SIZE MATTERS: A DECADE LONG COMPARISON OF TUMOUR MEASUREMENTS IN YOUNG VERSUS OLDER BREAST CANCER PATIENTS gabrielle.matthews2@health.qld.gov.au

 

SIZE MATTERS: A DECADE LONG COMPARISON OF TUMOUR MEASUREMENTS IN YOUNG VERSUS OLDER BREAST CANCER PATIENTS

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Australia

Oral or Poster

Accurate tumour measurement is essential for surgical planning in breast cancer. Preoperative ultrasound is commonly used to determine tumour dimensions. However, discordance between imaging and final histology may compromise resection adequacy. This study aimed to evaluate the concordance between USS and histological tumour size in younger and older patients, identifying clinical factors associated with significant measurement discrepancies.

A retrospective cohort of 179 patients diagnosed with breast cancer between 2013–2023 at a single quaternary centre was reviewed. Patients aged ≤40 (n=89) and ≥41 (n=90) were compared. Preoperative USS and histopathology reports were examined. Tumour type, presence of ductal carcinoma in situ, and neoadjuvant therapy were recorded.

Tumour size was underestimated by >10mm in 34% of younger versus 21% of older patients. Underestimation of 5–10mm occurred in 12% of younger and 11% of older patients. Ductal carcinoma in situ was present in 52% of younger and 42% of older patients, often associated with Invasive ductal carcinoma when histology measurements exceeded USS by >10mm. Neoadjuvant treatment was administered in 40% of younger and 44% of older patients with >10mm discordance. Invasive ductal carcinoma was the predominant tumour type.

Preoperative ultrasound frequently underestimates tumour size in young breast cancer patients, with age, ductal carcinoma in situ was present in 52% of younger and 42% of older patients, often associated with invasive ductal carcinoma when histology measurements exceeded USS by >10mm, and neoadjuvant therapy contributing to discordance. Surgeons should be cautious when relying solely on USS for operative planning.