A new study establishes the link between smoking and reduced use of cancer screening services among women, as well as advanced diseases after a cancer diagnosis.
The research team is composed of members from Stanford University School of Medicine and the Pritzker School of Medicine at the University of Chicago. Details and results of the study can be found in the online journal BMJ Open.
A Study on Almost 90,000 Women
Researchers are inquiring whether smoking history is related to cancer screening rates or the staging of cancer diagnoses. To do so, they have invited 89,058 postmenopausal women. The participants in the study have also joined the Women's Health Initiative Observational Cohort (WHI-OS) study.
From the dataset, 52.8 percent (47,021 women) said they never smoked, 40.8 percent (36,360 women) used to, while only 6.37 percent (5,677 women) were still smoking by the time of the survey. Researchers followed up on the participants on an average of 8.8 years, starting from 1993 to 2017. They then found out that those who were still smoking were faced with considerably fewer possibilities of getting breast, cervical, and colorectal cancer screen procedures compared with former smokers and more so compared to those who never smoked.
Also, during that time, more than 7,054 cases of breast cancer, 1,600 cases of colorectal cancer, and 61 cases of cervical cancer were observed. The research team noted that failure to take regular screening resulted in higher diagnoses at higher cancer stages. The odds ratio for breast cancer is at 2.78 (confidence interval at 95 percent, 1.64 to 4.70), and colorectal cancer at 2.26 (95 percent CI 1.01 to 5.05)
"Concern for personal health is the most common reason given for smoking cessation among former smokers, and may explain why this health-conscious population seeks cancer screening more frequently than never smokers," the researchers suggested in the BMJ open statement. However, the researchers noted that smokers appear to be very positive about their health and always underestimate the risks of cancer from smoking.
A Large and Diverse Dataset for the US
One of the strengths of this study, as noted by the research team, is that it has a large study size (more than 89,000 women), geographical and ethnical diversity of the WHI-OS participant cohort. Even the apparent long follow-up period, at 8.8 years, serves the study by letting the researchers observe the lack of cancer screening with incidents of late-stage cancers from the dataset.
On the other side, the study is mostly limited by its observational setup and its dataset containing only postmenopausal women.
The American Cancer Society has its own set of recommendations regarding screening for different types of cancer. For breast cancer, annual screening for women aged 40 to 44 is optional. However, women aged 45 to 54 are strongly advised to get mammograms annually. For women 55 years old or more, they can choose between annual screening, or get the test once every two years.
RELATED: Breast Cancer Screening Should Start at 40, New Study Suggests
To better understand the link between smoking and risks of breast cancer, watch the video from START UBC below:
