Very young women (<35 years) with operable breast cancer: features of disease at presentation.

BACKGROUND: Breast cancer rarely occurs in young women. Our knowledge about disease presentation, prognosis and treatment effects are largely dependent upon older series.
MATERIALS AND METHODS: We evaluated biological features and stage at presentation for 1427 consecutive premenopausal patients aged < or = 50 years with first diagnosis of invasive breast cancer referred to surgery at the European Institute of Oncology from April 1997 to August 2000. A total of 185 patients (13%) were aged < 35 years ('very young') and 1242 (87%) were aged 35-50 years ('less young'). The expression of estrogen receptors (ER), progesterone receptors (PgR), presence of vascular invasion (VI), grading (G), expression of Ki-67, HER2/neu overexpression, pathological stage according to TNM staging system (pTNM), pathological tumor size and number of axillary lymph node involvement were evaluated.
RESULTS: Compared with less young patients, the very young patient group had a higher percentage of tumors classified as ER negative (P < 0.001), PgR negative (P = 0.001), higher expression of Ki-67 > or = 20% of cells stained; 62.2% versus 53%, (P < 0.001), vascular or lymphatic invasion (48.6% versus 37.3%, P = 0.006), and pathological grade 3 (P < 0.0001). There was no difference between the two groups for pT, pathological tumor size (pN) and number of positive lymph nodes.
CONCLUSIONS: We conclude that compared with less young premenopausal patients, very young women have a greater chance of having an endocrine-unresponsive tumor, and are more likely to present with a higher grade, more extensively proliferating and vessel invading disease. Pathological tumor size, nodal status and number of positive axillary lymph-nodes have a similar distribution among the younger and the older cohorts, thus not supporting previous data indicating more advanced disease in younger patients at diagnosis of operable disease.