environmental Cancer and Radiation Epidemiology Study

BACKGROUND

Contralateral breast cancer (CBC) is the most common second primary cancer diagnosed in breast cancer survivors, yet the understanding of the genetic susceptibility of CBC, particularly with respect to common variants, remains incomplete. This study aimed to investigate the genetic basis of CBC to better understand this malignancy.

FINDINGS

We performed a genome-wide association analysis in the Women's Environmental Cancer and Radiation Epidemiology (WECARE) Study of women with first breast cancer diagnosed at age < 55 years including 1161 with CBC who served as cases and 1668 with unilateral breast cancer (UBC) who served as controls. We observed two loci (rs59657211, 9q32, SLC31A2/FAM225A and rs3815096, 6p22.1, TRIM31) with suggestive genome-wide significant associations (P < 1 × 10-6). We also found an increased risk of CBC associated with a breast cancer-specific polygenic risk score (PRS) comprised of 239 known breast cancer susceptibility single nucleotide polymorphisms (SNPs) (rate ratio per 1-SD change: 1.25; 95% confidence interval 1.14-1.36, P < 0.0001). The protective effect of chemotherapy on CBC risk was statistically significant only among patients with an elevated PRS (Pheterogeneity = 0.04). The AUC that included the PRS and known breast cancer risk factors was significantly elevated.

CONCLUSIONS

The present GWAS identified two previously unreported loci with suggestive genome-wide significance. We also confirm that an elevated risk of CBC is associated with a comprehensive breast cancer susceptibility PRS that is independent of known breast cancer risk factors. These findings advance our understanding of genetic risk factors involved in CBC etiology.

Response-shift effects in childhood cancer survivors: A prospective study

BACKGROUND

Treatment-related late effects can worsen over time among cancer survivors. Such worsening health states may trigger changes in internal standards, values, or conceptualization of quality-of-life (QOL). This "response-shift" phenomenon can jeopardize the validity of QOL assessment, and misrepresent QOL comparisons over time. This study tested response-shift effects in reporting future-health concerns among childhood cancer survivors who experienced progression in chronic health conditions (CHCs).

METHODS

2310 adult survivors of childhood cancer from St. Jude Lifetime Cohort Study completed a survey and clinical assessment at two or more timepoints. Based on 190 individual CHCs graded for adverse-event severity, global CHC burden was classified as "progression" or "non-progression". QOL was assessed using the SF-36^TM eight domains and physical- and mental-component summary scores (PCS, MCS). A single global item measured concerns about future health. Random-effects models comparing survivors with and without progressive global CHC burden (progressors vs. non-progressors) evaluated response-shift effects (recalibration, reprioritization, reconceptualization) in reporting future-health concerns.

RESULTS

Compared with non-progressors, progressors were more likely to de-emphasize (or downplay) overall physical and mental health in evaluating future-health concerns (p-values<0.05), indicating recalibration response-shift, and more likely to de-emphasize physical health earlier rather than later in follow-up (p-value<0.05), indicating reprioritization response-shift. There was evidence for a reconceptualization response-shift with progressor classification associated with worse-than-expected future-health concerns and physical health, and better-than-expected pain and role-emotional functioning (p-values<0.05).

CONCLUSION

We identified three types of response-shift phenomena in reporting concerns about future health among childhood cancer survivors. Survivorship care or research should consider response-shift effects when interpreting changes in QOL over time.

Examining the Effectiveness of the 2012 Canadian Graphic Warning Label Policy Change by Sex, Income, and Education

INTRODUCTION

We examined the differential impact of the 2012 Canadian GWL policy changes on key indicators of warning label impact and quit intentions using national cohorts of Canadian and U.S. adults who smoke.

AIMS AND METHODS

We used data from all waves of the International Tobacco Control surveys (2002-2020) in Canada and the United States. Our key measures were quit intentions and an index of warning label effectiveness (salience, cognitive and behavioral reactions). We estimated overall policy impact by comparing Canada (treatment group) with the United States (control group) using controlled interrupted time series (CITS) regression models, with interactions to examine whether policy impact varied by sex, education, and income.

RESULTS

The CITS model showed a statistically significant increase in the warning label effectiveness in Canada post-policy, compared to the United States (β = 0.84, 95% CI 0.35,1.33). Similarly, the odds of quit intentions were relatively higher among adults who smoked in Canada compared to the United States (OR = 1.89, 95% CI 1.51,2.36) post-policy. The three-way interaction model showed that these associations were greater among adults from low socioeconomic status (SES) groups than in high SES groups.

