Is Breast transillumination a viable option for breast cancer screening in limited resource settings?

Authors: Elobu EA1 M.Med, Galukande M1 M M.Med, MSc, FCS, Namuguzi D1 M.Med, Muyinda Z2 M.Med. Affiliations:

 1-Department of Surgery, College of Health Sciences, Makerere University 2-Department of Radiology, Mulago National Referral Hospital, Uganda Correspondence: Moses Galukande, Department of Surgery, College of Health Sciences, Makerere University P. O. Box 7072 Kampala, Uganda Email:

 

Abstract

Background: Mammography is an established screening tool for breast cancer in high-income countries but may not be feasible for most re-source poor nations. Alternative modalities are needed to mitigate the impact of the increasing incidence and mortality due to breast cancer. This may require the development of new technologies or reevaluation of old technologies applicable to resource limited settings.

 

Objective: To determine the sensitivity and specificity of breast transil-lumination as compared to mammography and to describe features of benign and malignant breast lesions as seen with breast transil-lumination.

 

Methods: A single group descriptive analytical study was conducted over a six month period (2011) in the breast unit of Mulago National hospital. Eligible participants were consecutively sampled. Participants underwent Clinical Breast Examination (CBE), breast transillumination (BT), mammography (MG) and histopathological analysis of identified breast lumps. Sensitivity, specificity and predictive values were calculated. Features of the masses detected by transillumination were then described.

 

Results: The number of participants recruited was 201 (mean age 42 years, range 30-80 years). The average palpable lump size was 3.8 cm (range 0.5 to 10 cm). BT had a sensitivity of 63.2% (PPV 86.8%) and a specificity of 89.5% (NPV 61.2%) with mammography as the reference standard. Also, 73.3% of breast lumps with irregular margins and 88.5% with dense opacity at transillumination turn out to be malignant at histopathology examination.

 

Conclusion: The Breast transillumination technique had a moderate sensitivity of 63.2%. This warrants a large scale population-based evaluation of BT as a screening tool. This technique may not substitute mammography but to be considered an option where mammography access is limited.

Introduction

Breast cancer accounts for about one third of all cancers diagnosed globally with both incidence and mortality re-ported to be increasing in sub-Saharan Africa. In Uganda breast cancer is the third most commonly diagnosed can-cer after Kaposi’s sarcoma and cancer of the cervix (1). The majority (77%) of women present in late stages (III & IV) with low 5-year survival (of 39%). In the past, resource allocation for health was skewed towards infectious dis-eases such as HIV/AIDS and malaria. Currently however, a rapidly growing burden of non-communicable diseases (NCDs) is demanding similar attention.

 

Screening reduces mortality due to breast cancer. Mam-mography has been shown to reduce breast cancer mor-tality by up to 25-30 % in women over 50 years old (2-4). Access to mammography is limited in developing countries. There are currently only a handful of mam-mography machines in Uganda which are not equitably distributed and some charge a fee thus precluding access for most women (5). Women below the age of 30 years are ineligible for mammography yet a sizeable portion of them are at risk and therefore need some form of screen-ing. Alternative screening modalities should therefore be explored either by re-evaluation of old techniques or in-vention of new ones (6,7). Culter first described the use of breast transillumination some 80 years ago (8). Advent of x-rays and mammogra-phy led to its abandon. There is justification for its revalu-ation with a view to determining its utility in areas where there is no mammography. The Breast light is a commer-cially available modification of earlier prototypes used for breast transillumination. It is comparatively much cheaper than mammography, easy to use and has mini-mal running costs.

 

The primary aim of this study therefore was to determine the sensitivity, specificity and predictive values of breast transillumination compared to mammography in a hos-pital setting. Is Breast transillumination a viable option for breast cancer screening in limited resource settings? Elobu EA, Galukande M, Namuguzi D, Muyinda Z

 

Methods

A descriptive study was conducted from January to June 2011 in the breast unit of Mulago Hospital, one of three national referral hospitals but the only public hospital with comprehensive breast care services in the country. Mulago has a bed capacity of 1500 and is the teaching Hospital for Makerere University College of Health Sci-ences. The outpatient Breast Clinic runs once a week and in the past three years over 600 incident cases of breast cancer were registered there.

 

All women aged 30 years or more who attended the breast clinic were prospectively included. Pregnant or lactating women and those with ulcerated breast lesions were excluded because of radiation risks in pregnancy and high breast density during lactation which inter-feres with mammography interpretation respectively. The sample size was determined using the formula for sample size for a descriptive study of a dichotomous variable (6, 7), alpha was 0.05 for 95% confidence interval, a sensitivity of BT of 67% was used. Consecutive sampling was done.

Procedure

CBE was performed to determine the presence or absence of a breast lump prior to transillumination. At transil-lumination, the number, size, site, density of opacity and regularity of margins of detected lumps were noted. Opacity was measured against a three point scale devised for this study as translucent, opaque or densely opaque. A lump with more than three quarters of its margin being even was considered regular, less than ¾ was considered irregular.

 

  • Translucent – most light comes through (Red/pink)

  • Opaque – some light comes through (Gray)

  • Densely opaque – no light comes through (Black)

 

In a dark room, the Breast light (model BL 801 manufac-tured by PWB health, G82 3PW, UK) was used by a single observer to examine the woman’s breasts in seated posi-tion with the arms raised to hold the back of the head. A water based gel lubricant was applied to both breasts to ease the examination for the user and make it more com-fortable for the participant. The light was switched on and applied firmly to the skin on the inferior aspect of the breast beginning with the right, thereby giving a cranio-caudal view. The Breast light was moved to either side up to the edge of the breast. The light was then moved for-ward and upwards over the breast to ensure that all parts of the breast were transilluminated. The Breast light was finally moved superolaterally along the milk line towards the axilla to examine the axillary tail. At all times the in-vestigator observed the transmission of light through the breast at a point directly opposite the light bulb of the Breast light. The same was repeated on the left breast. The participant was cleaned and allowed to dress.

Mammography was performed on all participants and read as normal (BI-RADS 1) or abnormal (BI-RADS 2-5) by a total of four consultant radiologists at different times. Participants who had a clinically palpable abnor-mality and consented underwent a core needle biopsy. Histopathological analysis was performed by an experi-enced team of pathologists. Findings were recorded in a structured data collection tool.

 

The investigators performing the breast transillumina-tion, mammography and histological examination were blinded to findings of any of the other tests.