Abstract. Neuroendocrine tumors (NET) include a spectrum of malignancies arising from neuroendocrine cells throughout the body. The objective of this clinical investigation of retrospectively and prospectively collected data was to describe the prevalence, demographic data, clinical symptoms and methods of diagnosis of NET and the treatment and long-term follow-up of patients with NET. Data were provided by the participating centers and assessed for consistency by internal reviewers. All the cases were centrally evaluated (when necessary) by the pathologists in our group. The tissue samples were reviewed by hematoxylin and eosin and immunohistochemical staining techniques to confirm the diagnosis of NET. In total, 532 cases were documented: 461 gastroenteropancreatic-NET (GEP-NET) and 71 bronchial NET (BNET). All the tumors were immunohistochemically defined according to the World Health Organization (WHO) and European Neuroendocrine Tumor Society criteria. The most common initial symptoms in GEP-NET were abdominal pain, diarrhea, bowel obstruction, flushing, gastrointestinal bleeding and weight loss. The most common tumor types were carcinoid (58.0%), non-functional pancreatic tumor (23.0%), metastatic NET of unknown primary (16.0%) and functional pancreatic tumor (3.0%). Of the BNET, 89.0% were typical and 11.0% atypical carcinoids. Of the patients with GEP-NET, 59.2% had distant metastasis at diagnosis. The locations of the primary tumors in GEP-NET were the small bowel (26.9%), pancreas (25.2%), colon-rectum (12.4%), appendix (7.6%), stomach (6.9%), esophagus (2.8%), duodenum (2.0%) and unknown primary (16.3%). The histological subtypes based on the WHO classification were well-differentiated NET (20.1%), well-differentiated neuroendocrine carcinomas (66.5%) and poorly differentiated neuroendocrine carcinomas (10.3%). Overall, 67.3% of the patients underwent surgery, 41.2% with curative intent and 26.1% for palliative purposes. The 5-year survival rates were 65.1% (95% confidence interval, 58.0-71.4%) in GEP-NET and 100.0% in typical carcinoid of the lung. This observational, non-interventional, longitudinal study aimed to accumulate relevant information regarding the epidemiology, clinical presentation and current practices in the treatment of NET patients in Argentina, providing insight into regional differences and patterns of care in this heterogeneous disease.

e22214 Background: Triple negative breast cancer (BC) is a distinct group of tumors that show common but heterogeneous morphologic, genetic, and immunophenotypic features. Despite differences in the definition and prevalence, it comprises 8% to 20% of all breast cancers and is associated with an aggressive clinical course with significant risk of either local or systemic relapse and subsequent increased risk of death on short term follow up (particularly in the first 5 years).We study the pathological characteristics and the clinical outcome of a cohort of 77 triple negative BC patients (pts) diagnosed at our Institution. Methods: Between January 1999 and September 2008, 77 (stage I to III) triple negative BC pts. were retrospectively analyzed. All pts had their receptor status, Her neu, ck-5, ck-6 and staining for EGFR by the same pathologist. Pathological parameters (Pp) analyzed were: status of axilary lymph nodes (LN), nuclear grade, histologic grade, mitotic index and vascular invasion and the use of antraciclins in the adjuvant setting. Univariate and multivariate analysis (proporcional hazard regression Cox model) for the Pp associated with relapse, and the log rank test to compare two curves of each Pp for disease free survival (DFS), and overall survival (OS) were performed. Results: The median age was 57.8 years (range 30–86 years).The median follow up time was 57.7 months (range, 4- 241). From 77 Pts. analized, 65 (84.4%) were basal-like and 43 (64.6%) of those were GH3. Stage at the time of presentation was: 16 (20,7%) stage I; 40 (51,9%) stage II; 21 (27,7%) stage III. Pre-menopausal status was 29,48% (23 pts.), and 61% (47 pts) were LN negative. Overall, relapse rate was 38.5 % (n= 30), 63 Pts (81.8%) are still alive. Median DFS was not reached. Global DFS and OS were 59% and 79% respectively, and status of LN was the only prognostic factor. LN- vs LN+ DFS (p< 00.02) and OS p (< 0.02).All others Pp analyzed were not statistically significative. Conclusions: Despite previous studies have demonstrated that triple negative is an independent marker of poor prognosis in BC as a whole, in the LN-negative, and LN-positive groups, in this basal like population only positive LN was an independent poor prognostic factor for DFS and OS. No significant financial relationships to disclose.

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers in Central and South America and one of the top causes of cancer death; however, these rates vary considerably between countries. This commentary focuses on clinical experiences in Argentina, highlighting results of the phase II ReDOS trial.

No abstract

We performed a retrospective study of LAG/GEJ cancers undergoing periop-FLOT during the last two years. The FLOT regimen was applied as in the FLOT4-AIO trial. Pathological tumor regression grade was done according to Modified Ryan Scheme (TRG0: complete response, TRG1: near-complete response, TRG2: partial response, TRG3: poor/no response) and DFS analysis was estimated by Kaplan-Meier method with SPSS.Results: Fifty-nine pts with LAG/GEJ cancers commenced on periop-FLOT. Demographics: male n¼43 (73%), median age 63 (range;34-85), performance status; PS0 n¼29 (49%), PS1 n¼20 (34%), PS2 n¼10 (17%). Tumor location gastric n¼38 (64%), GEJ n¼21 (36%). All of the pts were cT3/T4, and 55 (93%) were cN+. 53 pts (90%) received 4 cycles of neoadj-FLOT. 45 (76%) pts underwent curative surgery, and 40 (89%) of them had D1 lymphadenectomy. R0 resection was achieved in 44 pts (75%). TRG0 n¼5 (8%), TRG1 n¼9 (15%), TRG2 n¼5 (8%) and TRG3 n¼26 (44%) were reached, and 22 pts (37%) were detected as ypN0. 30 pts (51%) started adj-FLOT and 26 pts (44%) completed all cycles. The median follow-up was 11 months (range 4e 27), with a median DFS of 21.8 months (95% CI 18.9e24.9), and 9 of 45 pts (20%) relapsed. Significant differences in DFS between pts who received adj-FLOT (25.4 months, 95% CI 23.1e27) compared with no-adjuvant (13.6 months, 95% CI 10.2e 16.9) were found (p¼0.001), and also among ypN0 (26 months, 95% CI 24-28.1) compared with ypN+ (15.6 months, 95% CI 12.4-18.9) (p¼0.006). No effect of TRG's on DFS were detected (p>0,05). The median OS not reached. 56 pts (95%) had at least one any grade toxicity. Dose reduction was performed in 3 pts (5%). The most common grade 3/4 toxicities were neutropenia (n¼11;19%) and neutropenic fever (n¼7;12%) although we prescribed primary prophylactic G-CSF. Two toxic deaths occurred (3%) during the neoadjuvant period. Compared with the FLOT4-AIO trial, although our pts had a higher PS, they had similar rates of dose reduction (5% vs 6%), completing neoadjuvant (90% vs 90%) and adjuvant (44% vs 46%) treatments. R0 (75% vs 85%) and D2 (11% vs 92%) resection, ypN0 (37% vs 49%) and pCR rates (8% vs 16%) were lower in our pts, due to higher initial clinical stages.Legal entity responsible for the study: The authors.