Nonclinical factors prejudice breast ca screening, SLNB

April 1, 2008

Universal healthcare has been a hot button topic in the 2008 US presidential race. But there is more to universal healthcare than insurance coverage. A truly universal system would address-and possibly even eradicate-disparities in healthcare that are based on nonclinical factors, such as socioeconomics and gender.

Universal healthcare has been a hot button topic in the 2008 US presidential race. But there is more to universal healthcare than insurance coverage. A truly universal system would address-and possibly even eradicate-disparities in healthcare that are based on nonclinical factors, such as socioeconomics and gender.

Two recent papers took a closer look at the discrepancies in breast cancer screening and diagnosis. One group focused on how wealth and prognosis influence mammographic screening, while another looked at how income and other factors affect whether women are offered a less invasive diagnostic test.

Wealth and prognosis

Brie Williams, MD, and her colleagues at the University of California, San Francisco, Division of Geriatrics, mined their data from the 2002 and 2004 Health and Retirement Study (HRS). Their sample size consisted of 4,222 women who self-reported on their mammography use during HRS. Each woman’s net worth was calculated based on her assets and debts in 2002. The authors then calculated various predictor variables (see Table 1).

Women with higher net worth had a better life expectancy than those with a low net worth: 58% had a good prognosis (substantial life expectancy) while 4% had a limited prognosis (50% chance of dying within 5 years) vs 33% and 14%, respectively for those with a low net income.

Overall, 68% of the women underwent screening mammography. The authors found that 75% of women who fell into the higher net worth category had received a screening mammogram vs 60% of middle-income women and 56% of low-income women.

A higher net worth was associated with higher screening rates across all prognostic categories. Among the women with good prognoses who were more likely to benefit from screening, 82% fell into the high-net-worth category vs 68% of the women who met the same prognostic criteria but were considered low income.

Among the women with limited prognosis, who were less likely to benefit from mammography, 48% with a high net worth still underwent screening, compared with 32% of subjects with a low net worth.

Finally, among older women (age 80 and above) with a high net worth, 54% underwent screening while 41% of women in that same age group with a low net worth were screened.

“Guidelines recommend screening mammography for older women only when they have a favorable prognoses,” the authors said, citing screening criteria promoted by the American Cancer Society (ACS), American Geriatrics Society, and U.S. Preventive Services Task Force (Arch Intern Med 168:514-520, 2008).

They said that based on their analysis, women with limited prognoses and lower income were actually screened according to those guidelines. Unfortunately, appropriate guidelines-based screening had not been extended to low-income women with a good prognosis, they said.

Education would be a key in closing this gap, Dr. Williams’ group wrote. First, referring physicians need a better understanding of prognostic indices and whether their patients, regardless of income level, will benefit from screening based on those criteria.

Second, once women are properly informed of their prognosis based on age and other factors, there is a chance that they may chose to forgo screening.

Factors affecting use of SLNB

Four years ago, the ACS issued treatment guidelines in which sentinel lymph node biopsy (SLNB) was deemed an appropriate alternative to axillary lymph node dissection (ALND) for assessing lymph node status in breast cancer.

While clinical factors influence whether a woman undergoes SLNB or ALND, Amy Chen, MD, and colleagues found that nonclinical issues can also shape that decision (J Natl Cancer Inst 100:462-474, 2008).

“Better outcomes have been reported for patients receiving SLNB than for patients receiving ALND, including decreased edema, pain, hypoesthesia, and paresthesia,” wrote the authors from Emory University, the American College of Surgeons, The University of Texas Southwestern Medical School, and the ACS, which supported the study.

Dr. Chen’s group looked at the records of 490,899 women in the National Cancer Database to assess factors (see Table 2) that could predict the use of SLNB. Included in the analysis were SLNB and ALND procedures performed between 1998 and 2005.

A little over half (52.8%) of the 490,899 women had SLND while 47% underwent ALND. From 1998 to 2005, the use of SLNB jumped from 26.8% to 65.5%. In fact, the authors found that the year of diagnosis was the one variable associated with the greatest odds of SLNB being used.

However, women of color, older women, women with a lower income, and those on Medicare were less likely to receive SLNB. Also, women treated at community hospitals or community cancer centers had a lower likelihood of undergoing SLNB.

Patients with stage T2 disease were less likely to have SLNB than those with stage T1 disease. In addition, patients undergoing mastectomy were less likely to have SLNB than women undergoing breast-conserving surgery, although there are technical reasons for that, as lymph nodes are completely removed during mastectomy, Dr. Chen told ONI.

In another interesting finding, the authors recorded a steady upswing in the proportion of patients who had SLNB, regardless of the type of facility, until 2002 when that increase slowed down. Dr. Chen attributed this to the rapid integration of SLNB into routine clinical practice.

Whether economics played a role in women not undergoing SLNB could not be determined, Dr. Chen told ONI, based on the National Cancer Database. However, according to the American Medical Association, the reimbursement rate for ALND at $300.51 is slightly higher than that of SLNB at $202.24.

Dr. Chen called for more patient education on the pros and cons of SLNB. Referring physicians must also make it a point to send patients to facilities where SLNB is regularly performed, she said.