Targeted Cancer Therapy: Side Effects, Outcomes, and Shared Decision-Making

Targeted therapies attack specific molecular alterations driving cancer. Unlike chemotherapy, they spare most normal cells but have distinct toxicity profiles.

Acute Side Effects (Days–Weeks)

• Fatigue, nausea, diarrhea, rash, hepatotoxicity, hypertension, proteinuria
• Class-specific: EGFR inhibitors (acneiform rash, diarrhea), VEGF inhibitors (HTN, bleeding, thrombosis), BRAF/MEK inhibitors (fever, photosensitivity, cardiomyopathy), BTK inhibitors (bleeding, atrial fibrillation).

Long-Term and Late Effects

• Cardiotoxicity (HER2, VEGF, BTK inhibitors)
• Renal impairment (VEGF, mTOR)
• Endocrine: thyroid dysfunction (TKIs), adrenal insufficiency
• Secondary malignancies (rare, some TKIs)
• Ocular: retinal vein occlusion (VEGF), uveitis (MEK)

Efficacy and Durability

• Not curative alone in most advanced solid tumors.
• Induce deep responses; median PFS months to years.
• Resistance inevitable (on-target mutations, bypass pathways, histologic transformation).
• Sequencing strategies and combinations under study.

Monitoring and Communication

• Regular labs, imaging, cardiac surveillance per protocol.
• Report symptoms early; dose holds/reductions often maintain efficacy.
• Discuss goals: cure unlikely; focus on prolongation, quality of life.
• Financial toxicity: high cost; explore assistance programs.

Shared Decision-Making Questions

1. What is the target? Is it present in my tumor?
2. Expected benefit vs. standard therapy?
3. Typical side effects and management?
4. Impact on daily life? Monitoring schedule?
5. Options if progression occurs?