Preventive Care & Cancer Screening
A Step 2 CK–focused walkthrough of USPSTF cancer screening (breast, cervical, colorectal, lung, prostate) plus core adult preventive care, emphasizing exact ages/intervals, next-best-step decisions, and when NOT to screen.
How the boards test prevention
Preventive-care questions test one skill: matching the right patient to the right test at the right age and interval — and knowing when not to screen. On Step 2 CK the answer key is the USPSTF (Grade A/B = do it; Grade D = don't; Grade C = individualize). Two traps recur. First, never confuse screening an asymptomatic patient with the diagnostic workup of a symptom — a palpable breast mass or rectal bleeding is worked up, never 'screened.' Second, avoid over-screening at the extremes: stop after the organ is gone (post-hysterectomy) or when life expectancy is under ~10 years. Anchor every choice to age, risk factors, and life expectancy before ordering anything.
- Breast: biennial mammography, women 40–74 (2024 USPSTF, Grade B; classically 50–74). Add annual MRI if BRCA/high-risk (≥20% lifetime).
- Cervical: begin at 21. Ages 21–29 → Pap cytology q3y. Ages 30–65 → cytology q3y OR HPV q5y OR co-test q5y. Stop at 65 with adequate prior negatives; none <21 or after hysterectomy for benign disease.
- Colorectal: ages 45–75 → colonoscopy q10y, FIT annually, or sDNA-FIT q1–3y. Ages 76–85 individualize.
- Lung: annual low-dose CT, ages 50–80, ≥20 pack-years, current smoker or quit ≤15 yr.
- Prostate: PSA 55–69 by shared decision only (Grade C); do not screen ≥70 (Grade D).
Screening at a glance
| Cancer | Test | Age (start–stop) | Interval |
|---|---|---|---|
| Breast | Mammography | 40–74 | Every 2 yr |
| Cervical | Pap cytology | 21–29 | Every 3 yr |
| Cervical | HPV ± co-test | 30–65 | Every 5 yr |
| Colorectal | Colonoscopy | 45–75 | Every 10 yr |
| Colorectal | FIT | 45–75 | Annually |
| Lung | Low-dose CT | 50–80 | Annually |
| Prostate | PSA (shared) | 55–69 | Individualized |
Vignette 1: 51-yo average-risk man, never screened, healthy. → Next step: colonoscopy q10y (or annual FIT) — screening should have started at 45.
Vignette 2: 34-yo man; father had colon cancer at 44. → Begin colonoscopy now (10 yr before the relative's dx, or age 40 — whichever is earlier) and repeat every 5 yr.
Vignette 3: 60-yo woman, 30 pack-year history, quit 4 yr ago. → Annual low-dose CT (meets 50–80, ≥20 pack-yr, quit ≤15 yr).
Vignette 4 (trap): 32-yo woman with a palpable breast mass. → Diagnostic, not screening. At age ≥30, obtain ultrasound + diagnostic mammography, then core-needle biopsy (triple assessment). A dominant/persistent mass needs tissue even if imaging looks benign.
Other core adult preventive care:
- AAA: one-time abdominal ultrasound, men 65–75 who ever smoked (Grade B).
- Osteoporosis: DEXA in women ≥65 (or younger postmenopausal women with elevated FRAX risk).
- Statin (primary prevention): ages 40–75 with ≥1 CVD risk factor and ≥10% 10-yr ASCVD risk (Grade B; 7.5–<10% → selectively, Grade C).
- Aspirin (primary prevention): individualize only for 40–59 with ≥10% risk (Grade C); do not start at ≥60 (Grade D).
- HIV: screen at least once, ages 15–65. HCV: once for all adults 18–79. Diabetes: ages 35–70 if overweight/obese.
The 5 A's of smoking cessation (highest-yield counseling framework):
- Ask — about tobacco use at every visit
- Advise — to quit, clearly and personally
- Assess — readiness/willingness to quit
- Assist — counseling plus pharmacotherapy
- Arrange — follow-up
Pharmacotherapy: NRT, bupropion, or varenicline (most effective single agent) — always pair with behavioral support. Counseling + medication beats either alone.
When the best answer is 'don't screen':
Vignette 5: 67-yo woman, total hysterectomy (uterus + cervix) for fibroids, prior Paps normal. → Stop cervical screening — no cervix, benign indication, no high-grade history.
Vignette 6: 82-yo man with multiple comorbidities requests PSA and colonoscopy. → Decline routine screening: life expectancy <10 yr, so harms outweigh benefit (PSA already Grade D ≥70).
Vignette 7: 45-yo woman with ASC-US on Pap. → Reflex HPV testing; if HPV-positive → colposcopy, if negative → return to routine surveillance.
Vignette 8: 66-yo man who never smoked asks about AAA screening. → Not routinely recommended — one-time ultrasound is Grade B only for men 65–75 who ever smoked; in never-smokers it's a selective (Grade C) decision based on other risk factors (e.g., family history), not routine.
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