Potential contributions to these observed reduction come from primary prevention, chemoprevention, screening (secondary prevention), improved therapy (tertiary prevention), or combination of these. Nevertheless, approximately 10-15% of patients with breast cancer has an aggressive disease and develops distant metastases within 3 years after diagnosis of primary tumor (1). The risk of metastasis development increases directly with the presence of lymph node metastasis, a larger size of primary tumor and loss of histopathological grade (2), which are classically established breast cancer prognostic markers. Numerous studies, like the study of Bassett (3) have shown that mammographic screening, in comparison with physical examination, is able of detecting cancers of smaller size and at an earlier stage than those usually detected and diagnosed; so nonpalpable lesions have more frequently a smaller histological tumor size and grade (4).The objective of our study was to assess prognostic and predictive factors, treatment and clinical behavior in 649 patients with clinical T1 or T2 invasive breast cancer undergoing surgery from January 1995 to December 2005, comparing not palpable (group 1 = 201 cases) and palpable cancers (group 2 = 448 cases) on physical examination and so to confirm the better prognosis of nonpalpable breast carcinomas. Average age at time of diagnosis was 55.8 ± 13(24-89) years, most patients (62.9%) were postmenopausal; breast lesions were diagnosed, in the beginning, by mammographic screening in 293 cases and by palpation in the remaining 356 cases. Among the mammographically detected invasive cancers, 123 cases (42%) were £1 cm in histological size; regarding physical examination, 45.2% presented with nonpalpable lesion (group 1 = 201 cases) and 54.8% presented a palpable lesion (group 2 = 448 cases). Average size of the palpable lesion was 2.4 ± 0.9 cm (0.5-5); Statistically significant differences were found between group 1 and 2 regarding the majority of predictive and prognostic factors assessed. (Table 1); overall survival was 88% and 71% in group 1 and 2, respectively, at 140 months (p = 0.002) (Fig. 1); disease-free survival was 89% and 76% in group 1 and 2, respectively, at 140 months (p = 0.004). (Fig. 2).Multiple studies have shown that detection of smaller size and earlier stage cancers is associated with better prognosis (3) and nonpalpable lesions have more frequently a smaller histological tumor size and grade (4). In this study, we confirm these data, the group 1, nonpalpable cancers, presents a statistically significant better prognostic and predictive factors than group 2, palpable cancers ( Table 1) that leads to less need for either radical surgery or chemotherapy. Tabar has shown that reducing the size of invasive cancers at the time of diagnosis to <1 cm is one of the most significant factors associated with reduced mortality (5). In this study, group 1 presenting smaller histological size, 55% cases have pT £1 cm versus 22.8% in group 2 (p < 0.001); and thus presents signif...