Journal Club - 2007-04-18

Numeracy

1. http://bcra.nci.nih.gov/brc/q1.htm - obtain the absolute risk of breast cancer here.

2. For each review below, what it the relative risk of breast cancer among women receiving mammography?

1. Screening mammography in women 40 to 49 years of age: a systematic review for the American College of Physicians.

Armstrong K, Moye E, Williams S, Berlin JA, Reynolds EE.
Ann Intern Med 2007;146(7):516-26. PMID: 17404354

Abstract: PubMed		Fulltext options: Ann Intern Med - EBSCO - OVID
Summary: "Although few women 50 years of age or older have risks from mammography that outweigh the benefits, the evidence suggests that more women 40 to 49 years of age have such risks."

2. Screening for breast cancer with mammography.

Gøtzsche PC, Nielsen M.
Cochrane Database Syst Rev 2006;(4):CD001877. PMID: 17054145

Abstract: PubMed		Fulltext options: CrossRef - DOI - EBSCO - OVID
Summary: "Screening likely reduces breast cancer mortality. Based on all trials, the reduction is 20%, but as the effect is lower in the highest quality trials, a more reasonable estimate is a 15% relative risk reduction. Based on the risk level of women in these trials, the absolute risk reduction was 0.05%. Screening also leads to overdiagnosis and overtreatment, with an estimated 30% increase, or an absolute risk increase of 0.5%. This means that for every 2000 women invited for screening throughout 10 years, one will have her life prolonged. In addition, 10 healthy women, who would not have been diagnosed if there had not been screening, will be diagnosed as breast cancer patients and will be treated unnecessarily. It is thus not clear whether screening does more good than harm. Women invited to screening should be fully informed of both benefits and harms."

3. Breast cancer screening: a summary of the evidence for the U.S. Preventive Services Task Force.

Humphrey LL, Helfand M, Chan BK, Woolf SH.
Ann Intern Med 2002;137(5 Part 1):347-60. PMID: 12204020

Abstract: PubMed		Fulltext options: Ann Intern Med - EBSCO - OVID
Summary: "In the randomized, controlled trials, mammography reduced breast cancer mortality rates among women 40 to 74 years of age. Greater absolute risk reduction was seen among older women. Because these results incorporate several rounds of screening, the actual number of mammograms needed to prevent one death from breast cancer is higher. In addition, each screening has associated risks and costs." Synopsis at ACP J Club. 2003 Mar-Apr;138(2):38-9 Editorial at Ann Intern Med. 2002 Sep 3;137(5 Part 1):363-5

4. Chemoprevention of breast cancer: a summary of the evidence for the U.S. Preventive Services Task Force.

Kinsinger LS, Harris R, Woolf SH, Sox HC, Lohr KN.
Ann Intern Med 2002;137(1):59-69. PMID: 12093250

Abstract: PubMed		Fulltext options: Ann Intern Med - EBSCO - OVID
Summary: "Tamoxifen and raloxifene reduce the incidence of estrogen receptor-positive breast cancer in women. The relative risk reduction seems similar across all breast cancer risk groups. The absolute risk reduction varies by risk factors for breast cancer, however, and must be balanced against the potential harms to judge the appropriateness of treatment for individual women." Editorial at Ann Intern Med. 2002 Jul 2;137(1):52-4 Editorial at Ann Intern Med. 2002 Jul 2;137(1):56-8