The clinical impact of continued smoking in patients with breast and other hormone-dependent cancer: A systematic literature review.

We conducted a systematic review of studies that investigated whether quitting smoking at or around diagnosis improves survival of patients with hormone-dependent cancers (HDC). Nine studies published in 2013-2022 were included. Studies were very diverse in terms of design, definition of quitters and continued smokers, and prevalence of prognostic factors other than smoking cessation (e.g. patients' demographics, tumour characteristic, and treatments). For breast, ovarian, and endometrial cancer, all included studies found that quitters had better overall, disease specific, and disease-free survival than continued smokers. For prostate cancer, there was no evidence of an association of smoking cessation with improved survival. This literature review provided suggestive evidence that female smokers diagnosed with cancer of the breast, ovary, or endometrium may improve their chances of surviving by stopping smoking. Smoking cessation counselling should become part of standard oncological care for these patients and integrated into breast cancer screening programs.

The Prognostic Impact of Quitting Smoking at or around Diagnosis on the Survival of Patients with Gastrointestinal Cancers: A Systematic Literature Review.

Cigarette smoking is a strong risk factor for the occurrence of gastrointestinal cancers, and a substantial proportion of newly diagnosed patients is made up of active smokers, yet the impact of smoking cessation at or around diagnosis on the clinical course of these cancers (whose prognosis is often unfavourable) has never been summarized to date. We reviewed studies published until 30 April 2022 that investigated whether smoking cessation at or around diagnosis favourably affects the clinical course of gastrointestinal cancers patients. Six studies were included for colorectal cancer patients, which provided limited yet suggestive evidence that quitters may have longer disease-specific survival compared to continued smokers. Only one study each focused on patients with gastric or HBV-positive liver cancer (both reporting a survival advantage for quitters vs. continued smokers), while we found no eligible studies for patients with cancer at other sites within the digestive system. More research is urgently needed to expand the evidence on the topic, given the potentially major clinical implications for these patients. Moreover, health professionals should provide the necessary smoking cessation support to any smoker who is undergoing diagnostic work-up or treatment for gastrointestinal cancer.

Prognostic Impact of Post-Diagnosis Smoking Cessation among Bladder Cancer Patients: A Systematic Literature Review and Meta-Analysis.

We reviewed the studies examining whether quitting smoking at or around diagnosis favourably affects the prognosis of bladder cancer (BC) patients, who are often active smokers at diagnosis. We found only nine eligible articles published until 31 January 2022, which encompassed around 5500 BC in total, the majority of which were nonmuscle invasive BC (only one paper included muscle-invasive BC). We used random effects meta-analysis to obtain a summary hazard ratio (SHR) and 95% confidence intervals (CI). The median proportion of smokers who quit at or around diagnosis was 29.8% (range 8.4-43.1%). For the overall, BC-specific, and progression-free survival, the studies were limited in number (n = 3) and provided conflicting results. At the same time, quitters did not appear to have a lower risk of recurrence than continued smokers (SHR 0.99, 95% CI 0.61-1.61). In conclusion, while the evidence is currently not sufficient to draw firm conclusions (especially for patients with muscle-invasive BC), physicians should not refrain from educating smoking BC patients about the benefits of smoking cessation and provide the necessary support.

Post-diagnosis smoking cessation and survival of patients with head and neck cancer: a systematic review and meta-analysis.

Cigarette smoking is the main risk factor for head and neck cancer (HNC) and many HNC patients are active smokers at diagnosis. We conducted a systematic literature review and meta-analysis to quantify the survival impact of smoking cessation at or around the time of HNC diagnosis. We searched studies published until December 31, 2021, and used random-effects meta-analysis to pool study-specific estimates into summary hazard ratio (SHR) and corresponding 95% confidence intervals (CI). Sixteen studies were published between 1983 and 2021, and over 2300 HNC patients were included. Studies were diverse in terms of design, patients, tumours and treatment characteristics, and criteria used to discriminate quitters from continued smokers. HNC patients who quit smoking at or around diagnosis had significantly better overall survival than continued smokers (SHR 0.80, 95% CI 0.70-0.91, n studies = 10). A beneficial effect of post-diagnosis smoking cessation was suggested for other survival endpoints as well, but the results were based on fewer studies (n = 5) and affected by publication bias. Cessation counselling should be offered to all smokers who start a diagnostic workup for HNC and should be considered standard multidisciplinary oncological care for HNC patients. PROSPERO registration number CRD42021245560.

Quitting Smoking At or Around Diagnosis Improves the Overall Survival of Lung Cancer Patients: A Systematic Review and Meta-Analysis.

INTRODUCTION: Lung cancer (LC) remains a disease with poor prognosis despite recent advances in treatments. Here, we aimed at summarizing the current scientific evidence on whether quitting smoking at or around diagnosis has a beneficial effect on the survival of LC patients. METHODS: We searched MEDLINE and EMBASE for articles published until 31st October, 2021, that quantified the impact on LC patients' survival of quitting smoking at or around diagnosis or during treatment. Study-specific data were pooled into summary relative risk (SRR) and corresponding 95% confidence intervals (CI) using random effect meta-analysis models. RESULTS: Twenty-one articles published between 1980 and 2021 were included, which encompassed a total of over 10,000 LC patients. There was substantial variability across studies in terms of design, patients' characteristics, treatments received, criteria used to define smoking status (quitters or continued), and duration of follow-up. Quitting smoking at or around diagnosis was significantly associated with improved overall survival (SRR 0.71, 95% CI 0.64-0.80), consistently among patients with non-small cell LC (SRR 0.77, 95% CI 0.66-0.90, n studies = 8), small cell LC (SRR 0.75, 95% CI 0.57-0.99, n studies = 4), or LC of both or unspecified histological type (SRR 0.81, 95% CI 0.68-0.96, n studies = 6). CONCLUSIONS: Quitting smoking at or around diagnosis is associated with a beneficial effect on the survival of LC patients. Treating physicians should educate LC patients about the benefits of quitting smoking even after diagnosis and provide them with the necessary smoking cessation support.