Re: Breast Cancer Study

[hflong@postoffice.pacbell.net]

Selection  could explain  what Lubin calls "radiologic risk" [for breast

cancer] of radiology technicians.



Animal and ecologic studies -like Canadian women having more fluoroscopy (for

TB pneumothorax) having had LESS breast cancer - suggest to me that

mammography actually reduces breast cancer risk.



Were radiology technicians more intelligent, educated and unlikely to breast

feed  than women without these risks of breast cancer, which Lubin may have

chosen for controls? Controls must be identical in everything except the

factor being tested, to declare causality. Statistical correction  is

unproven, as with Field comparing radon "controls", 37% smokers, with lung

cancer cases, 90% smokers.



A placebo controlled trial is needed for confidence in causality or risk. I

had explored a randomized, double-blind study following 5 rem, 5 cGy (or sham)

chest x-ray for breast and lung cancer with yearly mammography and lung CT.

However, the CT itself  (over 1 rem, 1cGy) might give enough hormesis (cancer

prevention), to mask significant differences, so I abandoned that exploration.



Technicians prior to 1950 are not good controls for those after 1960 because

Lubin's ."subsequent decline in risk" was associated with  more enlightened

working conditions, and selection of technicians with less risk - as well as

with lower dose.



Howard Long (epidemiologist)



Thomas Jones wrote:



> It looks like Lubin has taken time away from his recent paper

> discediting Cohen's work to examine other radiation related health

> effects.

>

> J Natl Cancer Inst 2002 Jun 19;94(12):943-8

>

>

> Breast cancer mortality among female radiologic technologists in the

> United States.

>

> Mohan AK, Hauptmann M, Linet MS, Ron E, Lubin JH, Freedman DM,

> Alexander BH, Boice JD Jr, Doody MM, Matanoski GM.

>

> A. K. Mohan, M. Hauptmann, M. S. Linet, E. Ron, J. H. Lubin, D. M.

> Freedman, M. M. Doody, Division of Cancer Epidemiology and Genetics,

> National Cancer Institute, Bethesda, MD.

>

> We evaluated breast cancer mortality through 1997 among 69 525 female

> radiologic technologists who were certified in the United States from

> 1926 through 1982 and who responded to our questionnaire. Risk of

> breast cancer mortality was examined according to work history and

> practices and was adjusted for known risk factors. Breast cancer

> mortality risk was highest among women who were first employed as

> radiologic technologists prior to 1940 (relative risk [RR] = 2.92,

> 95% confidence interval [CI] = 1.22 to 7.00) compared with risk of

> those first employed in 1960 or later and declined with more recent

> calendar year of first employment (P for trend =.002). Breast cancer

> mortality risk increased with increasing number of years of

> employment as a technologist prior to 1950 (P for trend =.018).

> However, risk was not associated with the total number of years a

> woman worked as a technologist. Technologists who first performed

> fluoroscopy (RR = 1.69, 95% CI = 1.02 to 3.11) and multifilm

> procedures (RR = 1.87, 95% CI = 1.04 to 3.34) before 1950 had

> statistically significantly elevated risks compared with

> technologists who first performed these procedures in 1960 or later.

> The high risks of breast cancer mortality for women exposed to

> occupational radiation prior to 1950 and the subsequent decline in

> risk are consistent with the dramatic reduction in recommended

> radiation exposure limits over time.

>

> Sent by Law  Mail

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