Breast Cancer Awareness

1. Age Distribution

Age Group	% of New Cases	Risk Notes
<40 years	4%	Rare but aggressive (higher % of triple-negative)
40-49	15%	Screening typically begins at 40-45
50-64	44%	Peak incidence (menopausal transition)
65+	37%	Highest incidence but slower-growing tumors

Median age at diagnosis: 62 years (U.S.)

Under 50: ~9% of cases (but 13% of deaths due to late detection).

(U.S. data, SEER 2012–2018)

Status	Incidence Rate (per 100k)	5-Year Survival	Notes
Married	128.5	89%	Better access to care, earlier detection
Single/Never Married	118.2	83%	Lower screening adherence
Divorced/Separated	135.1	81%	Higher stress-linked risks
Widowed	142.3	78%	Older age at diagnosis

Key Insight: Married women have higher incidence (possibly due to more screening) but better survival.

Factor	Relative Risk	Notes
Early Menarche (<12)	1.2x	Longer lifetime estrogen exposure
Late Menopause (>55)	1.3x	Extended hormonal influence
Nulliparity (No births)	1.4x	Pregnancy reduces risk (especially before 30)
First Child After 30	1.2x	Each year delay increases risk slightly
Breastfeeding (12+ months)	0.7x	Protective effect per child

Pregnancy-Associated Breast Cancer (PABC):

Group	Incidence (per 100k)	Mortality (per 100k)	Notes
White	133	19	Higher incidence but better survival
Black	128	28	More aggressive subtypes (e.g., triple-negative)
Asian/Pacific Islander	97	11	Lower rates overall
Hispanic	99	14	Rising incidence with Westernization

Factor	Risk Increase	Population Impact
Obesity (Postmenopausal)	1.5x	20-30% of cases linked to weight
Alcohol (>3 drinks/week)	1.2x	15% higher risk per drink/day
HRT (Long-term estrogen-progestin)	1.7x	24% of cases in users
Physical Inactivity	1.3x	10-20% risk reduction with exercise

Age Matters: Risk rises sharply after 50, but younger cases are often deadlier.
Marriage Paradox: Married women are diagnosed more but survive longer (social support + healthcare access).
Pregnancy Protection: Childbirth before 30 and breastfeeding reduce risk.
Racial Disparities: Black women face higher mortality despite similar incidence.
Modifiable Risks: 30% of cases may be preventable through weight control, exercise, and limiting alcohol.