Personalized medicine show that there is not “ rigid” approach to treatment.

Upfront chemotherapy vs. standard-of-care hormone therapy

• Factors favoring hormone therapy:The cancer is HR+ (HER2 negative), a setting where endocrine therapy is often the standard first-line treatment. The patient has no significant comorbidities, good performance status, and significant symptom relief post-catheterization. Clinical trials (e.g., MONALEESA, PALOMA, MONARCH) have demonstrated excellent outcomes with endocrine therapy ± CDK4/6 inhibitors, even in metastatic settings.
• Factors favoring chemotherapy:If there were residual, refractory dyspnea or other signs of impending organ dysfunction after management of the effusion, chemotherapy might be considered. This approach could also be used if the disease shows aggressive biological features, such as rapid progression during prior endocrine therapy.
• Recommendation:Given the absence of visceral crisis and significant symptomatic improvement, standard-of-care hormone therapy with a CDK4/6 inhibitor (e.g., ribociclib, palbociclib, abemaciclib) is the preferred option. This approach balances efficacy with quality of life and avoids the toxicity of chemotherapy. Chemotherapy (single agent or combination) could be reserved for progression or non-response to endocrine therapy.

3. Follow-up considerations:

• Close monitoring of pleural effusion recurrence and overall disease progression is critical.
• Reassessment of systemic treatment may be required if clinical deterioration or new visceral involvement occurs.

Dr Perlat Kapisyzi gave you a comprehensive answer. For this particular case, if the pleural effusion is unilateral then endocrine therapy + CDK4/6i would be the best option for her if there is no other contraindication.

First, we should make it clear, what we are talking about. I guess, this is a HER2 negative metastatic breast cancer, because if it is HER2 positive, the first choice is not a hormonal therapy.

So, if this tumor is a HR+ HER2- MBC, as of recent guidelines, the treatment of choice is appropriate endocrine therapy in combination with one of CDK4/6 inhibitors. Pleural effusion itself, even if it is causing severe breathing difficulties, hard to be considered as a visceral crisis, because symptoms can be resolved by the drainage of the pleural fluid and pleurodesis can also be applied.

So, the answers are:

1.: No

2.: Yes

3.: No

What is written above is only a general approach, special conditions may influence the final decision.

No

I would prefer using CDK4 inhibitors in combination with AI

I WOULD SUGGETS;

1. NO CHEMO

2. STANDARD OF CARE HORMONTHERAPY +/- CD 4/6 INHIBITOR

3. THORACENTASIS / PLEURODESIS