Endocrine Abstracts

Background and objective: The number of reports of metastatic (secondary) pituitary tumors has been increasing with progression of diagnostic and treatment skills for cancer patients. However, there were no nation-wide epidemiologic surveys or epidemiologic reviews about this topic. We have started a multi-institutional joint research in Japan to understand clinical features of metastatic pituitary tumors.

Subjects and methods: We distributed 1069 closely-monitored questionnaires to the institutions with members of the Japan Society for Hypothalamic and Pituitary Tumor, the Japan Society of Stereotactic Radiosurgery and the Japan Endocrine Society. As of end of 2011, we have identified 164 patients with metastatic pituitary tumor treated during the period from 1996 through 2011.

Results: The patients were predominantly male (89 vs 75). The mean age of onset was 59.1 years ranging 26–86. The mean latency between the diagnosis of metastasis and the diagnosis of initial tumor was 744.5±884.4 (S.D.) days in 58 reported patients. Metastatic lesion was reported to be found earlier than the initial sites in eight patients. The main sites of primary lesions included lung (37.8%), breast (22%), kidney (7.3%), colon (6.1%), and miscellaneous (26.8%). The frequent symptoms were diabetes insipidus (24.3%), general fatigue (24.3%) and extra-ocular muscle palsy (18.3%). 36 patients had surgery for the tumor removal (22%), 108 patients (65.9%) had stereotactic radiation, and 25 patients (14.6%) underwent conventional radiation therapy. The mean survival time was 11.6 months in total 117 reported cases, in which the 3-year survival rate was 28.3%. The median survival time tended to be longer in stereotactic radiation group than in conventional radiation group; 11.6 vs 8.8 months, but not statistically significant (P=0.26, Logrank)

Conclusion: The Japanese Survey for Metastatic Pituitary Tumor is accumulating data on metastatic pituitary tumor, which must be conducive for early diagnosis and proper treatment of this pathologic entity.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.