Introduction/Background*CHEK2 gene is located on chromosome 22 and participates in the maintenance of the genome and control of the cell cycle and apoptosis. Mutations in this gene are considered to increase the risk of breast cancer. An accumulated risk throughout life is estimated at 28-37% in these patients.

Retrospective observational study Review of patients followed in the inherited cancer unit in a single tertiary centre between 1^st January 2012 until 28^th February 2021.

The statistical analysis was carried out using SPSS 22.0.

Result(s)*During the indicated period, we followed 401 patients with confirmed genetic mutations that predispose to developing gynaecological cancer. Of the total, 2.49% (10/401) were carriers of a CHEK2 mutation.

Within the cohort of patients carrying a CHEK2 mutation, 7/10 (70%) had a family history of breast cancer and 1/10 (10%) a gastric cancer. 6/10 patients were diagnosed with breast cancer at 23, 37, 37, 38, 44 and 52 years old. One of them had a second contralateral breast cancer at age 47.

The histology of the breast cancer was either ductal carcinoma in situ or invasive ductal carcinoma. Tumor stage was 0 in one case, I in one case, IIA in two cases and IIIA in two cases. Surgery treatment was: unilateral mastectomy with homolateral axillary lymphadenectomy in 3 patients, conservative surgery in 1 patient, conservative surgery with selective sentinel lymph node biopsy in 1 patient and conservative surgery with homolateral axillary lymphadenectomy in 1 patient. Adjuvant treatment was: chemotherapy and hormone therapy in one case, radiation therapy and chemotherapy in one case, radiation therapy and hormone therapy in one case and radiation therapy, chemotherapy and hormone therapy in the other two.

Characteristics of these patients are summarized in table 1.

Discussion There are several recommendations in the literature regarding the follow-up of patients carrying a CHEK2 mutation.

In general, it is recommended that all female carriers should be offered intensified surveillance programs for breast cancer including annual breast radiological testing.

Conclusion*Patients carrying CHEK2 mutations have a moderate risk of developing breast cancer and should be followed in specialized hereditary cancer units.