|Year : 2019 | Volume
| Issue : 1 | Page : 23-27
Suspicious and malignant features on mammogram among women in a group of communities within south east Nigeria
Eric O Umeh, Uzoamaka R Ebubedike, Brenda C Nwammuo
Radiology Department, Nnamdi Azikiwe University Teaching Hospital (NAUTH), Nnewi, Nigeria
|Date of Web Publication||1-Aug-2019|
Dr. Eric O Umeh
Radiology Department, Nnamdi Azikiwe University Teaching Hospital (NAUTH), Nnewi
Source of Support: None, Conflict of Interest: None
Introduction: Mammography services are not widely available in Nigeria due to inadequate numbers of mammography machines and shortage of the relevant skilled personnel. However, diagnostic and screening mammography was recently introduced at centre near Onitsha in south-east Nigeria to serve the immediate catchment area and surrounding communities. Objective: To determine the prevalence of suspicious findings and features suggestive of breast cancer (BIRADS categories 4, 5 and 6) among mammograms for women presenting at mammography imaging centre. Methodology: Retrospective study reviewing mammograms done at the Iyienu Mission Hospital between January 2013 and December 2015. Final BIRADS Categorization in line with the BIRADS lexicon was reported based on mammography findings and clinical history for each subject. Results: Mean age of study population was 49.1 years ±8.1. Mammographic findings for five percent of subjects were categorized BIRADS 4, while one (0.2%) was categorized BIRADS 5, and four (0.7%) were BIRADS Category 6. The proportion of cases within each age group categorized BIRADS 4 - 6 was 10.1% among subjects aged less than 40 years (p-value 0.19), 5.2% for subjects aged between 41 and 60 years (p-value 0.12) and 10.0% among subjects aged greater than 60 years (p-value 0.32). Conclusion: Study findings suggest higher prevalence of suspicious and malignant findings among the elderly, as well as young women. Future re-assessment of findings desirable using larger sample size. Initiatives for enlightenment on the relevance of cancer screening methods should target middle aged and elderly women, as well as younger women, especially those at risk.
Keywords: Breast, malignant, mammogram
|How to cite this article:|
Umeh EO, Ebubedike UR, Nwammuo BC. Suspicious and malignant features on mammogram among women in a group of communities within south east Nigeria. Int J Med Health Dev 2019;24:23-7
|How to cite this URL:|
Umeh EO, Ebubedike UR, Nwammuo BC. Suspicious and malignant features on mammogram among women in a group of communities within south east Nigeria. Int J Med Health Dev [serial online] 2019 [cited 2019 Dec 5];24:23-7. Available from: http://www.ijmhdev.com/text.asp?2019/24/1/23/263542
| Introduction|| |
Breast cancer is the most common malignancy among females in Nigeria, with the country’s breast cancer death rate ranked seventh in the world by the World Health Organization.,, Also, new cases of breast cancer appear to be on the increase in Nigeria with an incidence of 36.3 to 50.2/100,000 live births and are responsible for 16% of cancer-related deaths in the country.,, High mortality rate and poor outcome from breast cancer have been reported in the country and are linked to late presentation at an advanced stage of the disease possibly due to such factors as ignorance about breast cancer screening, lack of access to care, superstition, fear of mastectomy, and poverty.,
Mammography is the standard imaging technique for the early detection of breast cancer. However, mammography services are not widely available in Nigeria due to inadequate numbers of mammography machines and shortage of the relevant skilled personnel. Also, awareness about the imaging technique and its benefits is only just gaining ground within the country. Mammography services usually exist in two forms: screening mammography performed to facilitate early detection of breast cancer among asymptomatic women resulting in reduced mortality from the disease as obtained in many western countries and diagnostic mammography that is performed for women who present with signs and symptoms of breast disease such as palpable breast lump, breast pain, and nipple discharge.,,,, The sensitivity of mammography in the detection of breast cancer is between 83% and 95%., It is lower among young and nulliparous women due to increased breast density, and lesion detection may be dependent on timing within the menstrual cycle, quality of the acquired mammography images, and the interpretative skills of the radiologist.,, Suspicious findings and features suggestive of malignancy on mammogram are categorized as 4, 5, and 6, respectively by the American College of Radiology (ACR) Breast Imaging Reporting and Data System (BIRADS) classification. The ACR-BIRADS 5th edition proposed seven categories for mammographic findings, with categories 4, 5, and 6 relevant in this study. Category 4 (2%–95% likelihood of malignancy) signifies mammographic appearances suspicious for malignancy and do not show the classic features of malignancy but are sufficiently suspicious to justify a biopsy recommendation. Category 5 signifies features highly suggestive of malignancy with very high probability for malignancy (≥95%). In Category 6, breast cancer is biopsy proven. Features indicative of breast lesion on mammogram that call for suspicion or indicate malignancy include speculated or irregular outline, poorly defined opacity, high density, fine linear or branching segmental calcification, cluster of microcalcification with segmental or galactophorous distribution, nipple retraction, skin thickening, and evidence of interval growth.
