Findings from 752,081 clinical breast examinations reported to a national screening program from 1995 through 1998

BACKGROUND AND METHODS

Mammography programs have received extensive study, but little is known about the outcome of clinical breast examinations (CBEs) performed in community settings. Consequently, we analyzed data from the National Breast and Cervical Cancer Early Detection Program on CBEs provided to low-income women from 1995 through 1998 and determined the percentage of CBEs considered to be abnormal, suspicious for cancer; the rates of cancer detection; and the sensitivity, specificity, and positive predictive value of CBEs.

RESULTS

We analyzed data from 752081 CBEs and found that 6.9% of all CBEs were coded abnormal, suspicious for cancer, and that 5.0 cancers were detected per 1000 examinations (95% confidence interval [CI] = 4.9-5.2). The values observed for sensitivity (58.8%) and specificity (93.4%) were comparable to those reported for the CBE component of clinical trials. The observed positive predictive value was 4.3%. About 74% of all records also reported mammography results. The cancer-detection rate among records reporting an abnormal CBE and normal mammography was 7.4 cancers per 1000 records (95% CI = 6. 3-8.4). When the CBE was normal but the mammography was abnormal, the rate was 42.0 cancers per 1000 records (95% CI = 39.9-44.1). When both CBE and mammography results were abnormal, the rate was 170.3 cancers per 1000 records (95% CI = 162.7-177.9). Cancer detection could not be attributed entirely to CBE or mammography on 38% of the records in the latter subset because the tests were performed on the same day.

CONCLUSION

CBEs performed in community-based screening programs can detect breast cancers as effectively as CBEs performed in clinical trials and may modestly improve early-detection campaigns.

Cervical cancer screening among low-income women: results of a national screening program, 1991-1995

OBJECTIVE

To evaluate the results of cervical cytology screening in the National Breast and Cervical Cancer Early Detection Program and to compare the findings with results from other screening programs.

METHODS

We analyzed data on 312,858 women aged 18 years and older who received one or more Papanicolaou smears, and follow-up if indicated, from October 1991 through June 1995 at screening sites across the United States providing comprehensive National Breast and Cervical Cancer Early Detection Program services.

RESULTS

Of the women screened, more than half were 40 years or older; slightly less than half (44%) were of racial and ethnic minorities. During the first screening cycle, 3.8% of Papanicolaou tests were reported as abnormal (squamous intraepithelial lesion [SIL] or squamous cell cancer); proportions of abnormals decreased with increasing age. The age-adjusted rate of biopsy-confirmed cervical intraepithelial neoplasia (CIN) II or worse among women screened was 7.4 per 1000 Papanicolaou tests; rates of CIN were highest among young women, but cancer rates peaked among women in their 50s and 60s. The percentages of first screening cycle-Papanicolaou tests interpreted as high-grade SIL and squamous cell carcinoma associated with biopsy-confirmed CIN II or worse (the positive predictive value) were 56.0% for CIN II/III and 3.7% for invasive cancer. Of the 150 invasive cancers diagnosed, 54.0% were classified as local disease.

CONCLUSION

Observed results emphasize the duality of cervical neoplasia-CIN in younger women and invasive cancer in older women. This finding points to the importance of reaching both younger and older women for cervical cancer screening.