Because the database used in that study provided no information on age at gonadectomy, the study could not evaluate bone sarcoma risk in terms of duration of gonadal hormone exposure. (cebp.aacrjournals.org)
While the study set out to estimate incidence rates of each disease related to age at neutering, patients were diagnosed at different ages and with differing durations of the disease as well as varying years at risk from the effects of gonadal hormone removal. (journals.plos.org)
χ2 test for trend showed a highly significant inverse dose - response relationship between duration of lifetime gonadal exposure and incidence rate of bone sarcoma (P = 0.008 for males, P = 0.006 for females). (cebp.aacrjournals.org)