Mammography services including diagnostic imaging and breast cancer screening were recently introduced at a mission-owned secondary health center near Onitsha, Anambra state, in southeast Nigeria to facilitate the early detection of breast cancer and prompt treatment for the affected women. Prior to this initiative, efforts at early detection of breast cancer were limited to public enlightenment campaigns about breast cancer, advocacy to correct uneducated beliefs, and the promotion of breast self-examination by health personnel for women in the communities as described by Olasehinde et al. This facility was installed and adequately staffed to serve the immediate catchment areas including the city of Onitsha and environs with an estimated population of 1.4 million (National Population Commission) comprising approximately a third of the overall population of the state, which is the most densely populated in the southeast region of Nigeria. This study aimed to determine the prevalence of suspicious findings and features suggestive or indicative of breast cancer (ACR-BIRADS categories 4, 5, and 6) among mammograms for women at this center in southeast Nigeria.
| Materials and Methods|| |
This is a retrospective study reviewing the mammograms of 544 women presenting for diagnostic or screening mammography at the Iyi-Enu Mission Hospital between January 2013 and December 2015. At this center, screening mammography is performed on women aged 40 years and older, as well as those aged between 25 and 39 years with a positive family of breast cancer. Diagnostic mammography was also carried out for women of same age groups on referral. Demographic information and family history were obtained from the participants and documented, including subject’s age and history of previous mastectomy due to breast cancer. Participants underwent clinical breast examination before undergoing mammography. Mammograms performed on the contralateral breast for subjects with history of previous mastectomy were included in this study, whereas mammograms for lactating women were excluded.
The Metaltronica Denominazione/Equipment Mammo 10 machine was used in this study. Each subject was told to remove upper clothing and to wipe off artifact causing substances such as talc from regions of breast and armpit. Two standard views, cranio-caudal (CC) and mediolateral oblique (MLO), were carried out on each breast for each participant. For the CC view, height of the machine table was set at level of the inframammary crease. The breast was placed firmly in contact with the film horizontally with nipple in profile and skin wrinkles and folds smoothened out. Each subject stood erect, arms at sides, and face turned away from side being imaged. Compression of the breasts and close collimation were performed by the imaging scientist, and the central ray was made to pass through the center of base of the breast and perpendicular to the film. For the MLO view, each subject stood erect with breast supported by the film holder in the oblique sagittal position, rotated 45° and nipple in profile. Following close collimation and compression, the central ray was allowed to pass as performed in the CC view.
Mammograms were evaluated by one of two radiologists involved in this study, and findings documented include the mammographic breast composition, i.e. “a” category (almost entirely fatty), “b” category (scattered areas of fibroglandular density), “c” category (breasts are heterogeneously dense, which may obscure small masses), and “d” category (breasts are extremely dense), which lowers the sensitivity of mammography., Also documented were the presence and location of breast opacity, asymmetric density, nipple retraction, skin thickening, calcification, architectural distortion, and presence of axillary lymphadenopathy. Following an evaluation of the mammograms for breast composition and possible findings, also noting the indications for the study and the clinical history, the conclusion to a final assessment category was performed using the BIRADS categories 0–6 and the phrases associated with them.
Statistical analysis of the obtained data was conducted using the Statistical Package for the Social sciences version 20.0 for Windows (IBM Corporation). Associations between numeric variables were compared using the Student’s t test, whereas categorical variables were explored with the chi-square test. Associations were deemed significant if P value < 0.05.