CONCLUSIONS

The 2012 change in the Canadian GWL policy was associated with stronger cognitive and behavioral responses to GWLs and higher odds of quit intentions among adults who smoked in Canada when compared to the United States, specifically among individuals from low SES groups, suggesting a positive equity impact. Our findings affirm the need for countries to implement or enhance GWLs, in line with the WHO Framework Convention on Tobacco Control (FCTC).

IMPLICATIONS

The evidence on the potential health equity benefit of GWL policies is mixed. To further understand the influence of GWL policies on tobacco use disparities, more systematic research using pre/post-policy designs with control groups is needed. Using a CITS model, we aimed to strengthen the available evidence on the causal influence of this tobacco control approach. Our findings show that the 2012 GWL policy change had a greater impact on adults who smoked from low SES groups than it did on adults who smoked from high SES groups, indicating a potentially positive equity impact and confirming the need for countries to implement or maximize the size of GWLs, as recommended by the WHO FCTC.

KISS1 metastasis suppressor in tumor dormancy: a potential therapeutic target for metastatic cancers?

Present therapeutic approaches do not effectively target metastatic cancers, often limited by their inability to eliminate already-seeded non-proliferative, growth-arrested, or therapy-resistant tumor cells. Devising effective approaches targeting dormant tumor cells has been a focus of cancer clinicians for decades. However, progress has been limited due to limited understanding of the tumor dormancy process. Studies on tumor dormancy have picked up pace and have resulted in the identification of several regulators. This review focuses on KISS1, a metastasis suppressor gene that suppresses metastasis by keeping tumor cells in a state of dormancy at ectopic sites. The review explores mechanistic insights of KISS1 and discusses its potential application as a therapeutic against metastatic cancers by eliminating quiescent cells or inducing long-term dormancy in tumor cells.

Increased acrolein-DNA adducts in buccal brushings of e-cigarette users

DNA adducts are central in the mechanism of carcinogenesis by genotoxic agents. We compared levels of a DNA adduct of acrolein, a genotoxic carcinogen found in e-cigarette vapor, in oral cell DNA of e-cigarette users and non-users of any tobacco or nicotine product. e-Cigarette users and non-users visited our clinic once monthly for 6 months, and oral brushings and urine samples were collected. For this study, we analyzed oral cell DNA adducts from three monthly visits in e-cigarette users and non-users as confirmed by urinary cyanoethyl mercapturic acid and total nicotine equivalents. DNA was isolated from the oral brushings and analyzed by a validated liquid chromatography-nanoelectrospray ionization-high resolution tandem mass spectrometry method for the acrolein DNA adduct 8R/S-3-(2'-deoxyribos-1'-yl)-5,6,7,8-tetrahydro-8-hydroxypyrimido[1,2-a]purine-10-(3H)-one (γ-OH-Acr-dGuo). The median value of this DNA adduct in the e-cigarette users was 179 fmol/µmol dGuo (range 5.0 - 793 fmol/µmol dGuo) while that for non-users was 21.0 fmol/µmol dGuo (range 5.0 - 539 fmol/µmol dGuo), P = 0.001. These results demonstrate for the first time that e-cigarette users have elevated levels of a carcinogen-DNA adduct in their oral cells.

Identifying factors influencing sustainability of innovations in cancer survivorship care: a qualitative study

OBJECTIVES

Moving innovations into healthcare organisations to increase positive health outcomes remains a significant challenge. Even when knowledge and tools are adopted, they often fail to become integrated into the long-term routines of organisations. The objective of this study was to identify factors and processes influencing the sustainability of innovations in cancer survivorship care.

DESIGN

Qualitative study using semistructured, in-depth interviews, informed by grounded theory. Data were collected and analysed concurrently using constant comparative analysis.

SETTING

25 cancer survivorship innovations based in six Canadian provinces.

PARTICIPANTS

Twenty-seven implementation leaders and relevant staff from across Canada involved in the implementation of innovations in cancer survivorship.

RESULTS

The findings were categorised according to determinants, processes and implementation outcomes, and whether a factor was necessary to sustainability, or important but not necessary. Seven determinants, six processes and three implementation outcomes were perceived to influence sustainability. The necessary determinants were (1) management support; (2) organisational and system-level priorities; and (3) key people and expertise. Necessary processes were (4) innovation adaptation; (5) stakeholder engagement; and (6) ongoing education and training. The only necessary implementation outcome was (7) widespread staff and organisational buy-in for the innovation.

CONCLUSIONS

Factors influencing the sustainability of cancer survivorship innovations exist across multiple levels of the health system and are often interdependent. Study findings may be used by implementation teams to plan for sustainability from the beginning of innovation adoption initiatives.