Biomedical subjects

James Michaelson

Publications and source records attributed to James Michaelson.

4 recordsLinked to original sources

PubMed2005

Locoregional recurrence rates and prognostic factors for failure in node-negative patients treated with mastectomy: implications for postmastectomy radiation.

PURPOSE: Postmastectomy radiation therapy (PMRT) reduces locoregional recurrence (LRR) of breast cancer. Survival appears improved in patients at higher risk for LRR. This study addresses whether subsets of node-negative patients with sufficiently high risk of LRR might benefit from PMRT. METHODS: Retrospective analysis of a cohort of 877 cases of node-negative breast cancer treated with mastectomy, without adjuvant radiation, from 1980 to 2000. RESULTS: Median follow-up was 100 months. Ten-year cumulative incidence of LRR as first event was 6.0%. Size greater than 2 cm, margin less than 2 mm, premenopausal status, and lymphovascular invasion (LVI) were independently significant prognostic factors. Ten-year LRR was 1.2% for those with 0 risk factors, 10.0% for those with 1 risk factor, 17.9% for those with 2 risk factors, and 40.6% for those with 3 risk factors. The chest wall was the site of failure in 80% of patients. CONCLUSION: Postmastectomy radiation therapy has not been recommended for node-negative patients because the LRR rate is low in that population overall. This study suggests, however, that node-negative patients with multiple risk factors, including close margins, T2 or larger tumors, premenopausal status, and LVI, are at higher risk for LRR and might benefit from PMRT. Because the chest wall is the most common site of failure, treating the chest wall alone in these patients to minimize toxicity is reasonable.

Analysis of Variance↗

PubMed2004

A two-gene expression ratio predicts clinical outcome in breast cancer patients treated with tamoxifen.

Tamoxifen significantly reduces tumor recurrence in certain patients with early-stage estrogen receptor-positive breast cancer, but markers predictive of treatment failure have not been identified. Here, we generated gene expression profiles of hormone receptor-positive primary breast cancers in a set of 60 patients treated with adjuvant tamoxifen monotherapy. An expression signature predictive of disease-free survival was reduced to a two-gene ratio, HOXB13 versus IL17BR, which outperformed existing biomarkers. Ectopic expression of HOXB13 in MCF10A breast epithelial cells enhances motility and invasion in vitro, and its expression is increased in both preinvasive and invasive primary breast cancer. The HOXB13:IL17BR expression ratio may be useful for identifying patients appropriate for alternative therapeutic regimens in early-stage breast cancer.

Aged↗

PubMed2003

Racial differences in mammographic breast density.

BACKGROUND: African American women have a lower incidence but a higher mortality from breast carcinoma than Caucasians. A proposed explanation for this discrepancy is the decreased efficacy of screening among African American women. Increased breast density in African American women may result in decreased sensitivity of mammography. The purpose of this article is to determine whether there is a difference in mammographic breast density between African American and Caucasian women. METHODS: A series of 769 women were recruited from 5 sites. Mammograms were reviewed centrally by seven reviewers using Breast Imaging Reporting and Data System categories converted to numeric values. The mean mammographic densities for Caucasian, African American, and Latina patients were compared using a two-way analysis of covariance. The mean values for each race were estimated adjusting for the reader as well as for each patient's age and body mass index (BMI). RESULTS: African American women had the lowest mean breast density. The reported density in this group was 2.43, compared with 2.69 among Caucasians and 2.65 among Latina patients. After adjusting for age and BMI as well as the reader, there was still an independent racial effect on breast density (P = 0.0050). CONCLUSIONS: Mammographic breast density was lower in African American women than in Caucasians and Latinas. This discrepancy may be an intrinsic racial difference due to undetermined causes. Factors, such as the growth rate of tumors and the incidence of calcifications, must be studied to confirm that other forces do not have a negative impact on the efficacy of screening mammograms in African American women.

Adult↗

PubMed2002

The pattern of breast cancer screening utilization and its consequences.

BACKGROUND: The objective of this study was to describe the pattern of screening utilization and its consequences in terms of tumor size and time of tumor appearance of invasive breast carcinoma among a population of women who were examined at a large service screening/diagnostic program over the last decade. METHODS: Utilization of mammography was assessed from a population of 59,899 women who received 196,891 mammograms at the Massachusetts General Hospital Breast Imaging Division from January 1, 1990 to March 1, 1999, among which 604 invasive breast tumors were found. Two hundred six invasive, clinically detected tumors also were seen during this period among women who had no record of a previous mammogram. Additional information was available on screening of women from March 1, 1999 to June 1, 2001. RESULTS: Fifty percent of the women who used screening did not begin until the age of 50 years, although 25% of the invasive breast tumors were found in women age < 50 years. Relatively few of the women who used screening returned promptly for their annual examinations; by 1.5 years, only 50% had returned. Approximately 25% of the invasive breast tumors were found in women for whom there was no record of a previous screening mammogram, and these tumors were larger (median, 15 mm) than the screen-detected tumors (median, 10 mm). Approximately 30% of the 604 invasive breast tumors in the screening population were found on nonmammographic grounds, and they also were larger (median, 15 mm) than the screen-detected tumors (median, 10 mm). However, only 3% of these 604 tumors were found by nonmammographic criteria within 6 months of the previous negative examination, and only 12% were found within 1 year. By back calculating the likely size of each of these tumors at the time of the negative mammogram, it could be seen that most tumors probably emerged as larger, palpable masses not because they were missed at the previous negative mammogram, because most were too small then to have been detected, but because too much time had been allowed to pass. CONCLUSIONS: Far too many women did not comply with the American Cancer Society recommendation of prompt annual screening from the age of 40 years. Consequently, almost 50% of the invasive tumors emerged as larger and, thus, potentially more lethal, palpable masses.

Breast Neoplasms↗