Tracking what shoppers buy, via loyalty-card data, can help spot those with early signs of cancer, doctors who have been running a study say.

Frequent purchases of over-the-counter painkillers and indigestion tablets revealed a higher risk of ovarian cancer, they found.

Ovarian cancer is often diagnosed late.

There is no reliable screening test and the symptoms, such as bloating, can be vague and confused with other common, harmless conditions.

Symptoms include:

  • swollen or bloated stomach
  • indigestion
  • pelvic or abdominal pain
  • loss of appetite or feeling full quickly after eating
  • eeding to urinate more often

Early diagnosis improves the chance of successful treatment.