Uterine cancer deaths certified as part unspecified: an unsolved issue.

Objective: A large percentage of uterine cancer deaths worldwide are not attributed to the cervix or corpus, but classified as uterus part 'unspecified'. We provided the trend for the proportion of uterine cancer deaths certified as 'unspecified' in selected countries.

Methods: We derived the proportions of 'unspecified' uterine cancers for 20 selected high- and middle-income countries with reliable death certification over the period 1994-2021, using official mortality data from the WHO database coded according to the 10th Revision of the International Classification of Diseases.

Results: For the earliest available year, the proportion of deaths classified as 'unspecified' uterine cancers ranged from 5.8% in Mexico to 65.6% in Italy. In some countries only, this proportion decreased over time. For 10 countries the proportion of 'unspecified' uterus in the most recent available year was around 20%. The proportion of deaths at 20-44 years registered as uterus 'unspecified' was lower for all countries during the study period.

Conclusion: A substantial number of uterine cancer deaths worldwide coded as 'unspecified' was observed, also in high-income countries where death certification for other common neoplasms is accurate. Valid attribution of uterine cancer deaths to the cervix or corpus is feasible and should be adopted.