Early adoption and disturbing disparities in sentinel node biopsy in breast cancer

The pen and the scalpel: effect of diffusion of information on nonclinical variations in surgical treatment

BACKGROUND

As information is disseminated about best practices, variations in patterns of care should diminish over time.

OBJECTIVE

To test the hypotheses that differences in rates of a surgical procedure are associated with type of insurance in an era of evolving practice guidelines and that insurance and site differences diminish with time as consensus guidelines disseminate among the medical community.

METHODS

We use lymph node dissection among women with ductal carcinoma in situ (DCIS) as an example of a procedure with uncertain benefit. Using a sample of 1051 women diagnosed from 1985 through 2000 at 2 geographic sites, we collected detailed demographic, clinical, pathologic, and treatment information through abstraction of multiple medical records. We specified multivariate logistic models with flexible functions of time and time interactions with insurance and treatment site to test hypotheses.

RESULTS

Lymph node dissection rates varied significantly according to site of treatment and insurance status after controlling for clinical, pathologic, treatment, and demographic characteristics. Rates of lymph node dissection decreased over time, and differences in lymph node dissection rates according to site and generosity of insurance were no longer significant by the end of the study period.

CONCLUSIONS

We have demonstrated that rates of a discretionary surgical procedure differ according to nonclinical factors, such as treatment site and type of insurance, and that such unwarranted variation decreases over time with diminishing uncertainty and in an era of diffusion of clinical guidelines.

Patterns of treatment for early stage breast cancers at the M. D. Anderson Cancer Center from 1997 to 2004

BACKGROUND

The objectives of this study were to examine the patterns of use for adjuvant therapy and the changes in surgical practice for patients with early stage breast cancer and to describe how recent large clinical trial results impacted the patterns of care at The University of Texas M. D. Anderson Cancer Center (MDACC).

METHODS

The study included 5486 women who were diagnosed with stage I through IIIA breast cancer between 1997 and 2004 and received their treatment at MDACC. A chi-square trend test and multivariate logistic regression model were used to assess changes in treatment patterns over time.

RESULTS

Among lymph node-positive patients, the use of anthracycline plus taxane chemotherapy increased from 17% in 1997 to 81% in 2004 (P < .001). Meanwhile, the use of anthracyclines without taxanes dropped from 76% to 20% (P < .001) between 1997 and 2000. For postmenopausal patients who received endocrine therapy, the use of tamoxifen was replaced increasingly by the use of aromatase inhibitors (from 100% on tamoxifen in 1997 to 14% in 2004; P < .001). The percentage of women who underwent initial sentinel lymph node biopsy increased significantly during the period from 1997 to 2004 (from 1.8% to 69.7%, respectively, among patients who underwent mastectomy; and from 18.1% to 87.1%, respectively, among patients who underwent breast-conserving surgery; P < .001).

CONCLUSIONS

The results from this study suggested that key findings from adjuvant therapy and surgical procedures from large clinical trials often prompt immediate changes in the patient care practices of research hospitals like MDACC.