Table 1.
Study Population by Chief Complaint
| Breast lump N = 300 |
Rectal bleeding N = 300 |
p value* | |
|---|---|---|---|
| General patient characteristics | |||
| Age in years, mean ± standard deviation (SD) | 47 ± 11 | 56 ± 10 | < 0.01 |
| Age 30–39 years, % (n) | 25% (76) | – | NA |
| 40–49 | 42% (127) | 33% (98) | |
| 50–59 | 18% (53) | 35% (106) | |
| 60–69 | 9% (27) | 22% (65) | |
| ≥ 70 | 6% (17) | 10% (31) | |
| Female (%) | 100% (300) | 45% | < 0.01 |
| White race/ethnicity, % (n) | 36% (108) | 37% (111) | |
| Hispanic/Latino | 29% (88) | 27% (80) | |
| African American | 21% (63) | 21% (63) | 0.19 |
| Asian/Pacific Islander | 3% (10) | 8% (23) | |
| Other/unknown | 10% (24) | 7% (23) | |
| English as primary language, % (n) | 64% (191) | 63% (188) | 0.80 |
| Commercial insurance (%) | 43% (127) | 38% (114) | |
| Medicare | 7% (21) | 12% (36) | 0.99 |
| Medicaid | 50% (150) | 50% (150) | |
| Charlson Comorbidity Index ≥ 1, % (n) | 14% (43) | 31% (94) | < 0.01 |
| Documented prior screening, benign disease, and cancer risk factors | |||
| Prior corresponding† screening mammogram or colonoscopy documented, % (n) | 58% (175) | 48% (144) | 0.01 |
| Among those with prior corresponding† screening test, time in years since prior test, mean ± SD | 1.7 ± 2.7 | 4.2 ± 2.8 | NA |
| No documented cancer risk factors or characteristics suggestive of non-cancer diagnosis, % (n) | 60% (181) | 27% (80) | < 0.01 |
| ≥ 1 characteristic suggestive of non-cancer diagnosis‡, % (n) | 13% (38) | 50% (149) | NA |
| ≥ 1 suggestive of cancer, % (n) | 32% (97) | 50% (150) | |
| For breast lump presentation | |||
| Family history of breast cancer | 20% (66) | – | |
| Personal history of breast biopsy | 9% (25) | – | |
| Known carrier of BRCA mutation | 0.3% (1) | – | |
| Reproductive risk§ | 8% (26) | – | |
| For rectal bleeding presentation | |||
| Family history of colorectal cancer | – | 3% (10) | |
| Personal history of adenoma | – | 10% (27) | |
| Anemia | – | 7% (21) | |
| Unintentional weight loss | – | 2% (6) | |
| Change in bowel habits | 57% (112) | ||
*According to Student’s t tests for continuous variables and chi-squared tests for categorical ones
†Corresponding cancer indicates breast cancer for patients presenting with breast lump and colorectal cancer for ones presenting with rectal bleeding
‡Characteristic that is suggestive of potential non-breast cancer etiology of a lump would be personal history of breast cyst(s). Characteristic suggestive of potential non-colorectal cancer diagnosis would be history or physical exam finding of either hemorrhoids or diverticulosis
§Nulliparity, menarche ≤ 12 years of age, first birth ≥ 30 years of age; no patients had more than 5 years of combined hormone replacement therapy. NA not applicable