Photo: Gunilla Sonnebring
“Cervical cancer screening is one of the most successful cancer prevention programs which has greatly reduced cervical cancer incidence and mortality,” said Dr. Qing Shen, the corresponding author of the study and researcher in the Department of Medical Epidemiology and Biostatistics at the Karolinska Institutet in Stockholm. “Despite these substantial benefits, our research indicates that women with invasive cervical cancer experienced medical complications and psychological stress during their diagnostic workup, although at a very low level.”
Previous work conducted by Shen and colleagues demonstrated an increased risk of injuries during the time period before and after a diagnosis of any cancer.
Using data from the Swedish Total Population Register, the researchers identified over 3 million women who participated in cervical cancer screening during 2001-2012. Cross-linkage with multiple Swedish registries allowed for the identification of women within this cohort who received a diagnosis of invasive cervical cancer, cervical cancer precursor lesions, or had a normal smear during follow-up. The final cohort included roughly 1.85 million women with a normal smear, roughly 22,000 women with cervical intraepithelial neoplasia (CIN) grade 1, roughly 21,000 women with CIN2, roughly 37,000 with CIN3/adenocarcinoma in situ (AIS), and roughly 5,000 women with invasive cervical cancer.
The researchers examined the incidence of injuries during the diagnostic workup of patients who participated in cervical cancer screening. Among women with precursor lesions or cervical cancer, the diagnostic workup was defined as the time interval between the first Pap smear or punch biopsy until surgical treatment, or two months after the last smear or punch biopsy, if not treated surgically. Among women with normal smear results, the diagnostic workup was defined as the two months following the smear.
The researchers calculated incidence rates of both iatrogenic injuries and non-iatrogenic injuries that occurred during the diagnostic workup. Iatrogenic injuries, which were mostly related to receipt of a punch biopsy, that required at least two days of hospitalization were included in this analysis. Non-iatrogenic injuries, which included accidents and intentional self-harm, that required at least one day of hospitalization were included. Incidence rate ratios for injuries that occurred during the diagnostic workup, which were calculated by comparing women with a diagnosis of cervical cancer or its precursor lesions with women with a normal smear, were adjusted for age, calendar period, screening adherence, education, income, and marital status.
Compared with women with a normal smear, among whom injuries were extremely rare, women with a diagnosis of invasive cervical cancer had eight times the incidence of iatrogenic injuries, and women with CIN3/AIS had three times the incidence of iatrogenic injuries. Women with CIN1-2 did not have a significantly increased rate of iatrogenic injuries compared with women with a normal smear.
“Women with invasive cancer can have greater vascularity due to tumor growth, which can lead to hemorrhage and hematoma following a biopsy,” Shen explained.
Compared with women with a normal smear, women with a diagnosis of invasive cervical cancer had about twice the incidence of non-iatrogenic injuries. Women with CIN1-2, CIN3, or AIS did not have a significantly increased rate of non-iatrogenic injuries compared with women with a normal smear. The most common type of non-iatrogenic injuries were unintentional falls, Shen said.
“An increase in non-iatrogenic injuries points to high levels of psychological distress in relation to receiving a diagnosis of cervical cancer,” said Shen.
“This study for the first time systematically examined the risks of injuries during the cervical diagnostic workup. Although the chance of having such injuries was very rare, we found an increased risk of inpatient care for iatrogenic and non-iatrogenic injuries for women with invasive cervical cancer. It is important to emphasize, however, that cervical cancer screening is greatly beneficial for the early detection of cancer and is largely safe.”
Limitations of the study include a lack of information on non-surgical treatments among women with invasive cervical cancer, such as palliative care, chemotherapy, and radiotherapy, which could have potential implications for injuries. Further, because the authors only included iatrogenic injuries that required at least two days of inpatient care, only the more severe forms of these injuries were captured in this analysis.
The study was sponsored by the Swedish Cancer Society; the Swedish Research Council for Health, Working Life and Welfare; a Karolinska Institutet Senior Researcher Award and Strategic Research Area in Epidemiology Award; and by the China Scholarship Council.