Update on our investigation of malignant tumors associated with Peutz-Jeghers syndrome in Japan.

PURPOSE: To investigate the recent incidence of malignant tumors associated with Peutz-Jeghers syndrome (PJS) in Japan to clarify if there are any differences in malignant tumor risk and the spectrum of malignancies by reviewing the literature on this subject. METHODS: We reviewed PJS cases reported in 1115 papers in Japan between January, 1989 and December, 2014. RESULTS: Malignant tumors were identified in 186 of the total 583 PJS cases from 523 evaluable studies. The estimated cumulative risk of a malignant tumor was 83.0 % at 70 years of age. Compared with a previous study, on a collective 91 cases reported up until 1988 in Japan, the reported proportion of gastrointestinal malignancies decreased, from 82.4 to 48.3 %, whereas that of gynecological malignancies increased, from 8.8 to 34.3 % (P < 0.01). Moreover, breast cancers were occasionally reported (4.8 %), even though none were reported in the previous study. Adenocarcinoma of the uterine cervix was the most common malignant tumor (46.8 %) among women with PJS. CONCLUSIONS: The increased number of reports of cervical adenocarcinoma in women with PJS is the prominent trend in Japan, and a subject of concern among gynecologists. The risk of breast cancer seems to be increasing, but confirmation of this trend will require further investigation.