Univariate analysis comparing patient demographic characteristics, pathologic features and stage between breast cancers staged in the 2 years before the COVID-19 pandemic and in the first year of the pandemic
| Variable | No. (%) of cases* | Standardized difference | Stochastic dominance | OR (95% CI) | |
|---|---|---|---|---|---|
| 2 years before pandemic n = 788 | First year of pandemic n = 387 | ||||
| No. of cases per 30 d, mean | 32.4 | 31.8 | NA | ||
| Age, yr, median (IQR) | 64 (54–72) | 65 (55–73) | −0.079 | – | NA |
| Sex | |||||
| Female | 782 (99.2) | 383 (99.0) | 0.029 | 0.501 | 0.80 (0.22–2.85) |
| Male | 6 (0.8) | 4 (1.0) | 1.25 (0.35–4.46) | ||
| Screening-detected | |||||
| No | 462 (59.2) | 243 (63.0) | 0.078 | 0.481 | 1.16 (0.91–1.49) |
| Yes | 319 (40.8) | 143 (37.0) | 0.85 (0.66–1.09) | ||
| NA | 7 | 1 | |||
| Histologic subtype | |||||
| Ductal | 559 (71.1) | 273 (70.9) | 0.120 | – | 0.99 (0.76–1.29) |
| Lobular | 136 (17.3) | 60 (15.6) | 0.88 (0.63–1.23) | ||
| Mucinous | 31 (3.9) | 12 (3.1) | 0.79 (0.40–1.55) | ||
| Other | 60 (7.6) | 40 (10.4) | 1.41 (0.93–2.15) | ||
| NA | 2 | 2 | |||
| Grade | |||||
| 1 | 189 (24.2) | 97 (25.5) | 0.092 | 0.480 | 1.07 (0.81–1.42) |
| 2 | 369 (47.3) | 191 (50.1) | 1.12 (0.88–1.43) | ||
| 3 | 222 (28.5) | 93 (24.4) | 0.81 (0.61–1.07) | ||
| NA | 8 | 6 | |||
| Lymphovascular invasion | 142 (18.0) | 65 (16.8) | 0.032 | 0.494 | 0.92 (0.67–1.27) |
| Hormone status | 0.035 | ||||
| Other | 686 (87.4) | 342 (88.4) | 0.495 | 1.10 (0.76–1.60) | |
| HER2-overexpressed | 39 (5.0) | 19 (4.9) | 0.98 (0.56–1.72) | ||
| Triple-negative | 60 (7.6) | 26 (6.7) | 0.87 (0.54–1.41) | ||
| NA | 3 | 0 | |||
| Positive margin | 72 (9.1) | 39 (10.1) | 0.032 | 0.505 | 1.12 (0.74–1.69) |
| Extensive intraductal component | 78 (9.9) | 40 (10.3) | 0.015 | 0.502 | 1.05 (0.70–1.56) |
| Stage | |||||
| I | 420 (53.5) | 199 (51.7) | – | 0.508 | 0.93 (0.73–1.19) |
| II | 283 (36.0) | 145 (37.7) | 1.07 (0.83–1.38) | ||
| III | 82 (10.4) | 41 (10.6) | 1.02 (0.69–1.52) | ||
| NA | 3 | 2 | |||
Note: CI = confidence interval, HER2 = human epidermal growth factor receptor-2, IQR = interquartile range, NA = not applicable, OR = odds ratio.
↵* Except where noted otherwise.