What are the benefits and risks of each type of breast cancer screening investigation?


Benefits and risks of mammography


  • Mammography increases the physician's ability to detect smaller tumors.

  • The smaller the cancerous lumps, the more treatment options the patient has.

  • The use of mammography increases the detection of small abnormal tissue growths confined to the milk ducts of the breast, called ductal carcinoma in situ (DCIS). These early tumors rarely harm patients if removed at this stage, and mammography is the only proven method to detect these tumors safely. Mammography is also useful in detecting all types of breast cancer, including invasive ductal cancer and invasive lobular cancer.

  • Mammography has been shown to decrease deaths from breast cancer when used for screening.

  • No radiation remains in the patient's body after an x-ray mammogram.


  • There is always a small chance of developing cancer due to excessive lifetime exposure to radiation. However, the amount of radiation from a mammogram is very small and the benefit of an accurate diagnosis far outweighs the risk.

  • The effective radiation dose. This procedure can vary from case to case.

  • There is a risk of false-positive mammography results. Between 5 and 15 percent of screening mammograms require multiple tests, such as additional mammograms or ultrasounds. Most of these tests are normal. If there is an abnormal finding, it may be necessary to monitor the patient or, less frequently, to perform a biopsy.

  • Based on statistical studies of cancer incidence over time, some researchers have suggested that breast cancer screening identifies both potentially fatal disease and disease that would never have caused symptoms during a patient's lifetime, a phenomenon called overdiagnosis.

  • Overdiagnosis of breast cancer is likely to be very small. Scientists are working on methods to classify abnormal cells according to their potential to cause harm; however, at this time, physicians have no way to distinguish cancer cells that are not life-threatening from those that will cause advanced disease.

  • Women should always inform their doctor if there is any possibility that they are pregnant.

It's up to you! Don't miss your breast exam!

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Benefits and risks of breast ultrasound


  • Ultrasound is noninvasive (no needles or injections are used).

  • Occasionally, an ultrasound examination may be temporarily uncomfortable, but it is almost never painful.

  • Ultrasound is widely available, easy to use and less expensive than other imaging methods.

  • Ultrasound imaging is extremely safe and does not use ionizing radiation.

  • Breast ultrasound can provide a clear image of soft tissues that are not very visible on X-ray images.

  • Ultrasound imaging can help detect lesions in women with dense breasts that may not be visible on mammography.


For standard diagnostic ultrasound scans, there are no known adverse effects on patients. The interpretation of a breast ultrasound may result in additional procedures, such as monitoring and/or aspiration ultrasound or biopsy. Many of the areas considered to be of concern after a breast ultrasound are found to be non-cancerous (benign).

It's up to you! Don't miss your breast screening!

Chequeo de mama

Benefits and risks of breast magnetic resonance imaging


  • MRI is a non-invasive imaging technique that does not involve exposure to ionizing radiation.

  • MRI has proven valuable in detecting breast cancer and cancers that are not visible on mammography or ultrasound.

  • The ability of MRI to detect breast cancer does not appear to be compromised by breast density.

  • MRI complementary to mammography has been shown to be useful in evaluating women at high risk for breast cancer.

  • If a suspicious lesion is seen by MRI alone, MRI can serve as a guide for biopsy.


  • Many possible abnormalities seen on MRI turn out to be benign (false positives).

  • MRI poses almost no risk to the average patient when proper safety rules are followed.

  • Although the strong magnetic field is not harmful in itself, implanted medical devices containing metal can malfunction or cause problems during an MRI exam.

  • There is a very small risk of an allergic reaction if a contrast agent is injected. These reactions are usually mild and easily controlled with anti-allergic drugs.

  • Nephrogenic systemic fibrosis. Currently a recognized but rare complication of MRI, thought to be caused by the injection of high doses of gadolinium contrast agent in patients with very poor renal function.

  • Manufacturers of intravenous contrast recommend that mothers do not breastfeed their babies for 24 to 48 hours after administration of the contrast agent.

It's up to you! Don't miss your breast screening!

Chequeo de mama