In March, two fathers spoke via Skype at a news conference, with their voices masked electronically and their faces not shown. They did not want to reveal their identities.

The men, whose children have been diagnosed with thyroid cancer, were speaking at an event to mark the launch of 311 Thyroid Cancer Family Group.

One of the men said his teenage daughter had a hoarse voice after having half of her thyroid gland removed, leaving her with a temporary speech disorder and deep depression.