Determine Whether Administering Celecoxib During Radiotherapy Can Reduce the Risk of Recurrence of Triple-negative Breast Cancer. Pilot Study

Adults with non-metastatic TNBC will be recruited. The overall aim is to determine whether administering celecoxib during RT could reduce the risk of cancer recurrence. The hypothesis is that celecoxib will block the increase in cytokines, induced by RT, that are known to promote cancer cell invasion and metastasis. The primary objective of this pilot study is to assess the feasibility of recruiting participants and implementing the study steps, with the intention of conducting a large-scale study in the future.

Thirty participants will be recruited and randomized: fifteen will receive celecoxib, and fifteen will receive a placebo. Participants who take a COX-2 inhibitor for other medical indications or medications such as ibuprofen will be excluded.

Participants are recruited after chemotherapy and removal of the tumor by partial mastectomy. They take one capsule celecoxib (100 mg) or placebo after breakfast and one after supper, starting 7 days before RT and ending 14 days after RT. RT will consist of 26 Gy in 5 fractions or 40 Gy in 15 fractions if participants are under 50 years old with lymph node positivity. According to the RT plan, celecoxib will be taken for no longer than 40 days. In a logbook, participants will report when they take celecoxib and if they experience discomfort, such as skin rashes, headaches, or dizziness. Participant follow-up will last 5 years after treatment, according to clinical guidelines, which include a clinical examination and a mammogram every year. If breast density is categorized as D (extremely dense), an MRI will be performed in alternating years with the mammogram. A CT or PET scan will be conducted if symptoms such as bone pain are present. The date corresponding to the detection of a local or distant recurrence will be recorded in the participant's file to determine whether taking celecoxib could reduce the risk of regional or distant recurrence.

The secondary objective is to determine whether taking celecoxib will prevent the increase in cytokines induced by RT, some of which are known to stimulate the invasion capacity of cancer cells and the formation of metastases. This will be determined by collecting plasma samples at four time points: 1) the day before the start of taking celecoxib or placebo, which corresponds to 7 days before starting RT, 2) the day of the start of RT and just before administering the 1st fraction of radiation, 3) after the 4th fraction of radiation, and 4) 14 days after the end of RT and stopping taking celecoxib or placebo. During the blood draw, participants will be questioned by the research nurse to ensure that celecoxib is well tolerated. The impact of celecoxib on changes in cytokines will be determined using laser bead multiplexing.