In the Superior Court of Pennsylvania - How Appealing

The FDA–approved patient package insert for Premarin stated:
Cancer of the breast. The majority of studies have shown no
association with the usual doses used for estrogen replacement
therapy and breast cancer. Some studies have suggested a possible
increased incidence of breast cancer in those women taking estrogens
for prolonged periods of time and especially if higher doses are
used.
R.1679a (emphasis added).
The patient insert explained that physicians may choose to prescribe a
progestin in combination with Premarin, though the insert contained no mention of
any increased breast cancer risk that could result from that combination therapy:
R.1679a.
Some physicians may choose to prescribe another hormonal drug to be
used in association with estrogen treatment. These drugs, progestins,
have been reported to lower the frequency of occurrence of a possible
precancerous condition of the uterine lining. Whether this will provide
protection from uterine cancer has not been clearly established. There
are possible additional risks that may be associated with the inclusion
of a progestin in estrogen treatment. The possible risks include
unfavorable effects on blood fats and sugars. The choice of progestin
and its dosage may be important in minimizing these effects.
The patient insert and physician information provided with Provera, the
progestin–only drug that Upjohn manufactured, contained no human breast cancer
warning at any relevant time. The 1992 product information for Provera stated:
Beagle dogs treated with medroxyprogesterone acetate [the active
ingredient in Provera] developed mammary nodules some of which
were malignant. Although nodules occasionally appeared in control
animals, they were intermittent in nature, whereas the nodules in the
drug–treated animals were larger, more numerous, persistent, and
there were some breast malignancies with metastases. Their
significance with respect to humans has not been established.
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