ASCOBreast cancer patients receiving care in hospitals that
treat fewer than 25 patients a year have substantially lower survival
rates than women treated in larger-volume hospitals, according to a
study presented at a poster session of the 36th Annual
Meeting of the American Society of Clinical Oncology (ASCO), New Orleans.
Monica Morrow, MD, reported 5-year survival for breast cancer
patients treated with surgery and chemotherapy at 1,238 US hospitals.
Although hospital volume has been shown to influence outcome for
high-morbidity, complex cancer surgery and chemotherapy, this study
population is one that traditionally experiences negligible
We found that survival in the high-volume hospitals is about
20% greater than in the lower-volume hospitals, said Dr.
Morrow, professor of surgery and director of the Lynn Sage
Comprehensive Breast Program, Northwestern University Medical School.
This finding persists across all treatment combinations (see Figure),
and is not explained by failure of low-volume hospitals to refer
patients for systemic therapy. The difference was evident when
we looked at patients who were treated with surgery alone or surgery
plus systemic therapy, and those who had mastectomy or
breast-conserving therapy, Dr. Morrow said.
Data on 173,000 Patients
The investigators analyzed data for 173,401 patients with the
diagnosis of invasive breast cancer recorded in the National Cancer
Data Base (NCDB) from 1985 to 1991. The NCDB is a joint project of
the American College of Surgeons and the American Cancer Society. All
the survival data were adjusted for age and stage.
We only studied patients who underwent typical surgical
treatment and had a TNM stage, to make sure we were comparing like to
like, Dr. Morrow said. Metastatic breast cancer is not
included in this study.
The study showed that 35% of hospitals treated fewer than 25 cases
per year (8% of total patients). Conversely, only 12% of hospitals
treated more than 100 cases per year (35% of total patients). The
majority of patients (57%) were treated at hospitals that see 26 to
100 patients annually (53% of hospitals).
No relationship between volume and outcome was seen for patients with
ductal carcinoma in situ (DCIS), and differences were observed in
patients both over and under age 60, suggesting that these findings
are not simply a reflection of differences in comorbidity.
The message for small hospitals is not dont
treat, but learn how to treat better, Dr.
Morrow told ONI. She emphasized that the study does not
say that doctors in large hospitals are better than doctors in small
hospitals. It says that systems of care in large and small hospitals
may be different. We must figure out these differences in care and
apply what weve learned in larger hospitals to low-volume centers.
Systems of care that may lead to improved outcomes in large-volume
hospitals include greater expertise in mammography and pathology,
more aggressive use of systemic therapy, and treatment by
She said that the study serves as a starting point to allow detailed
examination of differences in systems of care between small- and
large-volume hospitals. Ultimately, she said, we will see if by
applying whats been learned in large hospitals to smaller
hospitals, we can improve treatment outcomes across the board.