SAN DIEGOEstrogen replacement therapy (ERT) does not increase
the risk of recurrence in patients who have had endometrial cancer
and should not be categorically ruled out in these women, according
to research presented at the 31st Annual Meeting of the Society of
Gynecologic Oncologists (SGO).
Kimberly A. Suriano, MD, Philip J. DiSaia MD, and their colleagues at
the University of California, Irvine, and the Chao Family
Comprehensive Cancer Center, Orange, California, conducted a cohort
study among women who had either begun or resumed ERT after primary
treatment for endometrial cancer.
We found no evidence that taking ERT following treatment for
endometrial cancer adversely affects outcome, Dr. DiSaia told
ONI in an interview. The results showed no increased risk of either
recurrence or death, he said. In fact, women who took ERT had a
longer disease-free interval and longer disease-free survival than
matched control subjects who had not taken ERT after endometrial
Dr. DiSaia was senior investigator of the study and is director of
the Division of Gynecologic Oncology, University of California Irvine
Dr. DiSaia said that this study disproves the assumption that if
the patient takes estrogen and has a focus of cancer, the estrogen
will ignite the cancer, like pouring fuel on a fire. What causes
cancer and what promotes it are two different things.
The study included 249 patients with surgical stage I, II, or III
endometrial cancer treated between 1984 and 1998, 130 of whom had
received ERT after primary cancer treatment. Among the 249 patients,
Dr. DiSaia and colleagues were able to identify 75 matched
treatment-control pairs. Pairs were matched for age at diagnosis,
parity, stage and grade of tumor, depth of myometrial invasion,
histology, surgical treatment, lymph node status, postoperative
radiation therapy, and concurrent diseases.
The study compared duration of estrogen use, recurrence, and death
due to endometrial cancer. All 150 patients underwent pelvic
examination and Pap test every 3 months for the first 2 years, then
every 6 months. At the time of the report, cases had been followed
for a mean of 83 months, and controls had been followed for a mean of
There were five endometrial cancer recurrences and two deaths from
endometrial cancer among the 130 patients on estrogen. Interestingly,
there were no recurrences among women who had a history of previous ERT.
Among the matched case-control patients, there were 2 recurrences
among the 75 patients who took ERT (1.4% recurrence rate) and 11
recurrences among the 75 who had not taken ERT (14.3% recurrence
rate). The difference was not statistically significant.
The investigators reported that the matched estrogen replacement
group experienced a longer disease-free interval than their control
counterparts (82 months vs 63 months) and longer disease-free
survival. Both of this findings were statistically significant (P =
.02 and P = .03, respectively).
Dr. DiSaia doubts that the improved disease-free interval in the
women who took ERT indicates a protective effect. Rather, he said,
this was more likely due to a bias in the selection of subjects in
this retrospective cohort study.
All Im pleading for is that we properly inform the
patient so that the patient can decide whether to take or continue
ERT, Dr. DiSaia said. I think that in most cases, a
reasonable person would decide to continue. Our job is to give
patients the facts and let them decide how they want to live. For
many women, ERT is an important quality-of-life issue. Unless
were sure it will harm them, we should not deny it to patients.
Dr. DiSaia pointed out that the general use of ERT following
endometrial cancer also will be affected by current FDA-required
labeling, which states that ERT is contraindicated in such cases.
I dont know what data that warning is based on, but it
does have medical-legal implications in the current climate, he said.
The effect of ERT following treatment for endometrial cancer is now
being studied in a major prospective randomized, controlled trial
conducted by the Gynecologic Oncology Group.