1. Aetna considers transillumination (light scanning or diaphanography) of the breast experimental and investigational because this technique has not been established by the peer-reviewed medical literature to be an acceptable alternative to conventional mammography in detecting breast cancer.

2. Aetna considers electrical impedance scanning (EIS) of the breast to be experimental and investigational because there is inadequate evidence in the peer-reviewed published medical literature of the ability of this method to distinguish benign from malignant breast lesions or the effectiveness of EIS of the breast in improving clinical outcomes.

See also CPB 105 - Magnetic Resonance Imaging (MRI) of the Breast; CPB 269 - Breast Biopsy Procedures; CPB 337 - BreastAlert Differential Temperature Sensor; CPB 517 - Breast Ductal Lavage and Fiberoptic Ductoscopy; and CPB 584 - Mammography.

Based on the theory that normal and abnormal tissues reflect different light intensities, transilluminators have been created to screen and diagnose cancers of the breast. One such breast transilluminator, the Lintroscan (Lintronics Technologies) produces video film of breast tissue with visible and infrared light passing through it for detection of breast abnormalities. Breast transilluminators have not been proven to be an acceptable alternative to conventional mammography. An Agency for Healthcare Research and Quality Clinical Practice Guideline (Bassett et al, 1994) concluded that “[l]ight scanning (diaphanography and transillumination) should not be used for screening or diagnostic evaluation of the breast”. The British Columbia Cancer Agency (2001) has concluded that “[a]t the present state of development, transillumination is not an appropriate imaging device for breast cancer screening.”

Experimental studies have shown that significant changes occur in the electrical properties of breast cancer tissue compared to the surrounding normal tissue. This phenomenon motivated studies on cancer detection using electrical impedance techniques. Some evidence has been found that malignant breast tumors have lower electrical impedance than surrounding normal tissues. This observation has led to the proposal that electrical impedance could be used as an indicator for breast cancer detection. However, the separation of malignant tumors from benign lesions based on impedance measurements needs further investigation. There are no prospective clinical studies demonstrating the clinical utility of electrical impedance scanning (EIS) in distinguishing benign from malignant breast lesions, either in place of or as an adjunct to mammography or magnetic resonance imaging. An assessment of technologies for breast cancer screening and diagnosis conducted by the Institute of Medicine of the National Academy of Sciences (2001) concluded that “[c]linical data suggest the technology [EIS] could play a role in breast cancer detection, but more study is needed to define a role in relation to existing technologies.”

Stojadinovic et al (2005) presented preliminary results on the use of EIS for the early detection of breast cancer in young women. They stated that EIS appears promising for early detection of breast cancer, and identification of young women at increased risk for having the disease at time of screening. Positive EIS-associated breast cancer risk compares favorably with relative risks of conditions commonly used to justify early breast cancer screening. The authors also noted that more data are needed to ascertain more accurately the actual sensitivity. These investigators also believe that EIS has promise as a breast cancer screening modality for a group of women for whom no effective screening modality currently exists. EIS seems to identify a population at increased risk for having breast cancer for whom further imaging examinations may be warranted.

On August 29, 2006, the Food and Drug Administration (FDA)'s Obstetrics and Gynecology Devices Panel voted unanimously not to recommend approval of Mirabel Medical Systems' T-Scan 2000 ED bioimpedance device, which is designed to evaluate the risk of breast cancer in asymptomatic women aged 30 to 39 years with no family history of breast cancer and no other known risk factors. The device would be employed in combination with clinical breast examination for this age group whose annual examination does not usually entail mammography.

The FDA panel decided that the data did not provide a reasonable assurance of the effectiveness to support the device's proposed indication. Furthermore, some panel members were concerned with other aspects of the clinical trial: (i) the apparent differences in the characteristics of the two trial populations (1751 women aged 30 to 39 years in the study arm designed to measure specificity and 390 women aged 30 to 45 years in the study arm measuring sensitivity), (ii) a lack of ethnicity data, and (iii) a "high" false positive rate (Taulbee, 2006).

Blackmore et al (2007) stated that risk assessment by parenchymal density pattern, a strong physical indicator of future breast cancer risk, is available with the onset of mammographic screening programmes. However, due to the use of ionizing radiation, mammography is not recommended for use in younger women, thereby rendering risk assessment unattainable at an earlier age. These investigators reported on the use of visible and near infra-red light on 292 women with radiologically normal mammograms to determine if transillumination breast spectroscopy (TIBS) can identify women with a high parenchymal density pattern as an intermediate indicator of breast cancer risk. Principal component analysis was used to reduce the spectral data and generate density scores for each woman. To assess the accuracy of TIBS, logistic regression was used to calculate crude and adjusted odds ratios (OR) and 95 % confidence intervals (CI) for each score. Receiver operator characteristic curves and area under the curve (AUC) were also calculated for the crude and adjusted logistic models. Optical information relating to tissue chromophores, such as water, lipid and haemoglobin content, was sufficient to identify women with high parenchymal density. The resulting AUC for the final and most parsimonious multi-variate logistic model was 0.922 (95 % CI 0.878 - 0.967). The authors concluded that TIBS provides information correlating to high parenchymal density and is a promising tool for risk assessment, particularly for younger women.

In a prospective, two-cohort trial of pre-menopausal women, Stojadinovic et al (2008) estimated the relative probability of breast cancer in T-Scan+ women compared to randomly selected young women. The Specificity (S(p))-Cohort evaluated T-Scan specificity in 1,751 asymptomatic women aged 30 to 39. The Sensitivity)S(n))-Cohort evaluated T-Scan sensitivity in 390 women aged 45 to 30 scheduled for biopsy. Specificity, sensitivity, and conservative estimate of disease prevalence were used to calculate relative probability. In the S(p)-Cohort, 93 of 1,751 women were T-Scan+ (S(p) = 94.7 %; 95 % CI: 93.7 - 95.7 %). In the S(n)-Cohort, 23 of 87 biopsy-proven cancers were T-Scan+ (S(n) = 26.4 %; 95 % CI: 17.4 - 35.4%). Given S(p) = 94.7 %, S(n) = 26.4 % and prevalence of 1.5 cancers/1,000 women (aged 30 to 39), the relative probability of a T-Scan+ woman having Br-Ca is 4.95: (95 % CI: 3.16 - 7.14). The authors concluded that EIS can identify a subset of young women with a relative probability of breast cancer almost 5 times greater than in the population of young women at-large. The drawbacks of this study were discussed by the afore-mentioned FDA panel.