The palpable breast lump: Information and recommendations to assist decision-making when a breast lump is detected

• Published in: Canadian Medical Association journal (CMAJ) Vol. 158; no. 3; p. S3
• Main Authors: Margolese, Richard G, Cantin, Jacques, Bouchard, Francoise, Caines, Judy
• Format: Journal Article
• Language: English
• Published: Ottawa CMA Impact, Inc 10.02.1998
• Subjects: Biopsy; Breast cancer; Clinical medicine; Clinical practice guidelines; Decision making; Diagnostic tests; Family medical history; Health care; Mammography; Radiation; Risk factors; Transplants & implants; Ultrasonic imaging; Canada
• ISSN: 0820-3946; 1488-2329

The presence of certain factors increases the likelihood of breast cancer developing. These factors include a history of a biopsy of either breast showing atypical hyperplasia,(f.1) lobular carcinoma in situ (LCIS)(f.2) or ductal carcinoma in situ (DCIS),(f.3) a history of a resected carcinoma(f.4) or radiation treatment for Hodgkin's disease in childhood,(f.5) or a strong family history of breast cancer (level III evidence).(f.6) The risk of breast cancer also increases with age (level III evidence). In Canada in 1992 the incidence per year of breast cancer in women was approximately 0.35/1000 for those aged 30 to 39 years, 2.2/1000 for those aged 50 to 59 years, and 4.0/1000 for those aged 70 to 79 years.(f.7) Although known risk factors, including aging, all increase the risk of breast cancer, they do not substantially influence the probability that any particular lump will be malignant. The fact remains that most women in whom breast cancer is diagnosed have no identifiable risk factors and breast cancer does not develop in most women with common risk factors. Because younger women tend to have mammographically dense breast tissue, a mammogram is unlikely to give useful information.(f.9) However, once a woman reaches her mid-30s its value becomes greater, and mammography should increasingly become part of the work-up of a suspicious breast lump (level IV evidence).(f.9) When a mammogram is interpreted by an experienced radiologist it can often clarify, the nature of the lump in question as well as provide information about other areas of the breast. Irregular or clustered calcifications seen in the area of the mass increase the suspicion of carcinoma. Mammography can also provide information about the opposite breast. Therefore, optimal mammographic imaging should normally be carried out, including 2 views of each breast with spot compression and/or magnification views of any abnormal areas. However, the overall level of sensitivity of mammography in palpable breast cancers may be no more than 82%(f.17) and may be even lower in premenopausal women (level III evidence).(f.18) Thus, although a suspicious mammogram may increase the probability of malignancy, a normal mammogram cannot exclude a cancer that is suspected on clinical grounds.