A new study in a British medical
  journal has stirred a passionate de-
  bate among doctors in Europe and
  the United States by asserting that
  mammograms do not prevent wom-
  en from dying of breast cancer or
  help them avoid mastectomies.
   The question is dividing experts
  and women's health advocates,
  many of whom acknowledge that
  they do not know what to think about
  the new report.  For more than two
  decades, annual mammograms have
  been part of life for millions of wom-
  en, with the American Cancer Soci-
  ety and the National Cancer Institute
  urging women to have them.
    Experts are still digesting the new
  findings, which appeared in the Oct.
  20 issue of the journal The Lancet,
 and few if any authorities in the.....
..................................
   Those studies that found benefits
  from mammography were flawed,
  say the investigators, Dr. Peter
  Gotzsche, director of the Nordic
  Cochrane Center in Copenhagen...
.........
    For example they criticize a Ney
  York study from more than a quar-
  ter of a century ago finding that 
  women who never had a   mammo-
  gram died of breast cancer at a rate
   30 percent higher than those who had
   the test. (Of the 30,565 who were
   never screened, 196 died over an 18-
   year period; of the 30,131 who  had
   the test, 153 died.)

       "The quality of the trials was very
      surprising because it is pretty low,"
      Dr. Gotzsche said in a telephone in-
      terview.  "Even if they are judged by
      yesterday's standards, the quality is
      low.  In some cases, we know why
  that happened - these trials were
      conducted by people who were unfa-
      miliar with clinical trial methodolo-
      gy.   They were run by enthusiastic
      clinicians."
       The researchers cite with greater
      approval a more recent study in
      Malmo, Sweden, that compared
      21,088 women who had mammo-
      grams to 21,195 who served as con-
      trols.  After nearly nine years, 63
      women in the mammogram group
      had died of breast cancer, compared
      with 66 in the control group - an
      insignificant difference.  The other
      study the researchers approved of,
      done in Canada, involved 44,925 wom-
      en who had mammograms and
      44,910 who did not.  There were 120
      deaths from breast cancer in      the
      screened group and 111 among      the
      women who served as controls.
           Nor did mammography lead to
      fewer mastectomies, the investiga-
      tors say.  In the Malmo study, for
      example, 424 women in the mam-
      mography group and just 339 in the
      control group had mastectomies.
      One reason may be that doctors ag-
      gressively treated some tiny tumors
      found in mammograms     -    tumors
      that might never have developed into
      cancer or might never have been
      noticed in a woman's lifetime.