NCCS Exposes Hundreds of HBOC Patients’ Details in Email Mistake

The National Cancer Centre Singapore (NCCS) reportedly exposed the identities and contact details of people associated with hereditary breast and ovarian cancer syndrome (HBOC) in an e-mail sent on 18 September. The invitation to a “Living with HBOC” event was sent to an NCCS mailing list, but recipients’ addresses were placed in the visible CC field rather than BCC, allowing people on the list to see one another’s details.

Screenshots shared with The Straits Times reportedly showed that some recipients’ workplaces were also exposed. One recipient, speaking anonymously, said the number of visible addresses was “too numerous to count” and estimated that more than 500 may have been disclosed. The incident could reveal sensitive information about individuals’ association with a heritable cancer condition, with potential implications for relatives, including offspring. The report does not state that the exposed information was accessed or misused beyond being visible to the e-mail’s recipients.