Table. Cancer Incidence per Mutated Gene and the Number of Colonoscopies and Gynecological Reviews That Would Be Performed if Surveillance Started at the Noted Patient Ages.
| Age at Surveillance Start | Mutated Gene | |||
|---|---|---|---|---|
| MLH1 | MSH2 | MSH6 | PMS2 | |
| CRC Surveillance a | ||||
| From age 25 y | ||||
| Colonoscopies to age 40 y, No. | 2691 | 3181 | 875 | 294 |
| CRCs found, ages 25-39 y, No. | 81 | 74 | 7 | 3 |
| Colonoscopies per CRC, %b | 3.0 | 2.3 | 0.8 | 1.0 |
| From age 30 y | ||||
| Colonoscopies to age 40 y, No. | 1740 | 2086 | 579 | 192 |
| CRCs found, ages 30-39 y, No. | 70 | 66 | 7 | 2 |
| Colonoscopies per CRC, % | 4.0 | 3.2 | 1.2 | 1.0 |
| From age 25 to age 30 yc | ||||
| Colonoscopies to age 30 y, No. | 951 | 1095 | 296 | 102 |
| CRCs found, ages 25-29 y, No. | 11 | 8 | 0 | 1 |
| Colonoscopies per CRC, % | 1.2 | 0.7 | 0 | 1.0 |
| Gynecological Surveillance a | ||||
| From age 25 y | ||||
| Annual reviews to age 40 y, No. | 2620 | 3616 | 923 | 293 |
| ECs or OCs found, ages 25-39 y, No. | 7 (1 OC) | 18 (7 OCs) | 0 | 0 |
| Annual EC or OC rate, % | 0.3 | 0.5 | 0 | 0 |
| From age 30 y | ||||
| Annual reviews to age 40 y, No. | 1688 | 2285 | 603 | 183 |
| ECs or OCs found, ages 30-39 y, No. | 7 (1 OC) | 15 (4 OCs) | 0 | 0 |
| Annual EC or OC rate, % | 0.4 | 0.7 | 0 | 0 |
| From age 35 y | ||||
| Annual reviews to age 40 y, No. | 816d | 1108 | 294 | 90 |
| ECs or OCs found, ages 35-39 y, No. | 5 | 8 | 0 | 0 |
| Annual EC or OC rate, % | 0.6 | 1.4 | 0 | 0 |
| From age 25 to age 30 y | ||||
| Annual reviews to age 30 y, No. | 749 | 908 | 318 | 101 |
| ECs or OCs found, ages 25-29 y, No. | 0 | 3 (3 OCs) | 0 | 0 |
| Annual EC of OC rate, % | 0 | 0.3 | 0 | 0 |
Abbreviations: CRC, colorectal cancer; EC, endometrial cancer; OC, ovarian cancer.
Number of screens assumes 2-yearly colonoscopy and annual gynecology reviews in the intervals described for all patients censored at current age, age at death, or relevant cancer (EC, OC, or CRC).
The rates of CRC and EC or OC per screen are given for each age range.
If CRC screening started aged 30 years, only 1 PMS2 or MSH6 mutation–associated CRC would have been missed for 398 screens, whereas for MLH1 or MSH2 mutations, 19 associated CRCs would have been missed for 2046 screens.
For truncating MLH1 mutations, if screening started aged 40 years, only 1 EC would have been missed for 340 annual reviews, a rate of 0.29% between ages 35 and 39 years, whereas for nontruncating MLH1 mutation carriers, 4 ECs would have been missed for 476 screens, a rate of 0.84%.