Cancer center's breast conservation rates don't tell the whole story

NEW YORK (Reuters Health) - Examining a cancer center's rates of breast conservation therapy as a measure of quality of care can be misleading unless other factors, such as the use of neo-adjuvant chemotherapy and genetic counseling, are considered as well, clinicians warn in a report in the January/February issue of The Breast Journal.

Today, most women diagnosed with breast cancer are eligible for breast conservation therapy (BCT), and for stage I or II breast cancer, "BCT is considered by many to be the standard of care," Dr. Michael S. Sabel and colleagues from the University of Michigan Comprehensive Cancer Center in Ann Arbor explain in their report.

"With this in mind, a surgeon's, practice's or hospital's breast conservation rate - the percentage of newly diagnosed breast cancer patients treated by lumpectomy and whole-breast irradiation, has become a marker of appropriate care," they note.

However, in an analysis of women treated for invasive breast cancer at UM's cancer center over a 3-year period, Dr. Sabel and colleagues found evidence that BCT rates alone are a "poor measure" of the overall quality of cancer care provided by an institution.

For example, their data show that it is critically important to differentiate women who require mastectomy from women who are eligible for BCT but choose mastectomy.

It's also important to realize, the investigators say, that the population of women referred to comprehensive cancer centers may be "heavily skewed" towards mastectomy due to the complexities of their disease.

In addition to tumor factors such as stage and histology, breast conservation rates "can be dramatically impacted by neo-adjuvant chemotherapy or genetic counseling," Dr. Sabel and colleagues found.

For example, the overall breast conservation rate during the 3-year period analyzed was 63%. However, the appropriate use of neo-adjuvant chemotherapy in an attempt to downstage the primary tumor and perform BCT drove the BCT rate higher, they observed. Without the use of neo-adjuvant chemotherapy, the BCT rate would have been only 53%, the investigators report.

"Thus, institutions with a less aggressive use of neo-adjuvant chemotherapy, or patient populations less willing to undergo neo-adjuvant chemotherapy, might have lower breast conservation rates."

In contrast, the BCT rate among younger women was "strongly driven" by a desire for prophylaxis and BCT eligible women choosing bilateral mastectomies, which may, in part, be due to an aggressive use of genetic counseling during the initial workup. "Again, institutions with older populations or those not offered genetic counseling to patients may ultimately have higher breast conservation rates," the authors point out.

Summing up, Dr. Sabel and colleagues note that insurance companies are interested in using BCT rates to gauge quality of breast cancer care. "As we move towards a performance-oriented compensation model, the consequences of selecting fair and accurate assessment tools is incalculable," they note.

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