FIRST-LINE TREATMENT OF PRIMARY METASTATIC HR+ HER2- BREAST CANCER
Kaja Cankar, dr. med., specializantka internistične onkologije
Doc. Dr. Erika Matos, dr. med., specialistka interne medicine in internistične onkologije
Female, 72Y.O.
Primary metastatic HR+ HER2-(IHC 2+) breast cancer diagnosed in September 2022.
Liver metastases at first presentation– confirmed with FNA (ER pos, HER2 neg).
No significant comorbidities, takes SSRI (citalopram).
Postmenopausal since51 y.
Negative family history.
Physical examination findings: PS 0, reported tenderness on liver palpation.
Laboratory values: LFTs and tumor markers were normal.
September 2022: ribociclib 600 mg/d 21+7 + letrozole 2.5 mg/d.
Citalopram was switched to sertraline (possible drug-drug interactions with dangerous QT interval prolongation).
ECG: QTc 423 ms, no prolongation at follow-up appointments.
First CT evaluation (December 2022): PR in liver.
No AEs reported in first 6 months of treatment.
At follow-up appointment after 7 cycles patient presented with vitiligo, G1 (<10 % BSA).
She was referred to dermatologist and continued with the same therapy (due to good response).
Dg.: Vitiligo, most probably related to ribociclib.
Ribociclib SmPC:
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Skin and subcutaneous tissue disorders |
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Alopecia, rash4, pruritus |
Very common (≥1/10) |
In May 2023 on regular follow-up, she presented with progressively worsening of skin discoloration, not limited to arms and legs, the skin of the whole body was affected (G2, >10 % BSA).
No other AEs reported (no hepatic or hematologic toxicity).
Ribociclib was discontinued, she continued with letrozole monotherapy (8 months on combination therapy).
CT evaluation (May 2023): SD in the liver, no new metastases.
After ribociclib discontinuation skin discolorations improved.
Re-initiation with ribociclib or a different iCDK4/6 was suggested, patient decided to continue with AI monotherapy.
CT evaluation (December 2023): SD compared to May 2023.
May 2024: Additional improvement in skin discoloration, no additional complaints, no new AEs, evaluation CTs scheduled for October 2024.
Ribociclib showed good efficacy in primary metastatic HR+HER2- breast cancer with visceral (liver) metastases.
Vitiligo is a known AE of ribociclib, it is reversable.
At disease progression re-initiation with iCDK4/6 + different ET is an option (no PD on ribociclib).