| Results|| |
Mean age of study population was 49.1 years ± 8.1, with a range of 28–75 years and median age of 48 years. [Table 1] shows that the largest and smallest age groups were 40–49 years (50.6%) and <40 years (5.9%), respectively. [Figure 1] shows the mammographic breast pattern for the right and left breasts were “c” category (heterogeneous dense [45.0% and 45.4%]), “b” category (scattered areas of fibroglandular density [26.7% and 26.5%]), “a” category (almost entirely fatty [24.6% and 24.5%]), and “d” category (homogenous dense [3.7% and 3.7%]). [Table 2] shows positive correlation between younger participants (<40 years) and the homogenous dense and heterogeneous fibroglandular pattern, and older participants (>60 years) with the fatty replaced and scattered fibroglandular breast pattern. [Table 3] shows largest proportion of cases (36.4%) were classified BIRADS Category 2, whereas 22.2%, 19.9%, 15.6%, and 5.0% were BIRADS categories 3, 0, 1, and 4 respectively. One subject (0.2%) was categorized BIRADS 5, whereas four patients (0.7%) were previously diagnosed with breast cancer (BIRADS Category 6) and undergone mastectomy on the affected breast. As seen in [Table 4], the proportion of cases within each age group categorized BIRADS 4–6 was 10.1% among subjects aged less than 40 years (P value 0.19), 5.2% for subjects aged between 41 and 60 years (P value 0.12), and 10.0% among subjects aged greater than 60 years (P value 0.32)., , , ,
| Discussion|| |
The mean age and most prevalent age group among women presenting for mammography at this center are fairly similar to figures from previous studies conducted at screening mammography in the north central region and among referred cases for mammography in the southwest region of Nigeria., The awareness campaigns conducted within the benefitting communities during the installation of the mammography imaging equipment clearly stated the age groups for women undergoing mammography, likely accounting for the most common age groups among presenters at 40–49 years (50.6%) and 50 years and above (43.6%). Also, the predominant age groups for subjects in this study may be indicative of greater awareness, interest, and positive attitude toward breast care among vulnerable groups within the communities, as well as willingness on the part of sensitized women to undergo mammographic breast examination during their active, reproductive, and perimenopausal years. Just over half of the participants (51.3%) had less dense breasts on mammography comprising the “b” category (scattered areas of fibroglandular density) and “a” category (almost entirely fatty), facilitating the evaluation of mammograms by the reporting radiologists and reducing the likelihood of false negatives. The study showed changes in the mammographic breast pattern with age, showing a positive correlation between younger participants (<40 years) and the “d” category (breasts are extremely dense), and the “c” category (breasts are heterogeneously dense), whereas older participants (>60 years) show positive correlation with the “a” category (almost entirely fatty) and “b” category (scattered areas of fibroglandular density), which are consistent with the expected changes in breast density with age largely due to an altered balance between quantities of fat and glandular tissue within the breast. Greater proportion of participants in the study showed less dense breasts on mammography (the “a” and “b” categories), which is consistent with findings from previous studies among women at screening mammography in the southwest and north central regions of Nigeria., Mammographic findings among our study participants were most frequently categorized ACR-BIRADS 2—benign finding (36.4%). There is some variation in the proportions of benign findings reported among women in combined screening and diagnostic mammography studies ranging from 6.4% in Sokoto, 29.6% in Enugu, and 51.2% in Lagos. It is possible that the awareness campaigns carried out within the communities benefitting from mammography services may have attracted women with preexisting breast symptoms or lesions that turned out to be predominantly benign on mammography.
Mammographic findings for participants in this study were classified as ACR-BIRADS category 4, 5, and 6 in 5.0%, 0.2%, and 0.7% of cases, respectively. However, wide variations in the proportions of suspicious (ACR-BIRADS 4) and likely malignant (ACR-BIRADS 5) findings on mammography may be reported among asymptomatic and symptomatic study groups in comparison with mixed study groups as is the case in this study. For instance, Shankar et al. reported significantly higher proportions for ACR-BIRADS 4 (31%) and ACR-BIRADS 5 (9%) among Indian women with symptomatic breast lesions. Also, the observed proportions of ACR-BIRADS 4 and 5 mammograms in this study are higher than the 0.4% of mammograms of same ACR-BIRADS categories among Brazilian asymptomatic women reported by Silva et al.. The observed variations in findings may be explained by the inclusion of only symptomatic women in the Indian study and asymptomatic women within a specific age group of interest (40–49 years) in the Brazilian study.
This study results show that women in the age groups younger than 40 years and older than 60 years showed the highest proportion of ACR-BIRADS categories 4, 5, and 6 within their respective age groups (10.1% and 10.0%, respectively) compared to 5.2% for females aged 40–60 years. These findings were not statistically significant. However, there is literature based on previous study reports on the diagnosis of breast cancer at an early age among black women.,,, Breast cancer in black women is reportedly more often diagnosed at an earlier age than white women and with a more aggressive disease. Peak age incidence of breast cancer in Nigeria as reported by various authors shows significant proportion of cases occur before middle age. Poopoola et al.6 reported 25% of breast cancer cases among women in Lagos Nigeria within age range 30–39 years, whereas Ihekwaba reported 70% of breast cancer cases among Nigerian women diagnosed between 26 and 50 years of age. Also, a previous study among women in southeastern Nigeria puts the mean and peak age for breast cancer at 44 years and 35–39 years, respectively. However, as stated earlier, findings from this study on the proportions of suspicious and malignant cases on mammography within age groups are not statistically significant and will need to be explored further using larger sample size for clarity.
| Conclusion|| |
The availability and utilization of mammography services for both diagnostic and screening purposes within the benefitting communities provide some insight into the prevalence and distribution of suspicious and malignant breast lesions. Study findings appear indicative of comparatively higher prevalence of suspicious and malignant findings on mammography among the elderly, as well as the young. Hence, in addition to targeting the middle-aged and elderly women for enlightenment on the relevance of the available breast evaluation and cancer screening methods, there is also the need to further target younger women for same, especially those at high risk.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4]