Increasing trends in cervical cancer mortality among young Japanese women below the age of 50 years: an analysis using the Kanagawa population-based Cancer Registry, 1975-2012

Abstract

Background: In Japan, cervical cancer (CC) deaths among women aged <50 years have doubled over the last three decades. Obtaining age-specific CC mortality rates among young women is important for taking measures against CC. Age-adjusted CC mortality rates for all ages are inadequate because of the classification of 'uterine cancer, not otherwise specified' (NOS uterine cancer) and CC mortality rates among elderly women. The aim of the present study was to calculate exact age-specific CC mortality rates in women aged <50 years in Kanagawa, taking into account the impact of NOS uterine cancer.

Methods: Using the Kanagawa Cancer Registry, CC deaths (1975-2012) were analyzed and CC mortality rates (age-adjusted, 20-29, 30-49, and ≥50 years) were calculated. In addition, hospitals were surveyed to reclassify cases of NOS uterine cancer. After reclassification, chronological trends were also analyzed.

Results: Age-specific CC mortality rates in Kanagawa and Japan overall showed increasing trends for ages 20-29 (P for trend<0.001) and 30-49 (P for trend<0.001). Rates of NOS uterine cancer death were significantly lower in Kanagawa than in Japan overall (P<0.05), except for patients aged <50 years in 2005-2009 (P=0.159).

Conclusions: The present study revealed concern for CC among Japanese women younger than 50 years. Well-organized CC screening and HPV vaccination should be provided to reduce CC mortality rates for these young women.

Keywords: Adult; Cancer registries; Female; Japan; Mortality; Papanicolaou test; Papillomavirus vaccine; Uterine cervical neoplasm; Uterine neoplasm.