Table 1.
Studies | Study populations | Patients with breast cancer | Patients with known breast cancer, n (%) | |
---|---|---|---|---|
Total | 83 | 91 | 26 788 | 24 213 (90.4%) |
| ||||
Race | ||||
Black† | 75 | 76 | 18 805 | 16 669 (88.6%) |
Non-black‡ | 8 | 15 | 7983 | 7544 (94.5%) |
| ||||
Region or country | ||||
Western Africa | 48 | 49 | ||
Nigeria | 36 | 37 | 8623 | 8407 (97.5%) |
Benin | 2 | 2 | 204 | 204 (100%) |
Ghana | 5 | 5 | 1969 | 1191 (60.5%) |
Mali | 2 | 2 | 324 | 324 (100%) |
Other§ | 3 | 3 | 797 | 719 (90.2%) |
Eastern or middle Africa | 19 | 19 | ||
Tanzania | 5 | 5 | 1310 | 1151 (87.7%) |
Kenya | 2 | 2 | 287 | 157 (54.7%) |
Ethiopia | 3 | 3 | 1267 | 841 (66.4%) |
Madagascar | 2 | 2 | 289 | 233 (80.6%) |
Uganda | 3 | 3 | 562 | 502 (89.3%) |
Other¶ | 4 | 4 | 445 | 302 (67.9%) |
Southern Africa | 16 | 23 | ||
South Africa | 16 | 23 | 10 711 | 10 182 (95.1%) |
| ||||
Study design | ||||
Convenience case series | 48 | 55 | 10 780 | 9788 (90.8%) |
Consecutive case series | 35 | 36 | 16 008 | 14 425 (90.1%) |
| ||||
Study population | ||||
Urban | 27 | 34 | 15 571 | 14 208 (91.2%) |
Mixed (rural and urban) | 56 | 57 | 11 217 | 10 005 (89.2%) |
| ||||
Type of health facility | ||||
Tertiary, secondary, or primary‖ | 9 | 12 | 1639 | 1503 (91.7%) |
Tertiary | 72 | 77 | 24 742 | 22 399 (90.5%) |
Not reported in original study | 2 | 2 | 407 | 311 (76.4%) |
| ||||
Age at diagnosis (years)** | ||||
<45 years | 28 | 29 | 5475 | 4840 (88.4%) |
>45 to <50 years | 36 | 37 | 7882 | 7218 (91.6%) |
>50 years | 16 | 22 | 11 056 | 9841 (89.0%) |
Not reported in original study | 3 | 3 | 2375 | 2314 (97.4%) |
| ||||
Year of diagnosis†† | ||||
Before 1980 | 11 | 16 | 3971 | 3782 (95.2%) |
1980–1999 | 32 | 34 | 11 125 | 10 737 (96.5%) |
2000 or after | 33 | 33 | 8648 | 6733 (77.8%) |
Not reported in original study | 7 | 8 | 3044 | 2961 (97.3%) |
| ||||
Staging methods | ||||
Clinical and imaging | 25 | 26 | 10 416 | 9516 (91.4%) |
Clinical only | 10 | 10 | 975 | 967 (99.2%) |
Not reported in original study | 48 | 55 | 15 397 | 13 730 (89.2%) |
| ||||
Staging classification | ||||
TNM | 50 | 57 | 20 388 | 18 048 (88.5%) |
Manchester | 11 | 11 | 1436 | 1426 (99.3%) |
Not reported in original study | 22 | 23 | 4964 | 4739 (95.5%) |
| ||||
Study quality scores‡‡ | ||||
>23 (highest quality) | 12 | 12 | 4067 | 3569 (87.8%) |
22–20 | 26 | 27 | 6181 | 5721 (92.6%) |
19–17 | 31 | 38 | 14 541 | 13 327 (91.7%) |
<17 (lowest quality) | 14 | 14 | 1999 | 1596 (79.8%) |
Data are n or n (%). TNM=Tumour, Lymph Node, and Metastasis staging system.
Five studies provided separate estimates for different subsets of participants (ie, for pregnant or lactating and non-pregnant or non-lactating women27 or different ethnic groups12,28–30).
Includes seven southern African studies12,28–30,39–41 that reported estimates for black women only; one southern African study18 that presented only an overall (all ethnic groups combined) estimate, but reported that >80% of their study population was black; nine studies5,37,38,42–47 from western and eastern Africa that were done exclusively in black women, as well as the remaining 58 studies from these two regions that did not report on race, but were assumed to have been done in predominantly black women (ie, >80% black; see appendix p 14), which corresponded to 76 study population groups because one Nigerian study27 presented separate estimates for pregnant or lactating and non-pregnant or non-lactating women (appendix p 14).
Includes 15 southern African study population groups: four studies14,48–50 that did not report on race but were assumed to be predominantly non-black, four studies36,51–53 that present only overall estimates but reported an ethnically mixed population with ≤80% being black, and four multi-ethnic studies12,28–30 that together reported separate estimates for seven non-black population groups (appendix p 14).
Includes one study from Guinea (178 cases, 124 cases with known stage), one from Niger (146 cases, 146 cases with known stage), and one from Senegal (473 cases, 449 cases with known stage).
Includes one study from Rwanda (145 cases, seven cases with known stage), one from Zimbabwe (84 cases, 79 cases with known stage), one from Eritrea (82 cases, 82 cases with known stage), and one from Democratic Republic of the Congo (formerly known as Zaire; 134 cases, 134 cases with known stage).
All studies that recruited participants from secondary and primary health centres also included a tertiary centre.
Mean or median age at breast cancer diagnosis. If only age categories were reported, mean or median age was estimated from the mid-point and the reported number in each age category. The three studies in which age was not reported in the original category did not provide sufficient information to allow their allocation into one of the three age categories: Ajekigbe54 reported that 50.8% of the participants were aged <50 years; Amir and colleagues55 reported that 90% of the participants were aged <50 years; and Pegoraro and colleagues36 reported that 50% were between aged 45–64 years (appendix p 14).
Middle year of the time interval during which patients were recruited.
Categories represent quartiles of the overall score distribution (appendix p 9).