J Breast Cancer.  2008 Dec;11(4):180-186. 10.4048/jbc.2008.11.4.180.

Breast Cancer Screening: A Medical Audit of the Screening Mammography Performed at One Institution for 10 Years

• Hur MH
• Lee HK
• Kang WN
• Yoon CS
• Ko SS
• Lee YJ
• Lee KS
• Cho BJ
• Kang SS

• KMID: 2286583
• DOI: http://doi.org/10.4048/jbc.2008.11.4.180

Abstract

PURPOSE: Screening for breast cancer has constantly been increasing since the benefit of screening for breast cancers was established. The purpose of this study was to investigate the efficacy of annual breast cancer screening at one institution for 10 years by conducting a medical audit.
METHODS
From March 1995 to July 2004, we performed 110,588 annual clinical examinations and mammographies on 58,024 women, who wanted to undergo breast cancer screening. Two hundred fourteen breast cancers were detected during screening, and one hundred sixty one of these patients were operated on. We then compared these results with the ideal rates for medical audits.
RESULTS
Of the 110,588 cases that were screened, the recall rate for further examination was 12.1% (n=13,423). The biopsy rate was 1.01% (n=1,116). Two hundred fourteen breast cancers were detected for a detection rate of 0.19%. The percent of stage 0 cancer among all the cancer was 23.6%, stage I was 40.4%, stage IIa was 19.9%, stage IIb and IIIa were a combined 6.2%, stage IIIc was 3.1%, and stage IV was 0.6%. The positive predictive value (PPV) based on the abnormal findings on the screening examinations was 1.6% (PPV1). The PPV when a biopsy or surgical consultation was recommended was 15.1% (PPV2). The percent of tumor found as stage 0 or I was 64% (103/161). The tumor found as minimal cancer (stage 0 or tumor lesser than 1 cm) was 38.5% (62/161). There were 38 cases of axillary lymph node metastasis (23.6%). The number of cases of cancers found per 1,000 cases was 1.7. The prevalence of cancer found per 1,000 first examinations was 2.3. The incidental cancer found per 1,000 follow-up examinations was 1.2. The recall rate for further evaluation was 12.1%. These results were compatible with the ideal rates for medical audits, except for the recall rate, the PPV1, the PPV2, and the cancers found per 1,000 cases.
CONCLUSION
On the base of these results, breast cancer screening was properly performed in this institution. Breast cancer screening using a clinical examination and a mammography is effective for the early detection of breast cancer.

Keyword

Breast cancer screening; Mammography; Medical audit

MeSH Terms

Biopsy
Breast
Breast Neoplasms
Female
Follow-Up Studies
Humans
Lymph Nodes
Mammography
Mass Screening
Medical Audit
Neoplasm Metastasis
Prevalence

Figure

• 

  Fig 1 Clinical symptom of breast cancer patients according to age groups (p=0.01). Total of two hundred fourteen breast cancers were detected by screening. Interestingly, age group of twenties is the most frequently symptomatic.

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  Fig 2 Age distribution and cancer detection rate of screenings according to age (n=110,558). Blue bar means number of screening, and red line with blue dot is number of cancer patients per 1,000 cases. Yellow letters in blue bar is number of cancer. The cancer detection rates per 1,000 cases among age groups were almost similar. *The reason of the highest cancer detection rate in twenties seems to result from the grouping bias that the majority of that age group is symptomatic.

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  Fig 3 Pathologic stage of breast cancers. One hundred sixty one patients among 214 breast cancers were actually operated.

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