Continued smoking after cancer diagnosis increases risk of adverse CVD event

8th June 2023

Ongoing smoking following a cancer diagnosis, elevates the risk of adverse cardiovascular disease (CVD) events, according to the findings of a study by Korean researchers.

Emerging data indicates how continued smoking following a cancer diagnosis increases the risk of cardiovascular disease mortality. In fact, nearly 20 per cent of cancer survivors continue to smoke. However, the differential effect on adverse cardiovascular outcomes, of either quitting smoking, cutting down or continuing to smoke is less clear.

The current study, published in the European Heart Journal, assessed the effect of changes to smoking habits on adverse cardiovascular outcomes. Smoking status was assessed two years before and three years after a cancer diagnosis. Participants were categorised as non-smokers; quitters, initiators and relapsers, and continued smokers. The primary outcome was a composite of CVD events, comprising hospitalisation for myocardial infarction or stroke, or CVD death.

Smoking status and adverse cardiovascular outcomes

Among 309,095 cancer survivors with a median age of 59 years (51.8% women), 80.9% were non-smokers, 10.1% quit, 7.5% initiated or relapsed to smoking and 7.5% continued to smoke.

During a median follow-up of 5.5 years, 10,255 new CVD events occurred. Using non-smokers as the reference point, the adjusted hazard ratio (aHR) for a CVD event among quitters was 20% higher (aHR = 1.20, 95% CI 1.12 – 1.28). But among those who continued to smoke, the risk was 86% higher (aHR = 1.86, 95% CI 1.74 – 1.98).

There were clear benefits for those who quit smoking. For example, the CVD event risk was significantly lower among those who quit compared to participants continuing to smoke (aHR = 0.64, 95% CI 0.59 – 0.70). These findings were consistent across both sexes as well as when classifying participants according to their primary cancers. Among those who continued to smoke, cutting down had no effect on their risk of a CVD event (HR = 0.99, 95% CI 0.80 – 1.22).

The authors suggested that continued smoking after a cancer diagnosis and its association with CVD events highlighted the urgent need for initiatives to promote smoking cessation and prevent smoking initiation and/or relapse among patients with cancer.

Cancer diagnoses in young people fell but ICU admissions increased during first wave of pandemic

19th November 2021

Cancer diagnoses in young people fell during the first-wave of the pandemic but were associated with a higher rate of ICU admissions

The level of cancer diagnoses in young people fell during the first-wave of the COVID-19 pandemic but there was also an increased likelihood of admission to intensive for cancers diagnosed during the period. This was the finding from a study by researchers from Oxford University, UK who discussed their findings in a poster presentation at the National Cancer Research Institute conference.

The COVID-19 pandemic has had a major impact on cancer services in the majority of countries across the world. In the UK, a survey by Cancer Research UK in July 2020, found that 2 in 3 cancer patients reported that their cancer care had been impacted and that ratings of overall cancer care as ‘very good’ decreased from 75% ‘before lockdown started’ to 37% ‘after lockdown started’. Moreover, other research shows that in England, there were approximately 3.4 million fewer key diagnostic tests performed between March and August 2020 compared with the same period in 2019.

Given the likely impact of delays in diagnostics, the Oxford team were interested in determining how in England, the first wave of the pandemic affected childhood, teenager and young adult cancer incidence rates, diagnostic and treatment time-intervals and cancer-related intensive care (ICU) admissions. They used the QResearch database, which is derived from the anonymised health records of over 35 million patients. In addition, since QReseaerch is also linked to linked to hospital admission, mortality and cancer diagnoses data held with a disease register, it was possible for the researchers to make links between these three factors. For the present study, researchers focused on central nervous system (CNS) tumours, lymphomas, leukaemias, sarcomas and renal tumours in those aged up to 25 years of age. They compared the incidence of these cancer diagnoses between 1^st February to the 15^th August 2020 and compared their findings to the three preceding pre-pandemic years. As well as the number of diagnoses, the team also analysed the length of time before treatment started after diagnosis and whether or not these patients were diagnosed after being admitted to intensive care.

Findings

A total of 2607 cancer diagnoses were made from 1^st January 2017-15^th August 2020, with 380 during the pandemic. Overall, this represented a 17% reduction (95% CI -38% to – 6%) in the incidence-rate-ratio during the first wave of the pandemic. In particular there was a 38% (95% CI -52% to -21%)] decrease in CNS tumours and a 28% (95% CI -45% to -5%) reduction in lymphomas. Interestingly, the researchers observed that childhood cancers that were diagnosed during the pandemic were more than twice as likely to be associated with an ICU admissions (adjusted odd ratio, OR = 2.2, 95% CI 1.33 – 3.47).

The researchers also observed that the median time to diagnosis was not significantly different across the different time periods (+4.5 days, 95% CI -20.5 days to +29.5) and the median time to treatment was actually shorter during the pandemic (-0.7 days, 95% CI -1.1 to -0.30).

The authors concluded that the COVID-19 pandemic led to substantial reduction in the detection of cancer in young adults but was also associated with an increase in cancer-related ICU admissions. They suggested that this was probably due to more severe baseline disease at diagnosis and that overall, their findings demonstrate a clear disruption to cancer diagnostic pathways in this age group which need to be addressed urgently in the recovery phase of the pandemic.

Citation

Saatci D et al. The impact of the COVID-19 pandemic on cancer diagnostic pathways in children, teenagers and young adults: a cohort study in England. NCRI conference 2021