Breast Cancer (BC) Is a Window of Opportunity for Smoking Cessation: Results of a Retrospective Analysis of 1234 BC Survivors in Follow-Up Consultation

Tobacco Cessation Interventions in Non-Respiratory Cancers: A Systematic Review With Meta-analysis of Randomized Controlled Trials

BACKGROUND

Considering the high rates of persistent tobacco use, effective cessation interventions are needed for cancer patients and caregivers. Despite the need, there is a significant lack of research on tobacco cessation, especially for non-respiratory cancers (breast, prostate, colorectal, cervical, and bladder cancer).

PURPOSE

The objective was to evaluate tobacco use and tobacco cessation interventions among patients and caregivers for non-respiratory cancers.

METHODS

Randomized controlled trials assessing tobacco cessation interventions were identified. Five electronic databases were searched in accordance with the Preferred Reporting Items for Systematic reviews and Meta-analyses guidelines through July 2023. Studies exclusive to lung, oral, thoracic, and head and neck cancers were excluded. Effect sizes were estimated; risk of bias was assessed.

RESULTS

Of 3,304 studies, 17 were included. Interventions included behavioral (n = 6), pharmacotherapy (n = 2), and a combination (n = 9) treatment. Eight studies included a health behavior model; mean behavioral change techniques were 5.57. Pooled magnitude of the odds of cessation was positive and significant (odds ratio = 1.24, 95% confidence interval [Lower Limit 1.02, Upper Limit 1.51]) relative to usual care/placebo. Cumulative meta-analysis examined the accumulation of results over-time and demonstrated that studies have been significant since 2020. Two studies included caregivers' who were involved in the provision of social support.

CONCLUSIONS

Current interventions have the potential to reduce tobacco use in non-respiratory cancers. Results may be beneficial for promoting tobacco cessation among non-respiratory cancers. There is a considerable lack of dyadic interventions for cancer survivors and caregivers; researchers are encouraged to explore dyadic approaches.

Differences in Smoking Behavior by Nativity, Race/Ethnicity, and Education among Women Diagnosed with Breast Cancer

BACKGROUND

We evaluated smoking differences across nativity and race/ethnicity among women diagnosed with breast cancer.

METHODS

In our Northern Californian pooled population of 5,653 [670 Asian, 690 Hispanic, and 4,300 non-Hispanic White (White)] women diagnosed with breast cancer, we evaluated smoking differences across nativity, race/ethnicity, and acculturation and effect modification of nativity by race/ethnicity and education.

RESULTS

Foreign-born women currently smoked less than US-born women [odds ratio (OR) = 0.46, 95% confidence limit (CL): 0.29-0.72]. Hispanic (OR = 0.50; 95% CL: 0.32-0.78) women currently smoked less than White women. Among those who ever smoked (n = 2,557), foreign-born women smoked 5.23 fewer pack-years (PY) than US-born women (95% CL: -2.75 to -7.70). Furthermore, Asian (-4.60, 95% CL: -0.81 to -8.39) and Hispanic (-6.79, 95% CL: -4.14 to -9.43) women smoked fewer PY than White women. Associations were generally suggestive of greater smoking with greater acculturation (immigration age, US years, survey language). Finally, associations for nativity differed by education but not race/ethnicity, with a higher likelihood of smoking in US-born women only among those with less than a bachelor's degree (OR = 2.84, 95% CL: 2.15-3.77; current smoking: P = 0.01, PY: P = 0.05).

CONCLUSIONS

Asian and Hispanic (vs. White) and foreign-born (vs. US-born) breast cancer survivors reported fewer smoking behaviors. Smoking differences across nativity and education were driven by higher rates of smoking in US-born women with lower educational attainment.

IMPACT

Smoking behavioral patterns were similar among breast cancer survivors and the general population, informing potential smoking interventions.

Changes in cigarette smoking behavior among breast cancer and unaffected women - A prospective study in the MARIE cohort

BACKGROUND

Smoking cessation after a cancer diagnosis can reduce adverse cancer treatment outcomes. Whether a breast cancer diagnosis, a cancer commonly seen as unrelated to smoking cigarettes, motivates changes in smoking behavior is not fully understood. We aimed to compare long-term changes at three follow-up times of cigarette smoking behavior in women with breast cancer and baseline age- and region-matched unaffected women.

METHODS

We used longitudinal data from the population-based case-control study MARIE (Mamma Carcinoma Risk Factor Investigation). Women with breast cancer (N = 3813) and unaffected women (N = 7341) aged 50-74 years were recruited from 2002 to 2005. Analyses on changes in smoking were based on data from those who also completed follow-up 1 in 2009-2012, follow-up 2 in 2014-2016 and follow-up 3 in 2020. Multinomial logistic regression for changes (quitting, stable, or start smoking) adjusted for age, study region, education, comorbidities, living situation, and follow-up time, was applied to examine the associations between breast cancer status and changes in smoking behavior.

RESULTS

Women with breast cancer had significantly higher odds than unaffected women of quitting smoking (OR = 1.38, 95 % CI: 1.01-1.89) and lower odds of returning to smoking (OR = 0.29, 95 % CI: 0.09-0.94) at follow-up 1, but were more likely to start or return to smoking at follow-up 2 (OR = 2.11, 95 % CI 1.08-4.15). No significant group differences were found for changes in smoking behavior at follow-up 3.

