To the Editor: Mr Riley and colleagues1 identified a significant increase of breast-conserving
surgery (BCS) as well as of radiation therapy following BCS from 1988 to 1993
in the Surveillance, Epidemiology, and End Results (SEER) program linked to
Medicare enrollment records. In our recent analyses using the SEER Public
Use Data Set, we found that the use of BCS without radiation therapy has,
in fact, also increased over time. We identified 35,267 women who were diagnosed
as having local or regional stage breast cancer at age 65 years or older between
1988 and 1993 and had either a mastectomy or BCS (the definition of the surgery
was the same as reported by Riley et al). The percentage of BCS increased
from 23.1% in 1988 to 40.5% in 1993. Of 11,409 patients who received BCS,
the use of radiation after BCS increased from 57.7% in 1988 to 63.9% in 1993.
Ironically, among patients who received surgery (mastectomy or BCS), there
was actually a net increase in the percentage of all women with breast cancer
who received BCS without radiotherapy, so-called nondefinitive therapy. The
odds ratios of the nondefinitive therapy were 1.16 (95% confidence interval
[CI], 1.02-1.31) for 1989, 1.20 (95% CI, 1.06-1.36) for 1990, 1.31 (95% CI,
1.17-1.49) for 1991, 1.30 (95% CI, 1.15-1.47) for 1992, and 1.46 (95% CI,
1.30-1.64) for 1993, respectively, compared with data from 1988, after adjusting
for age (65-74, 75-84, and ≥85 years), race (white, black, and others),
marital status (married and unmarried), cancer stage (local and regional),
tumor size (<0.5, 0.5 to <1, 1 to <2, 2 to <3, 3 to <4, and ≥4
cm), and 9 SEER areas. This was because the use of BCS increased more rapidly
than did the use of radiation therapy after surgery. Our article using the
SEER data from 1983 to 1995, which include all cancer patients with different
insurance coverage, also showed a similar finding.2
Physicians should strive to ensure that patients with early-stage breast cancer
receive more definitive therapies as justified by the research evidence3- 4 and recommended by the authorities.5