Neoplasms

Skin and Connective Tissue Diseases

All Conditions

Breast Neoplasms

Breast Diseases

Skin Diseases

All Drugs and Chemicals

Antineoplastic Agents

Hormones

Letrozole

Palbociclib

Prolactin Release-Inhibiting Factors

Aromatase Inhibitors

Protein Kinase Inhibitors

Enzyme Inhibitors

All patients will receive the standard of care treatment ie Palbociclib + letrozole for 24-26 weeks (a delay of +/- 2 weeks to initiate the locoregional treatment is authorized after the day 1 of cycle 1 of palbociclib plus letrozole). After this period, patient will have the most adapted locoregional treatment ie surgery (conservative or mastectomy) with or without radiotherapy, or radiotherapy. The palbociclib will be continued until progression

The included patients will first receive the following systemic treatment according standard of care:

* Non-steroidal aromatase inhibitor (letrozole)
* Palbociclib
* Monthly Luteinizing hormone-releasing hormone (LHRH) analogue for non-menopausal patients only. Surgical bilateral oophorectomy is an acceptable option.

After normally 6 courses of systemic treatment initiation, the loco-regional treatment of the primary tumour will be performed: surgery (conservative or mastectomy) with or without radiotherapy, or radiotherapy

locoregional treatment

Claire Bonneau, MD

Approximately 3.5% to 6% of newly diagnosed breast cancer patients are stage IV metastatic. De novo metastatic breast cancer accounts for 20% to 25% of these cases. Despite a decrease in mortality in Europe and North America due to early detection and access to treatment, breast cancer remains the 2ⁿᵈ leading cause of cancer deaths in developed countries after lung cancer and the world's leading cause.

In the ESME French national retrospective cohort (NCT03275311), the newly diagnosed estrogen receptor (ER)-positive and HER2-negative (luminal) metastatic patients had a 59.1 months overall survival (OS) for pre-menopausal women and 44.7 months for postmenopausal women. In the same cohort, the median OS was 47.4 months for de novo metastatic patients with hormone receptor (HR)-positive / HER2-negative breast cancer.

The most important current treatment for metastatic breast cancer remains systemic therapy. Surgery and radiation are mainly used to treat symptoms. However, more than 15 retrospective studies have assessed the impact of locoregional treatment on relapse and OS. These studies suggested an improvement of the OS in patients with de novo metastatic breast cancer thanks to the addition of locoregional treatment to systemic therapy. Recent data from the ESME cohort suggest that patients with de novo luminal or HER2-positive metastatic breast cancer may benefit from local treatment of the primary tumor.

Several prospective trials have attempted to demonstrate the benefit of locoregional treatment with mixed results. This can be explained by a limited power of statistical analysis, on the recruitment of patients with breast cancer of all types, and on a limited access to effective systemic therapies in some cases and all before the area of anti CD4/6 which is the current standard treatment in patients with HR-positive / HER2-negative luminal metastatic disease.

However, guidelines indicate that a "multimodal approach, including curative locoregional treatments, should be considered". As a result, many clinicians offer locoregional treatment of the primary tumor, especially if there is a good response to the first line of systematic treatment.

Taken together, these data underscore the need for an evaluation of the value of combined therapy - endocrine therapy - CDK4/6 inhibitor and locoregional treatment - in this population of patients with newly diagnosed HR-positive / HER2-negative breast cancer.

Locoregional Treatment and Palbociclib in de Novo, Treatment Naive, Stage IV ER+, HER2- Breast Cancer Patients

PALbociclib in Advanced Breast Cancer: Therapy INtegrating locorEgional Treatment and Palbociclib in de Novo, Treatment Naive, Stage IV ER+, HER2- Breast Cancer Patients

Unicancer will share de-identified individual data that underlie the results reported. A decision concerning the sharing of other study documents, including protocol and statistical analysis plan will be examined upon request.

Follow-up of the disease status by imaging exams until surgery

Pathological response (tumour size, cellularity... ) evaluated at the surgery or at the biopsy

Rate of modification of indication of mastectomy

Rate of locoregional recurrence after surgery and/or radiotherapy

Follow-up of the disease status by imaging exams

Will be evaluated using the National Cancer Institute - common terminology criteria for adverse events (NCI-CTCAE) v5.0

Records of cancer treatments prescribed to patients after disease progression

self-administered questionnaire of quality of life EORTC QLQ-C30 taking into account the patient's activity and his/her physical and psychological state

self-administered questionnaire of quality of life EORTC QLQ-BR23, complementary module to QLQ C30 questionnaire, is more specifically interested in patients with se cancer and the impact of treatment on their lives

self-administered questionnaire of quality of life Euroquol EQ-5D-5L consists of a descriptive system and a visual scale

Spots Global Cancer Trial Database for therapies combination