Breast Cancer: No Chemotherapy or Radiation

Breast Cancer Treatments Without Chemotherapy or Radiation

Patients may opt out of chemo/radiation due to age, stage of cancer, type of tumor, previous toxicities, genetic predispositions, or personal beliefs. In such cases, targeted therapy, hormone therapy, immunotherapy, and surgical options often take center stage.


1. Hormone (Endocrine) Therapy

Used for: Hormone-receptor-positive (ER+/PR+) breast cancers.

Main Medications:

  • Tamoxifen – blocks estrogen receptors (SERM).

  • Aromatase Inhibitors (AIs):

    • Anastrozole, Letrozole, Exemestane – reduce estrogen production in postmenopausal women.

  • Fulvestrant (Faslodex) – estrogen receptor degrader (SERD), injection form.

Immediate Side Effects:

  • Hot flashes, mood swings, fatigue

  • Vaginal dryness, decreased libido

  • Bone/joint pain (especially AIs)

Long-Term Effects:

  • Increased risk of blood clots (Tamoxifen)

  • Bone thinning/osteoporosis (AIs)

  • Liver enzyme elevations

  • Cognitive changes (“chemo brain” effect, even without chemo)


2. Targeted Therapy

Used for: HER2-positive cancers or cancers with specific mutations.

Main Medications:

  • Trastuzumab (Herceptin)

  • Pertuzumab (Perjeta)

  • Neratinib, Lapatinib (oral HER2 inhibitors)

  • CDK4/6 inhibitors: Palbociclib (Ibrance), Ribociclib, Abemaciclib

Immediate Side Effects:

  • Diarrhea (especially Neratinib, Abemaciclib)

  • Neutropenia (low white blood cells)

  • Heart toxicity (Herceptin requires cardiac monitoring)

  • Nausea, fatigue

Long-Term Effects:

  • Cardiac dysfunction (Herceptin)

  • Kidney and liver function changes (CDK4/6 inhibitors)

  • Possible chronic fatigue


3. Immunotherapy

Used in: Triple-negative breast cancer (TNBC), usually in combination with checkpoint inhibitors.

Main Drugs:

  • Atezolizumab, Pembrolizumab (Keytruda)

Immediate Side Effects:

  • Flu-like symptoms

  • Skin rash

  • Inflammation of organs (autoimmune responses)

    • Pneumonitis, colitis, hepatitis, endocrinopathies

Long-Term Effects:

  • Possible long-term organ inflammation

  • Adrenal or thyroid dysfunction


4. Injections: Faslodex & Others

  • Fulvestrant (Faslodex) is administered intramuscularly into the gluteal muscle, usually monthly.

  • Subcutaneous (SC) injections for Herceptin and similar drugs exist (e.g., Phesgo – combo of trastuzumab + pertuzumab).

Injection Site Effects:

  • Local irritation: swelling, pain, redness

  • Deep tissue necrosis (rare but possible with IM injections)

  • Lipodystrophy with repeated injections

  • Fibrosis or scar tissue buildup in injection zones


Liver & Kidney Considerations

Liver:

  • Primary site of drug metabolism

  • Many breast cancer drugs increase ALT/AST (transaminases), sometimes causing hepatotoxicity

  • Monitor for steatosis, fibrosis, or drug-induced hepatitis

Kidney:

  • Less involved in metabolism but critical in excretion (especially for small-molecule inhibitors)

  • CDK4/6 inhibitors and some HER2 drugs can cause proteinuria or electrolyte imbalance

Labs to Monitor:

  • LFTs (Liver Function Tests)

  • Creatinine, BUN

  • Electrolytes

  • Cardiac echo (for Herceptin)


 

Dietary Recommendations for Patients on Endocrine or Targeted Therapy

 General Guidelines:

  • Anti-inflammatory focus: leafy greens, berries, turmeric, ginger, green tea

  • Phytoestrogens (e.g., flaxseed, soy) – safe in moderation for ER+ patients

  • Cruciferous vegetables: broccoli, kale, cauliflower – aid detoxification

  • Liver support: dandelion root tea, milk thistle (only with medical approval)

  • Bone health: calcium + vitamin D, magnesium, boron

  • Limit alcohol, processed sugar, and saturated fats

 Avoid:

  • Grapefruit (CYP450 interaction with many drugs)

  • High-dose supplements without medical clearance

  • Fasting or detox diets during active treatment (unless under supervision)


Holistic & Lifestyle Support

Domain Recommendation
Sleep Minimum 7–8 hours, melatonin if needed (low dose)
Exercise Gentle weight-bearing + cardio for bone & mood
Emotional Support groups, therapy, journaling, spiritual grounding
Supplements Vitamin D, B-complex, omega-3s (check drug interactions)

 

References (Scientific & Clinical)

  1. National Cancer Institute (NCI):

  2. American Cancer Society:

  3. ASCO (American Society of Clinical Oncology):

  4. European Society for Medical Oncology (ESMO):

  5. FDA Drug Database:

  6. Journal of Clinical Oncology, 2022-2024 Issues

    • Recent studies on CDK4/6 inhibitors, HER2-targeted therapy, and long-term organ toxicity.

  7. National Comprehensive Cancer Network (NCCN):

  8. Memorial Sloan Kettering Cancer Center (MSKCC):

  9. PubMed/NIH Library (key peer-reviewed studies):


Glossary of Abbreviations

Abbreviation Full Term Explanation
ER+ Estrogen Receptor Positive Tumor grows in response to estrogen
PR+ Progesterone Receptor Positive Tumor grows in response to progesterone
HER2 Human Epidermal Growth Factor Receptor 2 Protein promoting cancer cell growth
SERM Selective Estrogen Receptor Modulator Blocks estrogen receptors (e.g., Tamoxifen)
SERD Selective Estrogen Receptor Degrader Degrades estrogen receptors (e.g., Fulvestrant)
AI Aromatase Inhibitor Prevents estrogen production (e.g., Letrozole)
CDK4/6 Cyclin-Dependent Kinase 4/6 Enzyme targets for cell cycle regulation
LFTs Liver Function Tests Measures liver health via enzymes
BUN Blood Urea Nitrogen Kidney function test
ALT/AST Alanine/ Aspartate Transaminase Liver enzymes tested in liver panels
IM Intramuscular Injection into muscle
SC Subcutaneous Injection under the skin
TNBC Triple-Negative Breast Cancer Lacks ER, PR, and HER2 receptors
CYP450 Cytochrome P450 Enzyme System Liver enzyme family responsible for drug metabolism