Post by Joe Neubarth on Jan 31, 2012 8:56:34 GMT -5
ratical.org/radiation/CNR/PBC/chp3F.html
Early-Onset Breast-Cancer: Evidence on Radiation-Induction
[...]In their 1993 paper, Land et al are reporting exclusively on female A-bomb survivors who received the bomb-exposure before the age of 20 years. Although Land et al do not say so, the number of females who were exposed by the bombs below age 20 was approximately 12,000, and their average age at the time of bombing was about 10 years old (calculated from Gofman 1990, Table 26-F). There are 205 incident cases of breast-cancer, reported between 1950-1985 for this group. The cases are segregated by Land et al into two main groups: Women whose breast-cancers occurred before age 35 years constitute one group, and women whose breast-cancers appeared after age 35 years, the other group. We repeat: All the women were less than age 20 at the time of exposure.
In the boxed tabulation, the entries for "fractional increase ... per rad" indicate a spectacular difference between early-onset cases versus cases occurring at age 35 and beyond. The difference is treated as real (not spurious) in both Land 1993 and Tokunaga 1994. We shall propose an explanation of the difference in Part 4. But here, we will focus on the breast-dose which, if delivered sometime before age 20, can double the rate of early-onset breast-cancer[...]
Early-Onset Breast-Cancer: Evidence on Radiation-Induction
[...]In their 1993 paper, Land et al are reporting exclusively on female A-bomb survivors who received the bomb-exposure before the age of 20 years. Although Land et al do not say so, the number of females who were exposed by the bombs below age 20 was approximately 12,000, and their average age at the time of bombing was about 10 years old (calculated from Gofman 1990, Table 26-F). There are 205 incident cases of breast-cancer, reported between 1950-1985 for this group. The cases are segregated by Land et al into two main groups: Women whose breast-cancers occurred before age 35 years constitute one group, and women whose breast-cancers appeared after age 35 years, the other group. We repeat: All the women were less than age 20 at the time of exposure.
In the boxed tabulation, the entries for "fractional increase ... per rad" indicate a spectacular difference between early-onset cases versus cases occurring at age 35 and beyond. The difference is treated as real (not spurious) in both Land 1993 and Tokunaga 1994. We shall propose an explanation of the difference in Part 4. But here, we will focus on the breast-dose which, if delivered sometime before age 20, can double the rate of early-onset breast-cancer[...]