Comparative study of clinical, pathological and biological characteristicsof symptomatic versus asymptomatic breast cancers

Background: It is well known that mammographic screening reduces breast can cer mortality. One possible explanation for this effect is that screening m akes it possible to detect smaller breast cancers with fewer involved nodes , but another hypothesis is that some screening-detected tumors are in a pa thologically and biologically different phase of evolution from those that are detected clinically. The aim of the present study was to compare the bi ological, pathological and clinical characteristics of symptomatic vs. asym ptomatic breast cancers. Patients and methods: The study considers a series of 1916 consecutive pati ents who underwent surgery for stage I and II infiltrating breast cancer at Verona hospitals after having undergone ultrasound and mammography (at lea st one of which was positive). They were divided into two groups on the bas is of why they decided to undergo the imaging examinations: group A refers to the 1247 patients with a palpable lump, and group B to the 616 who were asymptomatic. Results: The patients in group A were older, and had larger tumors and a hi gher percentage of positive nodes than those in group B; they also had sign ificantly higher grade tumors, higher Ki-67 levels, and a higher percentage of ER and PgR negative and c-erbB-2 positive tumors (all of the P-values w ere significant). A logistic regression analysis adjusted for tumor diamete r and age showed a reduction in the significance of each of the considered variables, but all of them remained significantly associated with the modal ity of diagnosis except ER, PgR and c-erbB-2. Conclusions: Our results suggest that asymptomatic tumors are biologically different from their clinically presenting counterparts, thus confirming th e hypothesis that progression towards greater malignancy may occur during t he natural history of breast cancer.