doi:10.1016/j.ijrobp.2006.03.059
CLINICAL INVESTIGATION Breast
EFFECT OF DISTANCE TO RADIATION TREATMENT FACILITY ON USE
OF RADIATION THERAPY AFTER MASTECTOMY IN ELDERLY WOMEN
R
INAA
S. P
UNGLIA
, M.D., M.P.H.,* J
ANE
C. W
EEKS
, M.D., M.S
C
.,
†
B
RIDGET
A. N
EVILLE
, M.P.H.,
†
AND
C
RAIG
C. E
ARLE
, M.D., M.S
C
.
†
*Department of Radiation Oncology, and
†
Division of Medical Oncology, Center for Outcomes and Policy Research, Dana-Farber
Cancer Institute, Boston, MA
Purpose: We sought to study the effect of distance to the nearest radiation treatment facility on the use of
postmastectomy radiation therapy (PMRT) in elderly women.
Methods and Materials: Using data from the linked Surveillance, Epidemiology, and End Results–Medicare
(SEER-Medicare) database, we analyzed 19,787 women with Stage I or II breast cancer who received mastectomy
as definitive surgery during 1991 to 1999. Multivariable logistic regression was used to investigate the association
of distance with receipt of PMRT after adjusting for clinical and sociodemographic factors.
Results: Overall 2,075 patients (10.5%) treated with mastectomy received PMRT. In addition to cancer and
patient characteristics, in our primary analysis, increasing distance to the nearest radiation treatment facility was
independently associated with a decreased likelihood of receiving PMRT (OR ؍ 0.996 per additional mile, p ؍
0.01). Secondary analyses revealed that the decline in PMRT use appeared at distances of more than 25 miles and
was statistically significant for those patients living more than 75 miles from the nearest radiation facility (odds
of receiving PMRT of 0.58 [95% CI ؍ 0.34– 0.99] vs. living within 25 miles of such a facility). The effect of
distance on PMRT appeared to be more pronounced with increasing patient age (>75 years). Variation in the
effect of distance on radiation use between regions of the country and nodal status was also identified.
Conclusions: Oncologists must be cognizant of the potential barrier to quality care that is posed by travel
distance, especially for elderly patients; and policy makers should consider this fact in resource allocation
decisions about radiation treatment centers. © 2006 Elsevier Inc.
Radiation therapy, Mastectomy, Elderly, Breast cancer, Barriers to care.
INTRODUCTION
Adjuvant external beam radiation therapy for breast cancer
commonly requires daily treatment for up to 7 weeks. Pre-
sumably because of inconvenience, longer distances to the
nearest radiation facility have been associated with omis-
sion of radiation after breast-conserving surgery (1–3). Ran-
domized trials have demonstrated a large survival benefit
for radiation use after mastectomy in specific patient sub-
groups (4–6). Although numbers of women receiving
breast-conserving surgery have been increasing, data from
national sources indicate that a large number of women with
early-stage breast cancer still undergo mastectomy (7, 8).
The influence of travel distance on receipt of radiation
therapy has not been studied in the postmastectomy setting.
Studying the determinants of postmastectomy radiation
therapy (PMRT) in older women may be especially infor-
mative. The proportion of women undergoing mastectomy
for early-stage breast cancer increases with patient age
(7–10), and locoregional recurrence after mastectomy re-
mains a problem in older women (11). One randomized study
found that patients aged 59 years or less benefited similarly to
those 60 years or more (5). However research has also dem-
onstrated that older women are vulnerable to unwarranted
variation in health care delivery (8, 10, 12, 13). Lack of access
to adequate transportation may be a critical determinant of
cancer care received among older patients (14, 15). The deter-
ring effect of transportation issues may be even more pro-
nounced when patients are faced with weeks of daily outpatient
treatment, as is needed for radiation therapy.
We sought to study receipt of PMRT in elderly women
diagnosed with early-stage breast cancer. Specifically, we
were interested in defining the clinical and sociodemo-
graphic factors, including distance to the nearest radiation
facility, that influence the receipt of PMRT.
METHODS AND MATERIALS
Data sources
Patients included in our study were taken from the linked
Surveillance, Epidemiology, and End Results–Medicare (SEER-
Medicare) database. The 11 tumor registries participating in the
Reprint requests to: Rinaa S. Punglia, M.D., M.P.H., Dana-Farber
Cancer Institute, Center for Outcomes and Policy Research, 454B
S21-24, 44 Binney Street, Boston, MA 02115. Tel: (617) 632-5430;
Fax: (617) 632-2270;
E-mail: rpunglia@lroc.harvard.edu
Received Jan 30, 2006, and in revised form March 21, 2006.
Accepted for publication March 23, 2006.
Int. J. Radiation Oncology Biol. Phys., Vol. 66, No. 1, pp. 56–63, 2006
Copyright © 2006 Elsevier Inc.
Printed in the USA. All rights reserved
0360-3016/06/$–see front matter
56