Background: Breast cancer is the most common cancer in females, especially for those in their middle age between 40 to 60 years. There are prognostic factors of breast cancer such as an intrinsic subtype called triple-negative breast cancer (TNBC), HER2 overexpression, poorly differentiated, large tumor size, axillary lymph node status, and staging. Age at diagnosis is usually associated with aggressive cancer and poorer outcomes.

Objective: To explore the age and prognostic factors for breast cancer in Thailand.

Materials and Methods: The data were collected from pathological data collection and medical records of Buddhasothorn Hospital, Chachoengsao, Thailand, between 2015 and 2018. All data were collected for studying the relationship between age at diagnosis and prognostic factors.

Results: Three hundred three cases were collected. It was found that the age between 35 to 69 years had breast cancer the most (83.83%). The intrinsic subtypes found were Hormonal receptor-positive (HR+) 67.33%, TNBC 22.11%, and HER2 overexpression 10.56%. Age under 35 years had a risk of poor prognostic factors such as poorly differentiated (OR 1.528, 95% CI 0.306 to 7.627, p=0.605), large tumor size greater than 5 cm (OR 2.145, 95% CI 0.560 to 8.221, p=0.266), and axillary lymph node metastasis (OR 1.409, 95% CI 0.345 to 5.762, p=0.633). Age of 70 years and over had more favorable prognostic factors such as well-differentiated (OR 1.691, 95% CI 0.645 to 4.436, p=0.286), no axillary lymph node metastasis (OR 1.734, 95% CI 0.886 to 3.393, p=0.108), and the HR+ subtype (OR 2.158, 95% CI 0.954 to 4.882, p=0.065). Nonetheless, the present study data did show statistical significance.

Conclusion: The evidence of breast cancer in Thailand found that the different age ranges affected the prognostic factors differently. Specifically, young age breast cancer had a higher risk of poor prognostic factors, whereas the elderly breast cancer was associated with more favorable prognostic factors. However, a larger number of patient data to the confirm relationship between age and prognostic factors is required.

Keywords: Breast cancer; Age-related; Prognostic factors

DOI: doi.org/10.35755/jmedassocthai.2021.07.12508

Received 22 February 2021 | Revised 1 June 2021 | Accepted 1 June 2021