Characteristics of patients with differentiated thyroid cancer (n = 36 531) by sex and pathway to diagnosis (incidentally detected v. nonincidentally detected), Ontario, 1998–2017*†
| Characteristic | Female patients n = 28 735; 78.7% of patients | Male patients n = 7796; 21.3% of patients | ||
|---|---|---|---|---|
| Incidentally detected; no. (%)‡ | Nonincidentally detected; no. (%)‡ | Incidentally detected; no. (%)‡ | Nonincidentally detected; no. (%)‡ | |
| Total | 2680 (9.3) | 26 055 (90.7) | 1314 (16.9) | 6482 (83.1) |
| Age, yr | ||||
| 15–29 | 170 (6.3) | 2596 (10.0) | 67 (5.1) | 540 (8.3) |
| 30–49 | 954 (35.6) | 12 563 (48.2) | 406 (30.9) | 2627 (40.5) |
| 50–69 | 1166 (43.5) | 9288 (35.6) | 623 (47.4) | 2755 (42.5) |
| 70–84 | 390 (14.6) | 1608 (6.1) | 218 (16.6) | 560 (8.6) |
| Mean ± SD | 52.7 ± 15.0 | 47.0 ± 13.7 | 54.7 ± 14.5 | 49.7 ± 14.0 |
| Diagnosis period | ||||
| 1998–2002 | 247 (9.2) | 3301 (12.6) | 128 (9.7) | 818 (12.6) |
| 2003–2007 | 494 (18.4) | 5599 (21.4) | 232 (17.6) | 1261 (19.4) |
| 2008–2012 | 843 (31.4) | 8271 (31.7) | 405 (30.8) | 1941 (29.9) |
| 2013–2017 | 1096 (40.9) | 8884 (34.1) | 549 (41.7) | 2462 (38.0) |
| Birth cohort | ||||
| 1913–1922 | 7 (0.2) | 26 (0.1) | –** | 12 (0.2) |
| 1918–1927 | 24 (0.9) | 98 (0.3) | 16 (1.2) | 38 (0.6) |
| 1923–1932 | 74 (2.7) | 255 (1.0) | 44 (3.3) | 90 (1.4) |
| 1928–1937 | 120 (4.4) | 516 (2.0) | 71 (5.4) | 191 (2.9) |
| 1933–1942 | 181 (6.7) | 899 (3.4) | 83 (6.3) | 282 (4.3) |
| 1938–1947 | 215 (8.0) | 1366 (5.2) | 123 (9.3) | 451 (6.9) |
| 1943–1952 | 288 (10.7) | 2086 (8.0) | 173 (13.1) | 655 (10.1) |
| 1948–1957 | 284 (10.6) | 2707 (10.4) | 164 (12.4) | 765 (11.8) |
| 1953–1962 | 330 (12.3) | 3358 (12.9) | 146 (11.1) | 833 (12.8) |
| 1958–1967 | 327 (12.2) | 3816 (14.6) | 145 (11.0) | 879 (13.5) |
| 1963–1972 | 281 (10.5) | 3379 (12.9) | 112 (8.5) | 751 (11.6) |
| 1968–1977 | 202 (7.5) | 2832 (10.8) | 101 (7.6) | 564 (8.7) |
| 1973–1982 | 144 (5.3) | 2104 (8.0) | 59 (4.5) | 422 (6.5) |
| 1978–1987 | 108 (4.0) | 1434 (5.5) | 36 (2.7) | 272 (4.2) |
| 1983–1992 | 62 (2.3) | 723 (2.7) | 21 (1.6) | 170 (2.6) |
| 1988–1997 | 24 (0.9) | 352 (1.3) | 15 (1.1) | 81 (1.2) |
| 1993–2002 | 9 (0.3) | 104 (0.4) | –** | 26 (0.4) |
| Alive | 2428 (90.6) | 25 162 (96.5) | 1094 (83.2) | 6035 (93.1) |
| Histologically confirmed | 2598 (96.9) | 25 325 (97.2) | 1279 (97.3) | 6321 (97.5) |
| Thyroid biopsy ≤ 6 mo before diagnosis date§ | 1609 (60.0) | 16 813 (64.5) | 765 (58.2) | 4220 (65.1) |
| Imaging modality¶ | ||||
| CT | 1760 (65.6) | NA | 960 (73.0) | NA |
| Carotid ultrasonography | 275 (10.2) | NA | 115 (8.7) | NA |
| MRI | 290 (10.8) | NA | 95 (7.2) | NA |
| SPECT | 355 (13.2) | NA | 140 (10.6) | NA |
Note: CT = computed tomography, MRI = magnetic resonance imaging, NA = not applicable, SD = standard deviation, SPECT = single-photon emission computed tomography.
↵* Incidentally detected status using a 3-month look-back period from patient index date (see main text).
↵† For each sex, except for histologic confirmation, characteristics differed significantly by incidentally detected status (χ2 test for categorical variables; t test for continuous variables; p < 0.001). The proportion of histologically confirmed cases did not vary by incidentally detected status (p > 0.990 for females and males).
↵‡ Unless stated otherwise.
↵§ Includes thyroid gland core biopsy, fine-needle aspiration biopsy and aspiration procedures (Ontario Health Insurance Plan fee codes Z727, Z771 and Z726, respectively).
↵¶ Positron emission tomography not shown because of few cases and thus values were randomly rounded to multiples of 5 to obscure back-calculation of those cases. Therefore, the modality strata do not total the counts by age group because of the rounding. Subtracting the counts by imaging modality strata from those by age group does not provide the actual counts for positron emission tomography–associated incidentally detected cases.
↵** Value suppressed owing to small sample size.