Cancers NOT Caused by Smoking
While smoking is causally linked to numerous malignancies, several major cancer types have no established causal relationship with tobacco use, including breast cancer, ovarian cancer, prostate cancer, and endometrial cancer (which is actually less common in smokers). 1
Cancers With No Established Link to Smoking
The following cancers are unlikely to be linked to tobacco use based on comprehensive epidemiologic evidence:
Definitively Not Smoking-Related
- Breast cancer - No causal association established 1
- Ovarian cancer - No causal association established 1
- Prostate cancer - No causal association established 1
- Endometrial cancer - Actually occurs less frequently in women who smoke cigarettes 1
Limited or Uncertain Evidence
While smoking causes approximately 30% of all cancer deaths in the United States 2, 3, certain malignancies have only weak or inconsistent associations:
- Colorectal cancer - Some data suggest increased risk only after extended latency periods 1
- Liver cancer - Limited suggestive evidence only 1
- Cervical cancer - Some data exist but relationship not definitively established 1
Context: What Smoking DOES Cause
To understand the scope, smoking has convincing evidence for causing cancers of:
- Lung (all four histologic types) 4
- Oral cavity and pharynx 5
- Larynx 1
- Esophagus 1
- Bladder 1
- Pancreas 1
- Kidney 1
- Stomach 1
- Myeloid leukemia 1, 3
Organs in direct contact with smoke face the greatest risk, with up to 90% of these cancers attributable to smoking 2, while distant organs show 50-200% increased rates among smokers 2.
Clinical Implications
The absence of a smoking-cancer link for breast, ovarian, and prostate cancers does not diminish the critical importance of smoking cessation, as tobacco remains the single most preventable cause of cancer death overall, responsible for 30% of all cancer mortality 3, 6. Even in cancers not caused by smoking, tobacco use negatively impacts treatment efficacy, toxicity, quality of life, and survival outcomes 3.