Data on over-the-counter (OTC) medicine purchases could spot ovarian cancer earlier, according to researchers in the U.K. The team hopes their findings will lead to an early alert system for this, and perhaps, other malignancies later.
The Cancer Loyalty Card Study (CLOCS) looked at data from almost 300 women to determine whether those diagnosed with ovarian cancer had a history of buying certain OTC medications. The study’s findings appeared last week in JMIR Public Health and Surveillance.
“Our study found a noticeable increase in purchases of pain and indigestion medications among women with ovarian cancer up to 8 months before diagnosis, compared with women without ovarian cancer. This suggests that long before women have recognized their symptoms as alarming enough to go to the GP [general practitioner], they may be treating them at home,” said James Flanagan, lead author for the study, from Imperial College’s Department of Surgery & Cancer.
Co-author Yasmine Hirst told Inside Precision Medicine, “The evidence for self-care behaviors prior to cancer diagnosis is often self-reported and examples of this can be found in qualitative research.” She is formerly of University College London and now at Lancaster University’s Medical School.
The team considered other data types, she added, but “Our findings showed that among social media, online searches, wearable devices, and mobile phone applications, purchase history data collected through loyalty cards had the highest public acceptability.”
Common and Deadly
Ovarian cancer is the sixth most common cancer in the U.K., with around 7,400 people diagnosed and more than 4,000 deaths each year. It is the eighth most common cancer worldwide, according to the World Cancer Research Fund.
Early signs of the disease include loss of appetite, stomach pain, and bloating, which patients may not see as very serious.
But diagnosing this disease at an earlier stage is one of the most effective ways to improve survival. The vast majority (93%) of patients survive their disease for 5 years or more if diagnosed at the earliest stage (stage 1) compared to just 13% when diagnosed at the latest stage (stage 4).
For women at high risk (e.g., those with a family history), genetic testing and prophylactic surgery may be recommended. There is also screening available using the CA 125 tumor marker blood test, or a combination of that with ultrasound. But such screening is not very accurate or widespread. A trial of screening in the U.K. found it led to no reduction in mortality from the disease (Menon et al., The Lancet, 2021). There is evidence, however, that even for women at high risk, extra surveillance is helpful.
Hirst said, “Self-care is an important part of recognizing and managing the early signs and symptoms of cancer which could resemble common illnesses and can be cared for without the guidance from healthcare providers. It is therefore crucial to understand to what extent this process may influence timely presentation in healthcare.”
This study included loyalty card data from two UK-based retailers. Of the 283 subjects, 153 were women who had been diagnosed with ovarian cancer. The researchers studied six years’ worth of purchase history.
Participants also completed a short questionnaire about ovarian cancer risk factors, along with any symptoms they experienced and the number of GP visits they made in the year leading up to a cancer diagnosis.
On average, participants with ovarian cancer began to notice their symptoms about 4 and a half months before diagnosis. Of those who visited a GP to check their symptoms, the first visit occurred, on average, about 3 and a half months before diagnosis.
Hirst says they aim to look at other cancers, and possibly data about diet as well as OTC purchases.