CONCLUSION

Our findings indicate that short-term changes in smoking behavior can be attributed to a breast cancer diagnosis, but that over time the effect diminishes and changes in smoking no longer differ between breast cancer and breast cancer-free women. To support smoking cessation and to prevent relapse, guidelines to address smoking in cancer care, as well as comprehensive tobacco treatment services, are needed.

Epigenetics and environment in breast cancer: New paradigms for anti-cancer therapies

Breast cancer remains the most frequently diagnosed cancer in women worldwide. Delayed presentation of the disease, late stage at diagnosis, limited therapeutic options, metastasis, and relapse are the major factors contributing to breast cancer mortality. The development and progression of breast cancer is a complex and multi-step process that incorporates an accumulation of several genetic and epigenetic alterations. External environmental factors and internal cellular microenvironmental cues influence the occurrence of these alterations that drives tumorigenesis. Here, we discuss state-of-the-art information on the epigenetics of breast cancer and how environmental risk factors orchestrate major epigenetic events, emphasizing the necessity for a multidisciplinary approach toward a better understanding of the gene-environment interactions implicated in breast cancer. Since epigenetic modifications are reversible and are susceptible to extrinsic and intrinsic stimuli, they offer potential avenues that can be targeted for designing robust breast cancer therapies.

The Impact of Treatment for Smoking on Breast Cancer Patients’ Survival

Simple Summary

This was a retrospective analysis of breast cancer patients who were self-identified as smokers at diagnosis and who were invited to participate in a comprehensive tobacco treatment program (TP) that provided pharmacotherapy and motivational counseling to quit smoking. Our study shows that quitting smoking is associated with improved survival among breast cancer patients who smoke across all tumor stages. In our survival analysis, tobacco abstainers were more likely than smokers to be alive with no evidence of disease (hazard ratio = 0.616 95%CI (0.402–0.945), p = 0.026). Comprehensive approach to address smoking cessation may prolong survival outcomes when started as early as the time of diagnosis.

Abstract

Background: Smoking negatively affects overall survival after successful breast cancer (BC) treatment. We hypothesized that smoking cessation would improve survival outcomes of BC patients who were smokers at the time of diagnosis. Methods: This was a retrospective analysis of self-identified smokers with BC treated at The University of Texas MD Anderson Cancer Center. Patient demographics, date of diagnosis, tumor stage, tobacco treatment program (TP) participation, and time to death were extracted from our departmental databases and institutional electronic health records. We examined associations between tobacco abstinence status and survival using survival models, with and without interactions, adjusted for personal characteristics and biomarkers of disease. Results: Among all 31,069 BC patients treated at MD Anderson between 2006 and 2017, we identified 2126 smokers (6.8%). From those 2126 self-identified smokers, 665 participated in the TP, reporting a conservative estimate of 31% abstinence (intent-to-treat) 9 months into the program. Patients without reported follow-up abstinence status (including TP and non-TP participants) were handled in the analyses as smokers. Survival analysis controlled for multiple factors, including disease characteristics and participation in the TP, indicated that abstainers were more likely to be alive with no evidence of disease compared to non-abstainers (HR, 0.593; 95% CI, 0.386–0.911; p = 0.017). Conclusion: Our results suggest that quitting smoking is associated with improved survival among BC patients who were smokers at time of diagnosis across all tumor stages. Comprehensive approaches for smoking cessation in patients diagnosed with BC may prolong survival when started as early as the time of diagnosis.

Smoking, DNA Methylation, and Breast Cancer: A Mendelian Randomization Study

Background

Smoking was strongly associated with breast cancer in previous studies. Whether smoking promotes breast cancer through DNA methylation remains unknown.

Methods

Two-sample Mendelian randomization (MR) analyses were conducted to assess the causal effect of smoking-related DNA methylation on breast cancer risk. We used 436 smoking-related CpG sites extracted from 846 middle-aged women in the ARIES project as exposure data. We collected summary data of breast cancer from one of the largest meta-analyses, including 69,501 cases for ER+ breast cancer and 21,468 cases for ER- breast cancer. A total of 485 single-nucleotide polymorphisms (SNPs) were selected as instrumental variables (IVs) for smoking-related DNA methylation. We further performed an MR Steiger test to estimate the likely direction of causal estimate between DNA methylation and breast cancer. We also conducted colocalization analysis to evaluate whether smoking-related CpG sites shared a common genetic causal SNP with breast cancer in a given region.

Results

We established four significant associations after multiple testing correction: the CpG sites of cg2583948 [OR = 0.94, 95% CI (0.91-0.97)], cg0760265 [OR = 1.07, 95% CI (1.03-1.11)], cg0420946 [OR = 0.95, 95% CI (0.93-0.98)], and cg2037583 [OR =1.09, 95% CI (1.04-1.15)] were associated with the risk of ER+ breast cancer. All the four smoking-related CpG sites had a larger variance than that in ER+ breast cancer (all p < 1.83 × 10^-11) in the MR Steiger test. Further colocalization analysis showed that there was strong evidence (based on PPH4 > 0.8) supporting a common genetic causal SNP between the CpG site of cg2583948 [with IMP3 expression (PPH4 = 0.958)] and ER+ breast cancer. There were no causal associations between smoking-related DNA methylation and ER- breast cancer.

Conclusions

These findings highlight potential targets for the prevention of ER+ breast cancer. Tissue-specific epigenetic data are required to confirm these results.